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To assess the feasibility and utility of introducing the following changes on to in-patient units:
Structural and cultural adaptation to create a sleep friendly ward environment
A “Protected Sleep Time” between midnight and 6am
Routine screening for sleep disorders, including obstructive sleep apnoea and restless leg syndrome
Insomnia and other sleep disturbances are cause, correlate and consequence of psychiatric disorders. Routine hourly night time observations, ward noise, bright lights at night time, sleep disorders, insufficient exercise, insufficient day light exposure, too much caffeine and inappropriate psychotropic use are all causes of disturbed sleep (Horne 2018).
Seven wards participated in a pilot (SleepWell). These consisted of one male and two female Acute Wards (General Adult), a High Dependency Unit, a Neurorehabilitation ward, an in-patient dementia service and one rehabilitation ward. These wards were supported via an existing trust management structure and the pilot was specifically supported by two trust managers (RW and RB) and by a clinical director (PK). The expectation was that each ward would identify a sleep champion from existing staff to facilitate the changes. A “product” was developed which identified core sleep management features but, in addition, wards were not confined to these. The existing policy that all inpatients should be checked each hour over night was suspended for the pilot wards and the patients had protected sleep time (PST) if the MDT agreed that it was clinically appropriate.
Quantitative and qualitative techniques were used to identify facilitators of change, impact on sleep and, outcome.
Protected sleep was viewed positively by all staff and approximately 50% of patients on the pilot wards were able to have PST at some point in their admission. Routine sleep disorder assessments were harder to implement and 33% of patients were screened. There were no deaths or significant events on patients due to PST. Hypnotic use on the pilot wards reduced. It is anticipated that PST where it is safe will be rolled out across all adult and old age wards in the trust.
With support, it has been feasible to change many aspects of sleep management across a breadth of inpatient units in a large NHS trust.
Sleep disturbance is common in psychiatry wards despite poor sleep worsening mental health. Contributory factors include the ward environment, frequent nightly checks on patients and sleep disorders including sleep apnoea. We evaluated the safety and feasibility of a package of measures to improve sleep across a mental health trust, including removing hourly checks when safe, sleep disorder screening and improving the ward environment.
During the pilot there were no serious adverse events; 50% of in-patients were able to have protected overnight sleep. Hypnotic issuing decreased, and feedback from patients and staff was positive. It was possible to offer cognitive–behavioural therapy for insomnia to selected patients.
Many psychiatry wards perform standardised, overnight checks, which are one cause of sleep disruption. A protected sleep period was safe and well-tolerated alongside education about sleep disturbance and mental health. Future research should evaluate personalised care rather than blanket observation policies.
This is a prospective study of 35 patients. The daily dosages were 2-20 mg of haloperidol and 2-8 mg of risperidonum. The scoring is according to Positive and Negative Symptoms Assessment Scoring Scale (PANSS) and to Liverpul's University Neuroleptics Side Effects Rating Scale (LUNSERS). The patients were treated in hospital and ambulatory. The patients included in the study are diagnosed with schizophrenia according the DSM- IV criteria. 23 of them are male and 12 are female, from 18-50 years old. The preliminary result of PANSS for is more than 60 points. Pregnant women or those during lactation, drug and alcohol users, patients with organic comorbidity, and those treated previously with atypical antipsychotic medications, were not included in the study.
Both medicaments are effective on improving the symptoms of schizophrenia, but a superiority of risperidonum on improving positive and negative symptoms of this syndrome, is noticed. Risperidonum is safer, since it causes less side effects (with the value of p=0.106 not statistically important) in comparison with haloperidol which causes more side effects, (with the value of p=0.001 statistically important).
Phased Array Feed (PAF) technology is the next major advancement in radio astronomy in terms of combining high sensitivity and large field of view. The Focal L-band Array for the Green Bank Telescope (FLAG) is one of the most sensitive PAFs developed so far. It consists of 19 dual-polarization elements mounted on a prime focus dewar resulting in seven beams on the sky. Its unprecedented system temperature of ~17 K will lead to a 3 fold increase in pulsar survey speeds as compared to contemporary single pixel feeds. Early science observations were conducted in a recently concluded commissioning phase of the FLAG where we clearly demonstrated its science capabilities. We observed a selection of normal and millisecond pulsars and detected giant pulses from PSR B1937+21.
