Human-induced earthquakes: E-PIE—a generic tool for Evaluating Proposals of Induced Earthquakes

The HiQuake database documents all cases of earthquake sequences proposed on scientific grounds to have been induced by anthropogenic industrial activity. Because these cases range from being highly plausible to unpersuasive, stakeholders have requested cases to be allocated plausibility grades. Since no questionnaire scheme existed that was sufficiently generalized to be applied to the diverse cases in HiQuake, we developed a new scheme for the task. Our scheme for Evaluating Proposals of Induced Earthquakes (E-PIE) comprises nine generalized questions with a simple weighting system to adjust for the variable diagnostic strength of different observations. Results are illustrated using a simple colored pie chart. We describe the E-PIE scheme and illustrate its application in detail using the example cases of the Groningen gas field in the Netherlands, the November 2017 M5.4 Pohang Enhanced Geothermal Systems-related earthquake sequence in South Korea, and the 2001 deep-penetrating bombing of Tora Bora, Afghanistan. To test the performance of E-PIE, five analysts independently applied it to a suite of 23 diverse cases from HiQuake. By far the most diagnostic questions are those concerning spatial and temporal correlations with industrial effects. Other data are diagnostically subsidiary. For individual cases, the agreement between analysts correlated positively with the strength of evidence for human induction. E-PIE results agree well with those from a specialist scheme tailored to fluid-injection cases. Its strong performance confirms its suitability to apply to the entire HiQuake database

The correlation consistent composite approach (cc CA

An alternative to the Gaussian-n (G1, G2, and G3) composite methods of computing molecular energies is proposed and is named the correlation consistent composite approach (ccCA, ccCA-CBS-1, ccCA-CBS-2). This approach uses the correlation consistent polarized valence (cc-pV XZ) basis sets. The G2-1 test set of 48 enthalpies of formation (ΔH f), 38 adiabatic ionization potentials (IPs), 25 adiabatic electron affinities (EAs), and 8 adiabatic proton affinities (PAs) are computed using this approach, as well as the ΔH f values of 30 more systems. Equilibrium molecular geometries and vibrational frequencies are obtained using B3LYP density functional theory. When applying the ccCA-CBS method with the cc-pVXZ series of basis sets augmented with diffuse functions, mean absolute deviations within the G2-1 test set compared to experiment are 1.33 kcal mol -1 for ΔH f, 0.81 kcal mol -1 for IPs, 1.02 kcal mol -1 for EAs, and 1.51 kcal mol -1 for PAs, without including the high-level correction (HLC) contained in the original Gn methods. Whereas the HLC originated in the Gaussian-1 method as an isogyric correction, it evolved into a fitted parameter that minimized the error of the composite methods, eliminating its physical meaning. Recomputing the G1 and G3 enthalpies of formation without the HLC reveals a systematic trend where most ΔH f values are significantly higher than experimental values. By extrapolating electronic energies to the complete basis set (CBS) limit and adding G3-like corrections for the core-valence and infinite-order electron correlation effects, ccCA-CBS-2 often underestimates the experimental ΔH f, especially for larger systems. This is desired as inclusion of relativistic and atomic spin-orbit effects subsequently improves theoretical ΔH f values to give a 0.81 kcal mol -1 mean absolute deviation with ccCA-CBS-2. The ccCA-CBS method is a viable black box method that can be used on systems with at least 10-15 heavy atoms. © 2006 American Institute of Physics

Isotopic and spin selectivity of H_2 adsorbed in bundles of carbon nanotubes

Due to its large surface area and strongly attractive potential, a bundle of carbon nanotubes is an ideal substrate material for gas storage. In addition, adsorption in nanotubes can be exploited in order to separate the components of a mixture. In this paper, we investigate the preferential adsorption of D_2 versus H_2(isotope selectivity) and of ortho versus para(spin selectivity) molecules confined in the one-dimensional grooves and interstitial channels of carbon nanotube bundles. We perform selectivity calculations in the low coverage regime, neglecting interactions between adsorbate molecules. We find substantial spin selectivity for a range of temperatures up to 100 K, and even greater isotope selectivity for an extended range of temperatures,up to 300 K. This isotope selectivity is consistent with recent experimental data, which exhibit a large difference between the isosteric heats of D_2 and H_2 adsorbed in these bundles.Comment: Paper submitted to Phys.Rev. B; 17 pages, 2 tables, 6 figure

