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1.
Astrobiology ; 22(4): 416-438, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35041521

RESUMO

The Mars 2020 Perseverance rover landed on February 18, 2021, and has started ground operations. The ExoMars Rosalind Franklin rover will touch down on June 10, 2023. Perseverance will be the first-ever Mars sample caching mission-a first step in sample return to Earth. SuperCam and Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) on Perseverance, and Raman Laser Spectrometer (RLS) on Rosalind Franklin, will comprise the first ever in situ planetary mission Raman spectroscopy instruments to identify rocks, minerals, and potential organic biosignatures on Mars' surface. There are many challenges associated when using Raman instruments and the optimization and quantitative analysis of resulting data. To understand how best to overcome them, we performed a comprehensive Raman analysis campaign on CanMars, a Mars sample caching rover analog mission undertaken in Hanksville, Utah, USA, in 2016. The Hanksville region presents many similarities to Oxia Planum's past habitable conditions, including liquid water, flocculent, and elemental compounds (such as clays), catalysts, substrates, and energy/food sources for life. We sampled and conducted a complete band analysis of Raman spectra as mission validation analysis with the RLS ExoMars Simulator or RLS Sim, a breadboard setup representative of the ExoMars RLS instrument. RLS Sim emulates the operational behavior of RLS on the Rosalind Franklin rover. Given the high fidelity of the Mars analog site and the RLS Sim, the results presented here may provide important information useful for guiding in situ analysis and sample triage for caching relevant for the Perseverance and Rosalind Franklin missions. By using the RLS Sim on CanMars samples, our measurements detected oxides, sulfates, nitrates, carbonates, feldspars, and carotenoids, many with a higher degree of sensitivity than past results. Future work with the RLS Sim will aim to continue developing and improving the capability of the RLS system in the future ExoMars mission.


Assuntos
Exobiologia , Marte , Planeta Terra , Exobiologia/métodos , Lasers , Minerais/análise
2.
Patient Prefer Adherence ; 15: 1621-1637, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34321870

RESUMO

BACKGROUND: There is evidence of improved adherence and treatment outcomes when patients' treatment preferences are considered, and shared decision making is utilized. PURPOSE: We aimed to better understand treatment preferences among Australians with treatment-resistant depression (TRD), focusing on the specific treatment attributes that people value (such as effectiveness, risk of side effects and cost) and their relative importance. The risk-benefit trade-offs that characterize treatment choices were also examined. PATIENTS AND METHODS: An online survey of 75 patients with experience of TRD was conducted, consisting of two discrete choice experiment (DCE) components - a medication DCE and a treatment plan DCE. Participants were able to prioritize and trade off different features of medications and treatment plans. Additional questions aimed to better define this population group, which in Australia is poorly understood. RESULTS: In both DCEs, two distinct latent classes were identified. In the medication DCE, the classes were distinguished by willingness to consider new treatment alternatives. Participants in class 1 were reluctant to give up current treatment, while those in the slightly larger class 2 preferred new treatment options. In both classes, treatment effectiveness and cost were the greatest contributors to preference. Similar behavior was seen in the treatment plan DCE, with the larger class more likely to choose a new plan over their current treatment arrangement. Participants preferred medications that were low-cost, taken orally, had a high percentage improvement in mood symptoms, high rate of remission and low risk of weight gain. A similar result was found in preferences for treatment plans such that plans with the greatest effectiveness and lowest cost were most favorable. CONCLUSION: Patient preferences should routinely be considered and discussed to guide informed decisions regarding the value of new and existing medications for TRD and how they sit in the context of treatment plans.

3.
Appl Spectrosc ; 75(9): 1093-1113, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33988039

RESUMO

One of the primary objectives of planetary exploration is the search for signs of life (past, present, or future). Formulating an understanding of the geochemical processes on planetary bodies may allow us to define the precursors for biological processes, thus providing insight into the evolution of past life on Earth and other planets, and perhaps a projection into future biological processes. Several techniques have emerged for detecting biomarker signals on an atomic or molecular level, including laser-induced breakdown spectroscopy (LIBS), Raman spectroscopy, laser-induced fluorescence (LIF) spectroscopy, and attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, each of which addresses complementary aspects of the elemental composition, mineralogy, and organic characterization of a sample. However, given the technical challenges inherent to planetary exploration, having a sound understanding of the data provided from these technologies, and how the inferred insights may be used synergistically is critical for mission success. In this work, we present an in-depth characterization of a set of samples collected during a 28-day Mars analog mission conducted by the Austrian Space Forum in the Dhofar region of Oman. The samples were obtained under high-fidelity spaceflight conditions and by considering the geological context of the test site. The specimens were analyzed using the LIBS-Raman sensor, a prototype instrument for future exploration of Mars. We present the elemental quantification of the samples obtained from LIBS using a previously developed linear mixture model and validated using scanning electron microscopy energy dispersive spectroscopy. Moreover, we provide a full mineral characterization obtained using ultraviolet Raman spectroscopy and LIF, which was verified through ATR FT-IR. Lastly, we present possible discrimination of organics in the samples using LIF and time-resolved LIF. Each of these methods yields accurate results, with low errors in their predictive capabilities of LIBS (median relative error ranging from 4.5% to 16.2%), and degree of richness in subsequent inferences to geochemical and potential biochemical processes of the samples. The existence of such methods of inference and our ability to understand the limitations thereof is crucial for future planetary missions, not only to Mars and Moon but also for future exoplanetary exploration.

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