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We report the serendipitous multiwavelength discovery of a candidate dual black hole system with a separation of ∼100 pc, in the gas-rich luminous infrared galaxy MCG-03-34-64 ( z = 0.016). Hubble Space Telescope/Advanced Camera for Surveys observations show three distinct optical centroids in the [O iii ] narrow-band and F814W images. Subsequent analysis of Chandra/ACIS data shows two spatially resolved peaks of equal intensity in the neutral Fe K α (6.2–6.6 keV) band, while high-resolution radio continuum observations with the Very Large Array at 8.46 GHz (3.6 cm band) show two spatially coincident radio peaks. Fast shocks as the ionizing source seem unlikely, given the energies required for the production of Fe K α . If confirmed, the separation of ∼100 pc would represent the closest dual active galactic nuclei reported to date with spatially resolved, multiwavelength observations.

This study uses the simplified patterns of temperature and effective precipitation approach from the Australian component of the international palaeoclimate synthesis effort (INTegration of Ice core, MArine and TErrestrial records – OZ-INTIMATE) to compare atmosphere–ocean general circulation model (AOGCM) simulations and proxy reconstructions. The approach is used in order to identify important properties (e.g. circulation and precipitation) of past climatic states from the models and proxies, which is a primary objective of the Southern Hemisphere Assessment of PalaeoEnvironment (SHAPE) initiative. The AOGCM data are taken from the Paleoclimate Modelling Intercomparison Project (PMIP) mid-Holocene (ca. 6000 years before present, 6 ka) and pre-industrial control (ca. 1750 CE, 0 ka) experiments. The synthesis presented here shows that the models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). The analysis shows that the lower temperatures in the Pacific at around 6 ka in the models may be the result of an enhancement of an existing systematic error. It is therefore difficult to decipher which one of the proxies and/or the models is correct. This study also shows that a reduction in the Equator-to-pole temperature difference in the Southern Hemisphere causes the mid-latitude westerly wind strength to reduce in the models; however, the simulated rainfall actually increases over the southern temperate zone of Australia as a result of higher convective precipitation. Such a mechanism (increased convection) may be useful for resolving disparities between different regional proxy records and model simulations. Finally, after assessing the available datasets (model and proxy), opportunities for better model–proxy integrated research are discussed.

Background: The prevalence of mental health disorders calls for valid and reliable instruments that are easy to administer and assess for clinicians and researchers. The Depression Anxiety Stress Scale-21 (DASS-21) is a commonly used instrument to assess psychological distress; however, model fit and internal reliability issues have been reported. Our objective was to assess the factorial and structural validity of the DASS-21. Methods: A confirmatory factor analysis (CFA) was conducted on the full sample (n = 1036) to assess the proposed three-factor DASS-21 using a priori cut-off values. Because model fit indices were not met, an exploratory factor analysis (EFA) was conducted to identify a parsimonious model. The resulting three-factor structure (i.e., DASS-9) was then assessed using CFA and multigroup invariance testing procedures. Results: The proposed three-factor DASS-21 did not meet model fit criteria. The DASS-9 did meet recommended model fit criteria and was invariant between sex, injury status, mental health diagnosis, and activity level groups. Statistically different group means were found between mental health diagnosis and activity level groups, while no differences between sex or injury status groups were found. Conclusions: The current study provides support to use a condensed DASS-21 instrument, such as the DASS-9. Future research is necessary to establish the DASS-9 prior to its adoption in research and clinical practice. Additionally, there is a need to identify and review all condensed versions of the DASS-21, so individuals know which instrument can be used for clinical or research purposes.

