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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 afterglow cooled from approximately 6400K to 2100K over a 7-day 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 (about 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., 26 pages, 9 figures, 15 tables

A 2D∕3D registration algorithm is proposed for registering orthogonal x-ray images with a diagnostic CT volume for high dose rate (HDR) lung brachytherapy.The algorithm utilizes a rigid registration model based on a pixel∕voxel intensity matching approach. To achieve accurate registration, a robust similarity measure combining normalized mutual information, image gradient, and intensity difference was developed. The algorithm was validated using a simple body and anthropomorphic phantoms. Transfer catheters were placed inside the phantoms to simulate the unique image features observed during treatment. The algorithm sensitivity to various degrees of initial misregistration and to the presence of foreign objects, such as ECG leads, was evaluated.The mean registration error was 2.2 and 1.9 mm for the simple body and anthropomorphic phantoms, respectively. The error was comparable to the interoperator catheter digitization error of 1.6 mm. Preliminary analysis of data acquired from four patients indicated a mean registration error of 4.2 mm.Results obtained using the proposed algorithm are clinically acceptable especially considering the complications normally encountered when imaging during lung HDR brachytherapy.

Resuscitation with tiny volumes of hypertonic solutions rapidly restores tissue perfusion while minimizing edema after hemorrhage and tissue trauma. Methods : We compared an O 2 -carrying fluid, Diaspirin Cross-Linked Hemoglobin (DCLHb), to 7.5% NS/Dextran-70 (HTS) or 0.9% saline (NS) in a trauma (celiotomy) hemorrhage model. Anesthetized rats (n = 10/group) underwent a tracheotomy, placement of jugular vein and carotid artery catheters, and placement of an abdominal aortic flow probe. Rats were hemorrhaged (20 mL/kg) from t = 0-15 minutes, and were given NS (group I), 60 mL/kg, HTS (group II), 4 mL/kg, or DCLHb (group III), 4 mL/kg, from t = 15-30 minutes. Sampling mandated removal of an additional 10 mL/kg of blood during the 2-hour experiment. Results : Mean arterial pressure was restored after hemorrhage in all groups. Oxygen delivery, which diminished dramatically after hemorrhage, was less than baseline in all groups after resuscitation. Oxygen consumption was restored in all groups after a sharp decrease during hemorrhage. Base deficit increased in the all groups but was greatest after normal saline or hypertonic saline resuscitation (t = 120 minutes ; I = 12 ± 0.4*, II = 13 ± 0.5* c, III = 10 ± 0.1* ; * = p < 0.05 versus baseline value within group for groups I, II, and III ; c = p < 0.05 group versus DCLHb (group II), by ANOVA). Conclusion : DCLHb restored mean arterial pressure and ameliorated the development of flow-dependent oxygen consumption. Base deficit, a reflection of systemic oxygen debt, was minimized with this blood substitute. DCLHb may represent a superior small volume resuscitative fluid after trauma and hemorrhage.

The AAO's DRAMA data acquisition environment provides a very successful flexible model for instrument control tasks based on the concept of named 'actions'. A task can execute a number of these actions simultaneously, and - something we have found to be of paramount importance in control systems - they can be cancelled cleanly if necessary. However, this flexibility has been achieved by use of what is essentially a collaborative multi-threading system, each action running in short 'stages' in a single-threaded task. The original DRAMA design pre-dated the general availability of multi-threading systems, but until now we have been reluctant to move to a multi-threading model because of the difficulties associated with attempting to cleanly cancel a thread stuck in a blocking operation. We now believe we have an acceptable solution to this problem, and are modifying the internals of DRAMA to produce an approach - compatible with the existing system - that will allow individual actions to execute in separate threads. It will be able to carry out dialogues with hardware in a much simpler manner than has been allowed so far, and this should simplify the coding of DRAMA tasks enormously.

Diabetics would benefit from a device capable of providing continuous non-invasive monitoring of their blood glucose levels. A feasibility study was performed to determine whether a technique applying spatially resolved diffuse reflectance measurements could be used to detect changes in the blood glucose levels of diabetic volunteers by monitoring the tissue reduced scattering coefficient. A correlation was observed between step changes in blood glucose concentration and tissue reduced scattering coefficient in 17 out of 22 subjects. A study on non-diabetic volunteers was used to estimate the physiological baseline noise level.

