Super-Earths in the TW Hya disc

We test the hypothesis that the sub-millimetre thermal emission and scattered light gaps seen in recent observations of TW Hya are caused by planet-disc interactions. We perform global three-dimensional dusty smoothed particle hydrodynamics simulations, comparing synthetic observations of our models with dust thermal emission, CO emission and scattered light observations. We find that the dust gaps observed at 24 au and 41 au can be explained by two super-Earths ($\sim 4 \mathrm{M}_{\oplus}$). A planet of approximately Saturn-mass can explain the CO emission and the depth and width of the gap seen in scattered light at 94 au. Our model produces a prominent spiral arm while there are only hints of this in the data. To avoid runaway growth and migration of the planets we require a disc mass of $\lesssim 10^{-2}\,\mathrm{M}_{\odot}$ in agreement with CO observations but 10$-$100 times lower than the estimate from HD line emission.Comment: 6 pages, 5 figures, accepted for publication in MNRA

Consequences of Discrimination at the Workplace

Nowadays, although work relationships should be based on the principle of equal treatment of employees, diversity at the workplace has led to an increase in employee inequality in treatment. Despite policies to regulate work-related inequalities, it still exists and develops on the basis of personal characteristics such as gender, age, geographical area, religion, sexual orientation or some chronic disease. Workplace inequality can be defined as that distinction in favor of or against a person or thing on grounds that relate to the group, class or category of which the person or work belongs and which is reflected in wage differences between men and womenunfair practices and opportunities for injustice, especially in regard to employment of people of different ethnic origins

Validity and intra-rater reliability of an Android phone application to measure cervical range-of-motion

Concurrent validity and intra-rater reliability using a customized Android phone application to measure cervical-spine range-of-motion (ROM) has not been previously validated against a gold-standard three-dimensional motion analysis (3DMA) system

Flybys in protoplanetary discs: I. Gas and dust dynamics

We present 3D smoothed particle hydrodynamics simulations of protoplanetary discs undergoing a flyby by a stellar perturber on a parabolic orbit lying in a plane inclined relative to the disc mid-plane. We model the disc as a mixture of gas and dust, with grains ranging from 1 {\mu}m to 10 cm in size. Exploring different orbital inclinations, periastron distances and mass ratios, we investigate the disc dynamical response during and after the flyby. We find that flybys induce evolving spiral structure in both gas and dust which can persist for thousands of years after periastron. Gas and dust structures induced by the flyby differ because of drag-induced effects on the dust grains. Variations in the accretion rate by up to an order of magnitude occur over a time-scale of order 10 years or less, inducing FU Orionis-like outbursts. The remnant discs are truncated and warped. The dust disc is left more compact than the gas disc, both because of disc truncation and accelerated radial drift of grains induced by the flyby.Comment: 27 pages, 24 figures, accepted for publication in MNRA

Kinematic evidence for an embedded protoplanet in a circumstellar disc

Discs of gas and dust surrounding young stars are the birthplace of planets. However, direct detection of protoplanets forming within discs has proved elusive to date. We present the detection of a large, localized deviation from Keplerian velocity in the protoplanetary disc surrounding the young star HD163296. The observed velocity pattern is consistent with the dynamical effect of a two Jupiter-mass planet orbiting at a radius $\approx$ 260au from the star.Comment: Accepted for publication to ApJL, 8 pages, 5 figure

Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome?

Background: Femoroacetabular impingement (FAI) syndrome is considered a motion-related condition. Little is known about the influence of symptom severity and cam morphology on hip biomechanics for individuals with FAI syndrome. Research question: Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome? Methods: Forty-nine male, sub-elite football (soccer or Australian football) players (mean age= 26 years) with FAI syndrome completed the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent radiographic evaluation. Biomechanical data were collected during overground running (3–3.5 m∙s−1) using three-dimensional motion capture technology and an embedded force plate. Various discrete hip angles and impulses of joint moments were analysed during the stance phase. Linear regression models investigated associations between running biomechanics data (dependent variables) and iHOT-33 and HAGOS scores and cam morphology size (independent variables). Results: Hip joint angles during running were not associated with symptom severity in football players with FAI syndrome. A positive association was found between the impulse of the hip external rotation moment and HAGOS-Sport scores, such that a smaller impulse magnitude occurred with a lower HAGOS-Sport score (0.026 *10−2 [95%CI &lt;0.001 *10−2 to 0.051 *10−2], P = 0.048). Larger cam morphology was associated with a greater peak hip adduction angle at midstance (0.073 [95%CI 0.002–0.145], P = 0.045). Significance: Hip biomechanics during running did not display strong associations with symptom severity or cam morphology size in male football players with FAI syndrome who were still participating in training and match play. Future studies might consider investigating associations during tasks that utilise end range hip joint motion or require greater muscle forces.</p

The reliability of a maximal isometric hip strength and simultaneous surface EMG screening protocol in elite, junior rugby league athletes

Objectives Firstly to describe the reliability of assessing maximal isometric strength of the hip abductor and adductor musculature using a hand held dynamometry (HHD) protocol with simultaneous wireless surface electromyographic (sEMG) evaluation of the gluteus medius (GM) and adductor longus (AL). Secondly, to describe the correlation between isometric strength recorded with the HHD protocol and a laboratory standard isokinetic device. Design Reliability and correlational study. Methods A sample of 24 elite, male, junior, rugby league athletes, age 16–20 years participated in repeated HHD and isometric Kin-Com (KC) strength testing with simultaneous sEMG assessment, on average (range) 6 (5–7) days apart by a single assessor. Strength tests included; unilateral hip abduction (ABD) and adduction (ADD) and bilateral ADD assessed with squeeze (SQ) tests in 0 and 45° of hip flexion. Results HHD demonstrated good to excellent inter-session reliability for all outcome measures (ICC\ua0=\ua00.76–0.91) and good to excellent association with the laboratory reference KC (ICC\ua0=\ua00.80–0.88). Whilst intra-session, inter-trial reliability of EMG activation and co-activation outcome measures ranged from moderate to excellent (ICC\ua0=\ua00.70–0.94), inter-session reliability was poor (all ICC\ua