Finite element discretization methods for velocity-pressure and stream function formulations of surface Stokes equations

In this paper we study parametric TraceFEM and parametric SurfaceFEM (SFEM) discretizations of a surface Stokes problem. These methods are applied both to the Stokes problem in velocity-pressure formulation and in stream function formulation. A class of higher order methods is presented in a unified framework. Numerical efficiency aspects of the two formulations are discussed and a systematic comparison of TraceFEM and SFEM is given. A benchmark problem is introduced in which a scalar reference quantity is defined and numerically determined.Comment: 26 page

KINETIC ANALYSIS OF THE BLOCK START AND FIRST TWO CONTACTS IN SPRINTING

The purpose of this study was to examine the force production characteristics of the arms and each leg in the block start and in the first two contacts of the acceleration phase in sprinting. The set-up consisted of six force platforms embedded in an indoor running track. A total of 61 starts from 19 male international level athletes were collected during maximal effort starts and accelerations between 10m and 40m. The average time over 10m was 1.648 ±0.048 seconds, measured using a Laveg speed gun. Results indicated that the arms accounted for 13.9% of the vertical impulse and -2% to horizontal impulse, the front leg 69% and 60% and the rear leg 25 and 33% respectively. Peak vertical and horizontal forces (relative to BW) in the front leg and their associated RFD’s produced the strongest correlations with time over 10m (all p\u3c0.001)

KINETIC COMPARISON OF THE SPRINT STARTS BETWEEN YOUTH AND SENIOR ELITE ATHLETES

The purpose of this study was to identify differences in force, impulse and power characteristics in block starts and first two contacts between youth academy (n=20) and elite senior male sprinters (n=17). Senior sprinters were significantly faster out of the blocks with a horizontal velocity of 3.35m/s ±0.15 compared to 3.14 ±0.16m/s, leading to 10m times of 1.64±0.045s and 1.706±0.06s respectively. Force application time of the arms, rear leg and front leg were significantly lower in the senior athletes (all

Growing in generosity?:The effects of giving magnitude, target, and audience on the neural signature of giving in adolescence

Giving is essential for forming and maintaining social relationships, which is an important developmental task for adolescents. This pre-registered fMRI study investigated behavioral and neural correlates of adolescents’ (N = 128, ages 9 – 19 years) small versus large size giving in different social contexts related to target (i.e., giving to a friend or unfamiliar peer) and peer presence (i.e., anonymous versus audience giving). Participants gave more in the small size than large size condition, more to friends than to unfamiliar peers, and more in the audience compared to anonymous condition. Giving very small or large amounts was associated with increased activity in the medial prefrontal cortex (mPFC) and anterior insula (AI), and older adolescents showed increased lateral and anterior PFC activation for small size giving. We observed activity in the intraparietal cortex (IPL), dorsolateral prefrontal cortex, and AI for giving to friends, but no age-related differences in this activity. Behaviorally, in contrast, we observed that older adolescents differentiated more in giving between friends and unfamiliar peers. Finally, we observed interactions between peer presence and target in the AI, and between giving magnitude and target in the precuneus. Together, findings reveal higher context-dependency of giving and more lateral PFC activity for small versus large giving in older adolescents

The Physical Properties of the Red Supergiant WOH G64: The Largest Star Known?

