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We have observed the G23 field of the Galaxy AndMass Assembly (GAMA) survey using the Australian Square Kilometre Array Pathfinder (ASKAP) in its commissioning phase to validate the performance of the telescope and to characterise the detected galaxy populations. This observation covers ~48 deg2 with synthesised beam of 32.7 arcsec by 17.8 arcsec at 936MHz, and ~39 deg2 with synthesised beam of 15.8 arcsec by 12.0 arcsec at 1320MHz. At both frequencies, the root-mean-square (r.m.s.) noise is ~0.1 mJy/beam. We combine these radio observations with the GAMA galaxy data, which includes spectroscopy of galaxies that are i-band selected with a magnitude limit of 19.2. Wide-field Infrared Survey Explorer (WISE) infrared (IR) photometry is used to determine which galaxies host an active galactic nucleus (AGN). In properties including source counts, mass distributions, and IR versus radio luminosity relation, the ASKAP-detected radio sources behave as expected. Radio galaxies have higher stellar mass and luminosity in IR, optical, and UV than other galaxies. We apply optical and IR AGN diagnostics and find that they disagree for ~30% of the galaxies in our sample. We suggest possible causes for the disagreement. Some cases can be explained by optical extinction of the AGN, but for more than half of the cases we do not find a clear explanation. Radio sources aremore likely (~6%) to have an AGN than radio quiet galaxies (~1%), but the majority of AGN are not detected in radio at this sensitivity.
Multi-layer reconstruction has become standard in endoscopic skull base surgery. The inlay component used can vary among autografts, allografts, xenografts and synthetics, primarily based on surgeon preference. The short- and long-term outcomes of collagen matrix in skull base reconstruction are described.
A case series of patients who underwent endoscopic skull base reconstruction with collagen matrix inlay were assessed. Immediate peri-operative outcomes (cerebrospinal fluid leak, meningitis, ventriculitis, intracranial bleeding, epistaxis, seizures) and delayed complications (delayed healing, meningoencephalocele, prolapse of reconstruction, delayed cerebrospinal fluid leak, ascending meningitis) were examined.
Of 120 patients (51.0 ± 17.5 years, 41.7 per cent female), peri-operative complications totalled 12.7 per cent (cerebrospinal fluid leak, 3.3 per cent; meningitis, 3.3 per cent; other intracranial infections, 2.5 per cent; intracranial bleeding, 1.7 per cent; epistaxis, 1.7 per cent; and seizures, 0 per cent). Delayed complications did not occur in any patients.
Collagen matrix is an effective inlay material. It provides robust long-term separation between sinus and cranial cavities, and avoids donor site morbidity, but carries additional cost.
Between 1964 and 1990, the notion of nonlocality in Bell's papers underwent a profound change as his nonlocality theorem gradually became detached from quantum mechanics, and referred to wider probabilistic theories involving correlations between separated beables. The proposition that standard quantum mechanics is itself nonlocal (more precisely, that it violates ‘local causality’) became divorced from the Bell theorem per se from 1976 on, although this important point is widely overlooked in the literature. In 1990, the year of his death, Bell would express serious misgivings about themathematical form of the local causality condition and leave ill-defined the issue of the consistency between special relativity and violation of the Bell-type inequality. In our view, the significance of the Bell theorem, in both its deterministic and stochastic forms, can only be fully understood by taking into account the fact that a fully Lorentz covariant version of quantum theory, free of action at a distance, can be articulated in the Everett interpretation.
