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We present the most sensitive and detailed view of the neutral hydrogen (
${\rm H\small I}$
) emission associated with the Small Magellanic Cloud (SMC), through the combination of data from the Australian Square Kilometre Array Pathfinder (ASKAP) and Parkes (Murriyang), as part of the Galactic Australian Square Kilometre Array Pathfinder (GASKAP) pilot survey. These GASKAP-HI pilot observations, for the first time, reveal
${\rm H\small I}$
in the SMC on similar physical scales as other important tracers of the interstellar medium, such as molecular gas and dust. The resultant image cube possesses an rms noise level of 1.1 K (
$1.6\,\mathrm{mJy\ beam}^{-1}$
)
$\mathrm{per}\ 0.98\,\mathrm{km\ s}^{-1}$
spectral channel with an angular resolution of
$30^{\prime\prime}$
(
${\sim}10\,\mathrm{pc}$
). We discuss the calibration scheme and the custom imaging pipeline that utilises a joint deconvolution approach, efficiently distributed across a computing cluster, to accurately recover the emission extending across the entire
${\sim}25\,\mathrm{deg}^2$
field-of-view. We provide an overview of the data products and characterise several aspects including the noise properties as a function of angular resolution and the represented spatial scales by deriving the global transfer function over the full spectral range. A preliminary spatial power spectrum analysis on individual spectral channels reveals that the power law nature of the density distribution extends down to scales of 10 pc. We highlight the scientific potential of these data by comparing the properties of an outflowing high-velocity cloud with previous ASKAP+Parkes
${\rm H\small I}$
test observations.
The Variables and Slow Transients Survey (VAST) on the Australian Square Kilometre Array Pathfinder (ASKAP) is designed to detect highly variable and transient radio sources on timescales from 5 s to
$\sim\!5$
yr. In this paper, we present the survey description, observation strategy and initial results from the VAST Phase I Pilot Survey. This pilot survey consists of
$\sim\!162$
h of observations conducted at a central frequency of 888 MHz between 2019 August and 2020 August, with a typical rms sensitivity of
$0.24\ \mathrm{mJy\ beam}^{-1}$
and angular resolution of
$12-20$
arcseconds. There are 113 fields, each of which was observed for 12 min integration time, with between 5 and 13 repeats, with cadences between 1 day and 8 months. The total area of the pilot survey footprint is 5 131 square degrees, covering six distinct regions of the sky. An initial search of two of these regions, totalling 1 646 square degrees, revealed 28 highly variable and/or transient sources. Seven of these are known pulsars, including the millisecond pulsar J2039–5617. Another seven are stars, four of which have no previously reported radio detection (SCR J0533–4257, LEHPM 2-783, UCAC3 89–412162 and 2MASS J22414436–6119311). Of the remaining 14 sources, two are active galactic nuclei, six are associated with galaxies and the other six have no multi-wavelength counterparts and are yet to be identified.
Retrospective self-report is typically used for diagnosing previous pediatric traumatic brain injury (TBI). A new semi-structured interview instrument (New Mexico Assessment of Pediatric TBI; NewMAP TBI) investigated test–retest reliability for TBI characteristics in both the TBI that qualified for study inclusion and for lifetime history of TBI.
Method:
One-hundred and eight-four mTBI (aged 8–18), 156 matched healthy controls (HC), and their parents completed the NewMAP TBI within 11 days (subacute; SA) and 4 months (early chronic; EC) of injury, with a subset returning at 1 year (late chronic; LC).
Results:
The test–retest reliability of common TBI characteristics [loss of consciousness (LOC), post-traumatic amnesia (PTA), retrograde amnesia, confusion/disorientation] and post-concussion symptoms (PCS) were examined across study visits. Aside from PTA, binary reporting (present/absent) for all TBI characteristics exhibited acceptable (≥0.60) test–retest reliability for both Qualifying and Remote TBIs across all three visits. In contrast, reliability for continuous data (exact duration) was generally unacceptable, with LOC and PCS meeting acceptable criteria at only half of the assessments. Transforming continuous self-report ratings into discrete categories based on injury severity resulted in acceptable reliability. Reliability was not strongly affected by the parent completing the NewMAP TBI.
Conclusions:
Categorical reporting of TBI characteristics in children and adolescents can aid clinicians in retrospectively obtaining reliable estimates of TBI severity up to a year post-injury. However, test–retest reliability is strongly impacted by the initial data distribution, selected statistical methods, and potentially by patient difficulty in distinguishing among conceptually similar medical concepts (i.e., PTA vs. confusion).
