The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with $\sim$ 15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination $+41^\circ$ made over a 288-MHz band centred at 887.5 MHz.

Knowledge of the intra-individual spatial and regional distribution of intestinal microbial populations is essential to understand gut host–microbial interactions. In this study, we performed a compositional analysis of luminal and mucosal samples from the small and large intestine of four organ donors by 16S rRNA amplicon sequencing and high-throughput quantitative polymerase chain reaction. Since the human microbiota is subject to selection pressure at lower taxonomic levels, we isolated over 400 bacterial strains and investigated strain-level variation of 11 Lactobacillus rhamnosus from different intestinal regions. Results substantiate reported inter-individual variability as well as intra-individual differences along the gastrointestinal tract. Although the luminal and mucosal-associated communities were similar within individuals, relative abundance reflected the donors’ demographic and potential pathologies. The total bacterial load of all donors increased from small intestine to colon, while Bifidobacterium was in greater abundance in the small intestine. Comparative genomic analysis of L. rhamnosus showed the strains segregated into two distinct clusters and identified no features specific to location. Analysis revealed genetic differences for exopolysaccharide production, carbohydrate utilization, pilus formation and vitamin K biosynthesis between clusters. This study contributes to the understanding of niche-specific microbial communities, encouraging subsequent studies to better understand microbial signatures at lower taxonomic levels.

The following fourteen reference patterns of boride, telluride, and oxide ceramics are reported. Included in the fourteen reference patterns are data for six high Tc superconducting oxide and related phases (Ba2CaCu2TI2O8, BaCuEu2O5, BaCuTm2O5, BaCuDy2O5, Ba3.2Cu1.7Y0.8O6.1·xCO2, Sr2Bi2O5). The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled step-scanning diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and to perform variable indexing and least-squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer method.

Intensities were measured as peak heights above background and were read manually from strip charts. To minimize preferred orientation effects, the powders were passed through a 400 mesh sieve and were mixed with an amorphous diluent, silica gel. Sample mounts were prepared by side-drifting and/or by dusting a thin layer of sample on a glass slide coated with a thin smear of silicone grease.

How do older workers keep up and adapt to a changing workplace after age 55? In exploring that question, this study specifically examined how age-related changes affect workers, how older workers deal with a loss of resources, how they engage in life management, and why some are more successful than others. An in-depth analysis was undertaken using 32 semi-structured interviews conducted with workers aged 55 to 64. Findings revealed that older workers use various strategies to adapt to a change in resources, and that these strategies help them cope and maintain their functioning in the workplace. Because older workers require different types of employer support, this study offers an understanding of how employers can provide that support to encourage older workers to remain in the workforce longer. Several avenues for future research are suggested, including an exploration of the role played by internal sources of support.

Fourteen reference patterns of oxide ceramics are reported. Included in the fourteen reference patterns are data for nine high critical temperature super-conducting oxide related phases: (BaCuEr2O5, Ba2Cu3EuO7, BaCuGd2O5, Ba2Cu3GdO7, Ba2.4Cu5La4O13, Ba1.9cu3La1.1O7, Ba2Cu3SmO7 and (Ba0.4Sr0.6)2Cu3 YO7). The general methods of producing these X-ray powder diffraction reference patterns were described previously in this journal (Vol. 1, No. 1, pg. 40 (1986)). The symbols used in this article are defined in the PDF cards.

Fifteen reference patterns of oxides, nitrides, borides, carbides, silicides, and sulfides are included in this report. The general methods of producing these X-ray powder diffraction reference patterns are described in this Journal, Vol. 1, No. 1, pg. 40(1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and to perform indexing and least-squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer program.

Intensities were measured as peak heights above background and were read manually from strip charts. To minimize preferred orientation effects, the powders were passed through a 400 mesh sieve and were mixed with an amorphous diluent material, glass powder. Samples were prepared by side-drifting the mixture into the holder or by dusting a thin layer on a glass slide coated with a thin smear of silicone grease.

The support and interest of the ICDD in this project is gratefully acknowledged. The expert guidance of R. Roth of the Ceramics Division on material synthesis and the careful review of the manuscript by S. Block of the Ceramics Division and A. D. Mighell of the Reactor Division are fully appreciated. Acknowledgement is also extended to D. Minor for performing sample analysis by using SEM. In the production of these standard powder patterns, the ability to search NBS CRYSTAL DATA has proven invaluable.

