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1. Organic Products of Fatty Acid and Magnesium Sulfate Mixtures after Gamma Radiolysis: Implications for Missions to Europa

Author

James M T Lewis, Dina M Bower, Alexander A Pavlov, Xiang Li, Sarinah Z Wahl, Jennifer L Eigenbrode, and Amy C McAdam

Subjects
Lunar and Planetary Science and Exploration
Abstract

If ocean-derived materials are present at Europa’s surface, they would represent accessible records of ocean chemistry and habitability, but such materials would be further processed by the moon’s harsh radiation environment. In this study, saturated fatty acids were precipitated onto a Europa-relevant hydrated magnesium sulfate and exposed to gamma radiation doses up to 2 MGy at -196° C. Alkane chains, with carbon numbers one less than those of the starting fatty acids, were the most abundant radiolysis products in solvent and thermal extracts analyzed by gas chromatography mass spectrometry. Detections of monounsaturated fatty acids and combined radiolysis products were attributed to the experiment’s Europa-like parameters. Additionally, elevated concentrations of shorter-chain saturated fatty acids suggest that gamma radiation induced charge remote fragmentation of the alkyl chains of some starting fatty acids under these experimental conditions. Quantitation of fatty acid concentrations in the irradiated samples enabled the calculation of a radiolysis constant that indicated exposure to a 5 MGy dose of gamma radiation would have resulted in a ~90% loss of the initial fatty acid population. The samples were further studied by Raman spectroscopy and laser desorption and ionization mass spectrometry, which characterized the distribution of fatty acids and their radiolysis products on sulfate surfaces. The substantial loss of starting fatty acids typically seen with increasing radiation dose, along with the remarkable diversity of radiolysis products identified, suggest that the detection of fatty acids in irradiated sulfate deposits on Europa will be challenged by rapid destruction of any initial fatty acid populations and scrambling of their residual signals by a myriad of organic radiolysis products. If missions to Europa encounter sulfate deposits, targeting minimally irradiated units may still enable the detection of surviving fatty acid signatures that could inform about Europa’s subsurface chemistry and habitability.

Published
2024
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2. Manufacturing an Exact Solution for 2D Thermochemical Mantle Convection Models

Author

S. J. Trim, S. L. Butler, S. S. C. McAdam, and R. J. Spiteri

Subjects
thermochemical, exact solution, method of characteristics, mantle convection, computer algebra, elliptic integrals, Geophysics. Cosmic physics, QC801-809, Geology, QE1-996.5
Abstract

Abstract In this study, we manufacture an exact solution for a set of 2D thermochemical mantle convection problems. The derivation begins with the specification of a stream function corresponding to a non‐stationary velocity field. The method of characteristics is then applied to determine an expression for composition consistent with the velocity field. The stream function formulation of the Stokes equation is then applied to solve for temperature. The derivation concludes with the application of the advection‐diffusion equation for temperature to solve for the internal heating rate consistent with the velocity, composition, and temperature solutions. Due to the large number of terms, the internal heating rate is computed using Maple™, and code is also made available in Fortran and Python. Using the method of characteristics allows the compositional transport equation to be solved without the addition of diffusion or source terms. As a result, compositional interfaces remain sharp throughout time and space in the exact solution. The exact solution presented allows for precision testing of thermochemical convection codes for correctness and accuracy.

Published
2023
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3. Diagnostic biosignature transformation under simulated martian radiation in organic-rich sedimentary rocks

Author

A. Roussel, A. C. McAdam, H. V. Graham, A. A. Pavlov, C. N. Achilles, C. A. Knudson, A. Steele, D. I. Foustoukos, and S. S. Johnson

Subjects
cosmic rays, biosignatures, Mars, analogs, irradiation, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract

As we look for traces of ancient life on Mars, we need to consider the impact of ionizing radiation in the biosignature preservation process. Here, we irradiated two organic rich terrestrial samples (Enspel and Messel shales) that have Martian analog mineralogies, with simulated cosmic rays to a dose of 0.9 MGy, equivalent of 15 million years of radiation exposure on the Martian surface. We compared a range of biosignatures before and after exposure, including total organic carbon, bulk stable carbon isotope ratios, diagnostic lipid biomarkers (hopanes and steranes), and Raman signatures akin to those collected by the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument on Perseverance. While we did not observe a significant difference in total organic carbon, bulk stable carbon isotopes, or Raman G-band signatures, we found that five lipid biomarkers decreased by a factor of two to three in the Enspel shale. This degree of degradation exceeds current predictions by existing models or experimental studies in organic rich samples and challenges our current understanding of complex biosignatures under ionizing irradiation.

Published
2022
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4. Evolved Gas Analyses of Sedimentary Rocks from the Glen Torridon Clay-Bearing Unit, Gale Crater, Mars: Results From the Mars Science Laboratory Sample Analysis at Mars Instrument Suite

Author

A. C. McAdam, B. Sutter, P. D. Archer, H. B. Franz, G. M. Wong, J. M. T. Lewis, J. V. Clark, M. Millan, A. J. Williams, J. L. Eigenbrode, C. A. Knudson, C. Freissinet, D. P. Glavin, J. C. Stern, R. Navarro-González, C. N. Achilles, D. W. Ming, R. V. Morris, T. F. Bristow, E. B. Rampe, M. T. Thorpe, C. H. House, S. Andrejkovičová, Alexander Bodkin Bryk, Valerie K Fox, S. S. Johnson, P. R. Mahaffy, and C. A. Malespin

Subjects
Space Sciences (General)
Abstract

Evolved gas analysis (EGA) data from the Sample Analysis at Mars (SAM) instrument suite indicated Fe-rich smectite, carbonate, oxidized organics, Fe/Mg sulfate, and chloride in sedimentary rocks from the Glen Torridon (GT) region of Gale crater that displayed phyllosilicate spectral signatures from orbit. SAM evolved H2O data indicated that the primary phyllosilicate in all GT samples was an Fe-rich dioctahedral smectite (e.g., nontronite) with lesser amounts of a phyllosilicate such as mixed layer talc-serpentine or greenalite-minnesotaite. CO(2) data supported the identification of siderite in several samples, and CO(2) and CO data was also consistent with trace oxidized organic compounds such as oxalate salts. SO(2) data indicated trace and/or amorphous Fe sulfates in all samples and one sample may contain Fe sulfides. SO(2) data points to significant Mg sulfates in two samples, and lesser amounts in several other samples. A lack of evolved O(2) indicated the absence of oxychlorine salts and Mn3+/Mn4+ oxides. The lack of, or very minor, evolved NO revealed absent or very trace nitrate/nitrite salts. HCl data suggested chloride salts in GT samples. Constraints from EGA data on mineralogy and chemistry indicated that the environmental history of GT involved alteration with fluids of variable redox potential, chemistry and pH under a range of fluid-to-rock ratio conditions. Several of the fluid episodes could have provided habitable environmental conditions and carbon would have been available to any past microbes though the lack of significant N could have been a limiting factor for microbial habitability in the GT region.

