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Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a ‘Phase A’ concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100–350
m images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200
m images will also have a factor
30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.
The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
People with cerebral palsy (CP) are less physically active than the general population and, consequently, are at increased risk of preventable disease. Evidence indicates that low-moderate doses of physical activity can reduce disease risk and improve fitness and function in people with CP. Para athletes with CP typically engage in ‘performance-focused’ sports training, which is undertaken for the sole purpose of enhancing sports performance. Anecdotally, many Para athletes report that participation in performance-focused sports training confers meaningful clinical benefits which exceed those reported in the literature; however, supporting scientific evidence is lacking. The aim of this paper is to describe the protocol for an 18-month study evaluating the clinical effects of a performance-focused swimming training programme for people with CP who have high support needs.
This study will use a concurrent multiple-baseline, single-case experimental design across three participants with CP who have high support needs. Each participant will complete a five-phase trial comprising: baseline (A1); training phase 1 (B1); maintenance phase 1 (A2); training phase 2 (B2); and maintenance phase 2 (A3). For each participant, measurement of swim velocity, health-related quality of life and gross motor functioning will be carried out a minimum of five times in each of the five phases.
The study described will produce Level II evidence regarding the effects of performance-focused swimming training on clinical outcomes in people with CP who have high support needs. Findings are expected to provide an indication of the potential for sport to augment outcomes in neurological rehabilitation.
Few studies have used genomic epidemiology to understand tuberculosis (TB) transmission in rural and remote settings – regions often unique in history, geography and demographics. To improve our understanding of TB transmission dynamics in Yukon Territory (YT), a circumpolar Canadian territory, we conducted a retrospective analysis in which we combined epidemiological data collected through routine contact investigations with clinical and laboratory results. Mycobacterium tuberculosis isolates from all culture-confirmed TB cases in YT (2005–2014) were genotyped using 24-locus Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats (MIRU-VNTR) and compared to each other and to those from the neighbouring province of British Columbia (BC). Whole genome sequencing (WGS) of genotypically clustered isolates revealed three sustained transmission networks within YT, two of which also involved BC isolates. While each network had distinct characteristics, all had at least one individual acting as the probable source of three or more culture-positive cases. Overall, WGS revealed that TB transmission dynamics in YT are distinct from patterns of spread in other, more remote Northern Canadian regions, and that the combination of WGS and epidemiological data can provide actionable information to local public health teams.
We present new observations of the large-scale radio emission surrounding the lenticular galaxy NGC 1534 with the Australia Telescope Compact Array and Murchison Widefield Array. We find no significant compact emission from the nucleus of NGC 1534 to suggest an active core, and instead find low-power radio emission tracing its star-formation history with a radio-derived star-formation rate of 0.38±0.03 M⊙ yr−1. The spectral energy distribution of the extended emission is well-fit by a continuous injection model with an ‘off’ component, consistent with dead radio galaxies. We find the spectral age of the emission to be 203 Myr, having been active for 44 Myr. Polarimetric analysis points to both a large-scale magneto-ionic Galactic foreground at +33 rad m−2 and a component associated with the northern lobe of the radio emission at -153 rad m−2. The magnetic field of the northern lobe shows an unusual circular pattern of unknown origin. While such remnant sources are rare, combined low- and high-frequency radio surveys with high surface-brightness sensitivities are expected to greatly increase their numbers in the coming decade, and combined with new optical and infrared surveys should provide a wealth of information on the hosts of the emission.
X-ray diffraction and electron microprobe analysis were used in combination to identify reaction phases that formed on the surfaces of low-carbon steel specimens reacted with a 75% basalt-25% bentonite mixture and anion-doped water in sealed pressure vessels at 100°C and 250°C. Reaction phases on specimen surfaces and in adhering geologic material were identified by conventional X-ray diffraction scans of entire specimens with intact reaction layers. Comparison of results from adhering geologic material and scans of selectively removed layers allowed establishment of approximate reaction gradients in the adhering packing material. Electron microprobe analysis of specimens in cross-section provided quantitative chemical analyses of adhering reaction phases, and identification of reaction layer composition gradients and thicknesses. Magnetite formed on the surface of specimens reacted at 250°C for 4 weeks. Iron-enriched clay was also observed on specimen surfaces and in the adjacent basalt-bentonite mixture. The 100°C experiments yielded surface films of a siderite-structure phase, (Fe,Ca,Mn)CO3, that were not observed in previous experiments with synthetic ground-water. Less extensive iron enrichment of the adjacent clays compared to that seen in the 250°C experiments was observed. The siderite-structure phase generally formed when no carbonate ion was present in the initial solution, implying dissolution of impurity calcite in the bentonite as the controlling factor in the reaction. The results demonstrate the utility of combining X-ray diffraction and electron microprobe analysis for characterization of reaction phases on alloys reacted with complex geologic materials.
