Optical tracking systems typically trade off between astrometric precision and field of view. In this work, we showcase a networked approach to optical tracking using very wide field-of-view imagers that have relatively low astrometric precision on the scheduled OSIRIS-REx slingshot manoeuvre around Earth on 22 Sep 2017. As part of a trajectory designed to get OSIRIS-REx to NEO 101955 Bennu, this flyby event was viewed from 13 remote sensors spread across Australia and New Zealand to promote triangulatable observations. Each observatory in this portable network was constructed to be as lightweight and portable as possible, with hardware based off the successful design of the Desert Fireball Network. Over a 4-h collection window, we gathered 15 439 images of the night sky in the predicted direction of the OSIRIS-REx spacecraft. Using a specially developed streak detection and orbit determination data pipeline, we detected 2 090 line-of-sight observations. Our fitted orbit was determined to be within about 10 km of orbital telemetry along the observed 109 262 km length of OSIRIS-REx trajectory, and thus demonstrating the impressive capability of a networked approach to Space Surveillance and Tracking.

Cell dimensions have been measured from correctly indexed powder patterns of thirty natural and two synthetic orthopyroxenes. The natural specimens (mostly metamorphic) contain exsolved phases largely avoided during microprobe chemical analysis. Linear regression analysis between the cell dimensions and Mg, Al, Ca contents (ignoring minor elements) was quite unsatisfactory until a term in Mg2 was added. Two separate regression analyses for the ranges Mg 0–0·5 and 0·5–1 using only Mg, Al, and Ca were satisfactory. Olivine yielded satisfactory regressions for the whole range without a term in Mg2 (Louisnathan and Smith, 1968). The difference between olivine and pyroxene results from absence of site preference by Mg and Fe in olivine compared to strong preference in pyroxene revealed by electron density and Mössbauer studies (Bancroft, Burns, and Howie, 1967; Ghose and Hafner, 1967).

The data were recalculated by means of a new best-fit procedure developed by Hey in which the errors in the chemical and physical parameters are considered simultaneously.

Earlier measurements of a and b for plutonic pyroxenes are consistent within possible experimental uncertainties with those given here; however a and b data obtained by Kuno and by Hess on volcanic specimens are considerably higher by variable amounts. Although there are uncertainties in the Ca content and its effect on a and b, the larger dimensions probably result from lower site preference as indicated by Mössbauer studies.

Prediction of Mg, Ca, and Al from just the cell dimensions is only moderately accurate even for metamorphic orthopyroxenes.

The results of a study on the suitability of the inductively coupled plasma source spectrometer for the analysis of rocks and minerals are presented. The preparation of a stable solution of the elements to be measured is a prerequisite, and methods of sample preparation are described. It is shown that it is possible to measure all the major elements (excluding H2O and Fe2+) with acceptable precision and accuracy, and a wide range of trace elements down to the ppm level in the rock or mineral. Excluding sample preparation time, analysis and print-out of results as percent or ppm requires 1–2 minutes for complete analysis. Data on possible interferences (spectral line overlap etc.) are presented and, using some analyses of rocks and minerals comparisons are made with other analytical methods.

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.

It is well established that altered maternal nutrition may induce long-term metabolic consequences in offspring. However, the effects of maternal undernutrition during different developmental windows on sex-specific growth and metabolism in offspring are not well defined. We investigated the effect of moderate maternal undernutrition during pregnancy and/or lactation on postnatal growth and metabolic outcomes in offspring. Wistar rats were randomly assigned to one of four groups: (1) control (CONT) dams fed a standard diet throughout pregnancy and lactation; (2) dams undernourished to 50 % of CONT during pregnancy (UNP); (3) dams fed at 50 % of CONT throughout lactation (UNL); (4) dams fed at 50 % of CONT throughout pregnancy and lactation (UNPL). UNP and UNPL offspring were lighter at birth compared to CONT and UNL. UNL and UNPL offspring were growth restricted at weaning and remained smaller into adulthood. UNP males and females developed increased adiposity and hyperleptinaemia in adulthood compared to all other groups. Adiposity in UNL and UNPL males was similar to CONT offspring. In UNL and UNPL females, adiposity was lower than for CONT females. Markers of bone mass, lipid metabolism and hepatic function were altered in UNP offspring but were similar in UNL and UNPL offspring compared to CONT. Lack of catch-up growth during lactation in offspring of undernourished mothers prevented development of adiposity and related metabolic disorders in later life. These data highlight that the timing and duration of undernutrition during critical windows of development exert differential effects on postnatal outcomes in a sex-specific manner.

This article describes cracking during microcompression of Si, InAs, MgO, and MgAl2O4 crystals and compares this with previous observations on Si and GaAs micropillars. The most common mode of cracking was through-thickness axial splitting, the crack growing downward from intersecting slip bands in pillars above a critical size. The splitting behavior observed in all of these materials was quantitatively consistent with a previous analysis, despite the differences in properties and slip geometry between the different materials. Cracking above the slip bands also occurred either in the side or in the top surface of some pillars. The driving forces for these modes of cracking are described and compared with observations. However, only through-thickness axial splitting was observed to give complete failure of the pillar; it is, therefore, considered to be the most important in determining the brittle-to-ductile transitions that have been observed.

Selection for increased growth rate in livestock may be accompanied by increases in requirements for energy and nutrients. It has been suggested that intensively selected broilers have altered food intake control mechanisms and could be constantly hungry, due to their high resource demands (Bokkers et al. 2004), which would be a major welfare issue. Such alterations in food intake control mechanisms as a side-effect of genetic selection would lead to changes in the feeding behaviour of birds, such as the clustering of visits into meals and the probability of birds starting a new meal in relation to the time since the last meal. The aim of this study was to test whether broilers intensively selected for growth showed any alteration in the structure of their feeding behaviour that would indicate a change in the underlying hunger and satiety control mechanisms.

1. Nine pig-rearing experiments designed to probe the causes of ill-health among young pigs farrowed and reared indoors suggested that the main cause of trouble was that the buildings were too cold, draughty and damp.

2. The superior health of pigs farrowed and reared outdoors appeared to depend less on their access to iron or unknown nutrients in soil and grass than to the greater comfort afforded by the wooden ark huts in which they were housed.

3. The clinical and pathological features of sick indoor pigs were essentially those of cardiac failure.

4. In a discussion of our own findings and the published reports of others we offer a working hypothesis to explain the sequence of events. We hope to explore its validity in future experiments.

Work on this subject was suggested by Mr Arthur Crichton and encouraged at all stages by his interest and advice.

A congruence ρ on a semigroup will be called idempotent-separating if each ρ-class contains at most one idempotent. It is shown below that there exists a maximum such congruence µ on every inverse semigroup S. Two characterisations of µ are found, and it is shown (a) that S/µ⋍E, the semilattice of idempotents of S, if and only if E is contained in the centre of S; (b) that µ is the identical congruence on S if and only if E is self-centralising, in a sense explained below.