Published
2022
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5. Evidence for Multiple Diagenetic Episodes in Ancient Fluvial‐Lacustrine Sedimentary Rocks in Gale Crater, Mars

Author

C. N. Achilles, E. B. Rampe, R. T. Downs, T. F. Bristow, D. W. Ming, R. V. Morris, D. T. Vaniman, D. F. Blake, A. S. Yen, A. C. McAdam, B. Sutter, C. M. Fedo, S. Gwizd, L. M. Thompson, R. Gellert, S. M. Morrison, A. H. Treiman, J. A. Crisp, T. S. J. Gabriel, S. J. Chipera, R. M. Hazen, P. I. Craig, M. T. Thorpe, D. J. Des Marais, J. P. Grotzinger, V. M. Tu, N. Castle, G. W. Downs, T. S. Peretyazhko, R. C. Walroth, P. Sarrazin, and J. M. Morookian

Published
2020
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6. Mineralogy of Vera Rubin Ridge from the Mars Science Laboratory CheMin Instrument

Author

E. B. Rampe, T. F. Bristow, R. V. Morris, S. M. Morrison, C. N. Achilles, D. W. Ming, D. T. Vaniman, D. F. Blake, V. M. Tu, S. J. Chipera, A. S. Yen, T. S. Peretyazhko, R. T. Downs, R. M. Hazen, A. H. Treiman, J. P. Grotzinger, N. Castle, P. I. Craig, D. J. Des Marais, M. T. Thorpe, R. C. Walroth, G. W. Downs, A. A. Fraeman, K. L. Siebach, R. Gellert, B. Lafuente, A. C. McAdam, P.-Y. Meslin, B. Sutter, and M. R. Salvatore

Subjects
Exobiology, Geosciences (General)
Abstract

Vera Rubin ridge (VRR) is an erosion-resistant feature on the northwestern slope of Mount Sharp in Gale crater, Mars, and orbital visible/short-wave infrared measurements indicate it contains red-colored hematite. The Mars Science Laboratory Curiosity rover performed an extensive campaign on VRR to study its mineralogy, geochemistry, and sedimentology to determine the depositional and diagenetic history of the ridge and constrain the processes by which the hematite could have formed. X-ray diffraction (XRD) data from the CheMin instrument of four samples drilled on and below VRR demonstrate differences in iron, phyllosilicate, and sulfate mineralogy and hematite grain size. Hematite is common across the ridge, and its detection in a gray-colored outcrop suggested localized regions with coarse-grained hematite, which commonly forms from warm fluids. Broad XRD peaks for hematite in one sample below VRR and the abundance of FeOT in the amorphous component suggest the presence of nano-crystalline hematite and amorphous Fe oxides/oxyhydroxides. Well-crystalline akaganeite and jarosite are present in two samples drilled from VRR, indicating at least limited alteration by acid-saline fluids. Collapsed nontronite is present below VRR, but samples from VRR contain phyllosilicate with d(001) = 9.6 Å, possibly from ferripyrophyllite or an acid-altered smectite. The most likely cementing agents creating the ridge are hematite and opaline silica. We hypothesize late diagenesis can explain much of the mineralogical variation on the ridge, where multiple fluid episodes with variable pH, salinity, and temperature altered the rocks, causing the precipitation and crystallization of phases that are not otherwise in equilibrium.

Published
2020
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7. In Situ Analysis of Opal in Gale Crater, Mars

Author

W. Rapin, B. Chauviré, T. S. J. Gabriel, A. C. McAdam, B. L. Ehlmann, C. Hardgrove, P.‐Y. Meslin, B. Rondeau, E. Dehouck, H. B. Franz, N. Mangold, S. J. Chipera, R. C. Wiens, J. Frydenvang, and S. Schröder

Published
2018
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8. Understanding the experiences of lung volume recruitment among boys with Duchenne muscular dystrophy: A multicenter qualitative study

Author

Sherri L. Katz, Henrietta Blinder, Dennis Newhook, Leana Azerrad, Stuart Nicholls, Hugh J. McMillan, Jean K. Mah, Craig Campbell, Laura C. McAdam, David Zielinski, Karine Toupin‐April, Franco Momoli, and Douglas A. McKim

Subjects
Pulmonary and Respiratory Medicine, Pediatrics, Perinatology and Child Health
Abstract

Despite recommendations for regular lung volume recruitment (LVR) use in clinical practice guidelines for children with neuromuscular disease, adherence to LVR is poor. We aimed to describe the experience of LVR by boys with Duchenne muscular dystrophy (DMD), their families, and healthcare providers (HCPs), as well as to identify the barriers and facilitators to LVR use.This multicenter, qualitative study evaluated boys with DMD (n = 11) who used twice-daily LVR as part of a randomized controlled trial, as well as their parents (n = 11), and HCPs involved in the clinical use of LVR (n = 9). Semistructured interviews were conducted to identify participants' understanding of LVR therapy and their beliefs, barriers and facilitators to its use. Thematic analysis was conducted using an inductive approach. A subanalysis compared adherent and nonadherent children.Seven themes were identified related to participants' beliefs and experiences with LVR: emotional impact, adaptation to LVR, perceived benefits of LVR, routine, family engagement, clinical resources, and equipment-related factors. Strategies to improve adherence were also identified, including education, reinforcement and demonstration of LVR benefit, as well as clinician support. There were no thematic differences between adherent and nonadherent children.Despite the benefits of LVR and positive experiences with it by many families, there remain barriers to adherence to treatment. HCPs need to balance the need for early introduction to give families time to adapt to LVR while ensuring that the benefit of LVR outweighs the burden. Clinician support is important for family engagement.

Published
2022
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11. Sedimentary Organics in Glen Torridon, Gale Crater, Mars: Results From the SAM Instrument Suite and Supporting Laboratory Analyses

Author

M. Millan, A. J. Williams, A. C. McAdam, J. L. Eigenbrode, A. Steele, C. Freissinet, D. P. Glavin, C. Szopa, A. Buch, R. E. Summons, J. M. T. Lewis, G. M. Wong, C. H. House, B. Sutter, O. McIntosh, A. B. Bryk, H. B. Franz, C. Pozarycki, J. C. Stern, R. Navarro‐Gonzalez, D. P. Archer, V. Fox, K. Bennett, S. Teinturier, C. Malespin, S. S. Johnson, and P. R. Mahaffy

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Published
2022
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12. Life Underground: Investigating Microbial Communities and Their Biomarkers in Mars‐Analog Lava Tubes at Craters of the Moon National Monument and Preserve

Author

M. M. Weng, E. Zaikova, M. Millan, A. J. Williams, A. C. McAdam, C. A. Knudson, S. R. Fuqua, N. Y. Wagner, K. Craft, S. Kobs Nawotniak, A. Shields, J. Bevilacqua, Y. Bai, S. S. Hughes, W. B. Garry, J. L. Heldmann, D. S. S. Lim, D. Buckner, P. Gant, and S. S. Johnson

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Published
2022
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14. Metagenome-Assembled Genome of a Putative Chemoheterotroph from Volcanic Terrain in Hawaii

Author

O. Gadson, J. G. Bevilacqua, C. B. Fishman, A. S. Hahn, A. C. McAdam, J. Bleacher, and S. S. Johnson

Subjects
Immunology and Microbiology (miscellaneous), Genetics, Molecular Biology
Abstract

Here, we present the draft genome for a new putative species, Gaiellasilicea maunaloa , most closely related to Gaiella occulta , within the phylum Actinobacteria. This group contains Gram-negative, aerobic mesophilic species. This metagenome-assembled genome (MAG) contributes to knowledge of life in volcanic environments and may inform investigations of life beyond Earth.

