ORCID Profile
0000-0002-2894-6936
Current Organisation
Australian National University
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Astronomical and Space Sciences | Galactic Astronomy | Astronomical and Space Instrumentation | Electrical and Electronic Engineering | Stellar Astronomy and Planetary Systems | Nanoscale Characterisation | Manufacturing Processes and Technologies (excl. Textiles) | Photodetectors, Optical Sensors and Solar Cells | Cosmology and Extragalactic Astronomy |
Expanding Knowledge in the Physical Sciences | Emerging Defence Technologies | Expanding Knowledge in Technology
Publisher: American Astronomical Society
Date: 04-09-2018
Publisher: Springer Science and Business Media LLC
Date: 18-05-2022
DOI: 10.1038/S41586-022-04616-1
Abstract: Reservoirs of dense atomic gas (primarily hydrogen) contain approximately 90 per cent of the neutral gas at a redshift of 3, and contribute to between 2 and 3 per cent of the total baryons in the Universe
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.790042
Publisher: American Astronomical Society
Date: 03-2022
Abstract: The symbiotic X-ray binary Sct X-1 was suggested to be the first known neutron star accreting from a red supergiant companion. Although known for nearly 50 yr, detailed characterization of the donor remains lacking, particularly due to the extremely high reddening toward the source ( A V ≳ 25 mag). Here, we present (i) improved localization of the counterpart using Gaia and Chandra observations, (ii) the first broadband infrared spectrum (≈1–5 μ m R ≈ 2000) obtained with SpeX on the NASA Infrared Telescope Facility, and (iii) the J -band light curve from the Palomar Gattini-IR survey. The infrared spectrum is characterized by (i) deep water absorption features (H 2 O index ≈ 40%), (ii) strong TiO, VO, and CO features, and (iii) weak/absent CN lines. We show that these features are inconsistent with known red supergiants but suggest an M8-9 III–type O-rich Mira donor star. We report the discovery of large- litude (Δ J ≈ 3.5 mag) periodic photometric variability, suggesting a pulsation period of 621 ± 36 (systematic) ± 8 (statistical) days, which we use to constrain the donor to be a relatively luminous Mira ( M K = −8.6 ± 0.3 mag) at a distance of 3.6 − 0.7 + 0.8 kpc. Comparing these characteristics to recent models, we find the donor to be consistent with a ≈3–5 M ⊙ star at an age of ≈0.1–0.3 Gyr. Together, we show that Sct X-1 was previously misclassified as an evolved high-mass X-ray binary instead, it is an intermediate-mass system with the first confirmed Mira donor in an X-ray binary. We discuss the implications of Mira donors in symbiotic X-ray binaries and highlight the potential of wide-field infrared time-domain surveys and broadband infrared spectroscopy to unveil their demographics.
Publisher: SPIE
Date: 27-08-2008
DOI: 10.1117/12.790281
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.PLACENTA.2010.12.019
Abstract: Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 there were twelve themed workshops, six of which are summarized in this report. 1. The immunology workshop focused on normal and pathological functions of the maternal immune system in pregnancy. 2. The transport workshop dealt with regulation of ion and water transport across the syncytiotrophoblast of human placenta. 3. The epigenetics workshop covered DNA methylation and its potential role in regulating gene expression in placental development and disease. 4. The vascular reactivity workshop concentrated on methodological approaches used to study placental vascular function. 5. The workshop on epitheliochorial placentation covered current advances from in vivo and in vitro studies of different domestic species. 6. The proteomics workshop focused on a variety of techniques and procedures necessary for proteomic analysis and how they may be implemented for placental research.
