Carbon nanomaterials in clean and contaminated soils: environmental implications and applications

The exceptional sorptive ability of carbon nanomaterials (CNMs) for hydrophobic organic contaminants (HOCs) is driven by their characteristically large reactive surface areas and highly hydrophobic nature. Given these properties, it is possible for CNMs to impact on the persistence, mobility and bioavailability of contaminants within soils, either favourably through sorption and sequestration, hence reducing their bioavailability, or unfavourably through increasing contaminant dispersal. This review considers the complex and dynamic nature of both soil and CNM physicochemical properties to determine their fate and behaviour, together with their interaction with contaminants and the soil microflora. It is argued that assessment of CNMs within soil should be conducted on a case-by-case basis and further work to assess the long-term stability and toxicity of sorbed contaminants, as well as the toxicity of CNMs themselves, is required before their sorptive abilities can be applied to remedy environmental issues

SurF: an innovative framework in biosecurity and animal health surveillance evaluation

Surveillance for biosecurity hazards is being conducted by the New Zealand Competent Authority, the Ministry for Primary Industries (MPI) to support New Zealand's biosecurity system. Surveillance evaluation should be an integral part of the surveillance life cycle, as it provides a means to identify and correct problems and to sustain and enhance the existing strengths of a surveillance system. The surveillance evaluation Framework (SurF) presented here was developed to provide a generic framework within which the MPI biosecurity surveillance portfolio, and all of its components, can be consistently assessed. SurF is an innovative, cross‐sectoral effort that aims to provide a common umbrella for surveillance evaluation in the animal, plant, environment and aquatic sectors. It supports the conduct of the following four distinct components of an evaluation project: (i) motivation for the evaluation, (ii) scope of the evaluation, (iii) evaluation design and implementation and (iv) reporting and communication of evaluation outputs. Case studies, prepared by MPI subject matter experts, are included in the framework to guide users in their assessment. Three case studies were used in the development of SurF in order to assure practical utility and to confirm usability of SurF across all included sectors. It is anticipated that the structured approach and information provided by SurF will not only be of benefit to MPI but also to other New Zealand stakeholders. Although SurF was developed for internal use by MPI, it could be applied to any surveillance system in New Zealand or elsewhere

Learning from Lockdown: Listening to students' voices about the challenges and benefits in the post-COVID-19 digital practices

The sudden move to remote teaching and learning in Spring 2020 brought together staff and students in order to learn from each other how to best address the challenges of the new ways of teaching and learning. In this synchronous presentation the seven authors will take turns: *to introduce the two institutionally-supported studies conducted last year, one surveying the UCL undergraduates, and the other one surveying the postgraduate taught students in the CPA department of UCL IoE; *to share the framework that guided the analysis of students’ views of their experiences and priorities surrounding online learning, gathered via online surveys and focussed group discussions; *to propose alternative conceptions for what could be a meaningful and rich online educative experience; *to discuss our findings and their implications for theory, research, policy and practice in a post-pandemic context; and last and most important, *to describe how staff and students collaborated on carrying out these projects, and later worked together to write an academic paper about to the two projects

Engagement discourses, relationality and the student voice: connectedness, questioning and inclusion in post-Covid digital practices

The Covid-19 crisis has led to a rapid pivot to online teaching and student engagement across higher education internationally, due to public health ‘lockdown’ measures. In March 2020 in the UK this move was sudden, and universities were forced to move their provision to digital formats with little preparatory time, and in many cases, inadequate training and experience. In the subsequent period, higher education institutions have prioritised the enhancement of digital education, with a range of strategic initiatives and training programmes for teaching staff. This paper, written by a staff-student partnership of authors, reports on two institutionally-supported studies conducted at a large, research-focused university in England, in which student views were sought on their experiences and priorities surrounding online engagement during the Covid-19 crisis. In our discussion of the findings, we argue that the student accounts challenge some of the mainstream assumptions about constructs such as student ‘inclusivity’, academic ‘community’ online, and teaching which encourages ‘questioning’, requiring us to think more deeply about what constitutes a meaningful and rich online educative experience. In the spirit of ‘lessons learned’ from the Covid-19 pandemic, the paper proposes alternative conceptions of these values, emphasising relationality, communities, difference, and the importance of an ethos of care. We conclude with a discussion of findings, implications for theory, research, policy and practice in a post-pandemic context, proposing that an ethos of care be recognised as central to the development of digital education and the practices and ethics of student engagement

Earliest Triassic microbialites in the South China Block and other areas; controls on their growth and distribution

Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (ca. 251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China block suggest geographic provinces, and ETMs are most abundant throughout the equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow-marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are interpreted as disaster taxa. In general, ETM occurrence suggests that microbially mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm aerated surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea, the earliest microbialites are late Early Triassic, but it is possible that ETMs could exist in western Pangea, if well-preserved earliest Triassic facies are discovered in future work

Exploring the Physical, Chemical and Biological Components of Soil: Improving Soil Health for Better Productive Capacity

“Soil health” is a term that is used to describe soil quality. The U.S. Department of Agriculture’s Natural Resources Conservation Service has defined soil health as “The continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans (NRCS 2018).” For a farmer, soil health is the productive capacity of the soil, or the capacity of the soil to produce a crop or pasture. Healthy soils produce more and with better quality. Soil health is critical for water and nutrient cycling. Soil captures rainwater and stores it for use by plants. Soil health is important to improve both the amount of water and nutrients that a soil can hold, and the availability of water and nutrients for plants. The storage of water and nutrients and subsequent transfer to plants are critical determinants of the productive capacity of the soil, and the soil health. Here, we explore the fundamental components of soil, and how each component contributes to soil health and soil productive capacity

Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array

We apply two methods to estimate the 21~cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly-spaced triangles of antenna tiles, as well as an estimate based on data gridded to the $uv$-plane. The direct and gridded bispectrum estimators are applied to 21 hours of high-band (167--197~MHz; $z$=6.2--7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 hours, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21~cm bispectrum may be accessible in less time than the 21~cm power spectrum for some wave modes, with detections in hundreds of hours.Comment: 19 pages, 10 figures, accepted for publication in PAS

Ecological succession of a Jurassic shallow-water ichthyosaur fall.

After the discovery of whale fall communities in modern oceans, it has been hypothesized that during the Mesozoic the carcasses of marine reptiles created similar habitats supporting long-lived and specialized animal communities. Here, we report a fully documented ichthyosaur fall community, from a Late Jurassic shelf setting, and reconstruct the ecological succession of its micro- and macrofauna. The early 'mobile-scavenger' and 'enrichment-opportunist' stages were not succeeded by a 'sulphophilic stage' characterized by chemosynthetic molluscs, but instead the bones were colonized by microbial mats that attracted echinoids and other mat-grazing invertebrates. Abundant cemented suspension feeders indicate a well-developed 'reef stage' with prolonged exposure and colonization of the bones prior to final burial, unlike in modern whale falls where organisms such as the ubiquitous bone-eating worm Osedax rapidly destroy the skeleton. Shallow-water ichthyosaur falls thus fulfilled similar ecological roles to shallow whale falls, and did not support specialized chemosynthetic communities