Abstract
The search for Terrestrial Analogues is essential for the development of future permanent or semi-permanent lunar bases. Terrestrial Analogues are zones where it is possible to probe not ...only scientific instruments, but also other astronaut capabilities in an environment that is similar to the geological context, geomorphology, mineralogy, geochemistry, etc. that we can find on Mars, the Moon and even asteroids. This work has focused on a multi-analytical characterization of Peñas de Tao geosite basalts in Lanzarote (Canary Islands, Spain). This characterization starts from a field campaign in which 3000 g of basalt rocks were selected. Subsequently, they were analysed by different techniques to determine their composition at a mineralogical and geochemical level, and the results were compared with data from other lunar simulants and from the Apollo 14 mission. After that, a set of petrophysical tests was carried out in order to determine its physical properties and evaluate its capacity as an analogous material for use in situ as a resource for further geological and astrobiological (future lunar habitability) essays.
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). ...The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
This work presents the geochemical characterization of two Martian analogues located in the Basque-Cantabrian Basin: Enekuri and Fruiz. In contrast to previous works carried out on the coastline ...analogues Meñakoz and Armintza (Biscay, Spain), these new outcrops are not in contact with sea-water nowadays. Hence, the weathering processes observed in Enekuri and Fruiz (inland) are different from those observed in Armintza and Meñakoz (coastline). In this way, among all the mineral phases found the only ones in common between inland and coastline outcrops are albite and chlorites, minerals that were formed in aqueous conditions. Understanding the differences presented in both types of outcrops could help to interpret the future results from the missions Mars2020 and the ExoMars2022, since coastline outcrops are affected by sea-water weathering and inland outcrops are altered by the high biological activity.
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•Geochemical characterization of the Enekuri and Fruiz Martian analogues•Using VNIR, Raman and XRF spectroscopies, as they are in future planetary missions•The presence of chlorite is an evidence of initial aqueous activity.•Inland outcrops weathering are characterized by biological activity.
Ferromanganese nodule fields and hardgrounds have recently been discovered in the Cadiz Contourite Channel in the Gulf of Cadiz (850–1000m). This channel is part of a large contourite depositional ...system generated by the Mediterranean Outflow Water. Ferromanganese deposits linked to contourites are interesting tools for palaeoenviromental studies and show an increasing economic interest as potential mineral resources for base and strategic metals. We present a complete characterisation of these deposits based on submarine photographs and geophysical, petrographic, mineralogical and geochemical data. The genesis and growth of ferromanganese deposits, strongly enriched in Fe vs. Mn (av. 39% vs. 6%) in this contourite depositional system result from the combination of hydrogenetic and diagenetic processes. The interaction of the Mediterranean Outflow Water with the continental margin has led to the formation of Late Pleistocene–Holocene ferromanganese mineral deposits, in parallel to the evolution of the contourite depositional system triggered by climatic and tectonic events. The diagenetic growth was fuelled by the anaerobic oxidation of thermogenic hydrocarbons (δ13CPDB=−20 to −37‰) and organic matter within the channel floor sediments, promoting the formation of Fe–Mn carbonate nodules. High 87Sr/86Sr isotopic values (up to 0.70993±0.00025) observed in the inner parts of nodules are related to the influence of radiogenic fluids fuelled by deep-seated fluid venting across the fault systems in the diapirs below the Cadiz Contourite Channel. Erosive action of the Mediterranean Outflow Water undercurrent could have exhumed the Fe–Mn carbonate nodules, especially in the glacial periods, when the lower core of the undercurrent was more active in the study area. The growth rate determined by 230Thexcess/232Th was 113±11mm/Ma, supporting the hypothesis that the growth of the nodules records palaeoenvironmental changes during the last 70ka. Ca-rich layers in the nodules could point to the interaction between the Mediterranean Outflow Water and the North Atlantic Deep Water during the Heinrich events. Siderite–rhodochrosite nodules exposed to the oxidising sea-bottom waters were replaced by Fe–Mn oxyhydroxides. Slow hydrogenetic growth of goethite from the seawaters is observed in the outermost parts of the exhumed nodules and hardgrounds, which show imprints of the Mediterranean Outflow Water with low 87Sr/86Sr isotopic values (down to 0.70693±0.00081). We propose a new genetic and evolutionary model for ferromanganese oxide nodules derived from ferromanganese carbonate nodules formed on continental margins above the carbonate compensation depth and dominated by hydrocarbon seepage structures and strong erosive action of bottom currents. We also compare and discuss the generation of ferromanganese deposits in the Cadiz Contourite Channel with that in other locations and suggest that our model can be applied to ferromanganiferous deposits in other contouritic systems affected by fluid venting.
