An ESA roadmap for geobiology in space exploration

This work was supported by the European Space Agency under the Topical Team, 'Geobiology in Space Exploration'. Claire Cousins is funded by a Royal Society of Edinburgh Research Fellowship, co-funded by the Marie Curie Actions FP7 Programme.Geobiology, and in particular mineral-microbe interactions, has a significant role to play in current and future space exploration. This includes the search for biosignatures in extraterrestrial environments, and the human exploration of space. Microorganisms can be exploited to advance such exploration, such as through biomining, maintenance of life-support systems, and testing of life-detection instrumentation. In view of these potential applications, a European Space Agency (ESA) Topical Team “Geobiology in Space Exploration” was developed to explore these applications, and identify research avenues to be investigated to support this endeavour. Through community workshops, a roadmap was produced, with which to define future research directions via a set of 15 recommendations spanning three key areas: Science, Technology, and Community. These roadmap recommendations identify the need for research into: (1) New terrestrial space-analogue environments; (2) Community level microbial-mineral interactions; (3) Response of biofilms to the space environment; (4) Enzymatic and biochemical mineral interaction; (5) Technical refinement of instrumentation for space-based microbiology experiments, including precursor flight tests; (6) Integration of existing ground-based planetary simulation facilities; (7) Integration of fieldsite biogeography with laboratory- and field-based research; (8) Modification of existing planetary instruments for new geobiological investigations; (9) Development of in situ sample preparation techniques; (10) Miniaturisation of existing analytical methods, such as DNA sequencing technology; (11) New sensor technology to analyse chemical interaction in small volume samples; (12) Development of reusable Lunar and Near Earth Object experimental platforms; (13) Utility of Earth-based research to enable the realistic pursuit of extraterrestrial biosignatures; (14) Terrestrial benefits and technological spin-off from existing and future space-based geobiology investigations; and (15) New communication avenues between space agencies and terrestrial research organisations to enable this impact to be developed.PostprintPeer reviewe

Plausible microbial metabolisms on Mars

Sophie L Nixon, Claire R Cousins and Charles S Cockell explore the possible ways in which any Martian life could get energy.Publisher PDFNon peer reviewe

Spectral identification and quantification of salts in the Atacama Desert

This work was part-funded by a Research Incentive Grant from The Carnegie Trust (REF: 70335) and a Royal Society of Edinburgh Research Fellowship to C. Cousins. J, Harris acknowledges funding from STFC (consolidated grant ST/N000528/1).Salt minerals are an important natural resource. The ability to quickly and remotely identify and quantify salt deposits and salt contaminated soils and sands is therefore a priority goal for the various industries and agencies that utilise salts. The advent of global hyperspectral imagery from instruments such as Hyperion on NASA’s Earth-Observing 1 satellite has opened up a new source of data that can potentially be used for just this task. This study aims to assess the ability of Visible and Near Infrared (VNIR) spectroscopy to identify and quantify salt minerals through the use of spectral mixture analysis. The surface and near-surface soils of the Atacama Desert in Chile contain a variety of well-studied salts, which together with low cloud coverage, and high aridity, makes this region an ideal testbed for this technique. Two forms of spectral data ranging 0.35 – 2.5 μm were collected: laboratory spectra acquired using an ASD FieldSpec Pro instrument on samples from four locations in the Atacama desert known to have surface concentrations of sulfates, nitrates, chlorides and perchlorates; and images from the EO-1 satellite’s Hyperion instrument taken over the same four locations. Mineral identifications and abundances were confirmed using quantitative XRD of the physical samples. Spectral endmembers were extracted from within the laboratory and Hyperion spectral datasets and together with additional spectral library endmembers fed into a linear mixture model. The resulting identification and abundances from both dataset types were verified against the sample XRD values. Issues of spectral scale, SNR and how different mineral spectra interact are considered, and the utility of VNIR spectroscopy and Hyperion in particular for mapping specific salt concentrations in desert environments is established. Overall, SMA was successful at estimating abundances of sulfate minerals, particularly calcium sulfate, from both hyperspectral image and laboratory sample spectra, while abundance estimation of other salt phase spectral end-members was achieved with a higher degree of error.Publisher PD

A Taxonomy of Arts Interventions for People With Dementia

Background and Objectives The current evidence base for the arts and dementia has several limitations relating to the description, explanation, communication, and simplification of arts interventions. Research addressing these challenges must be multidisciplinary, taking account of humanities and science perspectives. Consequently, this research aimed to produce a taxonomy, or classification, of arts interventions for people with dementia as a contribution to this growing field. Research Design and Methods This research was underpinned by taxonomy and realist methodology. Taxonomy, the science of classification, produces a common language to name, define, and describe the world around us. Realist theory explains how interventions “work” and produce their effects. The main findings in this paper were generated from a case study and a Delphi study. Results An arts and dementia taxonomy of 12 dimensions was developed: Art Form, Artistic elements, Artistic focus, Artistic materials, Arts activity, Arts approaches, Arts facilitators, Arts location, Competencies, Complementary arts, Intervention context, Principles. Discussion and Implications Arts interventions can be classified according to their contexts, mechanisms, and outcomes. A range of stakeholders could benefit from the taxonomy, including people with dementia, artists, practitioners, carers, care staff, funders, commissioners, researchers, and academics. Language relating to the arts and dementia can be adapted depending on the audience. This is a foundational model requiring further development within the arts and dementia community