Publisher: American Astronomical Society
Date: 10-02-2009
Publisher: American Astronomical Society
Date: 06-2018
Publisher: IOP Publishing
Date: 06-2012
DOI: 10.1086/666861
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1007/S00251-005-0071-4
Abstract: Nomenclature for Major Histocompatibility Complex (MHC) genes and alleles in species other than humans and mice has historically been overseen either informally by groups generating sequences, or by formal nomenclature committees set up by the International Society for Animal Genetics (ISAG). The suggestion for a Comparative MHC Nomenclature Committee was made at the ISAG meeting held in Göttingen, Germany (2002), and the committee met for the first time at the Institute for Animal Health, Compton, UK in January 2003. To publicize its activity and extend its scope, the committee organized a workshop at the International Veterinary Immunology Symposium (IVIS) in Quebec (2004) where it was decided to affiliate with the Veterinary Immunology Committee (VIC) of the International Union of Immunological Societies (IUIS). The goals of the committee are to establish a common framework and guidelines for MHC nomenclature in any species to demonstrate this in the form of a database that will ensure that in the future, researchers can easily access a source of validated MHC sequences for any species to facilitate discussion on this area between existing groups and nomenclature committees. A further meeting of the committee was held in September 2005 in Glasgow, UK. This was attended by most of the existing committee members with some additional invited participants (Table 1). The aims of this meeting were to facilitate the inclusion of new species onto the database, to discuss extension, improvement and funding of the database, and to address a number of nomenclature issues raised at the previous workshop.
Publisher: American Astronomical Society
Date: 12-07-2010
DOI: 10.1088/0004-6256/140/2/602
Abstract: The i -band observing conditions at Dome A on the Antarctic plateau have been investigated using data acquired during 2008 with the Chinese Small Telescope Array. The sky brightness, variations in atmospheric transparency, cloud cover, and the presence of aurorae are obtained from these images. The median sky brightness of moonless clear nights is 20.5 mag arcsec −2 in the SDSS i band at the south celestial pole (which includes a contribution of about 0.06 mag from diffuse Galactic light). The median over all Moon phases in the Antarctic winter is about 19.8 mag arcsec −2 . There were no thick clouds in 2008. We model contributions of the Sun and the Moon to the sky background to obtain the relationship between the sky brightness and transparency. Aurorae are identified by comparing the observed sky brightness to the sky brightness expected from this model. About 2% of the images are affected by relatively strong aurorae.
Publisher: SPIE
Date: 09-08-2016
DOI: 10.1117/12.2232212
Publisher: SPIE
Date: 28-07-2014
DOI: 10.1117/12.2055609
Publisher: Springer Science and Business Media LLC
Date: 07-2019
Publisher: EDP Sciences
Date: 2010
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.790154
Publisher: EDP Sciences
Date: 2008
DOI: 10.1051/EAS:0833004
Publisher: Elsevier BV
Date: 02-2008
Publisher: The Royal Society
Date: 11-2022
DOI: 10.1098/RSOS.220047
Abstract: In 2020, the COVID-19 pandemic led to a reduction in human activities and restriction of all but essential movement for much of the world's population. A large, but temporary, increase in air and water quality followed, and there have been several reports of animal populations moving into new areas. Extending on long-term monitoring efforts, we examined how coral reef fish populations were affected by the government-mandated lockdown across a series of Marine Protected Area (MPA) and non-Marine Protected Area (nMPA) sites around Moorea, French Polynesia. During the first six-week lockdown that Moorea experienced between March and May 2020, increases (approx. two-fold) in both harvested and non-harvested fishes were observed across the MPA and nMPA inner barrier reef sites, while no differences were observed across the outer barrier sites. Interviews with local amateur and professional fishers indicated that while rules regarding MPA boundaries were generally followed, some subsistence fishing continued in spite of the lockdown, including within MPAs. As most recreational activities occur along the inner reef, our data suggest that the lockdown-induced reduction in recreational activities resulted in the recolonization of these areas by fishes, highlighting how fish behaviour and space use can rapidly change in our absence.