► We study ferromanganese deposits in the Cadiz Contourite Channel. ► Sr isotopes and thermogenic hydrocarbons reveal palaeoenvironmental traces. ► Geochemistry and 230Thex/232Th dating show the growth history in the last 70ka. ► Fluid venting and sea bottom undercurrents act as mineralisation controls. ► A new genetic model for ferromanganese nodules on continental margins is proposed.
Many factors have been described to contribute to voriconazole (VCZ) interpatient variability in plasma concentrations, especially CYP2C19 genetic variability. In 2014, Hicks et al. presented data ...describing the correlation between VCZ plasma concentrations and CYP2C19 diplotypes in immunocompromised pediatric patients and utilized pharmacokinetic modeling to extrapolate a more suitable VCZ dose for each CYP2C19 diplotype. In 2017, in our hospital, a clinical protocol was developed for individualization of VCZ in immunocompromised patients based on preemptive genotyping of CYP2C19 and dosing proposed by Hicks et al., Clinical Pharmacogenetics Implementation Consortium (CPIC) clinical guidelines, and routine therapeutic drug monitoring (TDM). We made a retrospective review of a cohort of 28 immunocompromised pediatric patients receiving VCZ according to our protocol. CYP2C19 gene molecular analysis was preemptively performed using PharmArray
®
. Plasma trough concentrations were measured by immunoassay analysis until target concentrations (1–5.5 μg/ml) were reached. Sixteen patients (57.14%) achieved VCZ trough target concentrations in the first measure after the initial dose based on PGx. This figure is similar to estimations made by Hicks et al. in their simulation (60%). Subdividing by phenotype, our genotyping and TDM-combined strategy allow us to achieve target concentrations during treatment/prophylaxis in 90% of the CYP2C19 Normal Metabolizers (NM)/Intermediate Metabolizers (IM) and 100% of the Rapid Metabolizers (RM) and Ultrarapid Metabolizers (UM) of our cohort. We recommended modifications of the initial dose in 29% (
n
= 8) of the patients. In RM ≥12 years old, an increase of the initial dose resulted in 50% of these patients achieving target concentrations in the first measure after initial dose adjustment based only on PGx information. Our experience highlights the need to improve VCZ dose predictions in children and the potential of preemptive genotyping and TDM to this aim. We are conducting a multicenter, randomized clinical trial in patients with risk of aspergillosis in order to evaluate the effectiveness and efficiency of VCZ individualization: VORIGENIPHARM (EudraCT: 2019-000376-41).
Geoethics – Africa needs to be respected and heard Vasconcelos, Lopo; Martínez-Frías, Jesus; Mogessie, Aberra
Journal of African earth sciences (1994),
November 2015, 2015-11-00, Volume:
111
Journal Article
•Experimental scattering matrices at visible wavelengths.•We have studied five martian dust analog samples.•Experimental phase functions are a good approximation for martian dust.•Spectro-polarimetry ...appears to be a powerful tool for inferring dust properties.
We present measurements of the complete scattering matrix as a function of the scattering angle of five martian dust analogs, namely montmorillonite, two palagonite (JSC-1) samples, basalt, and calcite. The measurements are performed at 488 and 647nm, covering the scattering angle range from 3° to 177°. The experimental scattering matrices are compared with results of Lorenz–Mie calculations performed for the same size distributions and refractive indices as our analog samples. As expected, we find that scattering matrices of realistic polydispersions of dust particles cannot be replaced by such calculated matrices. In contrast, the measured phase functions for our martian dust analogs may be considered a good approximation for martian dust at the studied wavelengths. Further, because of the sensitivity of polarimetry to particle microphysics, spectro-polarimetric observations from the martian surface appear to be a powerful diagnostic tool to infer the composition of the dust in the martian atmosphere. To facilitate the use of the experimental matrices for multiple-scattering calculations with polarization included, we compute the corresponding synthetic scattering matrices based on the measurements and defined in the full angle range from 0° to 180°.
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