Understanding which characteristics of persons with dementia (PWD) and their caregivers are associated with unmet needs can inform strategies to address those needs. Our purpose was to determine the percentage of PWD having unmet needs and significant correlates of unmet needs in PWD.
Cross-sectional data were analyzed using bivariate and hierarchical multiple linear regression analyses.
Participants lived in the greater Baltimore, Maryland and Washington DC suburban area.
A sample of 646 community-living PWD and their informal caregivers participated in an in-home assessment of dementia-related needs.
Unmet needs were identified using the Johns Hopkins Dementia Care Needs Assessment. Correlates of unmet needs were determined using demographic, socioeconomic, clinical, functional and quality of life characteristics of the PWD and their caregivers.
PWD had a mean of 10.6 (±4.8) unmet needs out of 43 items (24.8%). Unmet needs were most common in Home/Personal Safety (97.4%), General Health Care (83.1%), and Daily Activities (73.2%) domains. Higher unmet needs were significantly related to non-white race, lower education, higher cognitive function, more neuropsychiatric symptoms, lower quality of life in PWD, and having caregivers with lower education or who spent fewer hours/week with the PWD.
Unmet needs are common in community-living PWD, and most are non-medical. Home-based dementia care can identify and address PWD’s unmet needs by focusing on care recipients and caregivers to enable PWD to remain safely at home.
Psychotic symptoms and psychotic disorders occur at increased rates in adults with intellectual disability, including borderline intellectual functioning, compared with the general population. Little is known about the development of such symptoms in this population.
To examine whether clinical factors predictive of psychotic disorder in a familial study of schizophrenia also apply to those with intellectual disability.
Adolescents with special educational needs (SEN) were assessed with the Structured Interview for Schizotypy (SIS) and Childhood Behavioural Checklist (CBCL). These scores were used to prospectively divide participants based on their anticipated risk for psychotic disorder. A subsample were reassessed three times over 6 years, using the Positive and Negative Syndrome Scale (PANSS).
The SEN group were more symptomatic than controls throughout (Cohen's d range for PANSS subscale scores: 0.54–1.4, all P < 0.007). Over 6 years of follow-up, those above the SIS and CBCL cut-off values at baseline were more likely than those below to display morbid positive psychotic symptoms (odds ratio, 3.5; 95% CI 1.3–9.0) and develop psychotic disorder (odds ratio, 11.4; 95% CI 2.6–50.1). Baseline SIS and CBCL cut-off values predicted psychotic disorder with sensitivity of 0.67, specificity of 0.85, positive predictive value of 0.26 and negative predictive value of 0.97.
Adolescents with SEN have increased psychotic and non-psychotic symptoms. The personality and behavioural features associated with later psychotic disorder in this group are similar to those in people with familial loading. Relatively simple screening measures may help identify those in this vulnerable group who do and do not require monitoring for psychotic symptoms.
We provide the first in situ measurements of antenna element beam shapes of the Murchison Widefield Array. Most current processing pipelines use an assumed beam shape, which can cause absolute and relative flux density errors and polarisation ‘leakage’. Understanding the primary beam is then of paramount importance, especially for sensitive experiments such as a measurement of the 21-cm line from the epoch of reionisation, where the calibration requirements are so extreme that tile to tile beam variations may affect our ability to make a detection. Measuring the primary beam shape from visibilities is challenging, as multiple instrumental, atmospheric, and astrophysical factors contribute to uncertainties in the data. Building on the methods of Neben et al. [Radio Sci., 50, 614], we tap directly into the receiving elements of the telescope before any digitisation or correlation of the signal. Using ORBCOMM satellite passes we are able to produce all-sky maps for four separate tiles in the XX polarisation. We find good agreement with the beam model of Sokolowski et al. [2017, PASA, 34, e062], and clearly observe the effects of a missing dipole from a tile in one of our beam maps. We end by motivating and outlining additional on-site experiments.
We describe the motivation and design details of the ‘Phase II’ upgrade of the Murchison Widefield Array radio telescope. The expansion doubles to 256 the number of antenna tiles deployed in the array. The new antenna tiles enhance the capabilities of the Murchison Widefield Array in several key science areas. Seventy-two of the new tiles are deployed in a regular configuration near the existing array core. These new tiles enhance the surface brightness sensitivity of the array and will improve the ability of the Murchison Widefield Array to estimate the slope of the Epoch of Reionisation power spectrum by a factor of ∼3.5. The remaining 56 tiles are deployed on long baselines, doubling the maximum baseline of the array and improving the array u, v coverage. The improved imaging capabilities will provide an order of magnitude improvement in the noise floor of Murchison Widefield Array continuum images. The upgrade retains all of the features that have underpinned the Murchison Widefield Array’s success (large field of view, snapshot image quality, and pointing agility) and boosts the scientific potential with enhanced imaging capabilities and by enabling new calibration strategies.