Published
2022

15. Basaltic Lava Tube Hosts a Putative Novel Genus in the Family Solirubrobacteraceae

Author

C. B. Fishman, J. G. Bevilacqua, O. Gadson, A. S. Hahn, A. C. McAdam, J. Bleacher, and S. S. Johnson

Subjects
Immunology and Microbiology (miscellaneous), Genetics, Molecular Biology
Abstract

We report the draft genome sequence of a putative new genus and species, Siliceabacter maunaloa , in the family Solirubrobacteraceae . The members of this family of Actinobacteria are generally Gram positive and mesophilic. Found within a Hawaiian lava tube, this microbe illuminates the types of prokaryotes inhabiting secondary minerals in subsurface basaltic environments.

Published
2022
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16. Oxidized and Reduced Sulfur Observed by the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover Within the Glen Torridon Region at Gale Crater, Mars

Author

Gregory M. Wong, Heather B. Franz, Joanna V. Clark, Amy C. McAdam, James M. T. Lewis, Maëva Millan, Douglas W. Ming, Felipe Gomez, Benton Clark, Jennifer L. Eigenbrode, Rafael Navarro‐González, and Christopher H. House

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous)
Published
2022
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17. Routine lung volume recruitment in boys with Duchenne muscular dystrophy:a randomised clinical trial

Author

Sherri L Katz, Jean K Mah, Hugh J McMillan, Craig Campbell, Vid Bijelić, Nick Barrowman, Franco Momoli, Henrietta Blinder, Shawn D Aaron, Laura C McAdam, The Thanh Diem Nguyen, Mark Tarnopolsky, David F Wensley, David Zielinski, Louise Rose, Nicole Sheers, David J Berlowitz, Lisa Wolfe, and Doug McKim

Subjects
Male, Muscular Dystrophy, Duchenne, Pulmonary and Respiratory Medicine, Duchenne muscular dystrophy, child, Cough, lung volume recruitment, respiratory therapy, Vital Capacity, randomized controlled trial, Humans, Lung Volume Measurements, Respiratory Function Tests
Abstract

BackgroundImpaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD.MethodsIn this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6–16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow.ResultsSixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5–13.5), median baseline FVC (IQR): 85% predicted (73–96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI −6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes.ConclusionThere was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified.Trial registration numberNCT01999075.

Published
2022
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18. Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X‐ray diffraction of the Windjana sample (Kimberley area, Gale Crater)

Author

Allan H. Treiman, David L. Bish, David T. Vaniman, Steve J. Chipera, David F. Blake, Doug W. Ming, Richard V. Morris, Thomas F. Bristow, Shaunna M. Morrison, Michael B. Baker, Elizabeth B. Rampe, Robert T. Downs, Justin Filiberto, Allen F. Glazner, Ralf Gellert, Lucy M. Thompson, Mariek E. Schmidt, Laetitia Le Deit, Roger C. Wiens, Amy C. McAdam, Cherie N. Achilles, Kenneth S. Edgett, Jack D. Farmer, Kim V. Fendrich, John P. Grotzinger, Sanjeev Gupta, John Michael Morookian, Megan E. Newcombe, Melissa S. Rice, John G. Spray, Edward M. Stolper, Dawn Y. Sumner, Ashwin R. Vasavada, and Albert S. Yen

Published
2016
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19. Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

Author

C. Freissinet, D. P. Glavin, P. R. Mahaffy, K. E. Miller, J. L. Eigenbrode, R. E. Summons, A. E. Brunner, A. Buch, C. Szopa, P. D. Archer, H. B. Franz, S. K. Atreya, W. B. Brinckerhoff, M. Cabane, P. Coll, P. G. Conrad, D. J. Des Marais, J. P. Dworkin, A. G. Fairén, P. François, J. P. Grotzinger, S. Kashyap, I. L. ten Kate, L. A. Leshin, C. A. Malespin, M. G. Martin, F. J. Martin‐Torres, A. C. McAdam, D. W. Ming, R. Navarro‐González, A. A. Pavlov, B. D. Prats, S. W. Squyres, A. Steele, J. C. Stern, D. Y. Sumner, B. Sutter, and M.‐P. Zorzano

Published
2015
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20. Organic carbon concentrations in 3.5-billion-year-old lacustrine mudstones of Mars

Author

Jennifer C. Stern, Charles A. Malespin, Jennifer L. Eigenbrode, Christopher R. Webster, Greg Flesch, Heather B. Franz, Heather V. Graham, Christopher H. House, Brad Sutter, Paul Douglas Archer, Amy E. Hofmann, Amy C. McAdam, Douglas W. Ming, Rafael Navarro-Gonzalez, Andrew Steele, Caroline Freissinet, and Paul R. Mahaffy

Subjects
Multidisciplinary
Abstract

The Sample Analysis at Mars instrument stepped combustion experiment on a Yellowknife Bay mudstone at Gale crater, Mars revealed the presence of organic carbon of Martian and meteoritic origins. The combustion experiment was designed to access refractory organic carbon in Mars surface sediments by heating samples in the presence of oxygen to combust carbon to CO 2 . Four steps were performed, two at low temperatures (less than ∼550 °C) and two at high temperatures (up to ∼870 °C). More than 950 μg C/g was released at low temperatures (with an isotopic composition of δ 13 C = +1.5 ± 3.8‰) representing a minimum of 431 μg C/g indigenous organic and inorganic Martian carbon components. Above 550 °C, 273 ± 30 μg C/g was evolved as CO 2 and CO (with estimated δ 13 C = −32.9‰ to −10.1‰ for organic carbon). The source of high temperature organic carbon cannot be definitively confirmed by isotopic composition, which is consistent with macromolecular organic carbon of igneous origin, meteoritic infall, or diagenetically altered biomass, or a combination of these. If from allochthonous deposition, organic carbon could have supported both prebiotic organic chemistry and heterotrophic metabolism at Gale crater, Mars, at ∼3.5 Ga.

