Gait Analysis of Horses for Lameness Detection with Radar Sensors

This paper presents the preliminary investigation of the use of radar signatures to detect and assess lameness of horses and its severity. Radar sensors in this context can provide attractive contactless sensing capabilities, as a complementary or alternative technology to the current techniques for lameness assessment using video-graphics and inertial sensors attached to the horses' body. The paper presents several examples of experimental data collected at the Weipers Centre Equine Hospital at the University of Glasgow, showing the micro- Doppler signatures of horses and preliminary results of their analysis

Grazing-angle reflectivity setup for the low-temperature infrared spectroscopy of two-dimensional systems

A new optical setup is described that allows the reflectivity at grazing incidence to be measured, including ultrathin films and two-dimensional electron systems (2DES) down to liquid-helium temperatures, by exploiting the Berreman effect and the high brilliance of infrared synchrotron radiation. This apparatus is well adapted to detect the absorption of a 2DES of nanometric thickness, namely that which forms spontaneously at the interface between a thin film of LaAlO3 and its SrTiO3 substrate, and to determine its Drude parameters

Clinical magnetic resonance image quality of the equine foot is significantly influenced by acquisition system

Background: Investigation of image quality in clinical equine magnetic resonance (MR) imaging may optimise diagnostic value. Objectives: To assess the influence of field strength and anaesthesia on image quality in MR imaging of the equine foot in a clinical context. Study design: Analytical clinical study. Methods: Fifteen equine foot studies (five studies per system) were randomly selected from the clinical databases of three MR imaging systems: low‐field standing (LF St), low‐field anaesthetised (LF GA) and high‐field anaesthetised (HF GA). Ten experienced observers graded image quality for entire studies and seven clinically important anatomical structures within the foot (briefly, grade 1: textbook quality, grade 2: high diagnostic quality, grade 3: satisfactory diagnostic quality, grade 4: non‐diagnostic). Statistical analysis assessed the effect of anaesthesia and field strength using a combination of the Pearson chi‐square test or Fisher’s exact test and Mann‐Whitney test. Results: There was no difference in the proportion of entire studies of diagnostic quality between LF St (90%, 95%CI 78‐97%) and LF GA (88%, 76‐95%, p = 0.7). No differences were evident in the proportion of diagnostic studies or median image quality gradings between LF St and LF GA when assessing individual anatomical structures (both groups all median grades=3). There was a statistically significant difference in the proportion of entire studies of diagnostic quality between LF GA and HF GA (100%, 95% CI lower bound 94%, p = 0.03). There were statistically significant differences in median image quality gradings between LF GA (all median grades=3) and HF GA (median grades=1 (5/7 structures) or 2 (2/7 structures) for all individual anatomical structures (all P<0.001). The reasons reported for reduced image quality differed between systems. Main limitations: Randomised selection of cases from clinical databases. Individual observer preferences may influence image quality assessment. Conclusions: Field strength is a more important influencer of image quality than anaesthesia for magnetic resonance imaging of the equine foot in clinical patients

Ultrasound-guided perineural injection of the tibial nerve in the horse versus a ‘blind’ technique

Background: Tibial perineural analgesia has often been reported to fail to achieve nerve desensitisation in horses. Ultrasound-guided (US-guided) techniques have recently been described to improve tibial perineural desensitisation. Objectives: To compare US-guided and ‘blind’ tibial perineural analgesia techniques in lameness investigation. Study design: Randomised clinical trial. Methods: Horses presenting for lameness investigation, which required tibial perineural analgesia, were randomly assigned either to a US-guided or blind injection group. The efficacy of perineural analgesia was assessed by testing the loss of skin sensation at the medial and lateral heel bulbs. Skin sensation was assessed, prior to injection and then at four intervals post-injection (10–15, 20–25, 30–35 and 40–45 min) using a hand-held digital algometer with a 1 mm diameter pin; a value of 25 N was defined as indicative of skin desensitisation. The time taken to perform each injection technique and any adverse reactions were recorded. Summary statistics were performed to examine differences between groups. The frequency of skin desensitisation was compared between groups using a Fisher's exact test and the length of time taken to perform injections was compared using a Mann–Whitney U test. Results: Sixteen US-guided and 11 blind injections were included in the study. All cases undergoing US-guided injection lost skin sensation, whereas this occurred in only one case receiving the blind injection. The US-guided group had a significantly higher probability of skin sensation loss (p < 0.001), although the injection technique took significantly longer to complete compared to the blind group (p < 0.001). No adverse reactions were noted with either perineural injection technique. Main limitations: Limited number of cases for each injection group. Conclusions: These findings suggest that US-guided tibial perineural injection is more likely to result in adequate and prompt tibial perineural analgesia compared to the blind injection technique, although it takes longer to complete

The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae

High resolution long-slit spectra obtained with the Phoenix spectrograph on Gemini South provide our most accurate probe of the three dimensional structure of the Homunculus around eta Car. The new near-infrared spectra dramatically confirm the double-shell structure inferred previously from thermal dust emission, resolving the nebula into a very thin outer shell seen in H2 21218, and a warmer, thicker inner layer seen in [Fe II] 16435. The thin H2 skin hints that the most important mass loss during the 19th century eruption had a very short duration of less than 5 yr. H2 emission traces the majority of the mass in the nebula, and has an average density of order 10^6.5 cm-3. This emission, in turn, yields our first definitive picture of the exact shape of the nebula, plus a distance of 2350pm50 pc and an inclination angle of 41deg (the polar axis is tilted 49deg from the plane of the sky). The distribution of the H2 emission provides the first measure of the latitude dependence of the speed, mass loss, and kinetic energy associated with eta Car's 19th century explosion. Almost 75 percent of the total mass and more than 90 percent of the kinetic energy in the ejecta were released at high latitudes. This rules out a model for the bipolar shape wherein an otherwise spherical explosion was pinched at the waist by a circumstellar torus. Also, the ejecta could not have been deflected toward polar trajectories by a companion star, since the kinetic energy of the polar ejecta is greater than the binding energy of the putative binary system. Instead, most of the mass appears to have been directed poleward by the explosion itself. [abridged]Comment: 25 pages, figs 2 and 3 in color. Accepted by Ap

PHASES Differential Astrometry and Iodine Cell Radial Velocities of the kappa Pegasi Triple Star System

kappa Pegasi is a well-known, nearby triple star system. It consists of a ``wide'' pair with semi-major axis 235 milli-arcseconds, one component of which is a single-line spectroscopic binary (semi-major axis 2.5 milli-arcseconds). Using high-precision differential astrometry and radial velocity observations, the masses for all three components are determined and the relative inclinations between the wide and narrow pairs' orbits is found to be 43.8 +/- 3.0 degrees, just over the threshold for the three body Kozai resonance. The system distance is determined to 34.60 +/- 0.21 parsec, and is consistent with trigonometric parallax measurements.Comment: Accepted for publication in ApJ, complete versions of tables 2 and 4 can be found at http://stuff.mit.edu/~matthew1/kapPegTables

La source froide des centrales nucléaires. Critères et méthodes de conception

Après avoir évalué les besoins en moyens de refroidissement des centrales nucléaires, les auteurs analysent les principaux critères conduisant au choix du type de réfrigération à adopter pour une installation donnée. Ils décrivent ensuite les effets sur l'environnement du refroidissement des centrales