It is increasingly common for models of shallow-layer overland flows to include equations for the evolution of the underlying bed (morphodynamics) and the motion of an associated sedimentary phase. We investigate the linear stability properties of these systems in considerable generality. Naive formulations of the morphodynamics, featuring exchange of sediment between a well-mixed suspended load and the bed, lead to mathematically ill-posed governing equations. This is traced to a singularity in the linearised system at Froude number ${\textit {Fr}} = 1$ that causes unbounded unstable growth of short-wavelength disturbances. The inclusion of neglected physical processes can restore well posedness. Turbulent momentum diffusion (eddy viscosity) and a suitably parametrised bed load sediment transport are shown separately to be sufficient in this regard. However, we demonstrate that such models typically inherit an associated instability that is absent from non-morphodynamic settings. Implications of our analyses are considered for simple generic closures, including a drag law that switches between fluid and granular behaviour, depending on the sediment concentration. Steady morphodynamic flows bifurcate into two states: dilute flows, which are stable at low ${\textit {Fr}}$, and concentrated flows which are always unstable to disturbances in concentration. By computing the growth rates of linear modes across a wide region of parameter space, we examine in detail the effects of specific model parameters including the choices of sediment erodibility, eddy viscosity and bed load flux. These analyses may be used to inform the ongoing development of operational models in engineering and geosciences.
In this paper, we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers $31\,\textrm{deg}^{2}$ at $800\,\textrm{MHz}$. As a two-dimensional array of 36$\times$12 m antennas, with baselines ranging from 22 m to 6 km, ASKAP also has excellent snapshot imaging capability and 10 arcsec resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 and $1800\,\textrm{MHz}$ and is expected to facilitate great advances in our understanding of galaxy formation, cosmology, and radio transients while opening new parameter space for discovery of the unknown.
High dietary phosphorus (P), particularly soluble salts, may contribute to chronic kidney disease development in cats. The aim of the present study was to assess the safety of P supplied at 1 g/1000 kcal (4184kJ) from a highly soluble P salt in P-rich dry format feline diets. Seventy-five healthy adult cats (n 25/group) were fed either a low P control (1·4 g/1000 kcal [4184kJ]; Ca:P ratio 0·97) or one of two test diets with 4 g/1000 kcal (4184 kJ); Ca:P 1·04 or 5 g/1000 kcal (4184kJ); Ca:P 1·27, both incorporating 1 g/1000 kcal (4184 kJ) sodium tripolyphosphate (STPP) – for a period of 30 weeks in a randomised parallel-group study. Health markers in blood and urine, glomerular filtration rate, renal ultrasound and bone density were assessed at baseline and at regular time points. At the end of the test period, responses following transition to a commercial diet (total P – 2·34 g/1000 kcal [4184kJ], Ca:P 1·3) for a 4-week washout period were also assessed. No adverse effects on general, kidney or bone (skeletal) function and health were observed. P and Ca balance, some serum biochemistry parameters and regulatory hormones were increased in cats fed test diets from week 2 onwards (P ≤ 0·05). Data from the washout period suggest that increased serum creatinine and urea values observed in the two test diet groups were influenced by dietary differences during the test period, and not indicative of changes in renal function. The present data suggest no observed adverse effect level for feline diets containing 1 g P/1000 kcal (4184 kJ) from STPP and total P level of up to 5 g/1000 kcal (4184 kJ) when fed for 30 weeks.
The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with
$\sim$
15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination
$+41^\circ$
made over a 288-MHz band centred at 887.5 MHz.
The association between surgery with general anesthesia (exposure) and cognition (outcome) among older adults has been studied with mixed conclusions. We revisited a recent analysis to provide missing data education and discuss implications of biostatistical methodology for informative dropout following dementia diagnosis.
Methods/study population:
We used data from the Mayo Clinic Study of Aging, a longitudinal study of prevalence, incidence, and risk factors for mild cognitive impairment (MCI) and dementia. We fit linear mixed effects models (LMMs) to assess the association between anesthesia exposure and subsequent trajectories of cognitive z-scores assuming data missing at random, hypothesizing that exposure is associated with greater decline in cognitive function. Additionally, we used shared parameter models for informative dropout assuming data missing not at random.