Ionic strength is a barrier to the habitability of Mars

The thermodynamic availability of water (water activity) strictly limits microbial propagation on Earth, particularly in hypersaline environments. A considerable body of evidence indicates the existence of hypersaline surface waters throughout the history of Mars, therefore it is assumed that, as on Earth, water activity is a major limiting factor for martian habitability. However, the differing geologic histories of the Earth and Mars have driven variations in their respective aqueous geochemistry, with as-yet-unknown implications for habitability. Using a microbial community enrichment approach, we investigated microbial habitability for a suite of simulated martian brines. Whilst the habitability of some martian brines was consistent with predictions made from water activity, others were uninhabitable even when the water activity was biologically permissive. We provide evidence that high ionic strength, driven to extremes on Mars by the ubiquitous occurrence of divalent ions, renders these environments uninhabitable despite the presence of biologically available water. These findings show how the respective geological histories of Earth and Mars, which have produced differences in the planets’ dominant water chemistries, have resulted in different physicochemical extremes which define the boundary space for microbial habitability

Refugees are a valuable but overlooked economic resource, and it is time to update our approach to migration

The view that welcoming refugees represents a cost to a country's welfare services has become anachronistic; nowadays refugees are increasingly recognised for their high levels of education and skills, and their ability to make an economic contribution to a host country. Yet, most states' approach to migration management prevents displaced people from migrating based on the human capital that they can supply. Australia is trialling a new approach that enables refugees to access skilled migration through employer sponsorship. This article describes the pilot project and suggests ways to encourage employers to view refugees as a valuable solution to workforce shortages

Peroneal artery pseudoaneurysm--a case report and literature review.

BACKGROUND: Aneurysms of the peroneal artery are infrequent and consist mainly of pseudoaneurysms. CASE PRESENTATION: This report describes an unusual case of peroneal pseudoaneurysm developing after thromoboembolectomy with a Fogarty catheter. It was managed successfully using an endovascular technique consisting of selective catheterization and coil embolization. The coils were placed in the peroneal artery, both proximal and distal to the pseudoaneurysm. CONCLUSION: Endovascular technique can be successfully used to treat pseudoaneurysms in difficult settings.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Metamorphic evolution of carbonate-hosted microbial biosignatures

This work was funded by a Royal Society of Edinburgh Research Fellowship. FF and FW acknowledge funding from the CNRS and CNES.Microbial biosignature assemblages captured within mineral substrates experience extreme pressures (P) and temperatures (T) during rock burial and metamorphism. We subjected natural microbial biofilms hosted within thermal spring carbonate to six high pressure, high temperature (HPHT) conditions spanning 500 and 800 MPa and 200 to 550 °C, to investigate the initial petrographic transformation of organic and inorganic phases. We find biogenic and amorphous silica mineralises increasingly mature organic matter (OM) as temperature and pressure increase, with OM expelled from recrystallised calcite at the highest HPHT, captured within a quartz phase. Sulfur globules associated with microbial filaments persist across all HPHT conditions in association with microbially-derived kerogen. These data demonstrate how microbial material captured within chemically-precipitated sediments petrographically evolves in high grade rocks during their first stages of transformation.Publisher PDFPeer reviewe

Ultradeep Microbial Communities at 4.4 km within Crystalline Bedrock : Implications for Habitability in a Planetary Context

The deep bedrock surroundings are an analog for extraterrestrial habitats for life. In this study, we investigated microbial life within anoxic ultradeep boreholes in Precambrian bedrock, including the adaptation to environmental conditions and lifestyle of these organisms. Samples were collected from Pyhasalmi mine environment in central Finland and from geothermal drilling wells in Otaniemi, Espoo, in southern Finland. Microbial communities inhabiting the up to 4.4 km deep bedrock were characterized with phylogenetic marker gene (16S rRNA genes and fungal ITS region) amplicon and DNA and cDNA metagenomic sequencing. Functional marker genes (dsrB, mcrA, narG) were quantified with qPCR. Results showed that although crystalline bedrock provides very limited substrates for life, the microbial communities are diverse. Gammaproteobacterial phylotypes were most dominant in both studied sites. Alkanindiges -affiliating OTU was dominating in Pyhasalmi fluids, while different depths of Otaniemi samples were dominated by Pseudomonas. One of the most common OTUs detected from Otaniemi could only be classified to phylum level, highlighting the uncharacterized nature of the deep biosphere in bedrock. Chemoheterotrophy, fermentation and nitrogen cycling are potentially significant metabolisms in these ultradeep environments. To conclude, this study provides information on microbial ecology of low biomass, carbon-depleted and energy-deprived deep subsurface environment. This information is useful in the prospect of finding life in other planetary bodies.Peer reviewe

Cryogenic silicification of microorganisms in hydrothermal fluids

Silica-rich hydrothermal fluids that experience freezing temperatures precipitate cryogenic opal-A (COA) within ice-bound brine channels. We investigated cryogenic silicification as a novel preservation pathway for chemo- and photo-lithotrophic Bacteria and Archaea. We find that the co-partitioning of microbial cells and silica into brine channels causes microorganisms to become fossilised in COA. Rod- and coccoidal-form Bacteria and Archaea produce numerous cell casts on COA particle surfaces, while Chloroflexus filaments are preserved inside particle interiors. COA particles precipitated from natural Icelandic hot spring fluids possess similar biomorphic casts, including those containing intact microbial cells. Biomolecules and inorganic metabolic products are also captured by COA precipitation, and are detectable with a combination of visible - shortwave infrared reflectance, FTIR, and Raman spectroscopy. We identify cryogenic silicification as a newly described mechanism by which microbial biosignatures can be preserved within silica-rich hydrothermal environments. This work has implications for the interpretation of biosignatures in relic hydrothermal settings, and for life-detection on Mars and Enceladus, where opaline silica indicative of hydrothermal activity has been detected, and freezing surface conditions predominate