Publisher: SPIE-Intl Soc Optical Eng
Date: 13-05-2022
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856644
Publisher: SPIE
Date: 17-09-2012
DOI: 10.1117/12.927313
Publisher: IOP Publishing
Date: 03-2010
DOI: 10.1086/651526
Publisher: EDP Sciences
Date: 2005
DOI: 10.1051/EAS:2005025
Publisher: SPIE
Date: 07-07-2004
DOI: 10.1117/12.566391
Publisher: American Astronomical Society
Date: 11-09-2020
Publisher: SPIE
Date: 24-09-2012
DOI: 10.1117/12.924729
Publisher: SPIE
Date: 09-08-2016
DOI: 10.1117/12.2231914
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856521
Publisher: American Astronomical Society
Date: 02-06-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2020
Publisher: American Astronomical Society
Date: 18-03-2014
Publisher: Elsevier BV
Date: 2010
Publisher: American Astronomical Society
Date: 30-10-2019
Publisher: American Astronomical Society
Date: 04-05-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Publisher: American Astronomical Society
Date: 24-04-2014
Publisher: SPIE
Date: 07-03-2003
DOI: 10.1117/12.461208
Publisher: American Astronomical Society
Date: 08-2022
Abstract: We present the discovery and multiwavelength characterization of SRGA J181414.6-225604, a Galactic hard X-ray transient discovered during the ongoing SRG/ART-XC sky survey. Using data from the Palomar Gattini-IR survey, we identify a spatially and temporally coincident variable infrared (IR) source, IRAS 18111-2257, and classify it as a very-late-type (M7–M8), long-period (1502 ± 24 days), and luminous ( M K ≈ −9.9 ± 0.2) O-rich Mira donor star located at a distance of ≈14.6 +2.9 −2.3 kpc. Combining multicolor photometric data over the last ≈25 yr, we show that the IR counterpart underwent a recent (starting ≈800 days before the X-ray flare) enhanced mass-loss (reaching ≈2.1 × 10 −5 M ⊙ yr −1 ) episode, resulting in an expanding dust shell obscuring the underlying star. Multi-epoch follow-up observations from Swift, NICER, and NuSTAR reveal a ≈200 day long X-ray outburst reaching a peak luminosity of L X ≈ 2.5 × 10 36 erg s −1 , characterized by a heavily absorbed ( N H ≈ 6 × 10 22 cm −2 ) X-ray spectrum consistent with an optically thick Comptonized plasma. The X-ray spectral and timing behavior suggest the presence of clumpy wind accretion, together with a dense ionized nebula overabundant in silicate material surrounding the compact object. Together, we show that SRGA J181414.6-225604 is a new symbiotic X-ray binary in outburst, triggered by an intense dust-formation episode of a highly evolved donor. Our results offer the first direct confirmation for the speculated connection between enhanced late-stage donor mass loss and the active lifetimes of symbiotic X-ray binaries.
Publisher: SPIE
Date: 02-08-2016
DOI: 10.1117/12.2233608
Publisher: SPIE
Date: 27-08-2008
DOI: 10.1117/12.788503
Publisher: Springer Science and Business Media LLC
Date: 27-02-2017
DOI: 10.1038/NG.3794
Publisher: Oxford University Press (OUP)
Date: 03-08-2018
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856475
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.788621
Publisher: American Astronomical Society
Date: 24-04-2014
Publisher: Cambridge University Press (CUP)
Date: 11-2009
DOI: 10.1017/S1743921310010811
Abstract: PLATO is a 6 tonne completely self-contained robotic observatory that provides its own heat, electricity, and satellite communications. It was deployed to Dome A in Antarctica in January 2008 by the Chinese expedition team, and is now in its second year of operation. PLATO is operating four 14.5cm optical telescopes with 1k × 1k CCDs, a wide-field sky camera with a 2k × 2k CCD and Sloan g, r, i filters, a fibre-fed spectrograph to measure the UV to near-IR sky spectrum, a 0.2m terahertz telescope, two sonic radars giving 1m resolution data on the boundary layer to a height of 180m, a 15m tower, meteorological sensors, and 8 web cameras. Beginning in 2010/11 PLATO will be upgraded to support a Multi Aperture Scintillation Sensor and three AST3 0.5m schmidt telescopes, with 10k × 10 CCDs and 100TB/annum data requirements.
