For refugee children, there are a number of risk factors for poor mental health and psychosocial well-being, many of them exacerbated for those refugee children living in low-resource settings. There is some evidence that caregiver warmth, parenting self-efficacy and positive relationships between caregivers and children can act as protective factors against poor mental health outcomes for children and adolescents. This study sought to assess if caregiver-level factors (parental warmth and affection, positive child-caregiver interaction and parenting self-efficacy) are protective for symptoms of child depression. To address these questions, a quantitative survey was implemented (n = 501) in the Imvepi refugee settlement in Uganda. Results indicated bivariate associations between several caregiver-level factors and child depression. However, in multivariate models, which included measures of economic stress, both parental warmth and affection and child-caregiver interaction were no longer significantly associated with child-reported depression. Parenting self-efficacy was found to be significantly associated with lower child-reported depression. These findings indicate the need to examine and explore how or if caregiver-level factors, such as warmth and parenting self-efficacy, as well as child-caregiver relationships overall, operate in the context of chronic stress. Whereas caregiver-level factors are potentially protective against poor mental health for refugee children, contextual factors, such as poverty and livelihood opportunities, may constrain the positive impacts of parenting.

We present a demonstration version of a commensal pipeline for Fast Radio Burst (FRB) searches using a real-time incoherent beam from the Murchison Widefield Array (MWA). The main science target of the pipeline are bright nearby FRBs from the local Universe (including Galactic FRBs like from SGR 1935+2154) which are the best candidates to probe FRB progenitors and understand physical mechanisms powering these extremely energetic events. Recent FRB detections by LOFAR (down to 110 MHz), the Green Bank Telescope (at 350 MHz), and Canadian Hydrogen Intensity Mapping Experiment (CHIME) detections extending down to 400 MHz, prove that there is a population of FRBs that can be detected below 350 MHz. The new MWA beamformer, known as the ‘MWAX multibeam beamformer’, can form multiple incoherent and coherent beams (with different parameters) commensally to any ongoing MWA observations. One of the beams is currently used for FRB searches (tested in 10 kHz frequency resolution and time resolutions between 0.1 and 100 ms). A second beam (in 1 Hz and 1 s frequency and time resolutions, respectively) is used for the Search for Extraterrestrial Intelligence (SETI) project. This paper focuses on the FRB search pipeline and its verification on selected known bright pulsars. The pipeline uses the FREDDA implementation of the Fast Dispersion Measure Transform algorithm (FDMT) for single pulse searches. Initially, it was tested during standard MWA observations, and more recently using dedicated observations of a sample of 11 bright pulsars. The pulsar PSR J0835-4510 (Vela) has been routinely used as the primary probe of the data quality because its folded profile was always detected in the frequency band 200 – 230 MHz with typical signal-to-noise ratio $>$10, which agrees with the expectations. Similarly, the low dispersion measure pulsar PSR B0950+08 was always detected in folded profile in the frequency band 140–170 MHz and so far has been the only object for which single pulses were detected. We present the estimated sensitivity of the search in the currently limited observing bandwidth of a single MWA coarse channel (1.28 MHz) and for the upgraded, future system with 12.8 MHz (10 channels) of bandwidth. Based on expected sensitivity and existing FRB rate measurements, we project an FRB detection rate between a few and a few tens per year with large uncertainty due to unknown FRB rates at low frequencies.

We present and evaluate the prospects for detecting coherent radio counterparts to gravitational wave (GW) events using Murchison Widefield Array (MWA) triggered observations. The MWA rapid-response system, combined with its buffering mode ($\sim$4 min negative latency), enables us to catch any radio signals produced from seconds prior to hours after a binary neutron star (BNS) merger. The large field of view of the MWA ($\sim$$1\,000\,\textrm{deg}^2$ at 120 MHz) and its location under the high sensitivity sky region of the LIGO-Virgo-KAGRA (LVK) detector network, forecast a high chance of being on-target for a GW event. We consider three observing configurations for the MWA to follow up GW BNS merger events, including a single dipole per tile, the full array, and four sub-arrays. We then perform a population synthesis of BNS systems to predict the radio detectable fraction of GW events using these configurations. We find that the configuration with four sub-arrays is the best compromise between sky coverage and sensitivity as it is capable of placing meaningful constraints on the radio emission from 12.6% of GW BNS detections. Based on the timescales of four BNS merger coherent radio emission models, we propose an observing strategy that involves triggering the buffering mode to target coherent signals emitted prior to, during or shortly following the merger, which is then followed by continued recording for up to three hours to target later time post-merger emission. We expect MWA to trigger on $\sim$$5-22$ BNS merger events during the LVK O4 observing run, which could potentially result in two detections of predicted coherent emission.

