Observations of the intracluster medium (ICM) in the outskirts of galaxy clusters reveal shocks associated with gas accretion from the cosmic web. Previous work based on non-radiative cosmological hydrodynamical simulations have defined the shock radius, $r_{\text{shock}}$, using the ICM entropy, $K \propto T/{n_\mathrm{e}}^{2/3}$, where T and $n_{\text{e}}$ are the ICM temperature and electron density, respectively; the $r_{\text{shock}}$ is identified with either the radius at which K is a maximum or at which its logarithmic slope is a minimum. We investigate the relationship between $r_{\text{shock}}$, which is driven by gravitational hydrodynamics and shocks, and the splashback radius, $r_{\text{splash}}$, which is driven by the gravitational dynamics of cluster stars and dark matter and is measured from their mass profile. Using 324 clusters from The Three Hundred project of cosmological galaxy formation simulations, we quantify statistically how $r_{\text{shock}}$ relates to $r_{\text{splash}}$. Depending on our definition, we find that the median $r_{\text{shock}} \simeq 1.38 r_{\text{splash}} (2.58 R_{200})$ when K reaches its maximum and $r_{\text{shock}} \simeq 1.91 r_{\text{splash}} (3.54 R_{200})$ when its logarithmic slope is a minimum; the best-fit linear relation increases as $r_{\text{shock}} \propto 0.65 r_{\text{splash}}$. We find that $r_{\text{shock}}/R_{200}$ and $r_{\text{splash}}/R_{200}$ anti-correlate with virial mass, $M_{200}$, and recent mass accretion history, and $r_{\text{shock}}/r_{\text{splash}}$ tends to be larger for clusters with higher recent accretion rates. We discuss prospects for measuring $r_{\text{shock}}$ observationally and how the relationship between $r_{\text{shock}}$ and $r_{\text{splash}}$ can be used to improve constraints from radio, X-ray, and thermal Sunyaev-Zeldovich surveys that target the interface between the cosmic web and clusters.

We introduce a natural two-cardinal version of Bagaria’s sequence of derived topologies on ordinals. We prove that for our sequence of two-cardinal derived topologies, limit points of sets can be characterized in terms of a new iterated form of pairwise simultaneous reflection of certain kinds of stationary sets, the first few instances of which are often equivalent to notions related to strong stationarity, which has been studied previously in the context of strongly normal ideals. The non-discreteness of these two-cardinal derived topologies can be obtained from certain two-cardinal indescribability hypotheses, which follow from local instances of supercompactness. Additionally, we answer several questions posed by the first author, Holy and White on the relationship between Ramseyness and indescribability in both the cardinal context and in the two-cardinal context.

Mixed Reality (MR) technologies are widely available and applied in a variety of design and engineering applications. MR prototypes capture the respective benefits of physical and digital prototypes by merging these domains saving the time and resources required to create them. This advantage is compelling in the context of design education where tight time and resource constraints exist. However, it is known that new digital prototyping tools can cause problems for students applying appropriate prototyping tools during practice-based studio design projects. Our paper contributes a systematic appraisal of MR prototyping's proposed dimensions value against constraints and issues in design studio education. This highlights MR Visualisation and Knowledge Management dimensions as most readily realised in education. Recommendations are then reflected on via an illustrative case study into the implementation of MR prototyping via these dimensions. Reflections corroborate the value proposition, but also highlight a need for further research exploring activities to scaffold MR prototyping to further support reflective design thinking.

Freshwater habitats in China are potentially suitable for invasive alien turtle species and, consequently, raising turtles in aquaculture facilities and the trade in turtles this supplies pose risks to habitats and native wetland communities when exotic turtles escape or are released deliberately. Online trade (e-commerce) is making an increasing contribution to turtle sales in China, seemingly driving demand and thus potentially exacerbating the risk of release. We document the scale and spatial pattern of online sales of non-native turtles over 90 days on China's Taobao.com e-commerce site. The majority of sales were in the ecologically sensitive middle and lower Yangtze river basin (82.35% of > 840,000 slider turtles Trachemys scripta elegans, and 68.26% of > 100,000 snapping turtles, Chelydridae spp.). These species are native to the Americas. Concurrently, over 2008–2018, we found 104 mentions of feral turtle issues listed on Baidu News where, among the 53 prefectures mentioned, issues with invasive turtle populations also focused predominantly in the middle and lower Yangtze river basin. Although circumstantial, this association suggests that the substantial online sale of alien turtles could be having detrimental effects in China's Yangtze river basin. It is important to safeguard these wetland habitats, which are of global importance, by improving policies for detecting and regulating invasive alien turtle issues and by warning consumers about the ecological hazard of their purchases.

