Characterization of the SKA1-Low prototype station Aperture Array Verification System 2

The low frequency component of the Square Kilometre Array (SKA1-Low) will be an aperture phased array located at the Murchison Radio-astronomy Observatory (MRO) site in Western Australia. It will be composed of 512 stations, each consisting of 256 log-periodic dual-polarized antennas, and will operate in the low frequency range (50 to 350 MHz) of the SKA bandwidth. The Aperture Array Verification System 2 (AAVS2), operational since late 2019, is the last full-size engineering prototype station deployed at the MRO site before the start of the SKA1-Low construction phase. The aim of this paper is to characterize the station performance through commissioning observations at six different frequencies (55, 70, 110, 160, 230, and 320 MHz) collected during its first year of activities. We describe the calibration procedure, present the resulting all-sky images and their analysis, and discuss the station calibratability and system stability. Using the difference imaging method, we also derive estimates of the SKA1-Low sensitivity for the same frequencies and compare them with those obtained through electromagnetic simulations across the entire telescope bandwidth, finding good agreement (within 13%). Moreover, our estimates exceed the SKA1-Low requirements at all considered frequencies by up to a factor of ∼2.3. Our results are very promising and allow for an initial validation of the AAVS2 prototype station performance, which is an important step toward the coming SKA1-Low telescope construction and science

The Arecibo Galaxy Environment Survey (AGES)

Context. Many galaxy properties are known to correlate with the environment in which the galaxies are embedded. Their cold, neutral gas content, which is usually assessed through 21 cm H 

Comparative analysis of the microbial communities in agricultural soil amended with enhanced biochars or traditional fertilisers

Biochar can have a positive effect on agricultural soils and plant yields. The underlying mechanisms that deliver beneficial outcomes are still poorly understood. Soils contain complex communities of hundreds or thousands of distinct microorganisms, and it has been shown that biochar can have an impact on their composition and function. Here we analyse the microbial communities in a controlled field trial that compared the effect of enhanced biochars (EBs) against a farmer practice (FP) of traditional fertilisation (urea, superphosphate and potash) on sweet corn yield. During sequential crop cycles (barley and sweet corn) two types of EBs were applied at low and high levels (total of 1.1 and 5.44 t ha−1, respectively). Samples were taken at the end of a second crop cycle and over 50,000 16S ribosomal RNA (16S rRNA) tag sequences were generated per sample to characterise microbial communities. Despite the lower amounts of nutrients provided by EBs, their amendment to soil produced similar crop yields to the FP. In addition, significant differences in microbial community composition were observed between the high EB and FP treatments. This was driven by differences in the relative abundances of only a few community members. Community level differences were also correlated with a higher soil pH associated with EB laden soil. Network analysis showed that the low EB application had more correlation patterns (co-occurrences and exclusions) between microbial taxa, and highlighted the importance of associations between members of the phyla Acidobacteria and Verrucomicrobia in the biochar environment. Overall, a large number of microorganisms appear to be influenced by EB amendment compared with fertiliser use leading to a complex re-wiring of community composition and associations

Recreational 3,4-methylenedioxy-N-methylamphetamine (MDMA) or ‘ecstasy’ and self-focused compassion: Preliminary steps in the development of a therapeutic psychopharmacology of contemplative practices

3,4-methylenedioxy-N-methylamphetamine (MDMA) produces diverse pro-social effects. Cognitive training methods rooted in Eastern contemplative practices also produce these effects through the development of a compassionate mindset. Given this similarity, we propose that one potential mechanism of action of MDMA in psychotherapy is through enhancing effects on intrapersonal attitudes (i.e. pro-social attitudes towards the self). We provide a preliminary test of this idea. Recreational MDMA (ecstasy)-users were tested on two occasions, having consumed or not consumed ecstasy. Selfcritical and self-compassionate responses to self-threatening scenarios were assessed before (T1) and after (T2) ecstasyuse (or no use), and then after compassionate imagery (T3). Moderating roles of dispositional self-criticism and avoidant attachment were examined. Separately, compassionate imagery and ecstasy produced similar sociotropic effects as well as increases and reductions in self-compassion and self-criticism respectively. Higher attachment-related avoidance was associated with additive effects of compassionate imagery and ecstasy on self-compassion. Findings were in line with MDMA’s neuropharmacological profile, its phenomenological effects and proposed adjunctive use in psychotherapy. However, although conditions were balanced, the experiment was non-blind and MDMA dose/purity was not determined. Controlled studies with pharmaceutically pure MDMA are still needed to test these effects rigorously.N/

Horizon scan of invasive alien species for the island of Ireland

Ireland, being an island situated on Europe’s western seaboard, has a fewer number of native species than mainland European Union Member States (MS). Increased numbers of vectors and pathways have reduced the island’s biotic isolation, increasing the risk of new introductions and their associated impacts on native biodiversity. It is likely that these risks are greater here than they are in continental Member States, where the native biodiversity is richer. A horizon scanning approach was used to identify the most likely IAS (with the potential to impact biodiversity) to arrive on the island of Ireland within the next ten years. To achieve this, we used a consensus-based approach, whereby expert opinion and discussion groups were utilised to establish and rank a list of 40 species of the most likely terrestrial, freshwater and marine IAS to arrive on the island of Ireland within the decade 2017–2027. The list of 40 included 18 freshwater invaders, 15 terrestrial IAS and seven marine species. Crustacean species (freshwater and marine) were taxonomically dominant (11 out of 40); this reflects their multiple pathways of introduction, their ability to act as ecosystem engineers and their resulting high impacts on biodiversity. Freshwater species dominated the top ten IAS (seven species out of ten), with the signal crayfish (Pacifastacus leniusculus) highlighted as the most likely species to arrive and establish in freshwaters, while roe deer (Capreolus capreolus) (second) and the warm-water barnacle (Hesperibalanus fallax) (fifth), were the most likely terrestrial and marine invaders. This evidence-based list provides important information to the relevant statutory agencies in both jurisdictions in Ireland to prioritise the prevention of the most likely invaders and aid in compliance with legislation, in particular the EU Regulation on Invasive Alien Species (EU 1143/2014). Targeted biosecurity in both jurisdictions is urgently required in order to manage the pathways and vectors of arrival, and is vital to maintaining native biodiversity on the island of Ireland