The name volkonskoite was first used in 1830 to describe a bright blue-green, chromiumbearing clay material from the Okhansk region, west of the Ural Mountains, U.S.S.R. Since that time, the name has been applied to numerous members of the smectite group of clay minerals, although the reported chromium content has ranged from 1% to about 30% Cr2O3. The name has also been applied to some chromian chlorites. Because volkonskoite has been used for materials that differ not only in their chromium content but also in their basic structure, the species status of the mineral has been unclear.

To resolve this uncertainty, two specimens of volkonskoite from (1) Mount Efimiatsk, the type locality in the Soviet Union (USNM 16308) and (2) the Okhansk region in the Perm Basin, U.S.S.R. (USNM R4820), were examined by several mineralogical techniques. Neotype sample 16308 has the following structural formula:

$({\text{Ca}}_{0.11}{\text{Mg}}_{0.11}{\text{Fe}}^{2+}{\hspace{0.17em}}_{0.03}{\text{K}}_{0.02})({\text{Cr}}_{1.18}{\text{Mg}}_{0.78}{\text{Fe}}^{3+}{\hspace{0.17em}}_{0.29}\text{Ca}{}_{0.02})({\text{Si}}_{3.50}{\text{Al}}_{0.51}){\text{O}}_{10}{(\text{OH})}_2\cdot 3.64{\text{H}}_2\text{O}.$

Sample R4820 has the following structural formula:

$({\text{Ca}}_{0.25}{\text{Mg}}_{0.05}{\text{Fe}}^{2+}{\hspace{0.17em}}_{0.01}{\text{K}}_{0.03}{\text{Mn}}_{0.01})({\text{Cr}}_{1.07}{\text{Mg}}_{0.75}{\text{Fe}}^{3+}{\hspace{0.17em}}_{0.35}({\text{Si}}_{3.59}{\text{Al}}_{0.43}){\text{O}}_{10}{(\text{OH})}_2\cdot 4.22{\text{H}}_2\text{O}.$

Mössbauer spectroscopy indicates that 91% and 98% of the iron is present as Fe3+ in samples 16308 and R4820, respectively. X-ray powder diffraction patterns of both samples have broad lines corresponding to minerals of the smectite group.

On the basis of these data, volkonskoite appears to be a dioctahedral member of the smectite group that contains chromium as the dominant cation in the octahedral layer. Smectites containing less than this amount of octahedral chromium should not be called volkonskoite, but should be named by chemical element adjectives, e.g., chromian montmorillonite, chromian nontronite.

Stable water isotope records of six firn cores retrieved from two adjacent plateaus on the northern Antarctic Peninsula between 2014 and 2016 are presented and investigated for their connections with firn-core glacio-chemical data, meteorological records and modelling results. Average annual accumulation rates of 2500 kg m−2 a−1 largely reduce the modification of isotopic signals in the snowpack by post-depositional processes, allowing excellent signal preservation in space and time. Comparison of firn-core and ECHAM6-wiso modelled δ18O and d-excess records reveals a large agreement on annual and sub-annual scales, suggesting firn-core stable water isotopes to be representative of specific synoptic situations. The six firn cores exhibit highly similar isotopic patterns in the overlapping period (2013), which seem to be related to temporal changes in moisture sources rather than local near-surface air temperatures. Backward trajectories calculated with the HYSPLIT model suggest that prominent δ18O minima in 2013 associated with elevated sea salt concentrations are related to long-range moisture transport dominated by westerly winds during positive SAM phases. In contrast, a broad δ18O maximum in the same year accompanied by increased concentrations of black carbon and mineral dust corresponds to the advection of more locally derived moisture with northerly flow components (South America) when the SAM is negative.

From the safety inside vehicles, Knowsley Safari offers visitors a close-up encounter with captive olive baboons. As exiting vehicles may be contaminated with baboon stool, a comprehensive coprological inspection was conducted to address public health concerns. Baboon stools were obtained from vehicles, and sleeping areas, inclusive of video analysis of baboon–vehicle interactions. A purposely selected 4-day sampling period enabled comparative inspections of 2662 vehicles, with a total of 669 baboon stools examined (371 from vehicles and 298 from sleeping areas). As informed by our pilot study, front-line diagnostic methods were: QUIK-CHEK rapid diagnostic test (RDT) (Giardia and Cryptosporidium), Kato–Katz coproscopy (Trichuris) and charcoal culture (Strongyloides). Some 13.9% of vehicles were contaminated with baboon stool. Prevalence of giardiasis was 37.4% while cryptosporidiosis was <0.01%, however, an absence of faecal cysts by quality control coproscopy, alongside lower than the expected levels of Giardia-specific DNA, judged RDT results as misleading, grossly overestimating prevalence. Prevalence of trichuriasis was 48.0% and strongyloidiasis was 13.7%, a first report of Strongyloides fuelleborni in UK. We advise regular blanket administration(s) of anthelminthics to the colony, exploring pour-on formulations, thereafter, smaller-scale indicator surveys would be adequate.

Research links life stressors, including acute, chronic, and early life stress, to the development of ruminative brooding. However, singular forms of life stress rarely occur in isolation, as adolescents typically encounter stressors that vary on important dimensions (e.g., types, timings, quantities) across development. The current study employs latent profile analysis (LPA) to identify natural clusters of life stress that, over time, may be differently associated with ruminative brooding. Evaluations of episodic, chronic, and early life stress were conducted with community-recruited mid-adolescents (N = 241, Mage = 15.90 years, 53% female) and their parents using the UCLA Life Stress Interview and lifetime adversity portions of the Youth Life Stress Interview. Analyses identified four distinct patterns: low stress, high peer stress, moderate home / family stress, and multifaceted / high school stress. Adolescents in the high peer stress and moderate home / family stress profiles were at highest risk for developing a brooding style over time. Despite high overall levels of stress, teens in the multifaceted / high school stress profile were at not at elevated risk for developing a brooding style. Findings demonstrate the utility of person-centered approaches to identify patterns of stress exposure that heighten risk for brooding over time.