We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60$\to$–70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.

We investigate the diversity in the sizes and average surface densities of the neutral atomic hydrogen (H i) gas discs in $\sim$280 nearby galaxies detected by the Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY). We combine the uniformly observed, interferometric H i data from pilot observations of the Hydra cluster and NGC 4636 group fields with photometry measured from ultraviolet, optical, and near-infrared imaging surveys to investigate the interplay between stellar structure, star formation, and H i structural parameters. We quantify the H i structure by the size of the H i relative to the optical disc and the average H i surface density measured using effective and isodensity radii. For galaxies resolved by $>$$1.3$ beams, we find that galaxies with higher stellar masses and stellar surface densities tend to have less extended H i discs and lower H i surface densities: the isodensity H i structural parameters show a weak negative dependence on stellar mass and stellar mass surface density. These trends strengthen when we limit our sample to galaxies resolved by $>$2 beams. We find that galaxies with higher H i surface densities and more extended H i discs tend to be more star forming: the isodensity H i structural parameters have stronger correlations with star formation. Normalising the H i disc size by the optical effective radius (instead of the isophotal radius) produces positive correlations with stellar masses and stellar surface densities and removes the correlations with star formation. This is due to the effective and isodensity H i radii increasing with mass at similar rates while, in the optical, the effective radius increases slower than the isophotal radius. Our results are in qualitative agreement with previous studies and demonstrate that with WALLABY we can begin to bridge the gap between small galaxy samples with high spatial resolution H i data and large, statistical studies using spatially unresolved, single-dish data.

In Paper I, we presented an overview of the Southern-sky MWA Rapid Two-metre (SMART) survey, including the survey design and search pipeline. While the combination of MWA’s large field-of-view and the voltage capture system brings a survey speed of ${\sim} 450\, {\textrm{deg}}^{2}\,\textrm{h}^{-1}$, the progression of the survey relies on the availability of compact configuration of the Phase II array. Over the past few years, by taking advantage of multiple windows of opportunity when the compact configuration was available, we have advanced the survey to 75% of the planned sky coverage. To date, about 10% of the data collected thus far have been processed for a first-pass search, where 10 min of observation is processed for dispersion measures out to 250 ${\textrm{pc cm}}^{-3}$, to realise a shallow survey that is largely sensitive to long-period pulsars. The ongoing analysis has led to two new pulsar discoveries, as well as an independent discovery and a rediscovery of a previously incorrectly characterised pulsar, all from ${\sim} 3\% $ of the data for which candidate scrutiny is completed. In this sequel to Paper I, we describe the strategies for further detailed follow-up including improved sky localisation and convergence to timing solution, and illustrate them using example pulsar discoveries. The processing has also led to re-detection of 120 pulsars in the SMART observing band, bringing the total number of pulsars detected to date with the MWA to 180, and these are used to assess the search sensitivity of current processing pipelines. The planned second-pass (deep survey) processing is expected to yield a three-fold increase in sensitivity for long-period pulsars, and a substantial improvement to millisecond pulsars by adopting optimal de-dispersion plans. The SMART survey will complement the highly successful Parkes High Time Resolution Universe survey at 1.2–1.5 GHz, and inform future large survey efforts such as those planned with the low-frequency Square Kilometre Array (SKA-Low).

