Coastal erosion reveals a potentially unique Oligocene and possible periglacial sequence at present-day sea level in Port Davey, remote South-West Tasmania

Cut-back of a sea-cliff at Hannant Inlet in remote South-West Tasmania has exposed Oligocene clays buried under Late Pleistocene “colluvium” from which abundant wood fragments protrude. The two units are separated by a transitional interval defined by mixed Oligocene and Pleistocene microfloras. Microfloras preserved in situ in the clay provide a link between floras in Tasmania and other Southern Hemisphere landmasses following onset of major glaciation in East Antarctica during the Eocene-Oligocene transition (c. 34 Ma). The Late Pleistocene “colluvium” preserves abundant fossil pollen of the shrub conifer genus Pherosphaera (al. Microstrobos). Assuming the parent plants had the same upper subalpine-alpine ecology as living Pherosphaera hookeriana, the microflora provides evidence for cold, wet conditions in the Port Davey lowlands during a low sea-level stand. The same data highlight the failure of Pherosphaera to regain its Pleistocene distribution during the Postglacial period. Our data are inconclusive whether Late Pleistocene conditions in Hannant Inlet were periglacial, i.e., the Oligocene sediments were turbated by freeze-thaw processes, or have been reworked by fluvial processes into the Pleistocene “colluvium”. Nevertheless, the inferred cold-climate is consistent with the former hypothesis. The sequence is sealed under cross-bedded coarse quartzite gravels of presumed Last Glacial Stage age

Did anoxia terminate Ediacaran benthic communities? Evidence from early diagenesis

The Ediacaran oceanic redox landscape was heterogeneous, where many basins had a shallow and highly dynamic chemocline above anoxic (ferruginous or euxinic) or low oxygen (manganous) waters. Seawater mMg/Ca ratio was also high, promoting early diagenetic dolomitisation. How the benthos responded to these conditions is fundamental to understanding their ecological dynamics. Here we utilise redox sensitive elements in early marine carbonate cements to investigate possible water column redox controls on the distribution and growth of the oldest metazoan communities. Skeletal communities in the Zaris Sub-Basin of the Nama Group, Namibia (∼550–547 Ma), grew in shallow waters where fine-grained carbonate sediment often shows evidence of early dolomitisation. Mid-ramp Cloudina reefs are composed of open, highly porous structures that formed multiple, successive assemblages. Each assemblage is terminated by thin (<1 mm), layers of dolomicrite sediment and dolomite cement. All dolomitic lithologies in the Nama Group analysed via Fe speciation suggest precipitation under anoxic ferruginous water column conditions. Reef cements show a paragenetic sequence from synsedimentary to early marine cement and final burial, which we infer were precipitated under dynamic redox conditions. First, acicular pseudomorphed aragonite cement formed under oxic conditions (low Fe and Mn). Next, the presence of iron-rich dolomicrite sediment, often associated with a recrystallised ferroan dolomite crust, suggests that originally aragonitic or calcitic sediment and a high-Mg precursor cement were preferentially dolomitised. Dolomitisation may have been enhanced either via upwelling of deeper water, anoxic, ferruginous seawater, or by later fluid remobilisation from adjacent shales. A following Mn-rich calcite cement is inferred to be early marine due to its inclusion-rich, fibrous form and well-preserved CL zonation. The final blocky cement precipitated under oxic conditions, probably during shallow burial. The cements likely record a general shallow to deeper water transect, from oxic shallow waters to low oxygen manganous waters, then to oxic, shallow burial conditions. We hypothesize that Cloudina reef communities were terminated by episodic sediment incursions during short-term, transgressive cycles, possibly accompanied by upwelled, anoxic, ferruginous and dolomitising waters, although the timing for this is poorly constrained. More generally, such incursions may have terminated Ediacaran benthic communities that grew close to the chemocline

Menstrual cycle phase does not predict political conservatism

Recent authors have reported a relationship between women's fertility status, as indexed by menstrual cycle phase, and conservatism in moral, social and political values. We conducted a survey to test for the existence of a relationship between menstrual cycle day and conservatism. 2213 women reporting regular menstrual cycles provided data about their political views. Of these women, 2208 provided information about their cycle date, 1260 provided additional evidence of reliability in self-reported cycle date, and of these, 750 also indicated an absence of hormonal disruptors such as recent hormonal contraception use, breastfeeding or pregnancy. Cycle day was used to estimate day-specific fertility rate (probability of conception); political conservatism was measured via direct self-report and via responses to the "Moral Foundations” questionnaire. We also recorded relationship status, which has been reported to interact with menstrual cycle phase in determining political preferences. We found no evidence of a relationship between estimated cyclical fertility changes and conservatism, and no evidence of an interaction between relationship status and cyclical fertility in determining political attitudes. Our findings were robust to multiple inclusion/exclusion criteria and to different methods of estimating fertility and measuring conservatism. In summary, the relationship between cycle-linked reproductive parameters and conservatism may be weaker or less reliable than previously thought

