The hypothesis that chemical remanent magnetization (CRM) in argillaceous rocks may be due to release of Fe during smectite illitization has been tested by study of spatial and temporal relationships of CRM acquisition, smectite illitization, and organic-matter maturation to deformation in the Montana Disturbed Belt. New K-Ar ages and stacking order and percentages of illite layers in illite-smectite (I-S) are consistent with conclusions from previous studies that smectite illitization of bentonites in Subbelts I and II of the Disturbed Belt was produced by thrust-sheet burial resulting from the Laramide Orogeny. Internally concordant, early Paleogene, K-Ar age values (55–57 Ma) were obtained from clay subfractions of thick bentonites which were significantly different in terms of their ages (i.e. Jurassic Ellis Formation and late Cretaceous Marias River Shale), further supporting a model of smectite illitization as a result of the Laramide Orogeny. Internally concordant K-Ar ages were found also for clay sub-fractions from a thick bentonite at Pishkun Canal (54 Ma) and from an undeformed bentonite near Vaughn on the Sweetgrass Arch (48 Ma). In Subbelts I and II, a greater degree of smectite illitization corresponds to increased thermal maturation, increased natural remanent magnetization intensity, and increased deformation (dip of beds). A dissolution-precipitation model over a short duration is proposed for the formation of illite layers in Subbelts I and II. A characteristic remanent magnetization was developed before or just after folding began in the early Paleogene. More smectite-rich I-S, low thermal maturity, and the absence of a CRM were noted in one outcrop of an undeformed rock on the Sweetgrass Arch. Strontium isotope data allow for the possibility that internal or externally derived fluids may have influenced illitization, but the K-Ar age values suggest that illitization was probably in response to conductive heating after the overthrusting had occurred. The differences in K-Ar dates among the bentonites studied herein may be due to differences in the timing of peak temperature related to differences in distance below the overthrust slab, in rates of burial and exhumation, and in initial temperature.

Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 native bird species (18% of the non-vagrant bird fauna and 25% of those species within the fox’s range), a smaller tally than for cats (343 species, including 297 within the fox’s Australian range, a subset of that of the cat). Most (81%) bird species eaten by foxes are also eaten by cats, suggesting that predation impacts are compounded. As with consumption by cats, birds that nest or forage on the ground are most likely to be consumed by foxes. However, there is also some partitioning, with records of consumption by foxes but not cats for 25 bird species, indicating that impacts of the two predators may also be complementary. Bird species ≥3.4 kg were more likely to be eaten by foxes, and those <3.4 kg by cats. Our compilation provides an inventory and describes characteristics of Australian bird species known to be consumed by foxes, but we acknowledge that records of predation do not imply population-level impacts. Nonetheless, there is sufficient information from other studies to demonstrate that fox predation has significant impacts on the population viability of some Australian birds, especially larger birds, and those that nest or forage on the ground.

We present the data and initial results from the first pilot survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The survey covers $270 \,\mathrm{deg}^2$ of an area covered by the Dark Energy Survey, reaching a depth of 25–30 $\mu\mathrm{Jy\ beam}^{-1}$ rms at a spatial resolution of $\sim$ 11–18 arcsec, resulting in a catalogue of $\sim$ 220 000 sources, of which $\sim$ 180 000 are single-component sources. Here we present the catalogue of single-component sources, together with (where available) optical and infrared cross-identifications, classifications, and redshifts. This survey explores a new region of parameter space compared to previous surveys. Specifically, the EMU Pilot Survey has a high density of sources, and also a high sensitivity to low surface brightness emission. These properties result in the detection of types of sources that were rarely seen in or absent from previous surveys. We present some of these new results here.

