Physical and Chemical Controls on Habitats for Life in the Deep Subsurface Beneath Continents and Ice

S.M. was funded by an STFC Aurora studentship (grant ST/1506102/1) and the NASA Astrobiology Institute Program on Foundations of Complex Life, Evolution, Preservation and Detection on Earth and Beyond (grant NNA13AA90A). J.P. was supported by NERC grant NE/G00322X/l.Peer reviewedPublisher PD

Sampling methane in basalt on Earth and Mars

Peer reviewedPublisher PD

Multi-Modal Trip Hazard Affordance Detection On Construction Sites

Trip hazards are a significant contributor to accidents on construction and manufacturing sites, where over a third of Australian workplace injuries occur [1]. Current safety inspections are labour intensive and limited by human fallibility,making automation of trip hazard detection appealing from both a safety and economic perspective. Trip hazards present an interesting challenge to modern learning techniques because they are defined as much by affordance as by object type; for example wires on a table are not a trip hazard, but can be if lying on the ground. To address these challenges, we conduct a comprehensive investigation into the performance characteristics of 11 different colour and depth fusion approaches, including 4 fusion and one non fusion approach; using colour and two types of depth images. Trained and tested on over 600 labelled trip hazards over 4 floors and 2000m$\mathrm{^{2}}$ in an active construction site,this approach was able to differentiate between identical objects in different physical configurations (see Figure 1). Outperforming a colour-only detector, our multi-modal trip detector fuses colour and depth information to achieve a 4% absolute improvement in F1-score. These investigative results and the extensive publicly available dataset moves us one step closer to assistive or fully automated safety inspection systems on construction sites.Comment: 9 Pages, 12 Figures, 2 Tables, Accepted to Robotics and Automation Letters (RA-L

Evidence for Seismogenic Hydrogen Gas, a Potential Microbial Energy Source on Earth and Mars

M thanks the STFC for a PhD studentship and the NASA Astrobiology Institute for additional funding (NNAI13AA90A; Foundations of Complex Life, Evolution, Preservation and Detection on Earth and Beyond). Alison Wright, Roger Gibson and Edward Lynch are thanked for contributing samples. We thank three anonymous reviewers for their insightful comments.Peer reviewedPostprin

Circumstellar habitable zones for deep terrestrial biospheres

SM and JOJ are grateful to the UK Science and Technology Facilities Council (STFC) for Aurora Studentships. We thank Dr. Stephen Clifford (LPI), Dr. Ravi Kopparapu (Penn State), and Claire Davis (St. Andrews) for generous technical advice. We thank Norm Sleep and two anonymous reviewers for constructive reviews of the manuscriptPeer reviewedPostprin

Scale and Contingency in Plant Demography: Quantitative Approaches and Inference

Ecologists have long recognized that patterns measured in nature often depend upon the context in which they are observed and the scale at which they are observed. When studying plant populations, the role of scale and contingency becomes crucial. Thinking about a plant community as a system is essential as populations of plants are centered within a network that influences their dynamics in direct and indirect ways. Plant populations are inherently scale-dependent because they have properties as a group that can be independent of their properties as individual stems. Although the challenge of interpreting population patterns in the face of contingency and scale has been addressed conceptually, there has been less success in applying those concepts to observational and experimental studies. This dissertation addresses the challenges of modeling the demographic dynamics of a forest understory herb, Eurybia chlorolepis (Asteraceae) or mountain aster. The study population consisted of twenty patches containing between 20 and 70 individual stems in each patch. These patches spanned three sites within the Indian Camp Creek watershed in the Cosby Ranger district of Great Smoky Mountains National Park. Plants in the forest understory in this dense old-growth forest are influenced by a myriad of biotic and abiotic components of the community: light, soil characteristics, other plant species, herbivores, pollinators, seed predators, and the feet of bears. This dissertation shows that the mechanisms that influence sexual reproduction of this plant are structured almost entirely on the stem-to-stem scale, indicating little coarse-scale influence of the environment over sexual reproduction. The use of a Bayesian learning network showed that the environmental influences (soil in particular) operated most importantly in the transition from juvenile stage to adult stage. Taken together, these analyses indicate that the coarse-environtment (such as gaps, soil profiles, soil moisture, and the presence of other plants) dictates where E. chlorolepis becomes reproductive, while the success of that reproduction is dictated by mechanisms operating between individual stems

Demonstrating deep biosphere activity in the geological record of lake sediments, on Earth and Mars

Acknowledgements. The sample of gypsum was kindly provided by John Marshall, University of Southampton. SM was funded by an STFC Aurora studentship (grant ST/1506102/1) and by the NASA Astrobiology Institute (NNA13AA90A Foundations of Complex Life). AJB is funded by NERC support of the Isotope Community Support Facility at SUERC.Peer reviewedPostprin

Knowledge Management: Style, Structure, And The Latent Potential Of Documented Knowledge

Despite the volume, growth, and accessibility of documented knowledge – the insights and experiences stored on paper and in electronic form - management research has yet to demonstrate the same usefulness for documented knowledge as that found in knowledge residing in human sources. This dissertation explores two areas of potential for documented knowledge, suggesting the efficacy of a piece of documented knowledge is contingent not only on content, but upon the style and structure associated with that content. Style, how cognitively \u27concrete\u27 and affectively \u27memorable\u27 documented knowledge is perceived to be, is hypothesized to affect how much attention it draws and, in turn, to impact its transfer to users. Structure, reflecting the level of parsimony and modularity in documented knowledge, is hypothesized to impact attention to and manipulation of knowledge such that it affects knowledge transfer and creation. Hypotheses were tested in two laboratory studies using scientific research as an exemplar of documented knowledge. Results indicated that style was associated with documented knowledge, but was not related to its transfer. Likewise, structuring documented knowledge for greater parsimony and modularity did not improve knowledge transfer or knowledge creation. Shortcomings of the empirical tests are evaluated and possibilities for future improvements are discussed

A Novel Multi-Spacecraft Interplanetary Global Trajectory Optimization Transcription

As the frontier of space exploration continues to advance, so does the design complexity of future interplanetary missions. One avenue of this increasing complexity includes a class of designs known as "Distributed Spacecraft Missions"; missions where multiple spacecraft coordinate to perform shared objectives. Current approaches for the global trajectory optimization of these Multi-Vehicle Missions (MVMs) are prone to shortcomings including laborious iterative design, considerable human-in-the-loop effort, treatment of the multi-vehicle problem as multiple separate trajectory optimization subproblems (resulting in suboptimal solutions where the whole is less than the sum of its parts), and poor handling of coordination objectives and constraints. There are only a handful of software platforms in existence capable of fully-automated, rapid, interplanetary mission and systems global optimization including the Parallel Global Multiobjective Optimizer (PaGMO), the Gravity Assisted Low-thrust Local Optimization Program (GALLOP), and the Evolutionary Mission Trajectory Generator (EMTG). However, none of these tools is capable of performing such tasks for MVM designs. The work outlined in this paper lays the groundwork for a technique to begin addressing these shortcomings. We present a fully-automated technique which frames interplanetary MVMs as Multi-Objective, Multi-Agent Hybrid Optimal Control Problems (MOMA HOCP). First, the basic functionality of this technique is validated on the single-vehicle problem of reproducing the Cassini interplanetary cruise