John S. Bell's last word on his celebrated nonlocality theorem and its interpretation appeared in his 1990 paper ‘La nouvelle cuisine’, first published in the year of his untimely death. Bell was careful here to distinguish between the issue of ‘no superluminal signalling’ in quantum theory (both quantum field theory and quantum mechanics) and a principle he first introduced explicitly in 1976 and called ‘local causality’ . In relation to the former, Bell expressed concerns that amplify doubts he had already expressed in 1976. These concerns touch on what is now widely known as the no-signalling theorem in quantum mechanics, and ultimately have to do with Bell's distaste for what he saw as an anthropocentric element in orthodox quantum thinking. In relation to local causality, Bell emphasised that his famous factorizability (no-correlations) condition is not to be seen ‘as the formulation of local causality, but as a consequence thereof’ and stressed how difficult he found it to articulate this consequence. He left the question of any strict inconsistency between violation of factorizability and special relativity theory unresolved, a not insignificant shift from his thinking up to the early 1980s.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
The superheating that usually occurs when a solid is melted by volumetric heating can produce irregular solid–liquid interfaces. Such interfaces can be visualised in ice, where they are sometimes known as Tyndall stars. This paper describes some of the experimental observations of Tyndall stars and a mathematical model for the early stages of their evolution. The modelling is complicated by the strong crystalline anisotropy, which results in an anisotropic kinetic undercooling at the interface; it leads to an interesting class of free boundary problems that treat the melt region as infinitesimally thin.
Nasolacrimal duct obstruction is common and is usually a result of benign stricture formation. Although neoplasia near or around the lacrimal system may produce epiphora, the incidence of neoplasia from within the lacrimal system as a cause of nasolacrimal duct obstruction is not well documented.
A retrospective study was performed on all patients undergoing dacryocystorhinostomy with a history of epiphora. The incidence of patients with operative findings of intra-lacrimal neoplasm was sought. Histopathologically confirmed cases were included.
The study comprised 537 patients, who underwent a total of 631 endoscopic dacryocystorhinostomy procedures between January 1998 and July 2013. Non-stenotic causes of nasolacrimal duct obstruction were encountered in 3.01 per cent of dacryocystorhinostomy procedures, and included neoplastic, inflammatory and infectious pathologies. Inverted papilloma was the most common cause, encountered in 0.79 per cent of dacryocystorhinostomy operations.
These findings suggest that neoplasia is an uncommon but not a rare cause of nasolacrimal duct obstruction. Surgical teams performing high numbers of dacryocystorhinostomy procedures should be aware of such pathology and patients counselled appropriately.
The impact of nanostructured broadband antireflection (AR) coatings on solar panel performance has been projected for a broad range of panel tilt angles at various locations. AR coated films have been integrated on test panels and the short-circuit current has been measured for the entire range of panel tilts. The integration of the AR coatings resulted in an increase in short-circuit current of the panels by eliminating front sheet reflection loss for a broad spectrum of light and wide angle of light incidence. The short-circuit current enhancement is 5% for normal light incidence and approximately 20% for off-angle light incidence. The National Renewable Energy Laboratory (NREL) System Advisor Model (SAM) predicts that this AR coating can yield at least 6.5% improvement in solar panel annual power output. The greatest enhancement, approximately 14%, is predicted for vertical panels. The AR coating’s contributions to vertical mount panels and building-integrated solar panels are significant. This nanostructured broadband AR coating thus has the potential to lower the cost per watt of photovoltaic solar energy.
Flexible copper indium gallium diselenide (CIGS) solar cells on lightweight substrates can deliver high specific powers. Flexible lightweight CIGS solar cells are also primary candidates for building-integrated panels. In all applications, CIGS cells can greatly benefit from the application of broadband and wide-angle AR coating technology. The AR coatings can significantly improve the transmittance of light over the entire CIGS absorption band spectrum. Increased short-circuit current has been observed after integrating AR coated films onto baseline solar panels. NREL’s System Advisor Model (SAM) has predicted up to 14% higher annual power output on AR integrated vertical or building-integrated panels. The combination of lightweight flexible substrates and advanced device designs employing nanostructured optical coatings together have the potential to achieve flexible CIGS modules with enhanced efficiencies and specific power.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
Correlating patient perception of nasal obstruction sidedness to causative anatomy is important in surgical planning. The accuracy of patient-perceived asymmetry of nasal obstruction, as regards objective measures, is described.
Cross-sectional study of patients undergoing nasal airflow assessment. Unilateral obstruction was assessed using visual analogue scale scores and anterior rhinomanometry, without decongestion. Subjective obstruction asymmetry was defined using either the absolute score difference (right vs left) or the minimal clinically important difference, derived statistically. Correlation between subjective and objective obstruction measures was assessed.