Rose gall wasps, Diplolepis Geoffroy (Hymenoptera: Cynipidae), induce structurally distinct galls on wild roses (Rosa Linnaeus; Rosaceae), which provide gallers with food and shelter. These galls are attacked by a wide variety of micro-hymenopterans, including Periclistus Förster (Hymenoptera: Cynipidae), which act as inquilines. Both Diplolepis and Periclistus are difficult to distinguish based on adult morphology, instead the structural appearance of galls is often used to distinguish species. Using the mitochondrial gene cytochrome c oxidase subunit I, we tested the species boundaries and built phylogenies of both Diplolepis and Periclistus. The molecular results have largely supported the validity of species described in the literature, with notable exceptions in four species groups. Periclistus exhibits a divide between the Palaearctic and Nearctic clades, and ranges from specialists to generalists in terms of host specificity. While it is premature to enact any taxonomic changes without additional molecular markers, this incongruence between morphological and molecular data indicates these groups need taxonomic revision and gall morphology alone may be inadequate to delimit species.

Metal chalcogenides have attracted great attention because of their broad applications. It has been well acknowledged that microstructure can alter the intrinsic properties and performance of metal chalcogenides. The structure–property–performance relationships can be investigated at atomic scale with scanning transmission and transmission electron microscopy (STEM and TEM). Nevertheless, careful specimen preparation is paramount for accurate analyses and interpretations. In this work, we compare the effects of a variety of well-established TEM specimen preparation methods on the observed microstructure of an ingot stoichiometric lead telluride (PbTe). Most importantly, from aberration corrected STEM and first principles calculations, we discovered that argon (Ar) ion milling can lead to surface irradiation damage in the form of Pb vacancy clusters and self-interstitial atom (SIA) clusters. The SIA clusters appear as orthogonal nanoscale features when characterized along the <001> crystal orientation of the rock salt structured PbTe. This obfuscates the interpretation of the intrinsic microstructure of metal chalcogenides, especially lead chalcogenides. We demonstrate that with sufficiently low energy (300 eV) Ar ion cleaning or appropriate high-temperature annealing, the surface damage layer can be properly cleaned and the orthogonal nanoscale features are significantly reduced. This reveals the materials’ intrinsic structure and can be used as the standard protocol for future TEM specimen preparation of lead-based chalcogenide materials.

The Beck’s Petrel Pseudobulweria beckii is a ‘Critically Endangered’ seabird whose breeding sites remain unknown. Historic observations suggest the species’ distribution is concentrated in the Bismarck Archipelago and particularly southern New Ireland. Over the course of two research expeditions in 2016 and 2017 we used on-land and at-sea observations, local interviews and satellite telemetry to understand the distribution of the species, its at-sea movements and potential breeding locations. Land-based and at-sea observations indicated that the area of Silur Bay in southern New Ireland was a significant site for Beck’s Petrel with numbers of birds increasing near shore prior to dusk and birds observed in spotlights over land. A local population is estimated to be in the low thousands. In 2017 a single Beck’s was captured at sea, fitted with a satellite transmitter and tracked for eight months. This bird maintained a core distribution off the south-east coast of New Ireland and north of Bougainville for 122 days. During the tracking period, the bird was located over land at night seven times; predominantly over southern New Ireland, where the signal was also lost for extended periods suggesting occupancy of an underground burrow. In August the bird migrated 1,400 km to a core pelagic habitat north of West Papua before the signal was eventually lost. Our combination of land- and sea-based observations and analysis of behaviour from satellite tracking supports the conclusion that a breeding site for Beck’s Petrel lies in the inland mountains of southern New Ireland and most likely in the high-altitude zone (> 2000 m) of the Hans Meyer Range. Further investigations are required to determine the exact location of breeding colonies in the mountains of southern New Ireland and the importance of a potential west Papuan non-breeding pelagic habitat for the species.

This paper presents a practical application of Answer Set Programming to the understanding of narratives about restaurants. While this task was investigated in depth by Erik Mueller, exceptional scenarios remained a serious challenge for his script-based story comprehension system. We present a methodology that remedies this issue by modeling characters in a restaurant episode as intentional agents. We focus especially on the refinement of certain components of this methodology in order to increase coverage and performance. We present a restaurant story corpus that we created to design and evaluate our methodology.

This paper presents a model-based approach for the first time to identify the crack location for the hinge-based planar RRR compliant mechanism, a parallel micro-motion stage driven by piezoelectric (PZT) actuators. However, cracks more likely occur on a flexure hinge because it usually undergoes a periodic deformation in service, which eventually compromises mechanism's performance, positioning accuracy for instance. In this work, the pseudo-rigid-body method is used to develop kinematic and dynamic models of the RRR mechanism both in healthy and damaged conditions, where the crack is considered in terms of the rotational compliance of a flexible hinge. The crack location is determined by measuring PZT elongations, which represents the driving toque deviation because of the crack presence. Numerical simulation is conducted to verify the proposed approach, and the results show good match of the identified crack location with the assumed location. Finally, experiments on the RRR mechanism with a prefabricated crack is performed to further validate the proposed models; the experimental results yield a good consistence.

