In this paper, we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers $31\,\textrm{deg}^{2}$ at $800\,\textrm{MHz}$. As a two-dimensional array of 36$\times$12 m antennas, with baselines ranging from 22 m to 6 km, ASKAP also has excellent snapshot imaging capability and 10 arcsec resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 and $1800\,\textrm{MHz}$ and is expected to facilitate great advances in our understanding of galaxy formation, cosmology, and radio transients while opening new parameter space for discovery of the unknown.

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.

We give a progress report on a programme of observations to obtain flux densities at 8.4 GHz for a large sample of radio sources selected from the Parkes 2700 MHz Survey. So far, about 1000 flux measurements have been made with a typical accuracy of 10%.

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.

The Parkes-MIT-NRAO (PMN) 4.85 GHz continuum radio survey of the southern sky was undertaken in 1990 June and November. This survey was performed on the Parkes 64 m telescope using the NRAO seven-beam receiver. A point-source catalogue of 36,640 radio sources has been produced for the Southern Survey zone −87.5° ≤δ ≤ −37° and for the Tropical Survey zone −29° ≤δ ≤ −9.5°. The flux limit of this survey varies with declination and is typically about 30 mJy.

We have begun to cross-correlate the PMN data with sources contained in catalogues compiled at radio, and other, wavelengths. We have found associations for 96% of the PKSCAT90 2700 MHz database sources, and 95% of the Molonglo 408 MHz Catalogue sources within in the PMN Southern and Tropical Survey zones.

A program to identify the optical counterparts of PMN Southern Survey point sources, S4.85 GHz ≥ 70 mJy, using the COSMOS database, is under way. To facilitate this programme we are improving the positional accuracy of PMN sources with observations made at the Australia Telescope National Facility compact array. We have developed a new “snapshot” mode of observing to process the large number of sources (~ 8000) in our sample. It is possible to obtain accurate positions from three snapshots efficiently with a total integration of < 3 minutes.

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.

Correlated responses in physiological traits to divergent selection on components of efficient lean growth identified physiological traits for use as predictors of genetic merit and provided a biological explanation for the between-selection line differences in protein and lipid deposition. Responses (differences between high (H) and low (L) selection lines) in protein metabolism during ad-libitum feeding were associated with divergent selection for daily food intake (DFI) (reduced serum creatinine concentration (H = 1·30 v. L = 1·56, s.e.d. 0·08 mg/dl)) and for lean growth rate on an ad-libitum feeding regime (LGA) (increased serum urea (H = 48 v. L = 36, s.e.d. 4 mg/dl) and creatinine (H = 1·74 v. L = 1·45 mg/dl)) concentrations, but not with selection for lean growth on a restricted feeding regime (LGS). Following 24-h fasting, responses in lipid metabolism, in the form of higher serum non-esterified fatty acid concentrations, were detected with divergent selection for both LGA (399 v. 248, s.e.d. 66 µmol/l) and LGS (H = 361 v. L = 107 µmol/l). The high LGS line appeared to ‘preserve’ protein to a greater extent than the high LGA line and similarly there was greater maintenance of lipid depots by the low LGS line compared with the low LGA line. A tentative ranking of the two pairs of lean growth selection lines on the basis of ‘importance’ of protein deposition would be high LGS, high LGA, low LGA and low LGS.

Coheritabilities for serum creatinine concentration with predicted lysine balance and lysine required for protein deposition (-0·17 and 0·17, s.e. 0·08) indicated that serum creatinine concentration may usefully be included in breeding value prediction for lysine requirement and protein deposition to increase the accuracy of predicted genetic merit.

Fasting did not increase the coheritabilities for serum creatinine concentration, so inclusion of serum creatinine concentration in a selection criterion for dietary lysine requirement or protein deposition does not require withdrawal of food before blood sampling animals.

An in vivo procedure to determine nutrient requirements for growing pigs would have substantial cost advantages over serial slaughter and furthermore repeated measurements would allow estimation of protein requirements at each stage of growth. Serum urea concentration (Urea) has been proposed as a candidate indicator of protein requirement as over-supply of protein will increase Urea (Chen et al., 1995). The study estimated genetic variation in Urea at different stages of performance test and the relationships between Urea and performance traits.

Insulin-like growth factor-1 has been positively associated components of growth in pigs, such as protein deposition. Therefore, serum insulin-like growth factor-1 concentration (IGF-1) was measured in lines of pigs divergently selected for daily food intake (DFI) or for efficient lean growth rate (LGS) to determine if there was a non-zero genetic association between IGF-1 and the selection criteria. If a genetic association did exist, then IGF-1 could be used as a physiological predictor of genetic merit in a breeding programme. The presence of a major gene effect on IGF-1 was also examined in the study.

The surface morphology and electronic properties of a low energy boron implanted diamond films with shallow doping, prepared by microwave plasma enhanced chemical vapour deposition (CVD), have been characterised by atomic force microscopy (AFM), scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) techniques.

Both AFM and STM images taken at different locations on the films have exhibited similar morphological features on the (100) crystal surfaces. The crystal surfaces are not atomically flat but are composed of many hillocks as shown in Fig 1(a) to 1(c). The majority of values measured from the peaks of hillocks to the valleys are in the range of 2 to 5 nm, and the diameter of these hillocks is in the range of 50 to 250 nanometers. These crystal surface morphological features are believed to be caused in the high energy boron ion implantation process.

The great cavern of Wookey-Hole is situated two miles to the north-west of the city of Wells, in the centre of Somerset, and immediately adjacent to the thriving- village which has taken the name of the cavern, and has depended for its prosperity on the existence of the copious and usually pellucid stream, which here bursts forth from Mendip's hidden reservoirs. This is the source of the Axe, which winds its way through the lower lands, and after uniting with the sister stream of Cheddar, flows into the sea near Weston-super-mare. From Wookey-Hole the southern slope of Mendip rises in an unbroken sweep till it reaches a thousand feet above the sea, commanding a magnificent view to the east, south, and west. It is not a limestone cave in the ordinary sense of the word, since every known cavity in the immediate vicinity is not in the Carboniferous Limestone, but in the Dolomitic Conglomerate, which here attains enormous thickness. To the north, the great mass of Carboniferous Limestone, receiving the water of innumerable springs from the Old Red Sandstone and Shales and from a generous rainfall, engulfs it in a countless number of swallets, many of which are insignificant, whilst some of the larger have been opened by our exploring parties during the past few years, and followed through unimagined beauties to profound depths.