In 145 patients (mean age ± standard deviation, 42.8 ± 16.6 years; 54.5 per cent female), objective obstruction was right-sided in 32.4 per cent, left-sided in 36.6 per cent and symmetrical in 31.0 per cent. Subjective perception of obstruction sidedness had a sensitivity and specificity of 86.9 and 41.1 per cent, respectively, using the minimal clinically important difference. Positive predictive value was 59.4 per cent using absolute score difference and 53.7 per cent using minimal clinically important difference. Receiver operator characteristic curve analysis indicated correlation between subjective and objective measures (p < 0.001).
Subjective perception of nasal obstruction asymmetry has limited accuracy. Corroboration with objective airway assessment may be helpful in patients whose symptoms are incongruous with clinical findings.
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.
To assess the clinical and radiological characteristics of the posterior prolongation of the cartilaginous nasal septum, an under-utilised source of autologous cartilage for nasal reconstruction.
Materials and methods:
Consecutive patients undergoing primary, external approach rhinoplasty were included. The septal cartilage was assessed intra-operatively prior to routine harvest. Cartilage use was recorded and post-operative cosmesis noted. Computed tomography scans from a separate patient group, with no septal surgery, were used to assess septal cartilage dimensions.
Of the 25 rhinoplasty patients studied, 24 had harvestable septal cartilage, with a posterior prolongation mean length ± standard deviation of 24.3 ± 8.40 mm, mean height of 4.33 ± 0.34 mm and mean width of 1.1 ± 0.35 mm. The mean post-operative cosmesis score was +2.41 ± 0.71 at a mean follow up of 45 ± 8.7 weeks. All 25 radiology patients had visible posterior prolongations on computed tomography (mean length, 18.1 ± 5.1 mm; mean height, 4.2 ± 1.1 mm; mean width 1.5 ± 0.63 mm).
Harvesting of the posterior prolongation would increase by 25 per cent the cartilage area available for autologous grafts. Endoscopic guidance aids this process. Cartilage is most commonly used for overlay grafts, with good cosmesis. The posterior prolongation is demonstrated on computed tomography, although dimensions may be underestimated.
Properties of radiatively cooled supersonic plasma jets formed by ablation of thin Al
foils driven by 1.4 MA, 250 ns current pulse are presented. The jets are highly collimated
with half-opening angles of ~2°. Measurements of the flow velocity (~60
km/s) and plasma temperature (~15 eV) in the jet with Thomson scattering diagnostic
give internal Mach number of M ~ 3, suggesting additional collimation of the jet by
toroidal magnetic fields.
The formation of supersonic, radiatively cooled plasma jets with applications to
laboratory astrophysics has been an active area of research on the MAGPIE generator. One
of the ways of producing astrophysically-relevant jets in the laboratory is by using the
ablation of plasma from a radial foil Z-pinch. In this configuration a ~1.4 MA, 250
ns current pulse is introduced into an aluminium disk with a thickness of 15
μm. The ablated plasma from the foil converges on the axis, producing a
steady and collimated jet with a typical axial velocity of ~100 km/s. The setup
allows for the addition of argon above the foil for jet-ambient interaction studies. The
interaction is characterised by the formation of several shock features, which are
presented and discussed from experimental data and numerical simulations.
In the summer of 2009, an outbreak of verocytotoxigenic Escherichia coli O157 (VTEC O157) was identified in visitors to a large petting farm in South East England. The peak attack rate was 6/1000 visitors, and highest in those aged <2 years (16/1000). We conducted a case-control study with associated microbiological investigations, on human, animal and environmental samples. We identified 93 cases; 65 primary, 13 secondary and 15 asymptomatic. Cases were more likely to have visited a specific barn, stayed for prolonged periods and be infrequent farm visitors. The causative organism was identified as VTEC O157 PT21/28 with the same VNTR profile as that isolated in faecal specimens from farm animals and the physical environment, mostly in the same barn. Contact with farm livestock, especially ruminants, should be urgently reviewed at the earliest suspicion of a farm-related VTEC O157 outbreak and appropriate risk management procedures implemented without delay.