Results:
A total of 1948 non-demented participants were included. Median age was 79 years, 49% were female, and 16% had MCI at enrollment. Among median follow-up of 4 study visits over 6.6 years, 172 subjects developed dementia, 270 died, and 594 participants underwent anesthesia. In LMMs, exposure to anesthesia was associated with decline in cognitive function over time (change in annual cognitive z-score slope = −0.063, 95% CI: (−0.080, −0.046), p < 0.001). Accounting for informative dropout using shared parameter models, exposure was associated with greater cognitive decline (change in annual slope = −0.081, 95% CI: (−0.137, −0.026), p = 0.004).
Discussion:
We revisited prior work by our group with a focus on informative dropout. Although the conclusions are similar, we demonstrated the potential impact of novel biostatistics methodology in longitudinal clinical research.
Obtaining objective, dietary exposure information from individuals is challenging because of the complexity of food consumption patterns and the limitations of self-reporting tools (e.g., FFQ and diet diaries). This hinders research efforts to associate intakes of specific foods or eating patterns with population health outcomes.
Design:
Dietary exposure can be assessed by the measurement of food-derived chemicals in urine samples. We aimed to develop methodologies for urine collection that minimised impact on the day-to-day activities of participants but also yielded samples that were data-rich in terms of targeted biomarker measurements.
Setting:
Urine collection methodologies were developed within home settings.
Participants:
Different cohorts of free-living volunteers.
Results:
Home collection of urine samples using vacuum transfer technology was deemed highly acceptable by volunteers. Statistical analysis of both metabolome and selected dietary exposure biomarkers in spot urine collected and stored using this method showed that they were compositionally similar to urine collected using a standard method with immediate sample freezing. Even without chemical preservatives, samples can be stored under different temperature regimes without any significant impact on the overall urine composition or concentration of forty-six exemplar dietary exposure biomarkers. Importantly, the samples could be posted directly to analytical facilities, without the need for refrigerated transport and involvement of clinical professionals.
Conclusions:
This urine sampling methodology appears to be suitable for routine use and may provide a scalable, cost-effective means to collect urine samples and to assess diet in epidemiological studies.
Introduction: Intoxicated patients with decreased Glasgow Coma Scale (GCS) are common presentations to emergency departments. These patients are often intubated due to presumed full stomachs and perceived aspiration risk. Gastric ultrasound (GUS) -- a simple, non-invasive and objective option -- could be applied to this problem. This pilot study uses GUS alongside usual care at a music festival; a bounded, intoxication-dense environment where airways are often managed using non-invasive airway strategies. We aim to (1) clarify the gastric contents of any intubated patients, and (2) assess if patients managed without intubation go on to have a lack of aspiration sequelae because of empty stomachs or in spite of full stomachs. Methods: A prospective cohort study was conducted at a multi-day music festival. Patients presenting to on-site medical services with GCS ≤ 13 and known or suspected substance use were included. Patients with trauma, instability, metabolic derangements or additional aspiration risk factors (eg morbid obesity, pregnancy) were excluded. Standard GUS was performed by a trained provider and results were categorized according to convention as FS (full stomach, ie solids or liquids >1.5mL/kg) or ES (empty stomach, ie empty or liquids <1.5mL/kg). Additional patient data were extracted from linked medical records post event. Results: 33 patients met inclusion criteria and 27 remained after exclusions were applied and consent obtained. 25 patients reported substance use and 19 polysubstance use. The FS group had 15 patients (7 solid & 8 liquid > 1.5), and the ES group had 12 patients (5 empty & 12 liquid < 1.5). The median low GCS documented for FS and ES was 7 and 11 respectively, and 10 patients total had a GCS of 8 or less (6 FS & 4 ES). No patients were intubated and all were managed conservatively according to usual care. 3 patients (2 FS, 1 ES) were transferred to hospital. No patients re-registered at medical for clinically significant aspiration. Conclusion: This pilot study demonstrates the potential utility of GUS in stratifying aspiration risk in intoxicated patients with decreased GCS. “Empty” stomachs might avoid intubation, while the implications and true risks of “full” stomachs for aspiration sequelae in the absence of intubation remain unclear. Due to the small numbers in this pilot study and the quoted GUS sensitivity (only 95%), further research is needed to evaluate the safe application of this modality to clinical decision-making in intoxicated patients.
Investigating genetic modulation of emotion processing may contribute to the understanding of heritable mechanisms of emotional disorders. The aim of the present study was to test the effects of catechol-O-methyltransferase (COMT) val158met and serotonin-transporter-linked promoter region (5-HTTLPR) polymorphisms on facial emotion processing in healthy individuals.