Published
2022
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21. Constraining Alteration Processes Along the Siccar Point Group Unconformity, Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument

Author

B. Sutter, A. C. McAdam, G. M. Wong, J. V. Clark, P. D. Archer, H. B. Franz, P. J. Gasda, D. W. Ming, A. Yen, J. M. T. Lewis, S. P. Schwenzer, S. M. R. Turner, E. B. Rampe, J. L. Eigenbrode, J. C. Stern, L. M. Thompson, E. Dehouck, C. Bedford, S. Banham, A. B. Bryk, C. O’Connell‐Cooper, C. S. House, M. Millan, C. Freissinet, R. Navarro‐Gonzalez, P. R. Mahaffy, C. A. Malespin, Jacobs Technology ESCG, NASA Goddard Space Flight Center (GSFC), Penn State Department of Geosciences, Pennsylvania State University (Penn State), Penn State System-Penn State System, NASA Johnson Space Center (JSC), NASA, Los Alamos National Laboratory (LANL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Physics and Astronomy [Washington], Howard University, School of Environment, Earth and Ecosystem Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Planetary and Space Science Centre (PASSC), University of New Brunswick (UNB), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Institute [Houston] (LPI), Department of Earth Science and Engineering [Imperial College London], Imperial College London, Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Department of Biology [Washington], Georgetown University [Washington] (GU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto de Ciencias Nucleares, UNAM, and Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM)

Subjects
Geophysics, Space and Planetary Science, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], Earth and Planetary Sciences (miscellaneous)
Abstract

International audience; Results from the Sample Analysis at Mars (SAM)-evolved gas analyzer (EGA) on board the Mars Science Laboratory Curiosity rover constrained the alteration history and habitability potential of rocks sampled across the Siccar Point unconformity in Gale crater.The Glasgow member (Gm) mudstone just below the unconformity had evidence of acid sulfate or Si-poor brine alteration of Fe-smectite to Fe amorphous phases, leaching loss of Fe-Mg-sulfate and exchange of unfractionated sulfur 34S (δ34S=2±7‰) with enriched 34S (20±5‰, V-CDT). Carbon abundances did not significantly change (322-661 μgC/g) consistent with carbon stabilization by amorphous Al- and Fe-hydroxide phases. The Gm mudstone had no detectable oxychlorine and extremely low nitrate. Nitrate (0.06 wt.% NO3), oxychlorine (0.13 wt% ClO4), high C (1472 μg C/g), and low Fe/Mg-sulfate concentration (0.24 wt.% SO3) depleted in 34S (δ34S = -27‰ ± 7), were detected in the Stimson formation (Sf) eolian sandstone above the unconformity. Redox disequilibrium through the detections of iron sulfide and sulfate supported limited aqueous processes in the Sf sandstone. Si-poor brines or acidic fluids altered the Gm mudstone just below the unconformity but did not alter underlying Gm mudstones further from the contact. Chemical differences between the Sf and Gm rocks suggested that fluid interaction was minimal between the Sf and Gm rocks. These results suggested that the Gm rocks were altered by subsurface fluids after the Sf placement. Aqueous processes along the unconformity could have provided habitable conditions and in some cases, C and N levels could have supported heterotrophic microbial populations.

Published
2022
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22. Continued Use of Exogenic Materials found on Mars as Planetary Research Tools

Author

James Ashley, Christian Schröder, Alastair W. Tait, Andrew G. Tomkins, Penelope J. Boston, Roger C. Wiens, Danika F. Wellington, Pierre-Yves Meslin, Amy C. McAdam, Matthew P. Golombek, Michael A. Velbel, Phil A. Bland, Steven W. Ruff, John F. Mustard, Aaron G. Curtis, Sara Motaghian, Brandi L. Carrier, William H. Farrand, Marc D. Fries, Peter Grindrod, Andrew Langedam, and Jérémie Lasue

Subjects
Engineering, Planetary science, business.industry, Mars Exploration Program, business, Astrobiology
Abstract

Whitepaper submitted to the Planetary Science and Astrobiology Decadal Survey 2023-2032. Additional co-authors: Sara Motaghian, Brandi L. Carrier, William H. Farrand, Marc D. Fries, Peter Grindrod, Andrew Langedam, Jeremie Lasue .

Published
2021
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23. Supporting Information for Yen et al. 'Formation of Tridymite and Evidence for a Hydrothermal History at Gale Crater, Mars'

Author

A. S. Yen, R. V. Morris, D. W. Ming, S. P. Schwenzer, B. Sutter, D. T. Vaniman, A. H. Treiman, R. Gellert, C. N. Achilles, J. A. Berger, D. F. Blake, N. I. Boyd, T. F. Bristow, S. Chipera, B. C. Clark, P. I. Craig, R. T. Downs, H. B. Franz, T. Gabriel, A. C. McAdam, S. M. Morrison, C. D. O'Connell-Cooper, E. B. Rampe, M. E. Schmidt, L. M. Thompson, and S. J. VanBommel

Subjects
Data_FILES, Mars, Tridymite, Curiosity Rover, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Hydrothermal, GeneralLiterature_MISCELLANEOUS, Gale Crater
Abstract

Supporting information file for Journal of Geophysical Research - Planets article.

Published
2020
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25. List of Contributors

Author

John C. Bridges, Frances E.G. Butcher, Stephen M. Clifford, Susan J. Conway, William H. Farrand, Justin Filiberto, Heather B. Franz, Fabrice Gaillard, Ralf Gellert, Leon J. Hicks, Bradley L. Jolliff, Penelope L. King, Andrew H. Knoll, Samuel P. Kounaves, Jérémie Lasue, Paul R. Mahaffy, Nicolas Mangold, Amy C. McAdam, Francis M. McCubbin, Scott M. McLennan, Douglas W. Ming, David W. Mittlefehldt, John F. Mustard, Elizabeth A. Oberlin, Karen Olsson-Francis, Ulrich Ott, Susanne P. Schwenzer, Brad Sutter, Timothy D. Swindle, G. Jeffrey Taylor, Allan H. Treiman, Tomohiro Usui, and Albert S. Yen

Published
2019
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26. Long-term effects of glucocorticoids on function, quality of life, and survival in patients with Duchenne muscular dystrophy: a prospective cohort study

Author

Craig M McDonald, Erik K Henricson, Richard T Abresch, Tina Duong, Nanette C Joyce, Fengming Hu, Paula R Clemens, Eric P Hoffman, Avital Cnaan, Heather Gordish-Dressman, Vijay Vishwanathan, S Chidambaranathan, W. Douglas Biggar, Laura C. McAdam, Jean K. Mah, Mar Tulinius, Lauren P. Morgenroth, Robert Leshner, Carolina Tesi-Rocha, Mathula Thangarajh, Andrew Kornberg, Monique Ryan, Yoram Nevo, Alberto Dubrovsky, Paula R. Clemens, Hoda Abdel-Hamid, Anne M. Connolly, Alan Pestronk, Jean Teasley, Tulio E. Bertorin, Richard Webster, Hanna Kolski, Nancy Kuntz, Sherilyn Driscoll, John B. Bodensteiner, Jose Carlo, Ksenija Gorni, Timothy Lotze, John W. Day, Peter Karachunski, Erik K. Henricson, Richard T. Abresch, Nanette C. Joyce, and Craig M. McDonald

