An experimental study of the development of gaseous ionization at ultra high frequencies

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Practitioner compression force variation in mammography : a 6 year study

The application of breast compression in mammography may be more heavily influenced by the practitioner rather than the client. This could affect image quality and will affect client experience. This study builds on previous research to establish if mammography practitioners vary in the compression force they apply over a six year period. This longitudinal study assessed 3 consecutive analogue screens of 500 clients within one screening centre in the UK. Recorded data included: practitioner code, applied pressure (daN), breast thickness (mm), BI-RADS® density category and breast dose. Exclusion criteria included: previous breast surgery, previous/ongoing assessment, breast implants. 344 met inclusion criteria. Data analysis: assessed variation of compression force (daN) and breast thickness (mm) over 3 sequential screens to determine whether compression force and breast thickness were affected by practitioner variations. Compression force over the 3 screens varied significantly; variation was highly dependent upon the practitioner who performed the mammogram. Significant thickness and compression force differences over the 3 screens were noted for the same client (<0.0001). The amount of compression force applied was highly dependent upon the practitioner. Practitioners fell into one of three practitioner compression groups by their compression force mean values; high (mean 12.6daN), intermediate (mean 8.9daN) and low (mean 6.7daN). For the same client, when the same practitioner performed the 3 screens, maximum compression force variations were low and not significantly different (p>0.31). When practitioners from different compression force groups performed 3 screens, maximum compression force variations were higher and significantly different (p<0.0001). The amount of compression force used is highly dependent upon practitioner rather than client. This has implications for radiation dose, patient experience and image quality consistency

Benefits of maximum likelihood estimators for fracture attribute analysis: Implications for permeability and up-scaling

The authors thank Andrew Hurst for support during the field work, and also Antonio Grippa, Giuseppe Palladino and Gustavo Zvirtes for help and constructive discussions during the field work. We are particularly grateful to Tom Manzocchi for his important comments that greatly improved the first version of this paper. We acknowledge constructive reviews by Julia Gale and Ken McCaffrey, which have greatly improved our manuscript. This work forms part of a NERC New Investigator award for David Healy (NE/I001743/1), which is gratefully acknowledged. Finally, Roberto Emanuele Rizzo is very appreciative of AFES (Aberdeen Formation Evaluation Society) for funding support during his PhD.Peer reviewedPublisher PD

Analysis of the vector form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ−(Q2)f^-_{K\pi}(Q^2) with light-cone QCD sum rules

In this article, we calculate the vector form factors $f^+_{K\pi}(Q^2)$ and $f^-_{K\pi}(Q^2)$ within the framework of the light-cone QCD sum rules approach. The numerical values of the $f^+_{K\pi}(Q^2)$ are compatible with the existing theoretical calculations, the central value of the $f^+_{K\pi}(0)$, $f^+_{K\pi}(0)=0.97$, is in excellent agreement with the values from the chiral perturbation theory and lattice QCD. The values of the $|f^-_{K\pi}(0)|$ are very large comparing with the theoretical calculations and experimental data, and can not give any reliable predictions. At large momentum transfers with $Q^2> 5GeV^2$, the form factors $f^+_{K\pi}(Q^2)$ and $|f^-_{K\pi}(Q^2)|$ can either take up the asymptotic behavior of $\frac{1}{Q^2}$ or decrease more quickly than $\frac{1}{Q^2}$, more experimental data are needed to select the ideal sum rules.Comment: 22 pages, 16 figures, revised version, to appear in Eur. Phys. J.

Erratum to: Search for diboson resonances in hadronic final states in 139 fb−1 of pp collisions at s√ = 13 TeV with the ATLAS detector

A mistake was identified for the paper [1] in the treatment of the radion [2] cross-sections, which resulted in multiple changes.(undefined)info:eu-repo/semantics/publishedVersio

Gender Differences in Publication Output: Towards an Unbiased Metric of Research Performance

We examined the publication records of a cohort of 168 life scientists in the field of ecology and evolutionary biology to assess gender differences in research performance. Clear discrepancies in publication rate between men and women appear very early in their careers and this has consequences for the subsequent citation of their work. We show that a recently proposed index designed to rank scientists fairly is in fact strongly biased against female researchers, and advocate a modified index to assess men and women on a more equitable basis

Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between protons $(p+\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2<{p_{T}}<3.0$ GeV/c is measured to be $1.19\pm0.05$(stat)$\pm0.03$(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of $(p+\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.Comment: 6 pages, 4 figures, 1 table. We extended the pion spectra from transverse momentum 1.8 GeV/c to 3. GeV/

Demonstration of the temporal matter-wave Talbot effect for trapped matter waves

We demonstrate the temporal Talbot effect for trapped matter waves using ultracold atoms in an optical lattice. We investigate the phase evolution of an array of essentially non-interacting matter waves and observe matter-wave collapse and revival in the form of a Talbot interference pattern. By using long expansion times, we image momentum space with sub-recoil resolution, allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure

Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

We present the first measurement of directed flow ($v_1$) at RHIC. $v_1$ is found to be consistent with zero at pseudorapidities $\eta$ from -1.2 to 1.2, then rises to the level of a couple of percent over the range $2.4 < |\eta| < 4$. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure