Hedge cactus (Cereus uruguayanus R. Kiesling; syn.: Cereus hildmannianus K. Schum.) is a columnar cactus that was introduced to Australia as an ornamental plant and has since become invasive in subhumid regions of Queensland and New South Wales. Compared with its congener, queen of the night (Cereus jamacaru DC.), which is currently invasive in both eastern and southern Africa, information on seed biology of C. uruguayanus is lacking. Experiments were conducted to study the effects of alternating day/night temperature, salt stress, water stress, and burial depth on germination and seedling emergence of four seed accessions of C. uruguayanus. Seeds were also subjected to a controlled aging test (CAT) to obtain an estimate of potential persistence under field conditions. The optimum temperature regime for germination of all accessions was 30/20 C. Germination decreased with an increase in sodium chloride (NaCl) concentration, but germination of all accessions (range 26% to 81%) occurred at 160 mM NaCl, indicating very high salt tolerance. Seed germination gradually decreased with an increase in water stress, but germination in all accessions (range 19% to 47%) occurred at −0.8 MPa. Seed viability and dormancy status were unaffected by exposure to salt level (320 mM NaCl) and water (−1.6 MPa) stress under which germination did not occur. Germination responses to all three factors were generally similar to those documented for C. jamacaru. The emergence of C. uruguayanus decreased with an increase in seed burial depth. The highest emergence (43%) was recorded for surface-sown seeds, and emergence was reduced to 0 at a burial depth of 2 cm. CAT results for two seed accessions indicated that seeds of C. uruguayanus are likely to demonstrate extended (>3 yr) persistence under field conditions, a prediction that is supported by evidence that germination of its small (2-mm) seeds is markedly reduced by burial.

Climate change is increasing the frequency of extreme weather events, such as drought and heat waves. In this paper, we assess the impact of drought and high temperatures on the employment outcomes of working-age individuals in South Africa between 2008 and 2017. We merge high-resolution weather data with detailed individual-level survey data on labor market outcomes, and estimate causal impacts using a fixed effects framework. We find that increases in the occurrence of drought reduce overall employment. These effects are concentrated in the tertiary sector, amongst informal workers, and in provinces with a higher reliance on tourism. Taken together, our results suggest that the impacts of climate change will be felt unequally by South Africa's workers.

A terrestrial (lacustrine and fluvial) palaeoclimate record from Hoxne (Suffolk, UK) shows two temperate phases separated by a cold episode, correlated with MIS 11 subdivisions corresponding to isotopic events 11.3 (Hoxnian interglacial period), 11.24 (Stratum C cold interval), and 11.23 (warm interval with evidence of human presence). A robust, reproducible multiproxy consensus approach validates and combines quantitative palaeotemperature reconstructions from three invertebrate groups (beetles, chironomids, and ostracods) and plant indicator taxa with qualitative implications of molluscs and small vertebrates. Compared with the present, interglacial mean monthly air temperatures were similar or up to 4.0°C higher in summer, but similar or as much as 3.0°C lower in winter; the Stratum C cold interval, following prolonged nondeposition or erosion of the lake bed, experienced summers 2.5°C cooler and winters between 5°C and 10°C cooler than at present. Possible reworking of fossils into Stratum C from underlying interglacial assemblages is taken into account. Oxygen and carbon isotopes from ostracod shells indicate evaporatively enriched lake water during Stratum C deposition. Comparative evaluation shows that proxy-based palaeoclimate reconstruction methods are best tested against each other and, if validated, can be used to generate more refined and robust results through multiproxy consensus.

Stars form in clusters, while planets form in gaseous disks around young stars. Cluster dissolution occurs on longer time scales than disk dispersal. Planet formation thus typically takes place while the host star is still inside the cluster. We explore how the presence of other stars affects the evolution of circumstellar disks. Our numerical approach requires multi-scale and multi-physics simulations where the relevant components and their interactions are resolved. The simulations start with the collapse of a turbulent cloud, from which stars with disks form, which are able to influence each other. We focus on the effect of extinction due to residual cloud gas on the early evolution of circumstellar disks. We find that this extinction protects circumstellar disks against external photoevaporation, but these disks then become vulnerable to dynamic truncation by passing stars. We conclude that circumstellar disk evolution is heavily affected by the early evolution of the cluster.

