33 research outputs found
A new method to force-feed and rear adult newts on board a space station
We developed a force-feed method for the adults of the newt, Pleuradeles waltl (urodele amphibian) under microgravity conditions on board the Mir space station, because the animals cannot take food themselves under such conditions. A cosmonaut introduced a catheter through the mouth into the stomach. The catheter was connected to a syringe containing food and allowed him to dose the quantity of injected food. The selected food was a complete diet for dogs and cats called âPrescription diet Canine/Feline a/d" made in USA and produced by the Hillâs Pet Nutrition SNC (Sofia-Antipolis, France). It was diluted, sterilized and conserved on board the Mir station at ambient temperature (20-30 C). The protocol of force-feeding was successfully performed on board the space station during five months. After the space mission, two females were in good health status. They laid fertilized eggs in flight and again in the ground laboratory after the landing. According to the results obtained with Pleurodeles females. such food could be used in future long space flights
Hyperspectral non-destructive analyses of Martian return samples under quarantine
International audienceIn preparation for the upcoming sample return missions containing potential biohazards which may have withstood the rigors of space travel we present a hyperspectral method of in-situ analysis of grains combining several non-destructive imaging diagnostics, performed in BSL4 quarantine conditions. This offers an alternative to the analyses in facilities at large, using optimized experimental setups while keeping the samples in conditions of quarantine. Our methodology was tested during analyses of meteorites and cometary and interstellar grains from the recent NASA Stardust mission
Non-desctructive X-Ray, Raman and IR Imaging of quarantined Mars return samples
73rd Annual Meeting of the Meteoritical-Society : New York, NY, July 26-30, 2010International audienceIn preparation for the upcoming international Mars Sample Return mission, bringing to Earth samples containing potential biohazards, we have implemented a hyperspectral method of analysis of grains performed in BSL4 quarantine conditions,by combining several non-destructive imaging diagnostics. This methodology was tested on meteorites [1, 2] and cometary grains from the recent NASA Stardust mission [3-6]
The trophic importance of epiphytic algae in a freshwater macrophyte system (Potamogeton perfoliatus L.): stable isotope and fatty acid analyses
Stable isotope and fatty acid analyses were used to study carbon sources for animals in a submerged plant bed. Epiphytes growing on Potamogeton perfoliatus, sand microflora, and alder leaves were the most important carbon sources. The most abundant macrophyte, P. perfoliatus was unimportant as a food source. Modelling (IsoSource) showed that epiphytes were the most important food source for the most abundant benthic invertebrates, the isopod Asellus aquaticus (annual mean contribution 64%), the amphipod Gammarus pulex (66%), and the gastropod Potamopyrgus antipodarum (83%). The mean annual contributions of sand microflora were, respectively, 21, 19, and 9%; and of alder leaves, 15, 15, and 8% for these three species. The relative importance of carbon sources varied seasonally. The relative contribution of epiphytes was lowest for all three grazer species in July: A. aquaticus 38%, G. pulex 43%, and P. antipodarum 42%. A decline in epiphyte biomass in summer may have caused this switch to less attractive food sources. P. perfoliatus provided habitat and shelter for consumers, but food was mainly supplied indirectly by providing space for attached epiphytes, which are fast-growing and provide a highly nutritious food source
The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description
On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds
COSPAR Sample Safety Assessment Framework (SSAF)
The Committee on Space Research (COSPAR) Sample Safety Assessment Framework (SSAF) has been developed by a COSPAR appointed Working Group. The objective of the sample safety assessment would be to evaluate whether samples returned from Mars could be harmful for Earth's systems (e.g., environment, biosphere, geochemical cycles). During the Working Group's deliberations, it became clear that a comprehensive assessment to predict the effects of introducing life in new environments or ecologies is difficult and practically impossible, even for terrestrial life and certainly more so for unknown extraterrestrial life. To manage expectations, the scope of the SSAF was adjusted to evaluate only whether the presence of martian life can be excluded in samples returned from Mars. If the presence of martian life cannot be excluded, a Hold & Critical Review must be established to evaluate the risk management measures and decide on the next steps. The SSAF starts from a positive hypothesis (there is martian life in the samples), which is complementary to the null-hypothesis (there is no martian life in the samples) typically used for science. Testing the positive hypothesis includes four elements: (1) Bayesian statistics, (2) subsampling strategy, (3) test sequence, and (4) decision criteria. The test sequence capability covers self-replicating and non-self-replicating biology and biologically active molecules. Most of the investigations associated