Fourteen reference patterns of oxide ceramics are reported. Included in the fourteen reference patterns are data for two high critical temperature superconducting oxide related phases (BaCuHo2O5 and Ba2YCu3O6.56). The general methods of producing these X-ray powder diffraction reference patterns were described previously in this journal (Vol. 1, No. 1, pg. 40 (1986)).

The following fifteen reference patterns of boride, silicide and oxide ceramics represent the first group of ceramic phases measured at the National Bureau of Standards under the project “High Quality Reference Patterns and Total Digital Powder Patterns of Technologically Important Ceramic Phases”. The support and interest of the JCPDS-ICDD in this project is gratefully acknowledged.

The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40(1986).

Fifteen reference patterns of oxide ceramics are reported. Included in the fifteen reference patterns are data for nine high critical temperature superconducting oxide and related phases Ba2Cu3ErO7, Ba3.2Cu1.7Er0.8O6.1·xCO2, Ba2Cu3HoO7, Ba2Cu3(Pr0.5Y0.5)O7, Ba3Dy4O9, Ba3Yb4O9, (Ba0.6Sr0.4)2Cu3YO7, (Ba0.8Sr0.2)2Cu3YO7, and CuNd2O4. The general methods of producing diese X-ray powder diffraction reference patterns were described previously in this journal (Vol. 1, No. 1, pg. 40 (1986)). The symbols used in diis article are defined in the PDF cards.

The following fourteen reference patterns of carbide, nitride, telluride, and oxide ceramics are reported. Included in the fourteen reference patterns are data for three high Tc superconducting oxide related phases (Ba2CuO3, CuSrO2, and Ba2Cu3YO6). The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and to perform variable indexing and least-squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer program.

The following sixteen reference patterns of boride, silicide, nitride and oxide ceramics represent the second group of reference patterns measured at the National Bureau of Standards under the project “High Quality Reference Patterns and Total Digital Powder Patterns of Technologically Important Ceramic Phases”. Included in the sixteen reference patterns are data for two high Tc superconducting oxide phases (CuSr0.2La1.8O4 and Ba2Cu3YO7) plus one related phase (BaCuY2O5). In addition to these new phases, five other patterns represent phases previously not contained in the PDF and eight represent major corrections to data in the file. The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1, No. 1, pg. 40 (1986).

Fifteen reference patterns of boride, silicide, selenide, telluride and oxide ceramics are reported. Included in the 15 reference patterns are data for three oxide phases which are related to high critical temperature (Tc) superconducting materials: BaCuO2, BaCuSm2O5 and BaCuYb2O5. Four other patterns are included which represent phases previously not contained in the PDF. The remaining six are major corrections of data already included in the file. Reference data for phases Ba2CuY3O6.8 and Ba2Y3CuO6 appeared in the special July superconductor issue of the Advanced Ceramic Materials, 1987. The general methods of producing these X-ray powder diffraction reference patterns are described in this journal, Vol. 1(1), 40 (1986).

Samples were mixed with one or two internal standards: silicon (SRM640a), silver, tungsten, or fluorophlogopite (SRM675). Expected 2θ values for these internal standards are specified in the methods described (ibid.). Data were measured with a computer controlled diffractometer. The POWDER-PATTERN system of computer programs was used to locate peak positions, to calibrate the patterns, and to perform variable indexing and least-squares cell refinement. A check on the overall internal consistency of the data was also provided by a computer program.

Light-emitting diodes (LEDs) based on p-GaN/ZnO heterojunction were fabricated. GaN was deposited on sapphire using metal-organic chemical vapor deposition (MOCVD), and two kinds of ZnO i.e. ZnO thin film deposited by sputtering and ZnO nanorods (NRs) grown by hydrothermal method were used as n-type layer respectively. MgO film with the thickness around 10 nm was deposited by electron-beam deposition to act as an interlayer between GaN and ZnO. Photoluminescence, electroluminescence and I-V curves were measured to compare the properties of GaN based heterojunction LEDs with different architectures. The existence of MgO interlayer as well as the morphology of ZnO obviously influenced the electrical and optical properties of GaN based LEDs. The effect of MgO interlayer on ZnO growth, properties and I-V curves and emission spectra of LEDs is discussed in detail.