We compare first-order (refractive) ionospheric effects seen by the MWA with the ionosphere as inferred from GPS data. The first-order ionosphere manifests itself as a bulk position shift of the observed sources across an MWA field of view. These effects can be computed from global ionosphere maps provided by GPS analysis centres, namely the CODE. However, for precision radio astronomy applications, data from local GPS networks needs to be incorporated into ionospheric modelling. For GPS observations, the ionospheric parameters are biased by GPS receiver instrument delays, among other effects, also known as receiver DCBs. The receiver DCBs need to be estimated for any non-CODE GPS station used for ionosphere modelling. In this work, single GPS station-based ionospheric modelling is performed at a time resolution of 10 min. Also the receiver DCBs are estimated for selected Geoscience Australia GPS receivers, located at Murchison Radio Observatory, Yarragadee, Mount Magnet and Wiluna. The ionospheric gradients estimated from GPS are compared with that inferred from MWA. The ionospheric gradients at all the GPS stations show a correlation with the gradients observed with the MWA. The ionosphere estimates obtained using GPS measurements show promise in terms of providing calibration information for the MWA.
GLEAM, the GaLactic and Extragalactic All-sky MWA survey, is a survey of the entire radio sky south of declination + 25° at frequencies between 72 and 231 MHz, made with the MWA using a drift scan method that makes efficient use of the MWA’s very large field-of-view. We present the observation details, imaging strategies, and theoretical sensitivity for GLEAM. The survey ran for two years, the first year using 40-kHz frequency resolution and 0.5-s time resolution; the second year using 10-kHz frequency resolution and 2 s time resolution. The resulting image resolution and sensitivity depends on observing frequency, sky pointing, and image weighting scheme. At 154 MHz, the image resolution is approximately 2.5 × 2.2/cos (δ + 26.7°) arcmin with sensitivity to structures up to ~ 10° in angular size. We provide tables to calculate the expected thermal noise for GLEAM mosaics depending on pointing and frequency and discuss limitations to achieving theoretical noise in Stokes I images. We discuss challenges, and their solutions, that arise for GLEAM including ionospheric effects on source positions and linearly polarised emission, and the instrumental polarisation effects inherent to the MWA’s primary beam.
The Murchison Widefield Array is a Square Kilometre Array Precursor. The telescope is located at the Murchison Radio–astronomy Observatory in Western Australia. The MWA consists of 4 096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays, and others by Graphics Processing Units housed in general purpose rack mounted servers. The correlation capability required is approximately 8 tera floating point operations per second. The MWA has commenced operations and the correlator is generating 8.3 TB day−1 of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper, we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces.
The science cases for incorporating high time resolution capabilities into modern radio telescopes are as numerous as they are compelling. Science targets range from exotic sources such as pulsars, to our Sun, to recently detected possible extragalactic bursts of radio emission, the so-called fast radio bursts (FRBs). Originally conceived purely as an imaging telescope, the initial design of the Murchison Widefield Array (MWA) did not include the ability to access high time and frequency resolution voltage data. However, the flexibility of the MWA’s software correlator allowed an off-the-shelf solution for adding this capability. This paper describes the system that records the 100 μs and 10 kHz resolution voltage data from the MWA. Example science applications, where this capability is critical, are presented, as well as accompanying commissioning results from this mode to demonstrate verification.
The graphics processing unit has become an integral part of astronomical instrumentation, enabling high-performance online data reduction and accelerated online signal processing. In this paper, we describe a wide-band reconfigurable spectrometer built using an off-the-shelf graphics processing unit card. This spectrometer, when configured as a polyphase filter bank, supports a dual-polarisation bandwidth of up to 1.1 GHz (or a single-polarisation bandwidth of up to 2.2 GHz) on the latest generation of graphics processing units. On the other hand, when configured as a direct fast Fourier transform, the spectrometer supports a dual-polarisation bandwidth of up to 1.4 GHz (or a single-polarisation bandwidth of up to 2.8 GHz).
We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.
Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.