The LSST DESC data challenge 1: Generation and analysis of synthetic images for next-generation surveys

Data Challenge 1 (DC1) is the first synthetic data set produced by the Rubin Observatory Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration (DESC). DC1 is designed to develop and validate data reduction and analysis and to study the impact of systematic effects that will affect the LSST data set. DC1 is comprised of r-band observations of 40 deg2 to 10 yr LSST depth. We present each stage of the simulation and analysis process: (a) generation, by synthesizing sources from cosmological N-body simulations in individual sensor-visit images with different observing conditions; (b) reduction using a development version of the LSST Science Pipelines; and (c) matching to the input cosmological catalogue for validation and testing. We verify that testable LSST requirements pass within the fidelity of DC1. We establish a selection procedure that produces a sufficiently clean extragalactic sample for clustering analyses and we discuss residual sample contamination, including contributions from inefficiency in star-galaxy separation and imperfect deblending. We compute the galaxy power spectrum on the simulated field and conclude that: (i) survey properties have an impact of 50 per cent of the statistical uncertainty for the scales and models used in DC1; (ii) a selection to eliminate artefacts in the catalogues is necessary to avoid biases in the measured clustering; and (iii) the presence of bright objects has a significant impact (2-6) in the estimated power spectra at small scales (&gt; 1200), highlighting the impact of blending in studies at small angular scales in LSST

Oxygenation of the Mesoproterozoic ocean and the evolution of complex eukaryotes

The Mesoproterozoic era (1,600–1,000 million years ago (Ma)) has long been considered a period of relative environmental stasis, with persistently low levels of atmospheric oxygen. There remains much uncertainty, however, over the evolution of ocean chemistry during this period, which may have been of profound significance for the early evolution of eukaryotic life. Here we present rare earth element, iron-speciation and inorganic carbon isotope data to investigate the redox evolution of the 1,600–1,550 Ma Yanliao Basin, North China Craton. These data confirm that the ocean at the start of the Mesoproterozoic was dominantly anoxic and ferruginous. Significantly, however, we find evidence for a progressive oxygenation event starting at ~1,570 Ma, immediately prior to the occurrence of complex multicellular eukaryotes in shelf areas of the Yanliao Basin. Our study thus demonstrates that oxygenation of the Mesoproterozoic environment was far more dynamic and intense than previously envisaged, and establishes an important link between rising oxygen and the emerging record of diverse, multicellular eukaryotic life in the early Mesoproterozoic

The Importance of Craniofacial Sutures in Biomechanical Finite Element Models of the Domestic Pig

Craniofacial sutures are a ubiquitous feature of the vertebrate skull. Previous experimental work has shown that bone strain magnitudes and orientations often vary when moving from one bone to another, across a craniofacial suture. This has led to the hypothesis that craniofacial sutures act to modify the strain environment of the skull, possibly as a mode of dissipating high stresses generated during feeding or impact. This study tests the hypothesis that the introduction of craniofacial sutures into finite element (FE) models of a modern domestic pig skull would improve model accuracy compared to a model without sutures. This allowed the mechanical effects of sutures to be assessed in isolation from other confounding variables. These models were also validated against strain gauge data collected from the same specimen ex vivo. The experimental strain data showed notable strain differences between adjacent bones, but this effect was generally not observed in either model. It was found that the inclusion of sutures in finite element models affected strain magnitudes, ratios, orientations and contour patterns, yet contrary to expectations, this did not improve the fit of the model to the experimental data, but resulted in a model that was less accurate. It is demonstrated that the presence or absence of sutures alone is not responsible for the inaccuracies in model strain, and is suggested that variations in local bone material properties, which were not accounted for by the FE models, could instead be responsible for the pattern of results

How victim age affects the context and timing of child sexual abuse: applying the routine activities approach to the first sexual abuse incident

The aim of this study was to examine from the routine activities approach how victim age might help to explain the timing, context and nature of offenders’ first known contact sexual abuse incident. One-hundred adult male child sexual abusers (M = 45.8 years, SD = 12.2; range = 20–84) were surveyed about the first time they had sexual contact with a child. Afternoon and early evening (between 3 pm and 9 pm) was the most common time in which sexual contact first occurred. Most incidents occurred in a home. Two-thirds of incidents occurred when another person was in close proximity, usually elsewhere in the home. Older victims were more likely to be sexually abused by someone outside their families and in the later hours of the day compared to younger victims. Proximity of another person (adult and/or child) appeared to have little effect on offenders’ decisions to abuse, although it had some impact on the level of intrusion and duration of these incidents. Overall, the findings lend support to the application of the routine activities approach for considering how contextual risk factors (i.e., the timing and relationship context) change as children age, and raise questions about how to best conceptualize guardianship in the context of child sexual abuse. These factors should be key considerations when devising and implementing sexual abuse prevention strategies and for informing theory development