Background: Researchers in the field of sport pedagogy have highlighted questioning as a behaviour that facilitates athletes' high-order thinking and problem-solving. However, previous studies have suggested that coaches ask a reduced number of questions during training that are typically convergent and lead players to predetermined responses. Formal coach development programmes (CDPs), intended to encourage the use of questioning, have been scrutinised for their limited impact on coaches' practice. These criticisms have been made without consideration of the instances and situations during training that might present a better opportunity for asking different question types. Purpose: The purpose of this study was to explore coaches' perceptions concerning potential 'teachable moments' to ask convergent and divergent questions during training at three data collection points, and to associate changes between knowledge and behaviour after a work-based CDP. Method: Six Spanish youth football coaches working for an elite academy were recruited to a longitudinal study. The study involved a six-week CDP delivered by a coach developer, in collaboration with the club's Academy Management Team, and an experienced research team. Data collection occurred throughout 24-months interspersed by a workshop and two directed tasks organised in several stages: (1) Pre-systematic observations (Sep-Dec 2018) and (2) pre-interviews (Jan 2019), to identify coaches' baseline behaviours and knowledge; (3) a workshop & directed task 1 (Feb 2019), encouraging coaches to experiment and self-discover how to implement questioning within their training contexts; (4) a directed task 2 (Feb-Mar 2019), facilitating coaches' video-based and dialogic reflections about their questions; (5) post-systematic observations (Mar-May 2019) and (6) post-interviews (May 2019), capturing changes in knowledge and questioning after the intervention; and (7) consolidation interviews (May 2020), recording coaches' knowledge stabilisation and further developments. Results and findings: Four coaches completed the full CDP, whilst the remaining two coaches did not participate in the second directed task. Qualitative data suggest that all coaches developed their understanding of which moments might be most appropriate to ask convergent or divergent questions. However, only the first group of coaches presented congruent changes between the timing in which they asked questions and their perceptions. This involved higher use of convergent questions (during practice) and divergent questions (in-between practices and when the coach stops practice). Conversely, coaches in the incomplete CDP, decreased or maintained their questioning values within most instances and suggested organisational and contextual factors hindering their engagement in this work-based CDP. Therefore, real opportunities to implement questioning techniques combined with reflective practice assisted by a coach developer are proposed to translate knowledge gained during CDPs into observable behaviours.

Flow in the wake of a coronary artery stenosis induces a bruit in the 300–1500 Hz range that can be heard at the chest wall. It has been hypothesised that this sound is caused by turbulence-induced shear waves which travel through the soft tissue of the thorax. This contribution describes a computational mathematical ‘forward solve’ method to simulate these shear waves in a virtual chest of tissue mimicking agarose gel. As the first stage in the development of a noninvasive diagnostic tool we also describe initial results towards the solution of the mathematical inverse problem. That is: to identify the source of the bruit given the surface measured signal. Objectives: To demonstrate proof-of-concept of a novel biotechnology that will use mathematical simulations to provide a non-invasive screening tool for coronary artery disease. Methods: Finite element based forward solvers for soft tissue response (given the source, generate the signal); optimisation-based inverse solver (given the signal, determine the source). Results: For a simple, small scale, and axisymmetric cylindrical gel configuration, and for a source at 500 Hz, the forward solve generates signals that agree with experimental data (using Kelvin-Voigt viscoelasticity). Also, with surface signals generated by simulated sources in this virtual environment the inverse algorithm is able to identify this source given only chest surface measurements, and an adequate initial datum from which to start the computation. Conclusions: While enormous challenges remain we have shown that this approach offers considerable promise in delivering a noninvasive diagnostic or screening tool.

Background: Turbulent flow downstream of atherosclerotic plaques produces low amplitude shear waves which travel through the chest and can be measured by skin sensors. This acoustic signature may provide a cheap non-invasive way to diagnose arterial disease. We report measurements of shearing oscillations and flow-induced turbulence in soft tissue-mimicking gels which provide input to a numerical model of soft tissue behaviour described in a companion presentation. Methods: Cylindrical specimens of 3% agarose gel were cast around an axial rod and bead connected to an electromechanical vibrator (figure 1), to generate shear-waves of known characteristics and location (frequency 250–750 Hz, amplitude 10–50 μm). Displacement was mapped optically by tracking the movement of carborundum particles on the surface. In the flow study (figure 2) a silicone rubber tube (i.d. 4.5mm) containing a stenosis was embedded in a cuboidal gel phantom and lateral displacement of the gel surface was mapped by a piezo-electric accelerometer. Results: Forced oscillations produced movement in the same direction at the gel surface, amplitude 10–50% of the bead’s movement. Amplitude modulation (≈5%) at around 40Hz, probably due to resonance in the gel, was also seen. Lateral movement (200–800Hz) of the gel surface caused by flow-induced turbulence increased monotonically with turbulence magnitude. Conclusions: The methods described above provide internally consistent and repeatable data, validating the numerical models. The next steps will compare computational results with measurements in progressively more realistic representations of the chest aiming ultimately to produce a device suitable for screening/diagnosis of coronary artery disease. Figure. 1. Forced vibration rig. Gels cast with bead in various positions. Laser measures bead movement; camera measures surface movement Figure 2. Steady flow rig. Measurements made at various flow rates, tube depths and stenosis severity. Accelerometer position varied.

