10 research outputs found

    A Pilot Survey for the H2_2O Southern Galactic Plane Survey (HOPS)

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    We describe observations with the Mopra radiotelescope designed to assess the feasibility of the H2_2O maser southern Galactic plane survey (HOPS). We mapped two one-square-degree regions along the Galactic plane using the new 12 mm receiver and the UNSW Mopra spectrometer (MOPS). We covered the entire spectrum between 19.5 and 27.5 GHz using this setup with the main aims of finding out which spectral lines can be detected with a quick mapping survey. We report on detected emission from H2_2O masers, NH3_3 inversion transitions (1,1), (2,2) and (3,3), HC3_3N (3-2), as well as several radio recombination lines.Comment: accepted by PAS

    Accurate water maser positions from HOPS

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    We report on high spatial resolution water maser observations, using the Australia Telescope Compact Array, towards water maser sites previously identified in the H2O southern Galactic Plane Survey (HOPS). Of the 540 masers identified in the single-dish observations of Walsh et al. (2011), we detect emission in all but 31 fields. We report on 2790 spectral features (maser spots), with brightnesses ranging from 0.06 Jy to 576 Jy and with velocities ranging from −238.5 to +300.5 kms−1. These spectral features are grouped into 631 maser sites. We have compared the positions of these sites to the literature to associate the sites with astrophysical objects. We identify 433 (69 per cent) with star formation, 121 (19 per cent) with evolved stars and 77 (12 per cent) as unknown. We find that maser sites associated with evolved stars tend to have more maser spots and have smaller angular sizes than those associated with star formation. We present evidence that maser sites associated with evolved stars show an increased likelihood of having a velocity range between 15 and 35 kms−1 compared to other maser sites. Of the 31 non-detections, we conclude they were not detected due to intrinsic variability and confirm previous results showing that such variable masers tend to be weaker and have simpler spectra with fewer peaks

    MALT-45: a 7 mm survey of the southern Galaxy - I. Techniques and spectral line data

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    We present the first results from the MALT-45 (Millimetre Astronomer's Legacy Team-45 GHz) Galactic Plane survey. We have observed 5 square degrees (l = 330°–335°, b = ±0 ∘ . 5) for spectral lines in the 7 mm band (42–44 and 48–49 GHz), including CS (1–0), class I CH3OH masers in the 7(0,7)–6(1,6) A+ transition and SiO (1–0) v = 0, 1, 2, 3. MALT-45 is the first unbiased, large-scale, sensitive spectral line survey in this frequency range. In this paper, we present data from the survey as well as a few intriguing results; rigorous analyses of these science cases are reserved for future publications. Across the survey region, we detected 77 class I CH3OH masers, of which 58 are new detections, along with many sites of thermal and maser SiO emission and thermal CS. We found that 35 class I CH3OH masers were associated with the published locations of class II CH3OH, H2O and OH masers but 42 have no known masers within 60 arcsec. We compared the MALT-45 CS with NH3 (1,1) to reveal regions of CS depletion and high opacity, as well as evolved star-forming regions with a high ratio of CS to NH3. All SiO masers are new detections, and appear to be associated with evolved stars from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Generally, within SiO regions of multiple vibrational modes, the intensity decreases as v = 1, 2, 3, but there are a few exceptions where v = 2 is stronger than v = 1

    Monitoring oral health of people in Early Intervention for Psychosis (EIP) teams: the extended Three Shires randomised trial

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    Background: The British Society for Disability and Oral Health guidelines made recommendations for oral health care for people with mental health problems, including providing oral health advice, support, promotion and education. The effectiveness of interventions based on these guidelines on oral health-related outcomes in mental health service users is untested. Objective:To acquire basic data on the oral health of people with or at risk of serious mental illness. To determine the effects of an oral health checklist in routine clinical practice. Design: Clinician and service user-designed cluster randomised trial. Settings and Participants: The trial compared a simple form for monitoring oral health care with standard care (no form) for outcomes relevant to service use and dental health behaviour for people with suspected psychosis in Mid and North England. Thirty-five teams were divided into two groups and recruited across 2012-3 with one year follow up. Results: 18 intervention teams returned 882 baseline intervention forms and 274 outcome sheets one year later (31%). Control teams (n=17) returned 366 baseline forms. For the proportion for which data were available at one year we found no significant differences for any outcomes between those allocated to the initial monitoring checklist and people in the control group (Registered with dentist (p=0.44), routine check-up within last year (p= 0.18), owning a toothbrush (p= 0.99), cleaning teeth twice a day (p=0.68), requiring urgent dental treatment (p=0.11). Conclusion: This trial provides no clear evidence that Care Co-ordinators (largely nursing staff) using an oral health checklist improves oral health behaviour or oral health state in those thought to be at risk of psychosis or with early psychosis