Darkness visible: reflections on underground ecology

1 Soil science and ecology have developed independently, making it difficult for ecologists to contribute to urgent current debates on the destruction of the global soil resource and its key role in the global carbon cycle. Soils are believed to be exceptionally biodiverse parts of ecosystems, a view confirmed by recent data from the UK Soil Biodiversity Programme at Sourhope, Scotland, where high diversity was a characteristic of small organisms, but not of larger ones. Explaining this difference requires knowledge that we currently lack about the basic biology and biogeography of micro-organisms. 2 It seems inherently plausible that the high levels of biological diversity in soil play some part in determining the ability of soils to undertake ecosystem-level processes, such as carbon and mineral cycling. However, we lack conceptual models to address this issue, and debate about the role of biodiversity in ecosystem processes has centred around the concept of functional redundancy, and has consequently been largely semantic. More precise construction of our experimental questions is needed to advance understanding. 3 These issues are well illustrated by the fungi that form arbuscular mycorrhizas, the Glomeromycota. This ancient symbiosis of plants and fungi is responsible for phosphate uptake in most land plants, and the phylum is generally held to be species-poor and non-specific, with most members readily colonizing any plant species. Molecular techniques have shown both those assumptions to be unsafe, raising questions about what factors have promoted diversification in these fungi. One source of this genetic diversity may be functional diversity. 4 Specificity of the mycorrhizal interaction between plants and fungi would have important ecosystem consequences. One example would be in the control of invasiveness in introduced plant species: surprisingly, naturalized plant species in Britain are disproportionately from mycorrhizal families, suggesting that these fungi may play a role in assisting invasion. 5 What emerges from an attempt to relate biodiversity and ecosystem processes in soil is our extraordinary ignorance about the organisms involved. There are fundamental questions that are now answerable with new techniques and sufficient will, such as how biodiverse are natural soils? Do microbes have biogeography? Are there rare or even endangered microbes

Understanding the relationship between costs and the modified Rankin Scale: a systematic review, multidisciplinary consensus and recommendations for future studies

Background and purpose: Cost-of-illness studies often describe a single aggregate cost of a disease state. This approach is less helpful for a condition with a spectrum of outcomes like stroke. The modified Rankin Scale is the most commonly used outcome measure for stroke. We sought to describe the existing evidence on the costs of stroke according to individual modified Rankin Scale categories. This may be useful in future cost effectiveness modelling studies of interventions where cost data have not been collected, but disability outcome is known. Methods: Systematic review of the published literature, searching electronic databases between 2004 and 2015 using validated search filters. Results were screened to identify studies presenting costs by individual modified Rankin Scale categories. Results: Of 17,782 unique identified articles, 13 matched all inclusion criteria. In only four of these studies were costs reported by modified Rankin Scale categories. Most studies included direct medical costs only. Societal costs were assessed in two studies. Overall, studies had a high methodological and reporting quality. The heterogeneity in costing methods used in the identified studies prevented meaningful comparison of the reported cost data. Despite this limitation, the costs consistently increased with greater severity (increasing modified Rankin Scale score). Conclusions: Few cost studies of stroke include information based on stroke recovery measured by individual modified Rankin Scale categories and the existing data are limited. To reliably capture this information, future studies are needed that preferably apply standardised costing methods to promote greater potential for use in cost-effectiveness analyses whereby direct collection of patient-level resource use has not been possible

EchidnaCSI: engaging the public in research and conservation of the short-beaked echidna

The short-beaked echidna is an iconic Australian animal and the most-widespread native mammal, inhabiting diverse environments. The cryptic nature of echidnas has limited research into their ecology in most areas; however, from the well-researched and endangered Kangaroo Island echidna population, we understand that the threats include habitat loss, roads, and invasive species. To obtain more information about echidnas Australia-wide, we established the Echidna Conservation Science Initiative (EchidnaCSI) citizen science project. EchidnaCSI calls on members of the public to submit photographs of wild echidnas and learn to identify and collect echidna scats for molecular analysis. To facilitate participation, we developed a smartphone application as well as ongoing social and traditional media activities and community events. In 3 y, more than 9,000 members of the public have downloaded the EchidnaCSI app, collecting 400 scats and submitting over 8,000 sightings of echidnas from across Australia. A subset of submitted scat samples were subjected to DNA extraction and PCR, which validated the approach of using citizen science for scat collection and viability for molecular analysis. To assess the impact of the project through public participation, we surveyed our participants (n = 944) to understand their demographics and motivations for engagement. Survey results also revealed that EchidnaCSI served as a gateway into citizen science more generally for many participants. EchidnaCSI demonstrates the potential for using citizen science approaches to collect high-quality data and material from a cryptic species over a very large geographic area and the considerable engagement value of citizen science research.Tahlia Perry, Alan Stenhouse, Isabella Wilson, Imma Perfetto, Michael W. McKelvey, Michelle Coulson, Rachel A. Ankeny, Peggy D. Rismiller, and Frank Grützne