Publisher: SPIE
Date: 27-08-2008
DOI: 10.1117/12.789783
Publisher: Springer Science and Business Media LLC
Date: 08-2015
DOI: 10.1038/NATURE14616
Abstract: The specifics of how galaxies form from, and are fuelled by, gas from the intergalactic medium remain uncertain. Hydrodynamic simulations suggest that 'cold accretion flows'--relatively cool (temperatures of the order of 10(4) kelvin), unshocked gas streaming along filaments of the cosmic web into dark-matter halos--are important. These flows are thought to deposit gas and angular momentum into the circumgalactic medium, creating disk- or ring-like structures that eventually coalesce into galaxies that form at filamentary intersections. Recently, a large and luminous filament, consistent with such a cold accretion flow, was discovered near the quasi-stellar object QSO UM287 at redshift 2.279 using narrow-band imaging. Unfortunately, imaging is not sufficient to constrain the physical characteristics of the filament, to determine its kinematics, to explain how it is linked to nearby sources, or to account for its unusual brightness, more than a factor of ten above what is expected for a filament. Here we report a two-dimensional spectroscopic investigation of the emitting structure. We find that the brightest emission region is an extended rotating hydrogen disk with a velocity profile that is characteristic of gas in a dark-matter halo with a mass of 10(13) solar masses. This giant protogalactic disk appears to be connected to a quiescent filament that may extend beyond the virial radius of the halo. The geometry is strongly suggestive of a cold accretion flow.
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.790250
Publisher: EDP Sciences
Date: 24-12-2009
DOI: 10.1051/EAS/1040009
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856501
Publisher: Cambridge University Press (CUP)
Date: 08-2013
DOI: 10.1017/S1743921313014798
Abstract: Gattini and CSTAR have been installed at Dome A, Antarctica, which provide time-series photometric data for a large number of pulsating variable stars. We present the study for several variable stars with the data collected with the two facilities in 2009 to demonstrate the scientific potential of observations from Dome A for asteroseismology.
Publisher: EDP Sciences
Date: 04-2022
DOI: 10.1051/0004-6361/202142158
Abstract: Aims. We present a detailed analysis of SN 2020qmp, a nearby Type IIP core-collapse supernova (CCSN) that was discovered by the Palomar Gattini-IR survey in the galaxy UGC07125 (distance of ≈15.6 ± 4 Mpc). We illustrate how the multiwavelength study of this event helps our general understanding of stellar progenitors and circumstellar medium (CSM) interactions in CCSNe. We highlight the importance of near-infrared (NIR) surveys for detections of supernovae in dusty environments. Methods. We analyze data from observations in various bands: radio, NIR, optical, and X-rays. We use optical and NIR data for a spectroscopic and spectro-polarimetric study of the supernova and to model its light curve (LC). We obtain an estimate of the zero-age main-sequence (ZAMS) progenitor mass from the luminosity of the [O I ] doublet lines ( λλ 6300, 6364) normalized to the decay power of 56 Co. We also independently estimate the explosion energy and ZAMS progenitor mass through hydrodynamical LC modeling. From radio and X-ray observations, we derive the mass-loss rate and microphysical parameters of the progenitor star, and we investigate possible deviations from energy equipartition of magnetic fields and electrons in a standard CSM interaction model. Finally, we simulate a s le of CCSNe with plausible distributions of brightness and extinction, within 40 Mpc, and test what fraction of the s le is detectable at peak light by NIR surveys versus optical surveys. Results. SN 2020qmp displays characteristic hydrogen lines in its optical spectra as well as a plateau in its optical LC, hallmarks of a Type IIP supernova. We do not detect linear polarization during the plateau phase, with a 3 σ upper limit of 0.78%. Through hydrodynamical LC modeling and an analysis of its nebular spectra, we estimate a ZAMS progenitor mass of around 11.0 M ⊙ and an explosion energy of around 0.8 × 10 51 erg. We find that the spectral energy distribution cannot be explained by a simple CSM interaction model, assuming a constant shock velocity and a steady mass-loss rate. In particular, the excess X-ray luminosity compared with the synchrotron radio luminosity suggests deviations from equipartition. Finally, we demonstrate the advantages of NIR surveys over optical surveys for the detection of dust-obscured CCSNe in the local Universe. Specifically, our simulations show that the Wide-Field Infrared Transient Explorer will detect up to 14 more CCSNe (out of the 75 expected in its footprint) within 40 Mpc over five years than would an optical survey equivalent to the Zwicky Transient Facility. Conclusions. We have determined or constrained the main properties of SN 2020qmp and its progenitor, highlighting the value of multiwavelength follow-up observations of nearby CCSNe. We have shown that forthcoming NIR surveys will enable us to improve constraints on the local CCSN rate by detecting obscured supernovae that would be missed by optical searches.