Subjects
0301 basic medicine, Adult, Male, Pediatrics, medicine.medical_specialty, Supine position, Movement disorders, Adolescent, Duchenne muscular dystrophy, Developmental Disabilities, Kaplan-Meier Estimate, 03 medical and health sciences, Young Adult, 0302 clinical medicine, Quality of life, medicine, Humans, Prospective Studies, Muscular dystrophy, Young adult, Prospective cohort study, Child, Glucocorticoids, Movement Disorders, business.industry, General Medicine, medicine.disease, Long-Term Care, Clinical trial, Muscular Dystrophy, Duchenne, 030104 developmental biology, Child, Preschool, Physical therapy, Disease Progression, Quality of Life, medicine.symptom, business, 030217 neurology & neurosurgery, Follow-Up Studies
Abstract

Glucocorticoid treatment is recommended as a standard of care in Duchenne muscular dystrophy; however, few studies have assessed the long-term benefits of this treatment. We examined the long-term effects of glucocorticoids on milestone-related disease progression across the lifespan and survival in patients with Duchenne muscular dystrophy.For this prospective cohort study, we enrolled male patients aged 2-28 years with Duchenne muscular dystrophy at 20 centres in nine countries. Patients were followed up for 10 years. We compared no glucocorticoid treatment or cumulative treatment duration of less than 1 month versus treatment of 1 year or longer with regard to progression of nine disease-related and clinically meaningful mobility and upper limb milestones. We used Kaplan-Meier analyses to compare glucocorticoid treatment groups for time to stand from supine of 5 s or longer and 10 s or longer, and loss of stand from supine, four-stair climb, ambulation, full overhead reach, hand-to-mouth function, and hand function. Risk of death was also assessed. This study is registered with ClinicalTrials.gov, number NCT00468832.440 patients were enrolled during two recruitment periods (2006-09 and 2012-16). Time to all disease progression milestone events was significantly longer in patients treated with glucocorticoids for 1 year or longer than in patients treated for less than 1 month or never treated (log-rank p0·0001). Glucocorticoid treatment for 1 year or longer was associated with increased median age at loss of mobility milestones by 2·1-4·4 years and upper limb milestones by 2·8-8·0 years compared with treatment for less than 1 month. Deflazacort was associated with increased median age at loss of three milestones by 2·1-2·7 years in comparison with prednisone or prednisolone (log-rank p0·012). 45 patients died during the 10-year follow-up. 39 (87%) of these deaths were attributable to Duchenne-related causes in patients with known duration of glucocorticoids usage. 28 (9%) deaths occurred in 311 patients treated with glucocorticoids for 1 year or longer compared with 11 (19%) deaths in 58 patients with no history of glucocorticoid use (odds ratio 0·47, 95% CI 0·22-1·00; p=0·0501).In patients with Duchenne muscular dystrophy, glucocorticoid treatment is associated with reduced risk of losing clinically meaningful mobility and upper limb disease progression milestones across the lifespan as well as reduced risk of death.US Department of Education/National Institute on Disability and Rehabilitation Research; US Department of Defense; National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases; and Parent Project Muscular Dystrophy.

Published
2017

27. PCN263 PROGNOSTIC VALUE OF HEALTH-RELATED QUALITY OF LIFE ON OVERALL SURVIVAL IN OLDER AMERICANS WITH KIDNEY CANCER: A POPULATION-BASED COHORT STUDY

Author

Nalin Payakachat, C. McAdam-Marx, Naleen Raj Bhandari, J.M. Tilford, Songthip T. Ounpraseuth, E.E. Kent, and M. Kamel

Subjects
Health related quality of life, Population based cohort, business.industry, Health Policy, Public Health, Environmental and Occupational Health, medicine, Overall survival, medicine.disease, business, Value (mathematics), Kidney cancer, Demography
Published
2019
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28. Fat Embolism Syndrome following minor trauma in Duchenne muscular dystrophy

Author

Laura C. McAdam, Anjali Rastogi, Kathleen Macleod, and W. Douglas Biggar

Subjects
Male, Resuscitation, medicine.medical_specialty, Adolescent, Duchenne muscular dystrophy, Embolism, Fat, Autopsy, Young Adult, Fatal Outcome, Adrenal Cortex Hormones, Fat embolism syndrome, medicine, Humans, In patient, Fat embolism, Respiratory system, Genetics (clinical), business.industry, medicine.disease, Surgery, Muscular Dystrophy, Duchenne, Neurology, Minor trauma, Pediatrics, Perinatology and Child Health, Wounds and Injuries, Female, Neurology (clinical), business
Abstract

We describe five patients with Duchenne muscular dystrophy who presented with acute neurologic and respiratory symptoms following minor trauma. Four of the five deteriorated rapidly and died within 36 h after falling. X-rays for fractures were negative. Four of the five patients were taking corticosteroids daily. All five patients fulfilled the clinical criteria for Fat Embolism Syndrome. Autopsy findings were consistent with fat embolism in two cases. Fat Embolism Syndrome needs to be considered in patients with Duchenne muscular dystrophy following minor trauma even without fractures. Early recognition of Fat Embolism Syndrome and aggressive resuscitation are important to improve survival. This report serves as an important reminder that seatbelts need to be used at all times.

Published
2012
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29. Mars atmosphere. The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars

Author

P R, Mahaffy, C R, Webster, J C, Stern, A E, Brunner, S K, Atreya, P G, Conrad, S, Domagal-Goldman, J L, Eigenbrode, G J, Flesch, L E, Christensen, H B, Franz, C, Freissinet, D P, Glavin, J P, Grotzinger, J H, Jones, L A, Leshin, C, Malespin, A C, McAdam, D W, Ming, R, Navarro-Gonzalez, P B, Niles, T, Owen, A A, Pavlov, A, Steele, M G, Trainer, K H, Williford, J J, Wray, and María-Paz, Zorzano Mier

Abstract

The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.

