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The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of the 4850 MHz data indicates that we will achieve a five sigma flux density limit of about 30 mJy. We estimate that we will find between 80 000 and 90 000 new sources above this limit. This is a revised version of the paper presented at the Regional Meeting by the first four authors; the surveys now have been completed.
Due to multiple issues, integrated interdisciplinary palliative care teams in a neonatal intensive care unit (NICU) may be difficult to access, sometimes fail to be implemented, or provide inconsistent or poorly coordinated care. When implementing an effective institution-specific neonatal palliative care program, it is critical to include stakeholders from the clinical, operational, and financial worlds of healthcare. In this study, researchers sought to gain a multidisciplinary perspective into issues that may impact the implementation of a formal neonatal palliative care program at a tertiary regional academic medical center.
In this focused ethnography, the primary researcher conducted semistructured interviews that explored the perspectives of healthcare administrators, finance officers, and clinicians about neonatal palliative care. The perspectives of 39 study participants informed the identification of institutional, financial, and clinical issues that impact the implementation of neonatal palliative care services at the medical center and the planning process for a formal palliative care program on behalf of neonates and their families.
Healthcare professionals described experiences that influenced their views on neonatal palliative care. Key themes included: (a) uniqueness of neonatal palliative care, (b) communication and conflict among providers, (c) policy and protocol discrepancies, and (d) lack of administrative support.
Significance of results:
The present study highlighted several areas that are challenging in the provision of neonatal palliative care. Our findings underscored the importance of recognizing and procuring resources needed simultaneously from the clinical, operational, and financial worlds in order to implement and sustain a successful neonatal palliative care program.
Raman spectra, measured on silica and silicophosphate aerogels in the range of 5 to 70 cm−1 , revealed a “particle band” that arises from the discrete particulate character of the gels at very small size scales. TEM measurements of the nanoscale structure in the gels correlate with the location of the particle band maximum.
The early stages of glass dissolution are marked by rapid changes in pH for leach solutions with low buffer capacity. Consideration of both dissolution reactions and the electrical neutrality requirement allow the calculation of exchanged cation equivalents from the depletion of the H+-ion reservoir. Comparison was made between sodium trisilicate glass, a commercial waste glass (PNL 76−68), and the defense waste reference glass. The released Na+ calculated from the pH curve of sodium trisilicate glass has the expected parabolic dependence on time. Thenuclear waste glasses react with H+ more slowly and the pH - time plots do not have the shape of a titration curve. The equivalents of cations released follow a power law function, the exponent of which depends on initial pH. There are two distinct rate regimes for all glasses with initial fast rates related to consumption of H+ and later, slower rates nearly independent of H+ activity.
The reaction between aqueous solutions and borosilicate glasses designed for commercial or defense waste immobilization produces a hydrated layer on the surface of the glass which can be characterized by infrared reflectance spectroscopy. Specular reflectance curves, obtained by Fourier transform infrared spectroscopy, can be deconvoluted by Kramers-Kronig analysis to obtain true absorption spectra. The pattern of Si-O stretching modes changes for alkali silicate glass, indicating changes in the network polymerization. The characteristic intense band of the borosilicate glasses simply changes intensity in a way that scales with degree of hydration. The progressive hydration of the glass surface also appears as a broad OH band which can be extracted from the reflectance curve by the deconvolution process.