Weed management is complicated by the presence of soil seed banks. The complexity of soil–seed interactions means that seed persistence in the field is often difficult to measure, let alone predict. Field trials, although accurate in their context, are time-consuming and expensive to conduct for individual species. Some ex situ techniques for estimating seed life expectancy have been proposed, but these fail to simulate the environmental complexity of the field. Also, it has been questioned whether techniques such as the controlled aging test (CAT) are useful indicators of field persistence. This study aimed to test the validity of the standard CAT (seed aging at 45 C and 60% relative humidity) in use at the Royal Botanic Gardens, Kew, U.K., for predicting field seed-persistence. Comparison of seed persistence and CAT data for 27 northwest European species suggested a significant positive correlation of 0.31. Subsequently, 13 species of emerging and common weeds of Queensland were assessed for their seed longevity using the CAT. The seed longevity data of these species in the CAT were linked with field seed-persistence data according to three broad seed-persistence categories: < 1 yr, 1 to 3 yr, and > 3 yr. We discuss the scope for using the CAT as a tool for rapid assignment of species to these categories. There is a need for further studies that compare predictions of seed persistence based on the CAT with seed persistence in the field for a larger range of species and environments.

To eradicate a weed invasion, its extent must be delimited and each infestation must be extirpated. Measures for both of these criteria are utilized to assess the progress of current eradication programs targeting mikania vine and limnocharis in northern Australia. The known infested area for each species is less than 5 ha and has remained largely static for the last 3 or more years against a backdrop of refined and enhanced detection methods. This suggests that delimitation has been approached, if not achieved. Different methods of detection have their places, relative to the stage of the program and the spatial distribution of infestations. Although all known infestations of both species are effectively monitored and controlled, ongoing emergence from persistent seed banks limits progress towards the extirpation of infestations to a slow, but measurable, rate.

Recently, PSR J0738-4042 has grown a bright new emission component in its average pulse profile. Using data from Parkes and HartRAO, spanning back to the early 1980s, and applying statistical techniques to model the pulse profile shape with time, we have uncovered unexpected long-term variability, which is very well correlated with changes in the spin-down rate. We present these findings in the context of a growing population of radio-variable pulsars with correlated timing irregularities, including the intermittent pulsars, state-changing pulsars and other individual examples.

Recent Genome-Wide Association Studies (GWAS) have identified four low-penetrance ovarian cancer susceptibility loci. We hypothesized that further moderate- or low-penetrance variants exist among the subset of single-nucleotide polymorphisms (SNPs) not well tagged by the genotyping arrays used in the previous studies, which would account for some of the remaining risk. We therefore conducted a time- and cost-effective stage 1 GWAS on 342 invasive serous cases and 643 controls genotyped on pooled DNA using the high-density Illumina 1M-Duo array. We followed up 20 of the most significantly associated SNPs, which are not well tagged by the lower density arrays used by the published GWAS, and genotyping them on individual DNA. Most of the top 20 SNPs were clearly validated by individually genotyping the samples used in the pools. However, none of the 20 SNPs replicated when tested for association in a much larger stage 2 set of 4,651 cases and 6,966 controls from the Ovarian Cancer Association Consortium. Given that most of the top 20 SNPs from pooling were validated in the same samples by individual genotyping, the lack of replication is likely to be due to the relatively small sample size in our stage 1 GWAS rather than due to problems with the pooling approach. We conclude that there are unlikely to be any moderate or large effects on ovarian cancer risk untagged by less dense arrays. However, our study lacked power to make clear statements on the existence of hitherto untagged small-effect variants.

Over the past 3 years, we have conducted a survey of 100 square degrees of the southern Galactic plane with the Mopra radiotelescope (HOPS). The survey includes observations of multiple spectral lines in the 12 mm band, with the most important being the water maser transition at 22.2 GHz and the non-metastable inversion transitions of ammonia. We report on initial results from HOPS, including the detection of 540 water masers, about two-thirds of which appear to be new detections. We also find widespread emission in the NH3 (1,1) line, as well as detec tions in the NH3 (2,2), (3,3), (6,6) and (9,9) lines.