    CORNISH: A 5 GHz VLA survey of the Galactic plane

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    Utility of Spectral Filtering to Improve the Reliability of Marine Fauna Detections from Drone-Based Monitoring

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    Monitoring marine fauna is essential for mitigating the effects of disturbances in the marine environment, as well as reducing the risk of negative interactions between humans and marine life. Drone-based aerial surveys have become popular for detecting and estimating the abundance of large marine fauna. However, sightability errors, which affect detection reliability, are still apparent. This study tested the utility of spectral filtering for improving the reliability of marine fauna detections from drone-based monitoring. A series of drone-based survey flights were conducted using three identical RGB (red-green-blue channel) cameras with treatments: (i) control (RGB), (ii) spectrally filtered with a narrow ‘green’ bandpass filter (transmission between 525 and 550 nm), and, (iii) spectrally filtered with a polarising filter. Video data from nine flights comprising dolphin groups were analysed using a machine learning approach, whereby ground-truth detections were manually created and compared to AI-generated detections. The results showed that spectral filtering decreased the reliability of detecting submerged fauna compared to standard unfiltered RGB cameras. Although the majority of visible contrast between a submerged marine animal and surrounding seawater (in our study, sites along coastal beaches in eastern Australia) is known to occur between 515–554 nm, isolating the colour input to an RGB sensor does not improve detection reliability due to a decrease in the signal to noise ratio, which affects the reliability of detections

    Classifying complex Faraday spectra with convolutional neural networks

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    Advances in radio spectropolarimetry offer the possibility to disentangle complex regions where relativistic and thermal plasmas mix in the interstellar and intergalactic media. Recent work has shown that apparently simple Faraday rotation measure spectra can be generated by complex sources. This is true even when the distribution of rotation measures in the complex source greatly exceeds the errors associated with a single component fit to the peak of the Faraday spectrum. We present a convolutional neural network that can differentiate between simple Faraday thin spectra and those that contain multiple (two) Faraday thin sources. We demonstrate that this network, trained for the upcoming Polarization Sky Survey of the Universe's Magnetism early science observations, can identify two component sources 99 per cent of the time, provided that the sources are separated in Faraday depth by >10 per cent of the full width at half-maximum of the Faraday point spread function, the polarized flux ratio of the sources is >0.1, and that the signal-to-noise ratio (S/N) of the primary component is >5. With this S/N cut-off, the false positive rate (simple sources misclassified as complex) is <0.3 per cent. Work is ongoing to include Faraday thick sources in the training and testing of the convolutional neural network

    The drone revolution of shark science: a review

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    Over the past decade, drones have become a popular tool for wildlife management and research. Drones have shown significant value for animals that were often difficult or dangerous to study using traditional survey methods. In the past five years drone technology has become commonplace for shark research with their use above, and more recently, below the water helping to minimise knowledge gaps about these cryptic species. Drones have enhanced our understanding of shark behaviour and are critically important tools, not only due to the importance and conservation of the animals in the ecosystem, but to also help minimise dangerous encounters with humans. To provide some guidance for their future use in relation to sharks, this review provides an overview of how drones are currently used with critical context for shark monitoring. We show how drones have been used to fill knowledge gaps around fundamental shark behaviours or movements, social interactions, and predation across multiple species and scenarios. We further detail the advancement in technology across sensors, automation, and artificial intelligence that are improving our abilities in data collection and analysis and opening opportunities for shark-related beach safety. An investigation of the shark-based research potential for underwater drones (ROV/AUV) is also provided. Finally, this review provides baseline observations that have been pioneered for shark research and recommendations for how drones might be used to enhance our knowledge in the future

    List of publications on the economic and social history of Great Britain and Ireland published in 2018

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