Reptiles as food: Predation of Australian reptiles by introduced red foxes compounds and complements predation by cats

Context: Invasive species are a major cause of biodiversity loss across much of the world, and a key threat to Australia’s diverse reptile fauna. There has been no previous comprehensive analysis of the potential impact of the introduced European red fox, Vulpes vulpes, on Australian reptiles. Aims: We seek to provide an inventory of all Australian reptile species known to be consumed by the fox, and identify characteristics of squamate species associated with such predation. We also compare these tallies and characteristics with reptile species known to be consumed by the domestic cat, Felis catus, to examine whether predation by these two introduced species is compounded (i.e. affecting much the same set of species) or complementary (affecting different groups of species). Methods: We collated records of Australian reptiles consumed by foxes in Australia, with most records deriving from fox dietary studies (tallying >35 000 samples). We modelled presence or absence of fox predation records against a set of biological and other traits, and population trends, for squamate species. Key results: In total, 108 reptile species (~11% of Australia’s terrestrial reptile fauna) have been recorded as consumed by foxes, fewer than that reported for cats (263 species). Eighty-six species have been reported to be eaten by both predators. More Australian turtle species have been reported as consumed by foxes than by cats, including many that suffer high levels of predation on egg clutches. Twenty threatened reptile species have been reported as consumed by foxes, and 15 by cats. Squamate species consumed by foxes are more likely to be undergoing population decline than those not known to be consumed by foxes. The likelihood of predation by foxes increased with squamate species’ adult body mass, in contrast to the relationship for predation by cats, which peaked at ~217 g. Foxes, but not cats, were also less likely to consume venomous snakes. Conclusions: The two introduced, and now widespread, predators have both compounding and complementary impacts on the Australian reptile fauna. Implications: Enhanced and integrated management of the two introduced predators is likely to provide substantial conservation benefits to much of the Australian reptile fauna

Explosive volcanic activity on Venus: The roles of volatile contribution, degassing, and external environment

We investigate the conditions that will promote explosive volcanic activity on Venus. Conduit processes were simulated using a steady-state, isothermal, homogeneous flow model in tandem with a degassing model. The response of exit pressure, exit velocity, and degree of volatile exsolution was explored over a range of volatile concentrations (H2O and CO2), magma temperatures, vent altitudes, and conduit geometries relevant to the Venusian environment. We find that the addition of CO2 to an H2O-driven eruption increases the final pressure, velocity, and volume fraction gas. Increasing vent elevation leads to a greater degree of magma fragmentation, due to the decrease in the final pressure at the vent, resulting in a greater likelihood of explosive activity. Increasing the magmatic temperature generates higher final pressures, greater velocities, and lower final volume fraction gas values with a correspondingly lower chance of explosive volcanism. Cross-sectionally smaller, and/or deeper, conduits were more conducive to explosive activity. Model runs show that for an explosive eruption to occur at Scathach Fluctus, at Venus’ mean planetary radius (MPR), 4.5% H2O or 3% H2O with 3% CO2 (from a 25 m radius conduit) would be required to initiate fragmentation; at Ma’at Mons (~9 km above MPR) only ~2% H2O is required. A buoyant plume model was used to investigate plume behaviour. It was found that it was not possible to achieve a buoyant column from a 25 m radius conduit at Scathach Fluctus, but a buoyant column reaching up to ~20 km above the vent could be generated at Ma’at Mons with an H2O concentration of 4.7% (at 1300 K) or a mixed volatile concentration of 3% H2O with 3% CO2 (at 1200 K). We also estimate the flux of volcanic gases to the lower atmosphere of Venus, should explosive volcanism occur. Model results suggest explosive activity at Scathach Fluctus would result in an H2O flux of ~107 kg s-1. Were Scathach Fluctus emplaced in a single event, our model suggests that it may have been emplaced in a period of ~15 days, supplying 1-2 x 104 Mt H2O to the atmosphere locally. An eruption of this scale might increase local atmospheric H2O abundance by several ppm over an area large enough to be detectable by near-infrared nightside sounding using the 1.18 µm spectral window such as that carried out by the Venus Express/VIRTIS spectrometer. Further interrogation of the VIRTIS dataset is recommended to search for ongoing volcanism on Venus