Published
2014

30. Abstracts

Author

C. A. Botero, C. E. Smith, C. Holbrook, A. C. Pinchak, David Johnson, Dorothy Thomson, Taras Mycyk, M. Burbridge, Irvin Mayers, nR. W. M. Wahba, F. Belque, S. J. Kleiman, Steven Parker, Peter Cox, Helen Holtby, Lawrence Roy, Marc A. St-Amand, John M. Murkin, Donna Baird, Donal B. Downey, Alan H. Menkis, Fan Yang, Éric Troncy, Martin Francœur, Marc Charbonneau, Patrick Vinay, Gilbert Blaise, William M. Splinter, David J. Roberts, Elliot J. Rhine, Helen B. MacNeill, Craig W. Reid, William PS McKay, Miklavs Erjavec, Benjamin W. S. McKay, Peter H. Gregson, Travis Blanchet, Guy Kember, Josée Lavoie, Daniel Vischoff, Louise Cyrenne, Edith Villeneuve, Pierre Williot, A. K. Raghupathy, R. Haug, B. Punjabi, F. Ditzig, Howard Melnik, Michael J. Tessler, L. Jill Krasner, David M. Corda, Kal Solanki, A. Joseph Layon, T. James Gallagher, Daniel P. Stoltzfus, Shannon L. Rabuka, Carol A. Moote, Robert J. B. Chen, Doreen A. Yee, Ellen Harrington, Beverley A. Orser, D. Mitch Giffin, Kenneth W. Gow, P. Terry Phang, Keith R. Walley, C. Brian Warriner, Matthew H. Cohen, Andrew J. Klahsen, Deirdre O’Reilly, John McBride, Margaret Ballantyne, Blair D. Goranson, Scott Lang, William N. Dust, Jeff McKerrell, Guy Martin, René Martin, Daniel Martin, Philippe Valet, Jean-Pierre Tétrault, Caroline Dagenais, Martine Pirlet, Dominique Dansereau, Pedro D’Orléans-Justes, Agnès Jankowska, Yves Veillette, Angela L. Mathieson, Howard Intrater, Lionel Cruickshank, P. C. Duke, B. Y. Ong, Vincent Woo, Donna Schimnowski, Sharon Trosky, Linda Dalton, Ibrahim Zabani, Colin R. Chilvers, Himat Vaghadia, Pamela M. Merrick, Ibrahim Kashkari, Hossam Al-Oufi, D. Jolly, B. T. Finucane, Wolfgang Weyland, Ulrich Fritz, Heike Landmann, Ingrid Schumacher, Michael English, Dietrich Kettler, Catherine M. Duffy, Pirjo H. Manninen, Frances Chung, Shanthini Sundar, Emilio B. Lobato, Orlando Florete, Glenn B. Paige, Thierry Daloze, Daniel A. Chartrand, Denis St-Laurent, Gordon S. Fox, Murray L. Rice, D. John Doyle, George A. Volgyesi, Joseph A. Fisher, Arthur Slutsky, Igor Salazkin, Karen A. Brown, Pradeep Kulkarni, Bibiana Cujec, Randy McCuaig, Tom Hurst, David Antecol, François Bellemare, Jacques Couture, Manon Marchand, Peter McNeil, Orlando Hung, Lily M. Ho-Tai, J. Hugh Devitt, Alva G. Noel, Michael P. O’Donnell, Robert J. Greenhow, Frank W. Cervenko, Brian Milne, Mark D. Peterson, Ian R. Thomson, Robert J. Hudson, Morley Rosenbloom, Michael Moon, Jitender Sareen, H. Locke Bingham, Steven B. Backman, Reuben D. Stein, C. Polosa, Michael Tessler, Salvatore M. Spadafora, John G. Fuller, Lisa Kim, Keyvan Karkouti, D. Keith Rose, Lorraine E. Ferris, DK Rose, MM Cohen, F. E. Ralley, B. DeVarennes, M. Robitaille, Norman Searle, Raymond Martineau, Peter Conzen, A. Al-Hasani, Tom Ebert, Michael Muzi, Jean-François Hardy, Sylvain Bélisle, André Couturier, Danielle Robitaille, Micheline Roy, Lyne Gagnon, Elisabeth J. Avraamides, P. J. Dryden, J. P. O’Connor, W. R. E. Jamieson, I. Reid, D. Ansley, H. Sadeghi, L. H. Burr, A. I. Munro, P. M. Merrick, Mark Benaroia, Andrew Baker, C. David Mazer, Lee Errett, Luc Frenette, Jerry Cox, Donna Kerns, Steve Pearce, David Mark, Paul McDonagh, Lulz DeLlma, Howard Nathan, Jean-Yves Dupuls, J.Earl Wynands, G. C. Moudgil, J. G. Johnson, G. M. Moudgil, Richard I. Hall, Connie MacLaren, M. J. Ali, M. Ballantyne, D. Norris, Stephen D. Beed, Eugene A. Menard, Leon P. Noel, Gary G. Bonn, William Clarke, H. Marion Gould, Leslie E. Hall, Philippe Bernard, Juan Bass, Ramona A. Kearney, Cheryl A. Mack, Lucy M. Entwistle, Joan C. Bevan, Andrew J. Macnab, Guy Veall, Colin Marsland, Craig R. Ries, Shahnaz K. Hamid, Ian R. Selby, Nancy Sikich, Elizabeth Hsu, Patricia McCarthy, Ching-Yue Yang, Wun-Chin Wu, Jiunn-Jye Huang, Shyu-Yin Chen, Hsiang-Ning Luk, Chok-Yung Chai, Gina K. Lafreniere, Donald G. Brunet, Joel L. Parlow, Hossam El-Beheiry, Aviv Ouanounou, Mary Morris, Peter Carlen, Pamela J. Morgan, Roger Chapados, Marlene Gauthier, John W. D. Knox, Jacques LeLorier, Roddy Lin, Keith Rose, Bernadette Garvey, Robert McBrobm, L. C. McAdam, J. F. MacDonald, B. A. Orser, Georgios koutsoukos, Susan Belo, Christopher A. Chin, Brendan O’Hare, Jerrold Lerman, Junko Endo, Arthur E. Schwartz, Oktavijan Minanov, J. Gilbert Stone, David C. Adams, Aqeel A. Sandhu, Mark E. Pearson, William L. Young, Robert E. Michler, Ernest Cutz, Matt M. Kurrek, Marsha M. Cohen, Kevin Fish, Pamela Fish, Patricia Murphy, Donald Fung, Alva Noel, John-Paul Szalai, Ari Robicsek, Joshua Rucker, Joshua Kruger, Mark Slutsky, Leeor Sommer, Jeff Silverman, Jodi Dickstein, Viren Naik, Douglas J. Hemphill, Regina Kurian, Khursheed N. Jeejeebhoy, Osama A. Alahdal, N. H. Badner, W. E. Komar, R. Bhandari, R. Craen, D. Cuillerier, W. B. Dobkowski, M. H. Smith, A. N. Vannelli, R. B. Bourne, C. H. Rorabeck, J. A. Doyle, Antoinette Corvo, Richard M. Wahba, Nathalie Scheffer, John Y. C. Tsang, Brad A. Brush, N. Q. N’Guyen, C. Orain, S. Tougui, G. Lavenac, D. Milon, Ewan D. Ritchie, Doris Tong, Andrew Norris, Anthony Miniaci, Santhira D. Vairavanathan, Timothy FitzPatrick, Mark Stafford-Smith, Ken Kardash, Toula Trihas, Simcha J. Kleiman, Michel Rossignol, Dominique Bérard, Brent Martel, J. P. Tétrault, Peter G. Lunt, Dennis W. Coombs, Stephen Halpern, Elizabeth A. Peter, Patricia Janssen, Jill Mahy, M. Joanne Douglas, Caroline S. Grange, Timothy J. Adams, Louis Wadsworth, Holly Muir, Romesh Shukla, Desmond Writer, Richard McLaren, Robert Liston, Don Paetkau, Bill Y. Ong, Ron Segstro, Judy Littleford, Cristina Hurtado, Ananthan Krishnathas, Marcelo Lannes, Joanne Fortier, Jun Su, Rubini Jeganathan, and Suzanne Vaillancourt