# Background The International Knee Document Committee Subjective Knee Form (IKDC-SKF) is a patient-reported outcome measure used in orthopedics and sports medicine. Further psychometric assessment is necessary to confirm measurement properties in a large, heterogenous sample. # Purpose The purpose of the study was to assess the psychometric properties of the IKDC-SKF in a large, heterogenous sample. # Study Design Cross-Sectional Study # Methods An exploratory factor analysis (EFA) was conducted to identify a sound latent structure and to assess internal consistency in a large sample of patients who underwent knee arthroscopy. A confirmatory factor analysis (CFA) was conducted to confirm structural validity. Multi-group invariance was conducted to assess factorial stability across sex and age groups, while longitudinal invariance procedures were performed to assess stability over time. # Results A 3-factor, 9-item IKDC-SKF short form was identified with EFA procedures. The model was confirmed with CFA (CFI = 0.983; TLI = 0.975; IFI = 0.983; RMSEA = 0.057), while a sound 2-factor, 6-item model was also identified (CFI = 1.0; TLI = 0.999; IFI = 1.0; RMSEA = 0.11). The 9-item IKDC-SKF short form was invariant across groups but not time; removal of a single item (i.e., 8-item IKDC-SKF short form) resulted in longitudinal invariance. The 6-item IKDC-SKF short form was invariant across groups and time. # Conclusion The 6-item, 8-item, and 9-item short form versions of the IKDC-SKF exceed contemporary fit recommendations and present as plausible alternatives to the IKDC-SKF with improved measurement properties, reduced scale response burden, and evidence of multi-group and longitudinal invariance. Further, the 6- and 8-item IKDC-SKF short forms may be used to assess group differences or change across time. # Level of evidence here Level 3

# Background Instrument-assisted soft tissue mobilization (IASTM) is a commonly utilized intervention for musculoskeletal pain and dysfunction. However, little is known regarding the reliability of forces applied by clinicians of different experience levels during an IASTM intervention. # Purpose The purpose of this pilot study was to assess intra-clinician reliability of IASTM force (i.e., mean normal force) during a simulated, one-handed stroke IASTM intervention across different levels of IASTM clinical experience. # Design Descriptive laboratory study. # Methods The researchers conducted a repeated measures trial in a laboratory setting with a convenience sample of ten participants who had previously completed professional IASTM training. Participants performed 15 one-handed sweeping strokes with an IASTM instrument on a skin simulant attached to a force plate for a standardized hypothetical treatment scenario. The participants performed the treatment on two separate days, 24-48 hours apart. The researchers examined the intra-rater reliability for average (mean) normal forces using Bland-Altman (BA) plots and Coefficient of Variation (CV) values. # Results The BA plot results indicated all participants (professional athletic training students = 4, athletic trainers = 6; males = 5, females = 5; age = 32.60 ± 8.71 y; IASTM experience = 3.78 ± 4.10 y), except participant D (1.9N, 190g), were consistently reliable within 1N (100g) or less of force for mean differences and within the maximum limits of agreement around 3.7N (370g). Most participants' CV scores ranged between 8 to 20% supporting reliable force application within each treatment session. # Conclusion The data indicated that IASTM trained clinicians could produce consistent forces within and across treatment sessions irrespective of clinical experience. # Level of Evidence 3

Background Women have been reported to have worse health‐related quality of life (HRQoL) following stroke than men, but uncertainty exists over the reasons for the sex difference. Methods and Results We included all ischemic strokes registered with the BASIC (Brain Attack Surveillance in Corpus Christi) project (May 2010–December 2016), a population‐based stroke study, who completed a 90‐day outcome interview. Information on baseline characteristics was obtained from medical records and in‐person interviews. HRQoL was measured by the 12‐item short‐form Stroke Specific Quality of Life Scale. Multivariable Tobit regression was used to estimate the mean difference in overall HRQoL scores (range, 1–5; higher indicating better HRQoL) between sexes and to identify contributing factors to the differences. We included 1061 cases with complete data on HRQoL and covariates (median age, 67 years; 51% women). In unadjusted analyses, women had poorer overall HRQoL than men (mean difference, −0.26 [95% CI, −0.40 to −0.13]). Contributors to this difference included sociodemographic/prestroke factors (eg, age, race and ethnicity, prestroke function), risk factors/comorbidities (eg, history of stroke, Alzheimer disease/dementia), and initial stroke severity. Sociodemographic/prestroke factors explained 62% of the sex difference (mean difference, −0.08 [95% CI, −0.21 to 0.04]). In a fully adjusted model that included adjustment for all confounding factors, the sex difference was eliminated and became nonsignificant (mean difference, −0.03 [95% CI, −0.16 to 0.09]). Conclusions Poorer HRQoL in women compared with men was observed and explained by the combination of sociodemographic and prestroke factors, including physical function before stroke and stroke severity. The findings suggest potential subgroups of women who might benefit from more targeted interventions before and after stroke to improve HRQoL.