Publisher: IOP Publishing
Date: 13-01-2020
Publisher: Oxford University Press (OUP)
Date: 26-10-2021
Abstract: We present observations of SN 2020fqv, a Virgo-cluster type II core-collapse supernova (CCSN) with a high temporal resolution light curve from the Transiting Exoplanet Survey Satellite (TESS) covering the time of explosion ultraviolet (UV) spectroscopy from the Hubble Space Telescope (HST) starting 3.3 d post-explosion ground-based spectroscopic observations starting 1.1 d post-explosion along with extensive photometric observations. Massive stars have complicated mass-loss histories leading up to their death as CCSNe, creating circumstellar medium (CSM) with which the SNe interact. Observations during the first few days post-explosion can provide important information about the mass-loss rate during the late stages of stellar evolution. Model fits to the quasi-bolometric light curve of SN 2020fqv reveal 0.23 M⊙ of CSM confined within 1450 R⊙ (1014 cm) from its progenitor star. Early spectra (& d post-explosion), both from HST and ground-based observatories, show emission features from high-ionization metal species from the outer, optically thin part of this CSM. We find that the CSM is consistent with an eruption caused by the injection of ∼5 × 1046 erg into the stellar envelope ∼300 d pre-explosion, potentially from a nuclear burning instability at the onset of oxygen burning. Light-curve fitting, nebular spectroscopy, and pre-explosion HST imaging consistently point to a red supergiant (RSG) progenitor with $M_{\\rm ZAMS}\\approx 13.5\\!-\\!15 \\, \\mathrm{M}_{\\odot }$, typical for SN II progenitor stars. This finding demonstrates that a typical RSG, like the progenitor of SN 2020fqv, has a complicated mass-loss history immediately before core collapse.
Publisher: SPIE
Date: 20-07-2000
DOI: 10.1117/12.391523
Publisher: SPIE
Date: 07-03-2003
DOI: 10.1117/12.462002
Publisher: SPIE
Date: 09-08-2016
DOI: 10.1117/12.2233317
Publisher: SPIE
Date: 25-08-1998
DOI: 10.1117/12.319289
Publisher: SPIE
Date: 14-06-2006
DOI: 10.1117/12.672625
Publisher: Bioscientifica
Date: 06-2011
DOI: 10.1530/REP-10-0462
Abstract: The invasive and fully antigenic trophoblast of the chorionic girdle portion of the equine fetal membranes has the capacity to survive and differentiate after transplantation to ectopic sites. The objectives of this study were to determine i) the survival time of ectopically transplanted allogeneic trophoblast cells in non-pregnant recipient mares, ii) whether equine chorionic gonadotropin (eCG) can be delivered systemically by transplanted chorionic girdle cells, and iii) whether eCG delivered by the transplanted cells is biologically active and can suppress behavioral signs associated with estrus. Ectopically transplanted chorionic girdle survived for up to 105 days with a mean lifespan of 75 days (95% confidence interval 55–94) and secreted sufficient eCG for the hormone to be measurable in the recipients’ circulation. Immunohistochemical labeling of serial biopsies of the transplant sites and measurement of eCG profiles demonstrated that graft survival was similar to the lifespan of equine endometrial cups in normal horse pregnancy. The eCG secreted by the transplanted cells induced corpora lutea formation and sustained systemic progesterone levels in the recipient mares, effects that are also observed during pregnancy. This in turn caused suppression of estrus behavior in the recipients for up to 3 months. Thus, ectopically transplanted equine trophoblast provides an unusual ex le of sustained viability and function of an immunogenic transplant in a recipient with an intact immune system. This model highlights the importance of innate immunoregulatory capabilities of invasive trophoblast cells and describes a new method to deliver sustained circulating concentrations of eCG in non-pregnant mares.
