Glaciers in the Russian High Arctic have undergone accelerated mass loss due to atmospheric and oceanic warming in the Barents–Kara Sea region. Most studies have concentrated on the western Barents–Kara sector, despite evidence of accelerating mass loss as far east as Severnaya Zemlya. However, long-term trends in glacier change on Severnaya Zemlya are largely unknown and this record may be complicated by surge-type glaciers. Here, we present a long-term assessment of glacier change (1965–2021) on Severnaya Zemlya and a new inventory of surge-type glaciers using declassified spy-satellite photography (KH-7/9 Hexagon) and optical satellite imagery (ASTER, Sentinel-2A, Landsat-4/5 TM and 8 OLI). Glacier area reduced from 17 053 km2 in 1965 to 16 275 in 2021 (−5%; mean: −18%, max: −100%), with areal shrinkage most pronounced at land-terminating glaciers on southern Severnaya Zemlya, where there is a recent (post-2010s) increase in summer atmospheric temperatures. We find that surging may be more widespread than previously thought, with three glaciers classified confirmed as surge-type, eight as likely to have surged and nine as possible, comprising 11% of Severnaya Zemlya's 190 glaciers (37% by area). Under continued warming, we anticipate accelerated retreat and increased likelihood of surging as basal thermal regimes shift.

Research on Palaeolithic hunter-gatherer diet has focused on the consumption of animals. Evidence for the use of plant foods is comparatively limited but is rapidly expanding. The authors present an analysis of carbonised macro-remains of processed plants from Franchthi Cave in the Aegean Basin and Shanidar Cave in the north-west Zagros Mountains. Microscopic examination of the charred food remains reveals the use of pounded pulses as a common ingredient in cooked plant foods. The results are discussed in the context of the regional archaeobotanical literature, leading the authors to argue that plants with bitter and astringent tastes were key ingredients of Palaeolithic cuisines in South-west Asia and the Eastern Mediterranean.

In recent decades, the use of conditionality backed by benefit sanctions for those claiming unemployment and related benefits has become widespread in the social security systems of high-income countries. Critics argue that sanctions may be ineffective in bringing people back to employment or indeed harmful in a range of ways. Existing reviews largely assess the labour market impacts of sanctions but our understanding of the wider impacts is more limited. We report results from a scoping review of the international quantitative research evidence on both labour market and wider impacts of benefit sanctions. Following systematic search and screening, we extract data for 94 studies reporting on 253 outcome measures. We provide a narrative summary, paying attention to the ability of the studies to support causal inference. Despite variation in the evidence base and study designs, we found that labour market studies, covering two thirds of our sample, consistently reported positive impacts for employment but negative impacts for job quality and stability in the longer term, along with increased transitions to non-employment or economic inactivity. Although largely relying on non-experimental designs, wider-outcome studies reported significant associations with increased material hardship and health problems. There was also some evidence that sanctions were associated with increased child maltreatment and poorer child well-being. Lastly, the review highlights the generally poor quality of the evidence base in this area, with few studies employing research methods designed to identify the causal impact of sanctions, especially in relation to wider impacts.

We investigate the turbulence statistics in a multiphase plume made of heavy particles (particle Reynolds number at terminal velocity is 450). Using refractive-index-matched stereoscopic particle image velocimetry, we measure the locations of particles whose buoyancy drives the formation of a multiphase plume, together with the local velocity of the induced flow in the ambient salt–water. Measurements of the mean axial flow in the plume centreplane follow Gaussian profiles and that of the mean radial flow is consistent with integral plume theory. The turbulence characteristics resemble those measured in a bubble plume, including strong anisotropy in the normal Reynolds stresses. However, we observe structural differences between the two multiphase plumes. First, the skewness of the probability density function of the axial velocity fluctuations is not that which would be predicted by simply reversing the direction of a bubble plume. Second, in contrast to a bubble plume, the particle plume has a non-negligible fluid-shear production term in the turbulent kinetic energy (TKE) budget. Third, the radial decay of all measured terms in the TKE budget is slower than those in a bubble plume. Despite these dissimilarities, a bigger picture emerges that applies to both flows. The TKE production by particles (or bubbles) roughly balances the viscous dissipation, except near the plume centreline. The one-dimensional power spectra of the velocity fluctuations show a $-3$ power law that puts both the particle and bubble plume in a category different from single-phase shear-flow turbulence.

Isotope ratios of tooth enamel from ten Early Neolithic individuals buried in a long cairn at Whitwell in central England were measured to determine where they sourced their childhood diet. Five individuals have low Sr concentrations (11–66 ppm) and high 87Sr/86Sr ratios (0.7164–0.7212). Three individuals have relatively low 87Sr/86Sr ratios (0.712–0.711) and Sr concentrations ranging between 54 and 109 ppm. Two individuals have strontium isotope values that bridge the gap between the isotope compositions of these two groups. The high 87Sr/86Sr values are rare in human enamel and exclude sources within the biosphere of central England. Oxygen isotope values are comparable to those found within human archaeological populations buried in temperate regions of Europe. The strontium isotope results should be interpreted in the context of other evidence for migration from northern France to Britain during the Early Neolithic.

