Evidence for Shape Co-existence at medium spin in 76Rb

Four previously known rotational bands in 76Rb have been extended to moderate spins using the Gammasphere and Microball gamma ray and charged particle detector arrays and the 40Ca(40Ca,3pn) reaction at a beam energy of 165 MeV. The properties of two of the negative-parity bands can only readily be interpreted in terms of the highly successful Cranked Nilsson-Strutinsky model calculations if they have the same configuration in terms of the number of g9/2 particles, but they result from different nuclear shapes (one near-oblate and the other near-prolate). These data appear to constitute a unique example of shape co-existing structures at medium spins.Comment: Accepted for publication in Physics Letters

Third-order relativistic many-body calculations of energies and lifetimes of levels along the silver isoelectronic sequence

Energies of 5l_j (l= s, p, d, f, g) and 4f_j states in neutral Ag and Ag-like ions with nuclear charges Z = 48 - 100 are calculated using relativistic many-body perturbation theory. Reduced matrix elements, oscillator strengths, transition rates and lifetimes are calculated for the 17 possible 5l_j-5l'_{j'} and 4f_j-5l_{j'} electric-dipole transitions. Third-order corrections to energies and dipole matrix elements are included for neutral Ag and for ions with Z60. Comparisons are made with available experimental data for transition energies and lifetimes. Correlation energies and transition rates are shown graphically as functions of nuclear charge Z for selected cases. These calculations provide a theoretical benchmark for comparison with experiment and theory.Comment: 8 page

Representation theory of some infinite-dimensional algebras arising in continuously controlled algebra and topology

In this paper we determine the representation type of some algebras of infinite matrices continuously controlled at infinity by a compact metrizable space. We explicitly classify their finitely presented modules in the finite and tame cases. The algebra of row-column-finite (or locally finite) matrices over an arbitrary field is one of the algebras considered in this paper, its representation type is shown to be finite.Comment: 33 page

New Insights into White-Light Flare Emission from Radiative-Hydrodynamic Modeling of a Chromospheric Condensation

(abridged) The heating mechanism at high densities during M dwarf flares is poorly understood. Spectra of M dwarf flares in the optical and near-ultraviolet wavelength regimes have revealed three continuum components during the impulsive phase: 1) an energetically dominant blackbody component with a color temperature of T $\sim$ 10,000 K in the blue-optical, 2) a smaller amount of Balmer continuum emission in the near-ultraviolet at lambda $<$ 3646 Angstroms and 3) an apparent pseudo-continuum of blended high-order Balmer lines. These properties are not reproduced by models that employ a typical "solar-type" flare heating level in nonthermal electrons, and therefore our understanding of these spectra is limited to a phenomenological interpretation. We present a new 1D radiative-hydrodynamic model of an M dwarf flare from precipitating nonthermal electrons with a large energy flux of $10^{13}$ erg cm$^{-2}$ s$^{-1}$. The simulation produces bright continuum emission from a dense, hot chromospheric condensation. For the first time, the observed color temperature and Balmer jump ratio are produced self-consistently in a radiative-hydrodynamic flare model. We find that a T $\sim$ 10,000 K blackbody-like continuum component and a small Balmer jump ratio result from optically thick Balmer and Paschen recombination radiation, and thus the properties of the flux spectrum are caused by blue light escaping over a larger physical depth range compared to red and near-ultraviolet light. To model the near-ultraviolet pseudo-continuum previously attributed to overlapping Balmer lines, we include the extra Balmer continuum opacity from Landau-Zener transitions that result from merged, high order energy levels of hydrogen in a dense, partially ionized atmosphere. This reveals a new diagnostic of ambient charge density in the densest regions of the atmosphere that are heated during dMe and solar flares.Comment: 50 pages, 2 tables, 13 figures. Accepted for publication in the Solar Physics Topical Issue, "Solar and Stellar Flares". Version 2 (June 22, 2015): updated to include comments by Guest Editor. The final publication is available at Springer via http://dx.doi.org/10.1007/s11207-015-0708-

Asymptotic expansions for renewal measures in the plane

Let P be a distribution in the plane and define the renewal measure R=ΣP *n where * denotes convolution. The main results of this paper are three term asymptotic expansions for R far from the origin. As an application, expansions are obtained for distributions in linear boundary crossing problems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47655/1/440_2004_Article_BF00348749.pd

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Short-term changes in median nerve neural tension after a suboccipital muscle inhibition technique in subjects with cervical whiplash: A randomised controlled trial.

Objectives To assess the immediate effect of a suboccipital muscle inhibition (SMI) technique on: (a) neck pain, (b) elbow extension rangeof motion during the upper limb neurodynamic test of the median nerve (ULNT-1), and (c) grip strength in subjects with cervical whiplash;and determine the relationships between key variables.Design Randomised, single-blind, controlled clinical trial.Setting Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Spain.Participants Forty subjects {mean age 34 years [standard deviation (SD) 3.6]} with Grade I or II cervical whiplash and a positive responseto the ULNT-1 were recruited and distributed into two study groups: intervention group (IG) (n = 20) and control group (CG) (n = 20).Interventions The IG underwent the SMI technique for 4 minutes and the CG received a sham (placebo) intervention. Measures were collectedimmediately after the intervention.Main outcome measures The primary outcome was elbow range of motion during the ULNT-1, measured with a goniometer. The secondaryoutcomes were self-perceived neck pain (visual analogue scale) and free-pain grip strength, measured with a digital dynamometer.Results The mean baseline elbow range of motion was 116.0◦(SD 10.2) for the CG and 130.1◦(SD 7.8) for the IG. The within-groupcomparison found a significant difference in elbow range of motion for the IG [mean difference −15.4◦, 95% confidence interval (CI) −20.1to −10.6; P = 0.01], but not for the CG (mean difference −4.9◦, 95% CI −11.8 to 2.0; P = 0.15). In the between-group comparison, thedifference in elbow range of motion was significant (mean difference −10.5◦, 95% CI −18.6 to −2.3; P = 0.013), but the differences in gripstrength (P = 0.06) and neck pain (P = 0.38) were not significant.Conclusion The SMI technique has an immediate positive effect on elbow extension in the ULNT-1. No immediate effects on self-perceivedcervical pain or grip strength were observed

Diverse collective excitations in 159Er up to high spin

A spectroscopic investigation of the γ decays from excited states in 159Er has been performed to study the changing structural properties exhibited as ultrahigh spins (I&gt;60) are approached. The nucleus of 159Er was populated by the reaction 116Cd(48Ca,5nγ) at a beam energy of 215 MeV, and the resulting γ decays were studied using the Gammasphere spectrometer. New rotational bands and extensions to existing sequences were observed, which are discussed in terms of the cranked shell model, revealing a diverse range of quasiparticle configurations. At spins around 50, there is evidence for a change from dominant prolate collective motion at the yrast line to oblate non-collective structures via the mechanism of band termination. A possible strongly deformed triaxial band occurs at these high spins, which indicates collectivity beyond 50. The high-spin data are interpreted within the framework of cranked Nilsson-Strutinsky calculations