Methods:
Two hundred and seventy five (167 female) participants were asked to complete a computerized facial affect recognition task, which involved four experimental conditions, each containing one type of emotional face (fearful, angry, sad or happy) intermixed with neutral faces. Participants were asked to indicate whether the face displayed an emotion or was neutral. The COMT-val158met and 5-HTTLPR polymorphisms were genotyped.
Results:
Met homozygotes (COMT) showed a stronger bias to perceive neutral faces as expressions of anger, compared with val homozygotes. However, the S-homozygotes (5-HTTLPR) showed a reduced bias to perceive neutral faces as expressions of happiness, compared to L-homozygotes. No interaction between 5-HTTLPR and COMT was found.
Conclusions:
These results add to the knowledge of individual differences in social cognition that are modulated via serotonergic and dopaminergic systems. This potentially could contribute to the understanding of the mechanisms of susceptibility to emotional disorders.
A number of studies have investigated white matter abnormalities in patients with bipolar disorder (BD) using diffusion tensor imaging. However, tractography studies yielded heterogeneous results partly due to small sample sizes.
Aims:
In this work we aimed to study white matter abnormalities using whole-brain tractography in a large multicenter sample of patients with BD I with and without psychotic features.
Objectives:
To compare mean generalized fractional anisotropy (GFA) along deep white matter tracts between patients with BD with a positive history of psychosis during illness phases, no such history and healthy controls.
Methods:
We acquired diffusion-weighted MRI for 118 patients with BD I and 86 healthy controls using the same acquisition parameters and scanning hardware. We used Q-ball imaging tractography and an automatized segmentation technique to reconstruct 22 known deep white matter tracts and to obtain the mean GFA along each tract.
Results:
Patients with BD had lower GFA values than controls along the corpus callosum (body and splenium), the left cingulum and the left arcuate fasciculus, when controlling for age, gender and acquisition site. All results with an exception for the long fibers of the left cingulum were driven by patients with a positive history of psychotic symptoms.
Conclusions:
We demonstrated a reduced integrity of interhemispheric, limbic and arcuate white matter tracts in patients with BD I. Further, interhemispheric pathways were more disrupted in patients with psychotic symptoms, underscoring the role of interhemispheric connectivity in the pathophysiology of BD with psychosis.
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
${\sim}60\%$
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
We present a detailed analysis of the radio galaxy PKS
$2250{-}351$
, a giant of 1.2 Mpc projected size, its host galaxy, and its environment. We use radio data from the Murchison Widefield Array, the upgraded Giant Metre-wavelength Radio Telescope, the Australian Square Kilometre Array Pathfinder, and the Australia Telescope Compact Array to model the jet power and age. Optical and IR data come from the Galaxy And Mass Assembly (GAMA) survey and provide information on the host galaxy and environment. GAMA spectroscopy confirms that PKS
$2250{-}351$
lies at
$z=0.2115$
in the irregular, and likely unrelaxed, cluster Abell 3936. We find its host is a massive, ‘red and dead’ elliptical galaxy with negligible star formation but with a highly obscured active galactic nucleus dominating the mid-IR emission. Assuming it lies on the local M–
$\sigma$
relation, it has an Eddington accretion rate of
$\lambda_{\rm EDD}\sim 0.014$
. We find that the lobe-derived jet power (a time-averaged measure) is an order of magnitude greater than the hotspot-derived jet power (an instantaneous measure). We propose that over the lifetime of the observed radio emission (
${\sim} 300\,$
Myr), the accretion has switched from an inefficient advection-dominated mode to a thin disc efficient mode, consistent with the decrease in jet power. We also suggest that the asymmetric radio morphology is due to its environment, with the host of PKS
$2250{-}351$
lying to the west of the densest concentration of galaxies in Abell 3936.
Despite increased focus on ascertaining the status of elasmobranch fish, the stock units for many species are uncertain. Data from mark-recapture tagging studies undertaken from 1959–2017 were analysed for 13 batoid species. Data were most comprehensive for skates (Rajidae), with 22,374 released and 3342 (14.9%) returned. Most data related to thornback ray Raja clavata, blonde ray R. brachyura and spotted ray R. montagui. Tags were generally returned from areas less than 50 km from their release, and usually from the ICES Division in which they were released. However, straight-line distances travelled of up to 910 km (R. brachyura) and 772 km (R. clavata) were recorded, highlighting that individual skates are capable of longer-distance movements. The maximum time at liberty was 16.6 years (R. clavata). Whilst mark-recapture data indicated that the current stock units used by ICES are broadly appropriate, southward movements of several skate species tagged off Northern Ireland (Division 6.a) to the Irish Sea (Division 7.a) were observed. In contrast, skates tagged in the Irish Sea and Bristol Channel (Division 7.f) generally remained in that area, with only occasional recaptures from Division 6.a.