with the SSAF would need to be carried out within biological containment. The SSAF is described in sufficient detail to support planning activities for a Sample Receiving Facility (SRF) and for preparing science announcements, while at the same time acknowledging that further work is required before a detailed Sample Safety Assessment Protocol (SSAP) can be developed. The three major open issues to be addressed to optimize and implement the SSAF are (1) setting a value for the level of assurance to effectively exclude the presence of martian life in the samples, (2) carrying out an analogue test program, and (3) acquiring relevant contamination knowledge from all Mars Sample Return (MSR) flight and ground elements. Although the SSAF was developed specifically for assessing samples from Mars in the context of the currently planned NASA-ESA MSR Campaign, this framework and the basic safety approach are applicable to any other Mars sample return mission concept, with minor adjustments in the execution part related to the specific nature of the samples to be returned. The SSAF is also considered a sound basis for other COSPAR Planetary Protection Category V, restricted Earth return missions beyond Mars. It is anticipated that the SSAF will be subject to future review by the various MSR stakeholders
(A bit) Earlier or later is always better:Phenological shifts in consumer-resource interactions
Phenology is a crucial life history trait for species interactions and it can have great repercussions on the persistence of communities and ecosystems. Changes in phenology caused by climate change can disrupt species interactions causing decreases in consumer growth rates, as suggested by the match-mismatch hypothesis (MMH). However, it is still not clear what the long-term consequences of such phenological changes are. In this paper, we present models in which phenology and consumer-resource feedbacks determine long-term community dynamics. Our results show that consumer viability is constrained by limits in the amount of phenological mismatch with their resources, in accordance with the MMH, but the effects of phenological shifts are often nonmonotonic. Consumers generally have higher abundances when they recruit some time before or after their resources because this reduces the long-term effects of overexploitation that would otherwise occur under closer synchrony. Changes in the duration of recruitment phenologies also have important impacts on community stability, with shorter phenologies promoting oscillations and cycles. For small community modules, the effects of phenological shifts on populations can be explained, to a great extent, as superpositions of their effects on consumer-resource pairs. We highlight that consumer-resource feedbacks and overexploitation, which are not typically considered in phenological models, are important factors shaping the long-term responses to phenological changes caused by climate change
In situ imaging of organic sulphur in 800 My-old neoproterozoic microfossils by x-ray spectromicroscopy at the S K-edge
The study of very ancient microfossils has recently raised contentious issues regarding interpretation of the biogenicity of the structures. In situ investigation of certain elements such as sulfur within potential microfossils is a powerful complement to other methods of investigation that can provide valuable information on biogenicity. We present here a first such study on Precambrian microfossils from the 700â800-My-old Neoproterozoic Draken Formation, Svalbard, using scanning X-ray microscopy (SXM) in the fluorescence mode and X-ray absorption near edge spectroscopy (XANES) at the sulfur K-edge. SXM allowed mapping of up to 300 ppm of probably endogenous sulfur within the kerogenous walls of Myxococcoides chlorelloidea microfossils. XANES showed that the sulfur is most likely contained in heterocyclic organic compounds, such as thiophene(s)
Encyclopedia of astrobiology
The interdisciplinary field of Astrobiology constitutes a joint arena where provocative discoveries are coalescing concerning, e.g. the prevalence of exoplanets, the diversity and hardiness of life, and its increasingly likely chances for its emergence. Biologists, astrophysicists, biochemists, geoscientists and space scientists share this exciting mission of revealing the origin and commonality of life in the Universe. The members of the different disciplines are used to their own terminology and technical language. In the interdisciplinary environment many terms either have redundant meanings or are completely unfamiliar to members of other disciplines. The Encyclopedia of Astrobiology serves as the key to a common understanding. Each new or experienced researcher and graduate student in adjacent fields of astrobiology will appreciate this reference work in the quest to understand the big picture. The carefully selected group of active researchers contributing to this work and the expert field editors intend for their contributions, from an internationally comprehensive perspective, to accelerate the interdisciplinary advance of astrobiology
Lithospace: an automated system for in situ petrographic thin section preparation on Mars
International audienceThe aim of the LithoSpace project, supported by the CNES since 2014, is to work on the development of an automated system permitting preparation of petrographic thin sections on extraterrestrial bodies, in particular, on Mars