Publisher: SPIE
Date: 08-08-2016
DOI: 10.1117/12.2233076
Publisher: Cambridge University Press (CUP)
Date: 08-2012
DOI: 10.1017/S1743921312017048
Abstract: Despite the absence of artificial light pollution at Antarctic plateau sites such as Dome A, other factors such as airglow, aurorae and extended periods of twilight have the potential to adversely affect optical observations. We present a statistical analysis of the airglow and aurorae at Dome A using spectroscopic data from Nigel, an optical/near-IR spectrometer operating in the 300–850 nm range. The median auroral contribution to the B , V and R photometric bands is found to be 22.9, 23.4 and 23.0 mag arcsec −2 respectively. We are also able to quantify the amount of annual dark time available as a function of wavelength on average twilight ends when the Sun reaches a zenith distance of 102.6°.
Publisher: SPIE
Date: 03-01-2020
DOI: 10.1117/12.2539594
Publisher: EDP Sciences
Date: 24-12-2009
DOI: 10.1051/EAS/1040007
Publisher: SPIE
Date: 29-09-2004
DOI: 10.1117/12.550292
Publisher: American Astronomical Society
Date: 26-06-2018
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.789777
Publisher: SPIE
Date: 26-07-2016
DOI: 10.1117/12.2233182
Publisher: SPIE
Date: 04-08-2016
DOI: 10.1117/12.2232491
Publisher: SPIE
Date: 08-07-2014
DOI: 10.1117/12.2057257
Publisher: SPIE
Date: 14-06-2006
DOI: 10.1117/12.672640
Publisher: SPIE
Date: 28-07-2014
DOI: 10.1117/12.2055599
Publisher: SPIE
Date: 13-07-2018
DOI: 10.1117/12.2312700
Publisher: Copernicus GmbH
Date: 19-04-2021
Abstract: Abstract. The area near Dome C, East Antarctica, is thought to be one of the most promising targets for recovering a continuous ice-core record spanning more than a million years. The European Beyond EPICA consortium has selected Little Dome C (LDC), an area ∼ 35 km southeast of Concordia Station, to attempt to recover such a record. Here, we present the results of the final ice-penetrating radar survey used to refine the exact drill site. These data were acquired during the 2019–2020 austral summer using a new, multi-channel high-resolution very high frequency (VHF) radar operating in the frequency range of 170–230 MHz. This new instrument is able to detect reflectors in the near-basal region, where previous surveys were largely unable to detect horizons. The radar stratigraphy is used to transfer the timescale of the EPICA Dome C ice core (EDC) to the area of Little Dome C, using radar isochrones dating back past 600 ka. We use these data to derive the expected depth–age relationship through the ice column at the now-chosen drill site, termed BELDC (Beyond EPICA LDC). These new data indicate that the ice at BELDC is considerably older than that at EDC at the same depth and that there is about 375 m of ice older than 600 kyr at BELDC. Stratigraphy is well preserved to 2565 m, ∼ 93 % of the ice thickness, below which there is a basal unit with unknown properties. An ice-flow model tuned to the isochrones suggests ages likely reach 1.5 Myr near 2500 m, ∼ 65 m above the basal unit and ∼ 265 m above the bed, with sufficient resolution (19 ± 2 kyr m−1) to resolve 41 kyr glacial cycles.
Publisher: SPIE
Date: 14-06-2006
DOI: 10.1117/12.672525
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.858187
Publisher: SPIE
Date: 29-09-2004
DOI: 10.1117/12.551004
Publisher: SPIE
Date: 28-09-2004
DOI: 10.1117/12.552057
Publisher: IOP Publishing
Date: 02-2009
DOI: 10.1086/597547
Publisher: Cambridge University Press (CUP)
Date: 08-2012
DOI: 10.1017/S174392131201664X
Abstract: At the summit of the Antarctic plateau, Dome A offers an intriguing location for future large scale optical astronomical observatories. The Gattini Dome A project was created to measure the optical sky brightness and large area cloud cover of the winter-time sky above this high altitude Antarctic site. The wide field camera and multi-filter system was installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in January 2008. This automated wide field camera consists of an Apogee U4000 interline CCD coupled to a Nikon fisheye lens enclosed in a heated container with glass window. The system contains a filter mechanism providing a suite of standard astronomical photometric filters (Bessell B, V, R) and a long-pass red filter for the detection and monitoring of airglow emission. The system operated continuously throughout the 2009, and 2011 winter seasons and part-way through the 2010 season, recording long exposure images sequentially for each filter. We have in hand one complete winter-time dataset (2009) returned via a manned traverse. We present here the first measurements of sky brightness in the photometric V band, cloud cover statistics measured so far and an estimate of the extinction.