During the summer of 2016, the Hawaii Department of Health responded to the second-largest domestic foodborne hepatitis A virus (HAV) outbreak in the post-vaccine era. The epidemiological investigation included case finding and investigation, sequencing of RNA positive clinical specimens, product trace-back and virologic testing and sequencing of HAV RNA from the product. Additionally, an online survey open to all Hawaii residents was conducted to estimate baseline commercial food consumption. We identified 292 confirmed HAV cases, of whom 11 (4%) were possible secondary cases. Seventy-four (25%) were hospitalised and there were two deaths. Among all cases, 94% reported eating at Oahu or Kauai Island branches of Restaurant Chain A, with 86% of those cases reporting raw scallop consumption. In contrast, a food consumption survey conducted during the outbreak indicated 25% of Oahu residents patronised Restaurant Chain A in the 7 weeks before the survey. Product trace-back revealed a single distributor that supplied scallops imported from the Philippines to Restaurant Chain A. Recovery, amplification and sequence comparison of HAV recovered from scallops revealed viral sequences matching those from case-patients. Removal of product from implicated restaurants and vaccination of those potentially exposed led to the cessation of the outbreak. This outbreak further highlights the need for improved imported food safety.
This pilot study explored the feasibility of a moderate time-restricted feeding (TRF) intervention and its effects on adiposity and metabolism. For 10 weeks, a free-living TRF group delayed breakfast and advanced dinner by 1·5 h each. Changes in dietary intake, adiposity and fasting biochemistry (glucose, insulin, lipids) were compared with controls who maintained habitual feeding patterns. Thirteen participants (29 (sem 2) kg/m2) completed the study. The average daily feeding interval was successfully reduced in the TRF group (743 (sem 32) to 517 (sem 22) min/d; P < 0·001; n 7), although questionnaire responses indicated that social eating/drinking opportunities were negatively impacted. TRF participants reduced total daily energy intake (P = 0·019) despite ad libitum food access, with accompanying reductions in adiposity (P = 0·047). There were significant between-group differences in fasting glucose (P = 0·008), albeit driven primarily by an increase among controls. Larger studies can now be designed/powered, based on these novel preliminary qualitative and quantitative data, to ascertain and maximise the long-term sustainability of TRF.
The intermittent energy restriction (IER) approach to weight loss involves short periods of substantial (>70 %) energy restriction (ER) interspersed with normal eating. Studies to date comparing IER to continuous energy restriction (CER) have predominantly measured fasting indices of cardiometabolic risk. This study aimed to compare the effects of IER and CER on postprandial glucose and lipid metabolism following matched weight loss. In all, twenty-seven (thirteen male) overweight/obese participants (46 (sem 3) years, 30·1 (sem 1·0) kg/m2) who were randomised to either an IER intervention (2638 kJ for 2 d/week with an overall ER of 22 (sem 0·3) %, n 15) or a CER intervention (2510 kJ below requirements with overall ER of 23 (sem 0·8) %) completed the study. Postprandial responses to a test meal (over 360 min) and changes in anthropometry (fat mass, fat-free mass, circumferences) were assessed at baseline and upon attainment of 5 % weight loss, following a 7-d period of weight stabilisation. The study found no statistically significant difference in the time to attain a 5 % weight loss between groups (median 59 d (interquartile range (IQR) 41–80) and 73 d (IQR 48–128), respectively, P=0·246), or in body composition (P≥0·437). For postprandial measures, neither diet significantly altered glycaemia (P=0·266), whereas insulinaemia was reduced comparatively (P=0·903). The reduction in C-peptide tended (P=0·057) to be greater following IER (309 128 (sem23 268) to 247781 (sem20 709) pmol×360 min/l) v. CER (297 204 (sem25 112) to 301 655 (sem32 714) pmol×360 min/l). The relative reduction in TAG responses was greater (P=0·045) following IER (106 (sem30) to 68 (sem 15) mmol×360 min/l) compared with CER (117 (sem 43) to 130 (sem 31) mmol×360 min/l). In conclusion, these preliminary findings highlight underlying differences between IER and CER, including a superiority of IER in reducing postprandial lipaemia, which now warrant targeted mechanistic evaluation within larger study cohorts.