The objective of this study was to describe the epidemiology of COVID-19 in Nigeria with a view of generating evidence to enhance planning and response strategies. A national surveillance dataset between 27 February and 6 June 2020 was retrospectively analysed, with confirmatory testing for COVID-19 done by real-time polymerase chain reaction (RT-PCR). The primary outcomes were cumulative incidence (CI) and case fatality (CF). A total of 40 926 persons (67% of total 60 839) had complete records of RT-PCR test across 35 states and the Federal Capital Territory, 12 289 (30.0%) of whom were confirmed COVID-19 cases. Of those confirmed cases, 3467 (28.2%) had complete records of clinical outcome (alive or dead), 342 (9.9%) of which died. The overall CI and CF were 5.6 per 100 000 population and 2.8%, respectively. The highest proportion of COVID-19 cases and deaths were recorded in persons aged 31–40 years (25.5%) and 61–70 years (26.6%), respectively; and males accounted for a higher proportion of confirmed cases (65.8%) and deaths (79.0%). Sixty-six per cent of confirmed COVID-19 cases were asymptomatic at diagnosis. In conclusion, this paper has provided an insight into the early epidemiology of COVID-19 in Nigeria, which could be useful for contextualising public health planning.

Lead halide perovskite nanocrystals (NCs) are promising for applications in light emitting devices owing to a strong emission spectrum that is tunable throughout the visible region by altering halide composition. However, in mixed-halide perovskite systems photoinduced migration drives formation of halide-segregated domains, altering the emission spectrum. The mechanism by which this segregation occurs is currently the subject of intense investigation. Processes involving the perovskite surface are expected to be of enhanced prevalence in NCs due to their large surface area to volume ratio. In this work, we use transient absorption spectroscopy to probe the excited-state dynamics of NCs before and after halide segregation. Comparison of global fit spectra of the measured signals suggests the accumulation of iodide at the surface, resulting in a redshifted emission spectrum.

Investigations of the stratigraphy and facies within a 2.69 m long gravity core (PS1423–2) from the southwestern Weddell Sea, Antarctica, indicate a significant change in the character of glaciomarine sedimentation since grounded ice withdrew from the continental shelf. Based on visual description, X-radiography, clast shape, particle-size analysis, physical properties and geochemical data, the core used in this analysis comprises five distinct units, from top to bottom: (i) massive diamicton, (ii) weakly to well-stratified diamicton, (iii) millimetre-scale laminated muds, with little or on coarse-clastic input, (iv) well- to weakly stratified diamicton, (v) massive diamicton. This succession is attributed to the variation in sedimentation associated with the recession of the grounding line of a previously advanced glacier. Grounded ice decoupled from the continental shelf to form an ice shelf, probably initiated by a rise in sea level in response to global climatic changes. Following disintegration of the ice shelf, sedimentation was influenced by marked variations in iceberg production. AMS-derived 14C ages from the upper 46 cm of the core indicate that the succession has been deposited since the end of the most recent glacial maximum (late Pleistocene), a conclusion supported by published data.

Mapping of the structural glaciology of Kongsvegen, Svalbard, reveals evidence for four main deformational structures. These are stratification, longitudinal foliation, thrusts and crevasse traces. These structures are considered in terms of their contribution to debris entrainment, transport and subsequent landform development. Stratification is associated with small amounts of supraglacial debris that has been folded with flow-parallel axes; longitudinal foliation in places incorporates basal glacial sediments along folds with flow-parallel axes; and thrusts transport basal debris to the glacier surface. Crevasse traces are not significant in terms of debris entrainment. The entrainment of basal debris along longitudinal foliation is not a universally recognised process. At Kongsvegen this process is attributed to the development of a transposition foliation, in combination with incorporation of debris-rich basal ice or soft basal sediment in the fold complex. Mapping of the landforms in the proglacial area shows that debris incorporated along longitudinal foliation is released as “foliation-parallel ridges” and that transverse ridges mark debris-bearing thrusts. The role of longitudinal foliation in landform development has never been documented in this manner. Although the preservation potential of such ridges may be limited, recognition of foliation-parallel ridges in the Pleistocene landform record has important implications for the interpretation of the dynamics of former ire masses.