Subjects
Anesthesiology and Pain Medicine, General Medicine
Published
1996
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31. The Canadian experience with long-term deflazacort treatment in Duchenne muscular dystrophy

Author

Laura C, McAdam, Amanda L, Mayo, Benjamin A, Alman, and W Douglas, Biggar

Subjects
Male, Canada, Adolescent, Deflazacort, Walking, Original Articles, Duchenne Muscular Dystrophy, Weight Gain, Body Height, Cataract, Spine, Muscular Dystrophy, Duchenne, Fractures, Bone, Adrenal Cortex Hormones, Bone Density, Pregnenediones, Spinal Injuries, Humans, Muscle Strength, Child, Immunosuppressive Agents
Abstract

Deflazacort is the most commonly prescribed corticosteroid for the treatment of Duchenne muscular dystrophy in Canada. We review the long term experience with deflazacort treatment at two centers in Canada; Montreal and Toronto. Deflazacort has benefitted both cohorts by prolonged ambulation, preserved cardiac and respiratory function, less scoliosis and improved survival. Common side effects in both cohorts include weight gain, decreased height and cataract formation. The Canadian experience supports the use of deflazacort in treating boys with Duchenne muscular dystrophy.

Published
2012

32. The Sample Analysis at Mars Investigation and Instrument Suite

Author

Paul R. Mahaffy, Christopher R. Webster, Michel Cabane, Pamela G. Conrad, Patrice Coll, Sushil K. Atreya, Robert Arvey, Michael Barciniak, Mehdi Benna, Lora Bleacher, William B. Brinckerhoff, Jennifer L. Eigenbrode, Daniel Carignan, Mark Cascia, Robert A. Chalmers, Jason P. Dworkin, Therese Errigo, Paula Everson, Heather Franz, Rodger Farley, Steven Feng, Gregory Frazier, Caroline Freissinet, Daniel P. Glavin, Daniel N. Harpold, Douglas Hawk, Vincent Holmes, Christopher S. Johnson, Andrea Jones, Patrick Jordan, James Kellogg, Jesse Lewis, Eric Lyness, Charles A. Malespin, David K. Martin, John Maurer, Amy C. McAdam, Douglas McLennan, Thomas J. Nolan, Marvin Noriega, Alexander A. Pavlov, Benito Prats, Eric Raaen, Oren Sheinman, David Sheppard, James Smith, Jennifer C. Stern, Florence Tan, Melissa Trainer, Douglas W. Ming, Richard V. Morris, John Jones, Cindy Gundersen, Andrew Steele, James Wray, Oliver Botta, Laurie A. Leshin, Tobias Owen, Steve Battel, Bruce M. Jakosky, Heidi Manning, Steven Squyres, Rafael Navarro-González, Christopher P. McKay, Francois Raulin, Robert Sternberg, Arnaud Buch, Paul Sorensen, Robert Kline-Schoder, David Coscia, Cyril Szopa, Samuel Teinturier, Curt Baffes, Jason Feldman, Greg Flesch, Siamak Forouhar, Ray Garcia, Didier Keymeulen, Steve Woodward, Bruce P. Block, Ken Arnett, Ryan Miller, Charles Edmonson, Stephen Gorevan, and Erik Mumm

Subjects
010504 meteorology & atmospheric sciences, 0103 physical sciences, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Published
2012
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34. Pediatric tumefactive demyelination: case series and review of the literature

Author

Susan Blaser, Brenda Banwell, and Laura C McAdam

Subjects
Male, Pathology, medicine.medical_specialty, Adolescent, Brain Abscess, Central nervous system disease, Diagnosis, Differential, Developmental Neuroscience, X ray computed, Tumefactive demyelination, Medicine, Humans, Child, business.industry, Brain Neoplasms, Brain, medicine.disease, Magnetic Resonance Imaging, Neurology, Child, Preschool, Pediatrics, Perinatology and Child Health, Female, Neurology (clinical), business, Tomography, X-Ray Computed, Demyelinating Diseases
Abstract

Tumefactive demyelinating lesions may be misdiagnosed as brain neoplasms or abscesses. In this paper, we present four cases of pediatric tumefactive demyelination. Twelve cases of pediatric tumefactive demyelination previously reported in the English literature are also summarized. We describe the neuroimaging characteristics and clinical presentation of tumefactive demyelination and how these features may be used in differentiating demyelination from other mass lesions.

Published
2002

36. Helmet hazards. Do'sdon'ts of football helmet removal

Author

D M, Kleiner, A N, Pollak, and C, McAdam

Subjects
Male, Immobilization, Transportation of Patients, Spinal Injuries, Practice Guidelines as Topic, Football, Humans, Head Protective Devices, Unconsciousness, Respiratory Insufficiency, Emergency Treatment
Abstract

EMS providers must use extreme caution when evaluating and treating an unconscious football player, especially when the extent of the injury remains unknown. Suspect any unconscious football player has an accompanying spinal injury until proven otherwise. If the football player isn't breathing or the possibility of respiratory arrest exists, it's essential that certified athletic trainers and EMS providers work quickly and effectively to remove the face mask and administer care. In most situations, the helmet doesn't need to be removed in the field. Proper management of head and neck injuries includes leaving the helmet in place whenever possible, removing only the face mask from the helmet and developing a plan to manage head- and neck-injured football players using well-trained sports medicine and EMS providers. EMS agencies should work with their local high school or college athletic trainers to practice these removal techniques prior to the start of the football season.