The nature of landscape use and residence patterns during the British earlier Neolithic has often been debated. Here we use strontium and oxygen isotope analysis of tooth enamel, from individuals buried at the Hambledon Hill causewayed enclosure monument complex in Dorset, England to evaluate patterns of landscape use during the earlier Neolithic. Previous analysis suggests that a significant proportion of the artefacts found at the site may originate from lithology of Eocene and Upper to Middle Jurassic age that the enclosures overlook to the immediate west and south. The excavators therefore argued that the sector of landscape visible from Hambledon Hill provides an approximate index for the catchment occupied by the communities that it served. Most of the burial population exhibit isotope ratios that could be consistent with this argument. Connections between Hambledon Hill and regions much further afield are also hypothesised, based on the presence of artefacts within the assemblage that could have been sourced from lithology in Somerset, Devon, and Cornwall in south-west England. However, few of the sampled individuals have strontium isotope ratios consistent with having obtained the majority of their diet from such areas during childhood. The individuals who exhibit the highest strontium isotope ratios are all adult males, whom the excavators suggest to have died during one or more episodes of conflict, following the burning and destruction of surrounding defensive outworks built during the 36th century bc. At least one of these individuals, who was found with an arrowhead amongst his ribs, did not obtain his childhood diet locally and has 87Sr/86Sr values that could be comparable to those bioavailable in the south-west peninsula.

Red Supergiant Stars (RSGs) are important probes of stellar and chemical evolution in star-forming environments. They represent the brightest near-IR stellar components of external galaxies and probe the most recent stellar population to provide robust, independent abundance estimates. The Local Group dwarf irregular galaxy, NGC6822, is a reasonably isolated galaxy with an interesting structure and turbulent history. Using RSGs as chemical abundance probes, we estimate metallicities in the central region of NGC6822, finding a suggestion of a metallicity gradient (in broad agreement with nebular tracers), however, this requires further study for confirmation. With intermediate resolution Multi-object spectroscopy (from e.g. KMOS, EMIR, MOSFIRE) combined with state-of-the-art stellar model atmospheres, we demonstrate how RSGs can be used to estimate stellar abundances in external galaxies. In this context, we compare stellar and nebular abundance tracers in NGC 6822 and by combining stellar and nebular tracers we estimate an abundance gradient of −0.18 ± 0.05 dex/kpc.

Metal–insulator–metal (MIM) resonant absorbers comprise a conducting ground plane, a thin dielectric, and thin separated metal top-surface structures. The dielectric SiO2 strongly absorbs near 9 µm wavelength and has correspondingly strong long-wave-infrared (LWIR) dispersion for the refractive index. This dispersion results in multiple absorption resonances spanning the LWIR, which can enhance broad-band sensitivity for LWIR bolometers. Similar considerations apply to silicon nitride Si3N4. TiO2 and AlN have comparatively low dispersion and give simple single LWIR resonances. These dispersion-dependent features for infrared MIM devices are demonstrated by experiment, electrodynamic simulation, and an analytic model based on standing waves.

Ternary lead chalcogenides, such as PbSxSe1-x, offer the possibility of room-temperature infrared detection with engineered cut-off wavelengths within the important 3-5 micron mid-wave infrared (MWIR) wavelength range. We present growth and characterization of aqueous spray-deposited thin films of PbSSe. Complexing agents in the aqueous medium suppress unwanted homogeneous reactions so that growth occurs only by the heterogeneous reaction on the hydrophilic substrate. The strongly-adherent films are smooth with a mirror-like finish. The films comprise densely packed grains with tens of nm dimensions and a total film thickness of ∼400-500 nm. Measured optical constants reveal absorption out to at least 4.5 μm wavelength and a ∼0.3 eV bandgap intermediate between those of PbS and PbSe. The semiconducting films are p-type with resistivity ∼1 and 85 Ohm-cm at 300 and 80 K, respectively. Sharp x-ray diffraction peaks identify the films as Clausthalite-Galena solid-state solution with a lattice constant that indicates an even mixture of PbS and PbSe. The photoconductive response is observed at both nitrogen and room temperature up to at least 2 kHz chopping frequency.

The development of algorithms for agile science and autonomous exploration has been pursued in contexts ranging from spacecraft to planetary rovers to unmanned aerial vehicles to autonomous underwater vehicles. In situations where time, mission resources and communications are limited and the future state of the operating environment is unknown, the capability of a vehicle to dynamically respond to changing circumstances without human guidance can substantially improve science return. Such capabilities are difficult to achieve in practice, however, because they require intelligent reasoning to utilize limited resources in an inherently uncertain environment. Here we discuss the development, characterization and field performance of two algorithms for autonomously collecting water samples on VALKYRIE (Very deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice Explorer), a glacier-penetrating cryobot deployed to the Matanuska Glacier, Alaska (Mission Control location: 61°42′09.3″N 147°37′23.2″W). We show performance on par with human performance across a wide range of mission morphologies using simulated mission data, and demonstrate the effectiveness of the algorithms at autonomously collecting samples with high relative cell concentration during field operation. The development of such algorithms will help enable autonomous science operations in environments where constant real-time human supervision is impractical, such as penetration of ice sheets on Earth and high-priority planetary science targets like Europa.