The Department of Materials and Metallurgical Engineering faculty at the South Dakota School of Mines and Technology (SDSM&T) has developed a unique undergraduate program that integrates research, extracurricular activities, and outreach experiences. A common thread throughout the program is an introduction to the artistic and historical background of metallurgical engineering. These activities use kinesthetic learning to promote student learning of metallurgical engineering, aspects often not traditionally included in engineering curricula. These programs are similar to those envisioned by the National Academy of Engineering in response to the changing needs of engineering. These are described in two visionary books published by the National Research Council.

A major focus of the program integrates blacksmithing activities with curricular, extracurricular, and outreach activities. All SDSM&T students are invited to a weekly blacksmithing activity called Hammer-in. Blacksmithing-related laboratories were added to the curriculum. Additionally, students developed a portable blacksmithing laboratory with faculty supervision. The laboratory has been taken to K-12 schools, including Native American schools on reservations, to reach out to regional students, thereby promoting interest in STEM careers. The success of these activities led to their incorporation into a National Science Foundation Research Experience for Undergraduate (REU) at SDSM&T called Back to the Future that focuses on understanding new technologies through historical antecedents. The SDSM&T students who participated in this REU used this experience as part of their junior/senior design courses. This program has increased enrollment in the department and has led to better learning outcomes for the students.

Our genome adapts slowly to changing conditions of existence. Many diseases of civilisation result from mismatches between our Paleolithic genome and the rapidly changing environment, including our diet. The objective of the present study was to reconstruct multiple Paleolithic diets to estimate the ranges of nutrient intakes upon which humanity evolved. A database of, predominantly East African, plant and animal foods (meat/fish) was used to model multiple Paleolithic diets, using two pathophysiological constraints (i.e. protein < 35 energy % (en%) and linoleic acid (LA) >1·0 en%), at known hunter–gatherer plant/animal food intake ratios (range 70/30–30/70 en%/en%). We investigated selective and non-selective savannah, savannah/aquatic and aquatic hunter–gatherer/scavenger foraging strategies. We found (range of medians in en%) intakes of moderate-to-high protein (25–29), moderate-to-high fat (30–39) and moderate carbohydrates (39–40). The fatty acid composition was SFA (11·4–12·0), MUFA (5·6–18·5) and PUFA (8·6–15·2). The latter was high in α-linolenic acid (ALA) (3·7–4·7 en%), low in LA (2·3–3·6 en%), and high in long-chain PUFA (LCP; 4·75–25·8 g/d), LCP n-3 (2·26–17·0 g/d), LCP n-6 (2·54–8·84 g/d), ALA/LA ratio (1·12–1·64 g/g) and LCP n-3/LCP n-6 ratio (0·84–1·92 g/g). Consistent with the wide range of employed variables, nutrient intakes showed wide ranges. We conclude that compared with Western diets, Paleolithic diets contained consistently higher protein and LCP, and lower LA. These are likely to contribute to the known beneficial effects of Paleolithic-like diets, e.g. through increased satiety/satiation. Disparities between Paleolithic, contemporary and recommended intakes might be important factors underlying the aetiology of common Western diseases. Data on Paleolithic diets and lifestyle, rather than the investigation of single nutrients, might be useful for the rational design of clinical trials.

Average heterozygosities for four communities (Savoonga and Gambell on St Lawrence Island, the King Island community now located in Nome, and Wales) are computed from blood allele frequencies. No significant relationship is found between this measure of heterozygosity and the amount of European admixture calculated from gamma globulin haplotype frequencies, indicating that forces other than European gene flow are affecting relative heterozygosity. However, within the two villages on St Lawrence Island, admixed individuals as a group have significantly higher average heterozygosity than non-admixed individuals. These results suggest that European gene flow significantly increases population heterozygosity when examined from a micro-populational or individual level, but may be obscured by other factors when several different populations are compared. This is probably because inter-village variation in admixture proportions, which range from zero to 8%, is small.