Methods for culling wild red deer (Cervus elaphus) were compared by observing behaviour and collecting post mortem samples from wild deer shot: (i) by a single stalker during daytime; (ii) by more than one stalker during daytime; (iii) by using a helicopter for the deployment of stalkers and carcase extraction; or (iv) by a single stalker at night, and compared with farmed red deer shot in a field or killed at a slaughterhouse. Culling by a single stalker during the day and shooting in a field were the most accurate in achieving placement of a shot in a target area, but when compared across all methods, there were no significant differences in the percentages of deer that were either wounded or appeared to have died immediately after the first shot. Plasma cortisol concentrations in deer shot using helicopter assistance were similar to those in deer at the slaughterhouse, but higher than deer shot at night or during the day by a single stalker, or in a field. Deer shot using helicopter assistance and also deer culled by a collaborative and single stalking during the day had lower muscle glycogen concentrations than those culled by a single stalker at night. There was no evidence that a particular culling method was associated with an increased risk of accidental or pre-culling injury. If a helicopter is used to assist culling, the deer are more likely to be disturbed before they are shot and therefore, measures should be taken to minimise the disturbance to the deer.

Background: In Canada, it’s unknown if the prevalence of stroke survivorship differs in the population with active cancer compared to those without cancer. Methods: We analyzed the 2015-2016 iteration of the Canadian Community Health Survey. The prevalence of stroke survivorship was compared across risk factors using descriptive statistics. A multivariable logistic regression model was used to assess the association between cancer and prevalence of stroke survivorship. Covariates were assessed for effect modification and confounding using the maximum likelihood estimation method. Results: We analyzed 89,285 subjects. The prevalence of cancer and the prevalence of suffering from the effects of a stroke were 2.09% and 1.56%, respectively. Cancer was significantly associated with an increased prevalence of stroke survivorship with an odds ratio (OR) of 1.56 (95%CI: 1.24 – 1.98) after adjusting for age, sex, smoking status, education, household income, dyslipidemia, hypertension, diabetes. The association was stronger in younger age groups: the youngest age group (18 – 49 years) had the highest OR (6.49, 95%CI:2.01 – 20.94) for suffering from the effects of a stroke in association with the presence of cancer. Conclusions: In Canada, the presence of active cancer increases the odds of suffering from the effects of a stroke, particularly in the youngest age group.

A chloroacetamide herbicide by application timing factorial experiment was conducted in 2017 and 2018 in Mississippi to investigate chloroacetamide use in a dicamba-based Palmer amaranth management program in cotton production. Herbicides used were S-metolachlor or acetochlor, and application timings were preemergence, preemergence followed by (fb) early postemergence, preemergence fb late postemergence, early postemergence alone, late postemergence alone, and early postemergence fb late postemergence. Dicamba was included in all preemergence applications, and dicamba plus glyphosate was included with all postemergence applications. Differences in cotton and weed response due to chloroacetamide type were minimal, and cotton injury at 14 d after late postemergence application was less than 10% for all application timings. Late-season weed control was reduced up to 30% and 53% if chloroacetamide application occurred preemergence or late postemergence only, respectively. Late-season weed densities were minimized if multiple applications were used instead of a single application. Cotton height was reduced by up to 23% if a single application was made late postemergence relative to other application timings. Chloroacetamide application at any timing except preemergence alone minimized late-season weed biomass. Yield was maximized by any treatment involving multiple applications or early postemergence alone, whereas applications preemergence or late postemergence alone resulted in up to 56% and 27% yield losses, respectively. While no yield loss was reported by delaying the first of sequential applications until early postemergence, forgoing a preemergence application is not advisable given the multiple factors that may delay timely postemergence applications such as inclement weather.

Genetic variation in parasites has important consequences for host–parasite interactions. Prior studies of the ecologically important parasite Metschnikowia bicuspidata have suggested low genetic variation in the species. Here, we collected M. bicuspidata from two host species (Daphnia dentifera and Ceriodaphnia dubia) and two regions (Michigan and Indiana, USA). Within a lake, outbreaks tended to occur in one host species but not the other. Using microsatellite markers, we identified six parasite genotypes grouped within three distinct clades, one of which was rare. Of the two main clades, one was generally associated with D. dentifera, with lakes in both regions containing a single genotype. The other M. bicuspidata clade was mainly associated with C. dubia, with a different genotype dominating in each region. Despite these associations, both D. dentifera- and C. dubia-associated genotypes were found infecting both hosts in lakes. However, in lab experiments, the D. dentifera-associated genotype infected both D. dentifera and C. dubia, but the C. dubia-associated genotype, which had spores that were approximately 30% smaller, did not infect D. dentifera. We hypothesize that variation in spore size might help explain patterns of cross-species transmission. Future studies exploring the causes and consequences of variation in spore size may help explain patterns of infection and the maintenance of genotypic diversity in this ecologically important system.

In this paper, we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers $31\,\textrm{deg}^{2}$ at $800\,\textrm{MHz}$. As a two-dimensional array of 36$\times$12 m antennas, with baselines ranging from 22 m to 6 km, ASKAP also has excellent snapshot imaging capability and 10 arcsec resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 and $1800\,\textrm{MHz}$ and is expected to facilitate great advances in our understanding of galaxy formation, cosmology, and radio transients while opening new parameter space for discovery of the unknown.