WOH G64 is an unusual red supergiant (RSG) in the Large Magellanic Cloud (LMC), with a number of properties that set it apart from the rest of the LMC RSG population, including a thick circumstellar dust torus, an unusually late spectral type, maser activity, and nebular emission lines. Its reported physical properties are also extreme, including the largest radius for any star known and an effective temperature that is much cooler than other RSGs in the LMC, both of which are at variance with stellar evolutionary theory. We fit moderate-resolution optical spectrophotometry of WOH G64 with the MARCS stellar atmosphere models, determining an effective temperature of 3400 +/- 25 K. We obtain a similar result from the star's broadband V - K colors. With this effective temperature, and taking into account the flux contribution from the aysmmetric circumstellar dust envelope, we calculate log(L/L_sun) = 5.45 +/- 0.05 for WOH G64, quite similar to the luminosity reported by Ohnaka and collaborators based on their radiative transfer modeling of the star's dust torus. We determine a radius of R/R_sun = 1540, bringing the size of WOH G64 and its position on the H-R diagram into agreement with the largest known Galactic RSGs, although it is still extreme for the LMC. In addition, we use the Ca II triplet absorption feature to determine a radial velocity of 294 +/- 2 km/s for the star; this is the same radial velocity as the rotating gas in the LMC's disk, which confirms its membership in the LMC and precludes it from being an unusual Galactic halo giant. Finally, we describe the star's unusual nebula emission spectrum; the gas is nitrogen-rich and shock-heated, and displays a radial velocity that is significantly more positive than the star itself by 50 km/s.Comment: 25 pages, 5 figures; accepted for publication in The Astronomical Journa

Deficiency of the zinc finger protein ZFP106 causes motor and sensory neurodegeneration

Acknowledgements We are indebted to Jim Humphries, JennyCorrigan, LizDarley, Elizabeth Joynson, Natalie Walters, Sara Wells and the whole necropsy, histology, genotyping and MLC ward 6 teams at MRC Harwell for excellent technical assistance. We thank the staff of the WTSI Illumina Bespoke Team for the RNA-seq data, the Sanger Mouse Genetics Project for the initial mouse characterization and Dr David Adams for critical reading of the manuscript. We also thank KOMP for the mouse embryonic stem cells carrying the knockout first promoter-less allele (tm1a(KOMP)Wtsi) within Zfp016. Conflict of Interest statement. None declared. Funding This work was funded by the UK Medical Research Council (MRC) to A.A.-A. and a Motor Neurone Disease Association (MNDA) project grant to A.A.-A. and EMCF. D.L.H.B. is a Wellcome Trust Senior Clinical Scientist Fellow and P.F. is a MRC/MNDA Lady Edith Wolfson Clinician Scientist Fellow. Funding to pay the Open Access publication charges for this article was provided by the MRC grant number: MC_UP_A390_1106.Peer reviewedPublisher PD

High contrast imaging with ELT/METIS: The wind driven halo, from SPHERE to METIS

International audienceMETIS is one of the three first-light instruments planned for the ELT, mainly dedicated to high contrast imaging in the mid-infrared. On the SPHERE high-contrast instrument currently installed at the VLT, we observe that one of the main contrast limitations is the wind driven halo, due to the limited AO running speed with respect to the atmospheric turbulence temporal evolution. From this observation, we extrapolate this signature to the ELT/METIS instrument, which is equipped with a single conjugated adaptive optics system and with several coronagraphic devices. By making use of an analytic AO simulator, we compare the amount of wind driven halo observed with SPHERE and with METIS, under the same turbulence conditions

High contrast imaging at the LBT: the LEECH exoplanet imaging survey

In Spring 2013, the LEECH (LBTI Exozodi Exoplanet Common Hunt) survey began its $\sim$130-night campaign from the Large Binocular Telescope (LBT) atop Mt Graham, Arizona. This survey benefits from the many technological achievements of the LBT, including two 8.4-meter mirrors on a single fixed mount, dual adaptive secondary mirrors for high Strehl performance, and a cold beam combiner to dramatically reduce the telescope's overall background emissivity. LEECH neatly complements other high-contrast planet imaging efforts by observing stars at L' (3.8 $\mu$m), as opposed to the shorter wavelength near-infrared bands (1-2.4 $\mu$m) of other surveys. This portion of the spectrum offers deep mass sensitivity, especially around nearby adolescent ($\sim$0.1-1 Gyr) stars. LEECH's contrast is competitive with other extreme adaptive optics systems, while providing an alternative survey strategy. Additionally, LEECH is characterizing known exoplanetary systems with observations from 3-5$\mu$m in preparation for JWST.Comment: 12 pages, 5 figures. Proceedings of the SPIE, 9148-2