Published
2001

37. The Influence of the Local Neighbourhood Environment on Walking Levels During the Www Pedometer-Based Community Intervention

Author

C. McAdam, C. Millington, P. Aspinall, L.B. Robertson, N. Mutrie, W. Thompson, C. McAdam, C. Millington, P. Aspinall, L.B. Robertson, N. Mutrie, and W. Thompson

Abstract

This paper reports on the findings of a study which investigated the influence of the local neighbourhood physical environment on participant’s walking levels during the Walking for Wellbeing in the West (WWW) pedometer-based community intervention, carried out in Glasgow, 2006-2009. As far as we are aware this is the first study to examine the influence of the environment on walking levels in the context of a walking intervention, and one of only a few studies to provide information on walking-physical environment relationships for a European city.Walking activity was recorded at four stages of the intervention: baseline (n=76), and at 3 months (n=57), 6 months (n=54) and 12 months (n=45) post-intervention. Step counts were monitored using sealed Omron pedometers, and objective physical environmental data were obtained from (i) GIS datasets and (ii) street surveys carried out prior to the intervention using the Scottish Walkability Audit Tool (SWAT). Data were summarised for 400 m radius zones around each participant’s home. A total of 69 environment variables were used, reduced to 8 environment factors using Principal Axis Factoring, prior to regression analyses. Hierarchical multiple linear regression was used to examine the relationship between the environment factors and (i) step counts, and (ii) the change in step counts relative to baseline. Demographic variables included in the analysis were age and gender.Five of the environment factors were found to be significant predictors of step counts over and above age and gender, but none were significant predictors of the change in step counts relative to baseline. Environment factors that were significantly associated with step counts were: (i) Green space and recreation facilities (-ve association, p<0.05); (ii) Commercial and residential land use mix (+ve association, p<0.05); (iii) Dangerous and busy roads (-ve association, p<0.05); (iv) Indoor fitness facilities and traffic calming features (+ve assoc

Published
2012

39. PDB70 BASELINE CHARACTERISTICS AND ANTIDIABETIC EXPOSURE IN PATIENTS WITH TYPE-2 DIABETES TREATED WITH LIRAGLUTIDE

Author

Diana I. Brixner, C. McAdam Marx, Mark Aagren, C Conner, and Jonathan Bouchard

Subjects
medicine.medical_specialty, Liraglutide, business.industry, Health Policy, Internal medicine, Baseline characteristics, Public Health, Environmental and Occupational Health, medicine, In patient, Type 2 diabetes, medicine.disease, business, medicine.drug
Published
2011
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41. Attitudes towards HIV testing of patients attending hospital

Author

SheilaM. Gore, C McAdam, Stephanie Lewis, A Richardson, and Raymond P Brettle

Subjects
Male, Inpatients, medicine.medical_specialty, business.industry, Public Health, Environmental and Occupational Health, AIDS serodiagnosis, AIDS Serodiagnosis, Dermatology, Hiv testing, Hospitals, Urban, Infectious Diseases, Scotland, Surveys and Questionnaires, Family medicine, Outpatients, Humans, Medicine, Female, Pharmacology (medical), business, Attitude to Health
Published
1997
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42. Electrochemical studies with dissolved and surface-confined forms of neo-pentyl-ferrocene-based polyesters utilising [NBu4][B(C6F5)4] and other electrolytes.

Author

Ayman Nafady, C. McAdam, Alan Bond, Stephen Moratti, and Jim Simpson

Subjects
*ELECTROCHEMICAL analysis, *VOLTAMMETRY, *CARBON electrodes, *POLYESTERS, *FERROCENE, *IONIC liquids, *MICROCRYSTALLINE polymers, *FUNCTIONAL groups
Abstract

Abstract  The voltammetric oxidation at a glassy carbon electrode of a series of ferrocenyl polyesters PmF{X}, (X=T, terephthalate; N, 2,6-naphthalene dicarboxylate; B, 4,4′-biphenyl dicarboxylate) is reported in the weakly donating and low-polarity CH2Cl2 solvent containing [NBu4][PF6], [NBu4][B(C6F5)4], or 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([bmpyr][TFSA]) as the supporting electrolyte. The one electron oxidation of the ferrocenyl groups is strongly influenced by the nature of the supporting electrolyte anion. Use of the conventional [PF6]− anion or the room temperature ionic liquid (RTIL), [bmpyr][TFSA] as the supporting electrolyte, gives rise to significant oxidation product interaction (precipitation and/or adsorption) with the electrode surface. In marked contrast, diffusion-controlled, chemically and electrochemically reversible processes are observed when the weakly coordinating [B(C6F5)4]− is used as the anionic component of the supporting electrolyte. In this case, data obtained via cyclic voltammetry, chronoamperometry and chronocoulometry are consistent with ideal reversible one electron oxidation processes and a soluble cationic product. Diffusion coefficients of the monomers, polymers, ferrocene and decamethyferrocene are reported in the CH2Cl2/[NBu4][B(C6F5)4] system. Importantly, reversible potentials that are easily obtained under these conditions show that the acyl or methyl linkers, through which the ferrocenyl group is attached to the neo-pentylenediol component, tune the redox properties of the polymers. Electrochemical studies with a glassy carbon electrode modified with microcrystals of the PmFT polymer conducted in aqueous (with KCl supporting electrolyte) or neat ionic liquid ([bmpyr][TFSA]) media also are reported. Different mechanisms apply in each of these cases. [ABSTRACT FROM AUTHOR]

Published
2009
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43. μ3-ethylidyne-triphenylphosphine-octacarbonyltricobalt: a re-determination from diffractometer data.

Author

C. McAdam, Brian Robinson, Jim Simpson, and Roderick Stanley

Subjects
*HYDROGEN bonding, *COBALT, *OPTICAL diffraction, *PHOSPHINE, *CARBYNES
Abstract

Abstract  The structure of the title compound was originally reported from film data (Brice et al., Inorg Chem 9:362, 1970) and comprises a triangle of cobalt atoms capped by an ethylidyne substituent to form an approximately tetrahedral cluster unit. The triphenylphosphine ligand lies in an equatorial position with respect to the plane of the cobalt triangle. Two carbonyl groups, one axial the other equatorial, complete the coordination sphere of the cobalt atom bound to phosphorus. The other two cobalt atoms each carry two equatorial and one axial carbonyl ligand. The Co–Co bond cis to the phosphine substituent is significantly longer than the other two Co–Co distances. The crystal structure is stabilised by C—H···π interactions and C—H···O hydrogen bonds. [ABSTRACT FROM AUTHOR]

Published
2008
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48. Wodginite--a new tin-manganese tantalite from Wodgina, Australia, and Bernic Lake, Manitoba

Author

John F. Rowland, Ernest H. Nickel, and R. C. McAdam

Subjects
Crystallography, Ixiolite, Mineral, chemistry, Wodginite, engineering, chemistry.chemical_element, Mineralogy, Manganese, engineering.material, Tin, Tantalate, Monoclinic crystal system
Abstract

"The mineral is monoclinic, space group C2/c or Cc, with cell parameters of a = 9.52 A, b = 11.47 A, c = 5.10 A and beta = 91 degrees 189 (Wodgina) and a = 9.47 A, b = 11.42 A, c = 5.09 A and beta = 91 degrees 029 (Bernic lake). Its composition is expressed by the formula A 16 O 32 , where A represents chiefly Ta, Sn and Mn, with lesser amounts of Nb, Fe and Ti. The relationship of wodginite to columbite-tantalite, ixiolite and olovotantalite is discussed."

Published
1963
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