Publisher: Oxford University Press (OUP)
Date: 09-06-2023
DOI: 10.1093/CID/CIAC453
Abstract: Nontuberculous Mycobacterium infections, particularly Mycobacterium abscessus, are increasingly common among patients with cystic fibrosis and chronic bronchiectatic lung diseases. Treatment is challenging due to intrinsic antibiotic resistance. Bacteriophage therapy represents a potentially novel approach. Relatively few active lytic phages are available and there is great variation in phage susceptibilities among M. abscessus isolates, requiring personalized phage identification. Mycobacterium isolates from 200 culture-positive patients with symptomatic disease were screened for phage susceptibilities. One or more lytic phages were identified for 55 isolates. Phages were administered intravenously, by aerosolization, or both to 20 patients on a compassionate use basis and patients were monitored for adverse reactions, clinical and microbiologic responses, the emergence of phage resistance, and phage neutralization in serum, sputum, or bronchoalveolar lavage fluid. No adverse reactions attributed to therapy were seen in any patient regardless of the pathogen, phages administered, or the route of delivery. Favorable clinical or microbiological responses were observed in 11 patients. Neutralizing antibodies were identified in serum after initiation of phage delivery intravenously in 8 patients, potentially contributing to lack of treatment response in 4 cases, but were not consistently associated with unfavorable responses in others. Eleven patients were treated with only a single phage, and no phage resistance was observed in any of these. Phage treatment of Mycobacterium infections is challenging due to the limited repertoire of therapeutically useful phages, but favorable clinical outcomes in patients lacking any other treatment options support continued development of adjunctive phage therapy for some mycobacterial infections.
Publisher: Oxford University Press (OUP)
Date: 25-10-2010
Publisher: SPIE
Date: 09-08-2016
DOI: 10.1117/12.2232952
Publisher: SPIE
Date: 07-03-2003
DOI: 10.1117/12.462333
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.857520
Publisher: SPIE
Date: 28-07-2014
DOI: 10.1117/12.2056839
Publisher: American Astronomical Society
Date: 12-11-2010
Publisher: SPIE
Date: 12-2002
DOI: 10.1117/12.461361
Publisher: American Astronomical Society
Date: 12-06-2017
Publisher: SPIE
Date: 27-08-2008
DOI: 10.1117/12.787166
Publisher: EDP Sciences
Date: 2007
DOI: 10.1051/EAS:2007069
Publisher: Informa UK Limited
Date: 06-2009
DOI: 10.1080/02640410902929366
Abstract: Using self-determination theory (Deci & Ryan, 1985) as the theoretical framework, we examined potential antecedents of athlete burnout in 201 elite Canadian athletes (121 females, 80 males mean age 22.9 years). Employing a cross-sectional design, our primary aims were to investigate the relationships between behavioural regulations and athlete burnout and to examine whether self-determined motivation mediated relationships between basic needs satisfaction and athlete burnout. Our self-determination theory-derived hypotheses were largely supported. Relationships among athlete burnout and behavioural regulations mostly varied according to their rank on the self-determination continuum, with less self-determined motives showing positive associations and more self-determined motives showing negative correlations with burnout. The basic needs of competence and autonomy, plus self-determined motivation, accounted for significant amounts of variance in athlete burnout symptoms (exhaustion, R(2) = 0.31 devaluation, R(2) = 0.49 reduced accomplishment, R(2) = 0.61 global burnout, R(2) = 0.74). Self-determined motivation fully mediated the relationships that competence and autonomy had with exhaustion. Analyses showed indirect relationships between these two needs and devaluation, through their associations with self-determined motivation. Motivation partially mediated the needs-reduced sense of accomplishment relationships, but the direct effects were more prominent than the indirect effects.
