Standing osteosynthesis of an accessory carpal bone fracture in a Warmblood mare with a 6‐hole 3.5 talonavicular fusion plate and 3.5‐mm screws

A 9-year-old Warmblood, high-level showjumping mare sustained an acute, closed, vertical, comminuted fracture of the left accessory carpal bone (ACB) during a fall. The fracture was repaired under standing sedation and local anaesthesia, using a 6-hole APTUS® 3.5 TFP and 5 × 3.5-mm self-tapping TriLock© screws. The mare recovered from surgery without complications. Upon follow-up examination 9 months post-operatively the mare was sound in all gaits and back to full athletic activity. The ACB fracture had completely healed. The displaced dorsoproximal fracture fragment was in a stationary position and there was evidence of mild nonprogressive osteoarthritis of the antebrachiocarpal joint

Energy-resolved neutron imaging for reconstruction of strain introduced by cold working

Energy-resolved neutron transmission imaging is used to reconstruct maps of residual strains in drilled and cold-expanded holes in 5-mm and 6.4-mm-thick aluminum plates. The possibility of measuring the positions of Bragg edges in the transmission spectrum in each 55 × 55 µm2 pixel is utilized in the reconstruction of the strain distribution within the entire imaged area of the sample, all from a single measurement. Although the reconstructed strain is averaged through the sample thickness, this technique reveals strain asymmetries within the sample and thus provides information complementary to other well-established non-destructive testing methods

Band-gap solitons in nonlinear optically-induced lattices

We introduce novel optical solitons that consist of a periodic and a spatially localized components coupled nonlinearly via cross-phase modulation. The spatially localized optical field can be treated as a gap soliton supported by the optically-induced nonlinear grating. We find different types of these band-gap composite solitons and demonstrate their dynamical stability.Comment: 4 pages, 5 figure

SU(2) reductions in N=4 multidimensional supersymmetric mechanics

We perform an su(2) Hamiltonian reduction in the bosonic sector of the su(2)-invariant action for two free (4, 4, 0) supermultiplets. As a result, we get the five dimensional N=4 supersymmetric mechanics describing the motion of an isospin carrying particle interacting with a Yang monopole. We provide the Lagrangian and Hamiltonian descriptions of this system. Some possible generalizations of the action to the cases of systems with a more general bosonic action, a four-dimensional system which still includes eight fermionic components, and a variant of five-dimensional N=4 mechanics constructed with the help of the ordinary and twisted N=4 hypermultiplets were also considered.Comment: 11 pages, LaTeX file, no figures; 3 references added, minor correction

N=4 mechanics, WDVV equations and roots

N=4 superconformal multi-particle quantum mechanics on the real line is governed by two prepotentials, U and F, which obey a system of partial differential equations linear in U and generalizing the Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equation for F. Putting U=0 yields a class of models (with zero central charge) which are encoded by the finite Coxeter root systems. We extend these WDVV solutions F in two ways: the A_n system is deformed n-parametrically to the edge set of a general orthocentric n-simplex, and the BCF-type systems form one-parameter families. A classification strategy is proposed. A nonzero central charge requires turning on U in a given F background, which we show is outside of reach of the standard root-system ansatz for indecomposable systems of more than three particles. In the three-body case, however, this ansatz can be generalized to establish a series of nontrivial models based on the dihedral groups I_2(p), which are permutation symmetric if 3 divides p. We explicitly present their full prepotentials.Comment: 1+25 pages; v2: major revision (more general analysis, new solutions, additional references); v3: improvements in sects.5,8,9, refs. adde

Wilson-'t Hooft operators in four-dimensional gauge theories and S-duality

We study operators in four-dimensional gauge theories which are localized on a straight line, create electric and magnetic flux, and in the UV limit break the conformal invariance in the minimal possible way. We call them Wilson-'t Hooft operators, since in the purely electric case they reduce to the well-known Wilson loops, while in general they may carry 't Hooft magnetic flux. We show that to any such operator one can associate a maximally symmetric boundary condition for gauge fields on AdS^2\times S^2. We show that Wilson-'t Hooft operators are classifed by a pair of weights (electric and magnetic) for the gauge group and its magnetic dual, modulo the action of the Weyl group. If the magnetic weight does not belong to the coroot lattice of the gauge group, the corresponding operator is topologically nontrivial (carries nonvanishing 't Hooft magnetic flux). We explain how the spectrum of Wilson-'t Hooft operators transforms under the shift of the theta-angle by 2\pi. We show that, depending on the gauge group, either SL(2,Z) or one of its congruence subgroups acts in a natural way on the set of Wilson-'t Hooft operators. This can be regarded as evidence for the S-duality of N=4 super-Yang-Mills theory. We also compute the one-point function of the stress-energy tensor in the presence of a Wilson-'t Hooft operator at weak coupling.Comment: 32 pages, latex. v2: references added. v3: numerical factors corrected, other minor change

A unified first-principles study of Gilbert damping, spin-flip diffusion and resistivity in transition metal alloys

Using a formulation of first-principles scattering theory that includes disorder and spin-orbit coupling on an equal footing, we calculate the resistivity $\rho$, spin flip diffusion length $l_{sf}$ and the Gilbert damping parameter $\alpha$ for Ni$_{1-x}$Fe$_x$ substitutional alloys as a function of $x$. For the technologically important Ni$_{80}$Fe$_{20}$ alloy, permalloy, we calculate values of $\rho = 3.5 \pm 0.15$ $\mu$Ohm-cm, $l_{sf}=5.5 \pm 0.3$ nm, and $\alpha= 0.0046 \pm 0.0001$ compared to experimental low-temperature values in the range $4.2-4.8$ $\mu$Ohm-cm for $\rho$, $5.0-6.0$ nm for $l_{sf}$, and $0.004-0.013$ for $\alpha$ indicating that the theoretical formalism captures the most important contributions to these parameters.Comment: Published in Physical Review Letter

WISE colours and star-formation in the host galaxies of radio-loud narrow-line Seyfert 1

We investigate the mid-infrared properties of the largest (42 objects) sample of radio-loud narrow-line Seyfert 1 (RL NLS1) collected to date, using data from the Wide-field Infrared Survey Explorer (WISE). We analyse the mid-IR colours of these objects and compare them to what is expected from different combinations of AGN and galaxy templates. We find that, in general, the host-galaxy emission gives an importan contribution to the observed mid-IR flux in particular at the longest wavelengths (W3, at 12micron, and W4, at 22micron). In about half of the sources (22 objects) we observe a very red mid-IR colour (W4-W3>2.5) that can be explained only using a starburst galaxy template (M82). Using the 22micron luminosities, corrected for the AGN contribution, we have then estimated the star-formation rate for 20 of these "red" RL NLS1, finding values ranging from 10 to 500 Msun/y. For the RL NLS1 showing bluer colours, instead, we cannot exclude the presence of a star-forming host galaxy although, on average, we expect a lower star-formation rate. Studying the radio (1.4GHz) to mid-IR (22micron) flux ratios of the RL NLS1 in the sample we found that in ~10 objects the star-forming activity could represent the most important component also at radio frequencies, in addition (or in alternative) to the relativistic jet. We conclude that both the mid-IR and the radio emission of RL NLS1 are a mixture of different components, including the relativistic jet, the dusty torus and an intense star-forming activity.Comment: Accepted for publication in MNRAS, 11 pages, 7 figures, 2 table