We have performed differential display comparing gene expression from cell lines derived from human colorectal tumors. The cell lines were selected for study based on their ability to form metastases following injection into athymic mice. One gene which was expressed exclusively by the metastatic lines was identified as human acylphosphatase (e.c. 3.6.1.7, acylphosphate phosphohydrolase). The expression of this gene was confirmed by RT-PCR using gene-specific primers. This gene product catalyzes the hydrolysis of phosphorylated intermediates of Na+/K(+)-ATPase and of Ca(2+)-ATPases of mammalian cells. Changes in the activity of the Na+/K(+)-ATPase pump, regulated by acylphosphatase, have been previously reported in chemically-induced colonic tumors. The differential expression of this gene in the human metastatic colorectal lines suggests it may be involved in the metastatic phenotype.

The photodynamic threshold dose in normal rat liver was determined from the measured depth of necrosis following surface irradiation. The threshold was determined for the photosensitizing drugs Photofrin and monosulfonated aluminum chlorophthalocyanine, AlPcS1, at 24 h postinjection and was found to be (3.4 x/divided by 1.3) x 10(18) and (8.2 x/divided by 1.5) x 10(18) photons cm-3, respectively, compared with the previously reported value of (38 +/- 2) x 10(18) photons cm-3 for the tri/tetrasulfonated phthalocyanine, AlPcS4. These values were independent of drug concentration or total light fluence. For all three drugs the depth of tissue necrosis decreased as the time between drug and light administration increased from 10 min to 72 h. This decrease can be attributed both to the change in the tissue drug concentration as well as to changes in the efficiency of photodynamic therapy for producing tissue damage, related to the photodynamic necrosis threshold. The threshold values for all three photosensitizers were lowest at 10 min post injection: (1.4 x/divided by 1.4) x 10(18), (1.6 x/divided by 1.3) x 10(18) and (23 x/divided by 1.3) x 10(18) photons cm-3 for Photofrin, AlPcS1 and AlPcS4, respectively. The changes in necrosis threshold with time may be due to an initial change from entirely vascular to a combination of vascular and cellular damage, with later redistribution of the photosensitizer to targets at the subcellular level.

The feasibility of using triple photon absorptiometry (TPA) for the measurement of bone mineral mass about a hip prosthesis was examined. A theoretical expression describing the variance of TPA measurements was verified using a triple photon source and phantom materials which simulate the soft tissue-bone mineral-metal prosthesis system. The expression for the variance was used to determine an optimized set of photon energies. It was shown that a precision of 3% could be obtained for reasonable measurement times using this optimized set of energies, and that TPA should be a feasible approach for measurement of bone mineral about a hip prosthesis.

The sensitivity of a technique for the measurement of trabecular bone mineral concentration has been examined theoretically and experimentally. The technique is based on coherent gamma ray scattering and corrections for attenuation are obtained from transmitted photons rather than Compton scattered photons. For an incident photon energy of 60 keV, the minimum detectable bone mineral difference is practically independent of scattering angle while for an incident energy of 100 or 122 keV the scattering angle must be less than 70 degrees to optimize the minimum detectable difference.

A rotating cardiac phantom with three possible ejection fraction (EF) values was used in conjunction with a scintillation camera employing energy correction and count skim arithmetic for uniformity correction. Studies were collected with and without any correction, with the energy window of the analyzer set properly, and with the camera properly tuned. The uniformity was then degraded in one experiment by off-setting the analyzer window both high and low with respect to the primary photopeak and in another experiment by de-tuning a selected photomultiplier tube. In both experiments studies were taken with no correction enabled, and then with each of the correction options enabled. The results of both experiments show that ejection fraction values could be in error when the differential uniformity using National Electrical Manufacturers Association (NEMA) protocols exceeds 10%. If either energy correction alone, or energy correction combined with count skim correction is used, the ejection fraction values return to more acceptable values. Asymmetric windows, improper setting of the energy window or a badly tuned photomultiplier will likely result in poor analog images before the effect on ejection fraction measurements becomes evident. Uniformity correction devices do not adversely affect the numerical results obtained from these phantom studies, but should, nevertheless, be used with caution.