Publisher: SPIE
Date: 26-08-2022
DOI: 10.1117/12.2629072
Publisher: American Astronomical Society
Date: 06-2023
Abstract: We report observations of the optical counterpart of the long gamma-ray burst GRB 221009A. Due to the extreme rarity of being both nearby ( z = 0.151) and highly energetic ( E γ ,iso ≥ 10 54 erg), GRB 221009A offers a unique opportunity to probe the connection between massive star core collapse and relativistic jet formation across a very broad range of γ -ray properties. Adopting a phenomenological power-law model for the afterglow and host galaxy estimates from high-resolution Hubble Space Telescope imaging, we use Bayesian model comparison techniques to determine the likelihood of an associated supernova (SN) contributing excess flux to the optical light curve. Though not conclusive, we find moderate evidence ( K Bayes = 10 1.2 ) for the presence of an additional component arising from an associated SN, SN 2022xiw, and find that it must be substantially fainter ( % as bright at the 99% confidence interval) than SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt to constrain the SN parameters ( M Ni , M ej , and E KE ) under several different assumptions with respect to the host galaxy’s extinction. We find properties that are broadly consistent with previous GRB-associated SNe: M Ni = 0.05–0.25 M ⊙ , M ej = 3.5–11.1 M ⊙ , and E KE = (1.6–5.2) × 10 52 erg. We note that these properties are weakly constrained due to the faintness of the SN with respect to the afterglow and host emission, but we do find a robust upper limit on M Ni of M Ni 0.36 M ⊙ . Given the tremendous range in isotropic gamma-ray energy release exhibited by GRBs (seven orders of magnitude), the SN emission appears to be decoupled from the central engine in these systems.
Publisher: SPIE
Date: 30-09-2004
DOI: 10.1117/12.550963
Publisher: Wiley
Date: 04-1995
Publisher: Cambridge University Press (CUP)
Date: 08-2012
DOI: 10.1017/S1743921312016936
Abstract: In 2008 January the 24th Chinese expedition team successfully deployed the Chinese Small Telescope ARray (CSTAR) to Dome A, the highest point on the Antarctic plateau. CSTAR consists of four 14.5cm optical telescopes, each with a different filter ( g , r , i and open) and has a 4.5°×4.5° field of view (FOV). Based on the CSTAR data, initial statistics of astronomical observational site quality and light curves of variable objects were obtained. To reach higher photometric quality, we are continuing to work to overcome the effects of uneven cirrus cloud cirrus, optical “ghosts” and intra-pixel sensitivity. The snow surface stability is also tested for further astronomical observational instrument and for glaciology studies.
Publisher: American Astronomical Society
Date: 23-04-2019
Publisher: Springer Science and Business Media LLC
Date: 11-03-2021
DOI: 10.1007/S10686-021-09705-Z
Abstract: The era of all-sky space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or milliarcsec per year) accuracy level. Hipparcos has now been superseded by the results of the Gaia mission. The second Gaia data release contained astrometric data for almost 1.7 billion sources with tens of microarcsec (or microarcsec per year) accuracy in a vast volume of the Milky Way and future data releases will further improve on this. Gaia has just completed its nominal 5-year mission (July 2019), but is expected to continue in operations for an extended period of an additional 5 years through to mid 2024. Its final catalogue to be released $\\sim $ ∼ 2027, will provide astrometry for $\\sim $ ∼ 2 billion sources, with astrometric precisions reaching 10 microarcsec. Why is accurate astrometry so important? The answer is that it provides fundamental data which underpin much of modern observational astronomy as will be detailed in this White Paper. All-sky visible and Near-InfraRed (NIR) astrometry with a wavelength cutoff in the K-band is not just focused on a single or small number of key science cases. Instead, it is extremely broad, answering key science questions in nearly every branch of astronomy while also providing a dense and accurate visible-NIR reference frame needed for future astronomy facilities.
Publisher: SPIE
Date: 12-07-2008
DOI: 10.1117/12.788019
Publisher: arXiv
Date: 2022
Location: United States of America
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 06-2015
End Date: 12-2017
Amount: $760,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2021
End Date: 04-2022
Amount: $837,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2021
End Date: 01-2022
Amount: $632,000.00
Funder: Australian Research Council
View Funded Activity