The Murchison Widefield Array (MWA) is one of three Square Kilometre Array Precursor telescopes and is located at the Murchison Radio-astronomy Observatory in the Murchison Shire of the mid-west of Western Australia, a location chosen for its extremely low levels of radio frequency interference. The MWA operates at low radio frequencies, 80–300 MHz, with a processed bandwidth of 30.72 MHz for both linear polarisations, and consists of 128 aperture arrays (known as tiles) distributed over a ~3-km diameter area. Novel hybrid hardware/software correlation and a real-time imaging and calibration systems comprise the MWA signal processing backend. In this paper, the as-built MWA is described both at a system and sub-system level, the expected performance of the array is presented, and the science goals of the instrument are summarised.
The discovery of a pulsar or pulsars orbiting near the Galactic Center (GC) could offer an unprecedented probe of strong-field gravity, the properties of our galaxy's supermassive black hole and insights into the paradoxical star formation history of the region. However, searching for pulsars near the GC is severely hampered by the large electron densities along our line of sight and the scattering-induced pulse broadening of the pulsar emission observed through it. As the broadened pulse length approaches the pulsar period, the periodicity in pulsar emission becomes nearly undetectable. Searches extended to higher frequencies, in an effort to reduce scattering, suffer from reduced intrinsic flux, higher system temperatures and increased atmospheric opacity. We are currently attempting to mitigate the challenges associated with searching for pulsars near the GC by employing new wide bandwidth receivers, upgraded IF distribution systems and novel digital spectrometers in a GC pulsar search campaign at the Green Bank Telescope in West Virginia, USA.
Our search will cover two frequency bands, from 12-15 GHz (Ku Band) and 18-26 GHz (K Band), during a total of approximately 30 hours of observations, with expected characteristic 10-sigma sensitivities between 5-10 micro-Jy. Our first observations are scheduled for mid-March 2012. Here we will present the status of our observations and initial results.
The far-ultra violet (6 – 13.6 eV) photons from the OB stars in Ultra-compact HII regions (UCHs) produce photo-dissociation regions (PDRs) at the interface between the ionized and the natal molecular material. In this paper, we show that carbon recombination lines (CRLs) at frequencies greater than a few GHz are detectable from these PDRs and such observations can be used to: (1) estimate the physical properties of the PDR material; (2) study the kinematics of the PDR material relative to the HII region gas; (3) constrain the magnetic fields in the vicinity of UCHs and (4) address the lifetime problem of UCHs.
A complete survey of radio recombination lines (RRLs) near 327 MHz from the galactic plane (l = 330° − 0°-89°, b = 0°) was carried out using a section of the Ooty Radio Telescope (ORT) with an angular resolution of 2° × 2°. A subset of regions in the same area was observed using the whole telescope which has a beam of 2° × 6'. Hydrogen RRLs were detected in most of the positions that were observed. The lv diagram and radial distribution computed from the observed spectra and their comparison with other species in the galactic plane indicate that the low density gas detected in the survey is distributed similar to the star forming regions. For an assumed temperature of 7000 K, we estimate that the densities and sizes of the regions are in the range 1 — 10 cm−3 and 20 — 200 pc respectively. Our data suggests that the low density ionized gas is in the form of outer envelopes of normal HII regions.
A survey of radio recombination lines (RRLs) in the Galactic plane (l = 332° − 0° − 89°) near 327 MHz made using the Ooty Radio Telescope (ORT) has detected carbon RRLs from all the positions in the longitude range 0° < l < 20° and from a few positions at other longitudes. The carbon lines detected in the survey are, most likely, emission counterparts of the absorption lines observed at frequencies below 150 MHz. Observations towards l = 13°.9, b = 0°.0 indicate that the broader (∼ 38 km s−1) carbon line detected in the lower resolution observation consists of multiple narrow components (∼ 10 km s−1) with different central velocities. The implications of the presence of such narrow components for the modeling of line emission is discussed.
A pilot project to observe recombination lines of hydrogen and carbon from Galactic HII regions near 20cm (n = 168) and 49cm (n = 220) using the 30-station correlator at the Giant Metre-wave Radio Telescope was undertaken. The preliminary results from observations of the HII regions W3 and S106 are presented here.
The electron temperatures of the compact cores of the galactic HII regions S206 and S209 have been determined by radio continuum observations near 235, 327 and 610 MHz using the Giant Meterwave Radio Telescope (GMRT). The resolution of our maps are 11″ and 6″ at 327 and 610 MHz respectively. These are the highest resolution low frequency maps of these HII regions.
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