A Non-Perturbative Chiral Approach for Meson-Meson Interactions

A non-perturbative method which combines constraints from chiral symmetry breaking and coupled channel unitarity is used to describe meson-meson interactions up to \sqrt{s}\lesssim 1.2 GeV, extending in this way the range of applicability of the information contained in Chiral Perturbation Theory (\chi PT), since this perturbative series is typically restricted to \sqrt{s}\lesssim 500 MeV. The approach uses the O(p^2) and O(p^4) \chiPT Lagrangians. The seven free parameters resulting from the O(p^4) Lagrangian are fitted to the experimental data. The approach makes use of the expansion of T^{-1} instead of the amplitude itself as done in \chiPT. The former expansion is suggested by analogy with the effective range approximation in Quantum Mechanics and it appears to be very useful. The results, in fact, are in good agreement with a vast amount of experimental analyses.Comment: 4 pages, 2 figures, LaTeX, Talk given at PANIC99, Uppsala (Sweden), June 10-16, 199

A Kinetic Analysis of Footfall Patterns at Landing in Netball: A Follow-up Study

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INSTRUMENTED START BLOCKS: A QUANTITATIVE COACHING AID

To effect improvement in a skill such as the block start in sprinting, immediate quantitative feedback pertaining to the forces generated during the start is invaluable to both the coach and athlete. The purpose of the present study was to design a set of instrumented starting blocks, appropriate for use in the field, which would provide immediate feedback pertaining to the kinetics of a block start. Design considerations included: resolution of orthogonal force components for right and left foot pedals independently; adjustability to enable and athlete's normal foot and block placement; and adhering to standard international starting block design specifications in terms of dimensions and rigidity. The starting blocks consisted of two standard adjustable stadium starting block pedals suspended clear of the ground via two instrumented axles. The mild steel rod axles were milled to dimensions which allowed the axles to deflect minimally under expected loads. Each axle was attached laterally (and directed medially) from a 230 mm wide mild steel parallel flange channel. This base plate was firmly affixed to the synthetic track surface by six 12 mm commercial shoe spikes. Eight 3 mm student strain gauges were adhered to each axle with 4 gauges aligned to each orthogonal axis. The gauges were incorporated into a Wheatstone Bridge circuitry and arranged to measure the shear force on the axle by utilising the bending moment difference method. Using this bending moment difference method, the magnitude of the force signal recorded was unaffected by the position of force application across the block pedal. Each of the 4 orthogonal channels contained a separate amplifier to magnify the differential signal from the gauges. Calibration was accomplished via static loading of each axle in the orthogonal plane with known loads. The differential signal developed from the strain gauge circuitry under load was amplified and sampled (1000 Hz) by a personal computer using a WIN 30-D A-D converter card. From this data useful variables such as maximum horizontal and vertical force, impulse, block time, block velocity and block acceleration were quantified using custom software and were immediately available to the athlete and coach. Analysis of data obtained from the blocks for state level, national level and the current male 100 m world champion indicated the instrumented blocks were able to provide immediate relevant kinetic data for use by sprint coaches in the field

Beta-backscatter thickness measurements of deposited niobium carbide on flat graphite surfaces

Within the scope of this work, these data indicate that Micro-Derm beta-backscattering measurements can be achieved within ten percent of the results obtained by metallographic direct measurements

Beta-Backscatter Thickness Measurements of Deposited Niobium Carbide on Flat Graphite Surfaces

Within the scope of this work, these data indicate that Micro-Derm beta-backscattering measurements can be achieved within ten percent of the results obtained by metallographic direct measurements

What do people do with porn? qualitative research into the consumption, use and experience of pornography and other sexually explicit media

This article reviews qualitative research into the consumption of pornography and other sexually explicit media emerging from a range of subject areas. Taking a critique of quantitative methods and a focus on measuring sexual effects and attitudes as a starting point, it considers the proposition that qualitative work is more suited to an examination of the complex social, cultural and political constructions of sexuality. Examining studies into the way men, women and young people see, experience, and use explicit media texts, the article identifies the key findings that have emerged. Qualitative work shows that sexuality explicit media texts are experienced and understood in a variety of ways and evoke strong and often contradictory reactions, not all of which are represented in public debates about pornography. These texts function in a range of different ways, depending on context; as a source of knowledge, a resource for intimate practices, a site for identity construction, and an occasion for performing gender and sexuality. The article reviews these studies and their findings, identifying what they suggest about directions for future research, both in terms of developing methodology and refining approaches to sexuality and media consumption.</p

Intersectional Value? A Pilot Study Exploring Educational Outcomes for African American Women in Historically Black Sororities Versus Non-Historically Black Sororities

The purpose of this pilot study was to initially explore if there is value added in terms of educational outcomes for Black women involved in historically Black sororities by comparing them to Black women involved in non-historically Black sororities, given the racial-gender support historically Black sororities offer. Main findings suggest Black women involved in historically Black sororities were more socially involved than Black women involved in non-historically Black sororities. The article closes with implications for practice and future research

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results