In the recent years, technology has been an important component in teaching and learning. The literature has highlighted many studies investigations on the students' intention to use technology in many Western, African and South East Asian countries. This article brings in the factors influencing students' adoption of ICT tools in higher education institutions in India. The Unified Theory of Acceptance and Use of Technology (UTAUT) model was used to determine the predictors of ICT adoption in learning their coursework in colleges. The results were obtained by structural equation modelling, using the data collected from 398 students doing their undergraduate engineering programs. The findings show that performance expectancy, effort expectancy and social influence has a positive significant relationship on behavioral intention to use ICT tools and facilitating conditions has a direct relationship with usage behaviour. The findings have led to relevant theoretical and practical implications and future researches are suggested.

Background We aimed to determine if there is an association between hospital quality and the likelihood of a given hospital being a preferred transfer destination for stroke patients. Methods and Results Data from Medicare claims identified acute ischemic stroke transferred between 394 northeast US hospitals from 2007 to 2011. Hospitals were categorized as transferring (n=136), retaining (n=241), or receiving (n=17) hospitals based on the proportion of acute ischemic stroke encounters transferred or received. We identified all 6409 potential dyads of sending and receiving hospitals, and categorized dyads as connected if ≥5 patients were transferred between the hospitals annually (n=82). We used logistic regression to identify hospital characteristics associated with establishing a connected dyad, exploring the effect of adjusting for different quality measures and outcomes. We also adjusted for driving distance between hospitals, receiving hospital stroke volume, and the number of hospitals in the receiving hospital referral region. The odds of establishing a transfer connection increased when rate of alteplase administration increased at the receiving hospital or decreased at the sending hospital, however this finding did not hold after applying a potential strategy to adjust for clustering. Receiving hospital performance on 90‐day home time was not associated with likelihood of transfer connection. Conclusions Among northeast US hospitals, we found that differences in hospital quality, specifically higher levels of alteplase administration, may be associated with increased likelihood of being a transfer destination. Further research is needed to better understand acute ischemic stroke transfer patterns to optimize stroke transfer systems.

The Regional Arctic System Model version 1 (RASM1) has been developed to provide high-resolution simulations of the Arctic atmosphere–ocean–sea ice–land system. Here, we provide a baseline for the capability of RASM to simulate interface processes by comparing retrospective simulations from RASM1 for 1990–2014 with the Community Earth System Model version 1 (CESM1) and the spread across three recent reanalyses. Evaluations of surface and 2 m air temperature, surface radiative and turbulent fluxes, precipitation, and snow depth in the various models and reanalyses are performed using global and regional datasets and a variety of in situ datasets, including flux towers over land, ship cruises over oceans, and a field experiment over sea ice. These evaluations reveal that RASM1 simulates precipitation that is similar to CESM1, reanalyses, and satellite gauge combined precipitation datasets over all river basins within the RASM domain. Snow depth in RASM is closer to upscaled surface observations over a flatter region than in more mountainous terrain in Alaska. The sea ice–atmosphere interface is well simulated in regards to radiation fluxes, which generally fall within observational uncertainty. RASM1 monthly mean surface temperature and radiation biases are shown to be due to biases in the simulated mean diurnal cycle. At some locations, a minimal monthly mean bias is shown to be due to the compensation of roughly equal but opposite biases between daytime and nighttime, whereas this is not the case at locations where the monthly mean bias is higher in magnitude. These biases are derived from errors in the diurnal cycle of the energy balance (radiative and turbulent flux) components. Therefore, the key to advancing the simulation of SAT and the surface energy budget would be to improve the representation of the diurnal cycle of radiative and turbulent fluxes. The development of RASM2 aims to address these biases. Still, an advantage of RASM1 is that it captures the interannual and interdecadal variability in the climate of the Arctic region, which global models like CESM cannot do.