We present an overview of the Southern-sky MWA Rapid Two-metre (SMART) pulsar survey that exploits the Murchison Widefield Array’s large field of view and voltage-capture system to survey the sky south of 30$^{\circ}$ in declination for pulsars and fast transients in the 140–170 MHz band. The survey is enabled by the advent of the Phase II MWA’s compact configuration, which offers an enormous efficiency in beam-forming and processing costs, thereby making an all-sky survey of this magnitude tractable with the MWA. Even with the long dwell times employed for the survey (4800 s), data collection can be completed in $<$100 h of telescope time, while still retaining the ability to reach a limiting sensitivity of $\sim$2–3 mJy (at 150 MHz, near zenith), which is effectively 3–5 times deeper than the previous-generation low-frequency southern-sky pulsar survey, completed in the 1990s. Each observation is processed to generate $\sim$5000–8000 tied-array beams that tessellate the full $\sim 610\, {\textrm{deg}^{2}}$ field of view (at 155 MHz), which are then processed to search for pulsars. The voltage-capture recording of the survey also allows a multitude of post hoc processing options including the reprocessing of data for higher time resolution and even exploring image-based techniques for pulsar candidate identification. Due to the substantial computational cost in pulsar searches at low frequencies, the survey data processing is undertaken in multiple passes: in the first pass, a shallow survey is performed, where 10 min of each observation is processed, reaching about one-third of the full-search sensitivity. Here we present the system overview including details of ongoing processing and initial results. Further details including first pulsar discoveries and a census of low-frequency detections are presented in a companion paper. Future plans include deeper searches to reach the full sensitivity and acceleration searches to target binary and millisecond pulsars. Our simulation analysis forecasts $\sim$300 new pulsars upon the completion of full processing. The SMART survey will also generate a complete digital record of the low-frequency sky, which will serve as a valuable reference for future pulsar searches planned with the low-frequency Square Kilometre Array.

The present study covers rank correlated use of soft flooring during partial replacement (45% of the total floor space) of concrete slatted floor by rubber covering. For this purpose, the rank position of 19 cows within a 50 Brown Swiss dairy cattle herd was evaluated by calculating the individual dominance index. A clear rank affiliation could be found for 16 cows (eight cows with a rank index 0.67 – 1.0 (ie high ranking) and eight cows with a rank index 0.0 – 0.25 (ie low ranking). Using focal sampling, the 16 cows were observed with time-lapse video recording before and after floor replacement (8.5 hours per day for 10 days with each floor kind). After replacing 45% of the concrete floor surface with soft flooring in a test area far from the milking parlour, high ranking cows used this area significantly longer ie 105.5 ± 36.2 min more than before compared with lower ranking herd members, who did so 17.6 ± 24.6 min less. Before replacement, low ranking cows spent significantly more time on the concrete slatted floor of the test area (147.6 ± 13.2 min) than high ranking cows (80.9 ± 17.3 min). The results of the observation demonstrate that the extent of use of soft rubber flooring correlates to rank-order and illustrates the importance of barn designs in terms of meeting their specific needs in spite of an existing rank order.

We investigated seroprevalence and factors associated with Leptospira spp. infections in humans in rural Northern Germany. Sera of 450 participants were tested for leptospira-reactive IgG antibodies by two enzyme-linked immunosorbent assays (ELISA). A narrow (specific) and a broad (sensitive) case definition were applied and results compared in the analysis. Personal data were collected via questionnaire and associations with the serostatus were investigated by multivariable logistic regression. The seroprevalence estimates were 1.6% (95%-confidence interval (CI) = 0.63–3.2) under the narrow and 4.2% (95%-CI = 2.6–6.5%) under the broad case definition. Few (14%) participants knew about the pathogen. No seropositive participant recalled a prior leptospirosis diagnosis. Spending more than two hours a week in the forest was significantly associated with anti-leptospira IgG in both models (broad case definition: adjusted odds ratio (aOR) = 2.8, 95%-CI = 1.2–9.1; narrow case definition: aOR = 11.1, 95%-CI = 1.3–97.1). Regular cleaning of storage rooms was negatively associated in the broad (aOR = 0.17, 95%-CI = 0.03–0.98) and touching a dead rodent in the past 10 years in the narrow case definition model (aOR = 0.23, 95%-CI = 0.05–1.04). Our findings support risk factors identified in previous investigations. To counter the low awareness for the pathogen, we recommend that health authorities communicate risks and preventive measures to the public by using target-group specific channels.