The helium ion microscope (HeIM) holds immense promise for nano-engineering and imaging with scope for in-situ chemical analysis. Here we will examine the potential of secondary electron hyperspectral imaging (SEHI) as a new route to exploring chemical variations in both two and three dimensions. We present a range of early applications in the context of image interpretation in wider materials science and process control in ion beam-based nano-engineering. Necessary steps for SEHI in the HeIM to evolve into a reliable technique which can be fully embedded into nano-engineering workflows are considered.

In their focal article, Cucina, Walmsley, Gast, Martin, and Curtin (2017) raise an important and timely issue, but go too far in arguing that practitioners should abandon survey key driver analysis (SKDA) altogether. There are many valuable benefits to using SKDA, and rather than discontinuing the practice entirely, we suggest that a better approach is to focus on ways to make it even more valuable to organizations. It is true that this area is in need of further research, but instead of asking whether we are driving down the right road, perhaps the right question is, “Are we there yet?”

The critical period of weed control for crops grown under conventional tillage systems has been well studied, and the results generated by these studies have been proven to be very useful in developing ecologically and economically sound weed management practices. However, these management systems may not be directly applicable under no-till situations because the species composition, total amount, and temporal pattern of seedling emergence change substantially with tillage. The objective of this study was to identify the critical period of weed control for soybean and corn in fields that had been under no-till management for 1 yr. Although estimates of the critical period for a crop vary from year to year and site to site, some interesting comparisons can be made between no-till and conventional tillage. The start of the critical period in no-till corn was stable, usually beginning at the six-leaf stage. The end of the critical period was more variable ranging from the 9- to 13-leaf stage. The critical period for corn under no-till conditions tended to start and end earlier than under conventional tillage practices. In soybean, we were unable to identify a critical period at one of the sites. At the other location (sandy loam soil), the critical period was estimated to begin at the first or second node developmental stage, whereas the end was determined to be at the R1 stage (early flowering). The critical period in soybean was longer than that observed under conventional tillage.

A field study was conducted in 2002 and 2003 to evaluate tolerance of eight rice cultivars to clomazone at 896 g ai/ha impregnated onto urea fertilizer. Rice foliar bleaching was 16 to 20% at 14 d after rice rooting (DAR) for long-grain cultivars ‘Ahrent’, ‘Cheniere’, ‘Cocodrie’, ‘Cypress’, ‘Francis’, and ‘Wells’ and 23 and 30% for medium-grain ‘Bengal’ and short-grain ‘Pirogue’, respectively, when clomazone was impregnated onto urea. Clomazone reduced the number of tillers/ m2 21 DAR for all cultivars. Early season height reductions occurred for all cultivars; however, Pirogue was the only cultivar shorter than the nontreated at harvest. There were no yield reductions with regard to the medium and long-grain cultivars when compared with respective nontreated cultivars. However, yield of short-grain Pirogue treated with clomazone was 1,740 kg/ha less than the nontreated.

The high Antarctic plateau provides exceptional conditions for infrared observations on account of the cold, dry and stable atmosphere above the ice surface. This paper describes the scientific goals behind the first program to examine the time-varying universe in the infrared from Antarctica — the Kunlun Infrared Sky Survey (KISS). This will employ a 50cm telescope to monitor the southern skies in the 2.4μmKdark window from China's Kunlun station at Dome A, on the summit of the Antarctic plateau, through the uninterrupted 4-month period of winter darkness. An earlier paper discussed optimisation of the Kdark filter for sensitivity (Li et al. 2016). This paper examines the scientific program for KISS. We calculate the sensitivity of the camera for the extrema of observing conditions that will be encountered. We present the parameters for sample surveys that could then be carried out for a range of cadences and sensitivities. We then discuss several science programs that could be conducted with these capabilities, involving star formation, brown dwarfs and hot Jupiters, exoplanets around M dwarfs, the terminal phases of stellar evolution, fast transients, embedded supernova searches, reverberation mapping of AGN, gamma ray bursts and the detection of the cosmic infrared background.

Outliers in terrain data are an obstacle to achieving accurate and robust solutions of Underwater Terrain Relative Navigation (UTRN). If not handled properly, navigation may be degraded or even divergent. To address the problem, this paper proposes a terrain-matching algorithm based on the robust estimation theory. In contrast to the conventional approach, the proposed algorithm can significantly reduce the interference of the outliers. Experimental results confirm the good performance of the proposed method.