The likelihood that Palaeolithic artisans sometimes used natural objects as models for their image-making has long been suggested, yet well-contextualized and stratified examples have remained rare. This study examines a series of natural and fabricated items from the Natufian settlement of Wadi Hammeh 27 in Jordan (12,000–12,500 cal. bc) to propose that the site occupants collected a variety of found objects such as fossils, unusually shaped stones and animal bones, which they utilized as templates in the production of geometric art pieces. Natural and fabricated objects were woven into complex schemes of relation by Natufian artisans. Existing patterns were copied and applied to a variety of representational images. Found objects were sometimes subtly modified, whereas at other times they were transformed into finished artefacts. The scute pattern on the tortoise carapace, in particular, appears to have formed the basis of important ritual beliefs across the Natufian culture area. At Wadi Hammeh 27, it was evoked in various media and at various scales to form interrelating tableaux of representation.
Flexible piezoelectric generators (PEGs) present a unique opportunity for renewable and sustainable energy harvesting. Here, we present a low-temperature and low-energy deposition method using solvent evaporation-assisted three-dimensional printing to deposit electroactive poly(vinylidene fluoride) (PVDF)-trifluoroethylene (TrFE) up to 19 structured layers. Visible-wavelength transmittance was above 92%, while ATR-FTIR spectroscopy showed little change in the electroactive phase fraction between layer depositions. Electroactivity from the fabricated PVDF-TrFE PEGs showed that a single structured layer gave the greatest output at 289.3 mV peak-to-peak voltage. This was proposed to be due to shear-induced polarization affording the alignment of the fluoropolymer dipoles without an electric field or high temperature.
The MESSENGER mission provided a wealth of discoveries regarding Mercury’s present and past magnetic field and completed the first-order characterization of the magnetic fields of the solar system’s inner planets. MESSENGER demonstrated that Mercury is the only inner planet other than Earth to possess a global magnetic field generated by fluid motions in its liquid iron core. The field possesses some similarities to that of Earth, particularly its dipolar nature, but it is more than a factor of 100 weaker at the surface and unlike Earth’s field is highly asymmetric about the geographic equator. This structure constrains the dynamo process that generates the field and in turn the compositional and thermal structure of Mercury’s interior. Measurements made by MESSENGER less than 100 km above the planetary surface revealed signatures of crustal magnetization, at least some of which were acquired in a very ancient global magnetic field. Electric currents flow in the planet’s interior as a result of the dynamic interactions of the global magnetic field with the solar wind. These currents provide information on the radius of Mercury’s electrically conductive core, as well as the conductivity structure of the crust and mantle, which in turn reflects interior composition and temperature.
Research on the causes of sheep death in sea voyages from Australia to the Middle East is limited, in particular little is known about the influence of climatic factors. Mortality data from 417 shipments of sheep exported over an 11-year period (November 2004 to June 2015) were modelled retrospectively to determine associated climatic factors. The statistical analysis were performed for both the full data set with 417 voyages based on actual and estimated departure and arrival dates and a restricted data set with 71 voyages based on actual dates. The results of the full data set demonstrated a seasonal mortality pattern, with more deaths occurring on sea voyages leaving Australia in the southern hemisphere winter or spring than those departing in Australian summer or autumn. Heat stress and inadequate fat mobilisation for energy supply when sheep are inappetant on shipments may explain this seasonality. Based on these two models, the voyage and weather factors associated with sheep mortalities included departure year, autumn departure in the southern hemisphere, voyage duration, single or multiple loading port(s), weekly mean dry bulb temperature and wind speed at departure ports, and humidity at destination ports. Significant correlations were observed between weather variables at the departure ports in the Australian winter and a high sheep mortality rate during voyages. This, together with the anticipated increased heat stress risk as a result of climate change, suggests that there could be review of the trade from Australia in the southern hemisphere winter. The influence of weather at the departure ports should be considered in sheep mortality prediction models, especially Australia’s heat stress risk assessment model.