Design and Development of a Miniaturized Double Latching Solenoid Valve for the Sample Analysis at Mars Instrument Suite

NASA Technical Reports Server (NTRS)

Smith, James T.

2008-01-01

The development of the in-house Miniaturized Double Latching Solenoid Valve, or Microvalve, for the Gas Processing System (GPS) of the Sample Analysis at Mars (SAM) instrument suite is described. The Microvalve is a double latching solenoid valve that actuates a pintle shaft axially to hermetically seal an orifice. The key requirements and the design innovations implemented to meet them are described.

Active Region Soft X-Ray Spectra as Observed Using Sounding Rocket Measurements from the Solar Aspect Monitor (SAM), - a Modified SDO/EVE Instrument

NASA Astrophysics Data System (ADS)

Wieman, S. R.; Didkovsky, L. V.; Woods, T. N.; Jones, A. R.; Caspi, A.; Warren, H. P.

2015-12-01

Observations of solar active regions (ARs) in the soft x-ray spectral range (0.5 to 3.0 nm) were made on sounding rocket flight NASA 36.290 using a modified Solar Aspect Monitor (SAM), a pinhole camera on the EUV Variability Experiment (EVE) sounding rocket instrument. The suite of EVE rocket instruments is designed for under-flight calibrations of the orbital EVE on SDO. While the sounding rocket EVE instrument is for the most part a duplicate of the EVE on SDO, the SAM channel on the rocket version was modified in 2012 to include a free-standing transmission grating so that it could provide spectrally resolved images of the solar disk with the best signal to noise ratio for the brightest features on it, such as ARs. Calibrations of the EVE sounding rocket instrument at the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility (NIST SURF) have provided a measurement of the SAM absolute spectral response function and a mapping of wavelength separation in the grating diffraction pattern. For solar observations, this spectral separation is on a similar scale to the spatial size of the AR on the CCD, so dispersed AR images associated with emission lines of similar wavelength tend to overlap. Furthermore, SAM shares a CCD detector with MEGS-A, a separate EVE spectrometer channel, and artifacts of the MEGS-A signal (a set of bright spectral lines) appear in the SAM images. For these reasons some processing and analysis of the solar images obtained by SAM must be performed in order to determine spectra of the observed ARs. We present a method for determining AR spectra from the SAM rocket images and report initial soft X-ray spectra for two of the major active regions (AR11877 and AR11875) observed on flight 36.290 on 21 October 2013 at about 18:30 UT. We also compare our results with concurrent measurements from other solar soft x-ray instrumentation.

Sample Analysis at Mars (SAM) Media Day

NASA Image and Video Library

2017-12-08

On Saturday, November 26, NASA is scheduled to launch the Mars Science Laboratory (MSL) mission featuring Curiosity, the largest and most advanced rover ever sent to the Red Planet. The Curiosity rover bristles with multiple cameras and instruments, including Goddard's Sample Analysis at Mars (SAM) instrument suite. By looking for evidence of water, carbon, and other important building blocks of life in the Martian soil and atmosphere, SAM will help discover whether Mars ever had the potential to support life. Curiosity will be delivered to Gale crater, a 96-mile-wide crater that contains a record of environmental changes in its sedimentary rock, in August 2012. ----- NASA image November 18, 2010 The Sample Analysis at Mars (SAM) instrument is considered one of the most complicated instruments ever to land on the surface of another planet. Equipped with a gas chromatograph, a quadruple mass spectrometer, and a tunable laser spectrometer, SAM will carry out the initial search for organic compounds when the Mars Science Laboratory (MSL) rover lands in 2012. Credit: NASA/GSFC/Ed Campion NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover

NASA Technical Reports Server (NTRS)

Mahaffy, P. R.; Bleacher, L.; Jones, A.; Conrad, P. G.; Cabane, M.; Webster, C. R.; Atreya, S. A.; Manning, H.

2010-01-01

An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments [1] and the other Curiosity investigations [2] is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers.

Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover

NASA Astrophysics Data System (ADS)

Mahaffy, P. R.; Bleacher, L.; Jones, A.; Atreya, S. K.; Manning, H. L.; Cabane, M.; Webster, C. R.; Sam Team

2010-12-01

Introduction: An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments [1] and the other Curiosity investigations [2] is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers. SAM Instrument Suite: SAM’s instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). SAM can identify organic compounds in Mars rocks to sub-ppb sensitivity and secure precise isotope ratios for C, H, and O in carbon dioxide and water and measure trace levels of methane and its carbon 13 isotope. The SAM gas processing system consists of valves, heaters, pressure sensors, gas scrubbers and getters, traps, and gas tanks used for calibration or combustion experiments [2]. A variety of calibrant compounds interior and exterior to SAM will allow the science and engineering teams to assess SAM’s performance. SAM has been calibrated and tested in a Mars-like environment. Keeping Educators and the Public Informed: The Education and Public Outreach (EPO) goals of the SAM team are to make this complex chemical laboratory and its data widely available to educators, students, and the public. Formal education activities include developing templates for professional development workshops for educators to teach them about SAM and Curiosity, incorporating data into Mars Student Data Teams, and writing articles

Wide Range Vacuum Pumps for the SAM Instrument on the MSL Curiosity Rover

NASA Technical Reports Server (NTRS)

Sorensen, Paul; Kline-Schoder, Robert; Farley, Rodger

2014-01-01

Creare Incorporated and NASA Goddard Space Flight Center developed and space qualified two wide range pumps (WRPs) that were included in the Sample Analysis at Mars (SAM) instrument. This instrument was subsequently integrated into the Mars Science Laboratory (MSL) "Curiosity Rover," launched aboard an Atlas V rocket in 2011, and landed on August 6, 2012, in the Gale Crater on Mars. The pumps have now operated for more than 18 months in the Gale Crater and have been evacuating the key components of the SAM instrument: a quadrupole mass spectrometer, a tunable laser spectrometer, and six gas chromatograph columns. In this paper, we describe the main design challenges and the ways in which they were solved. This includes the custom design of a miniaturized, high-speed motor to drive the turbo drag pump rotor, analysis of rotor dynamics for super critical operation, and bearing/lubricant design/selection.

Search for Chemical Biomarkers on Mars Using the Sample Analysis at Mars Instrument Suite on the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Conrad, P.; Dworkin, J. P.; Eigenbrode, J.; Mahaffy, P. R.

2011-01-01

One key goal for the future exploration of Mars is the search for chemical biomarkers including complex organic compounds important in life on Earth. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) will provide the most sensitive measurements of the organic composition of rocks and regolith samples ever carried out in situ on Mars. SAM consists of a gas chromatograph (GC), quadrupole mass spectrometer (QMS), and tunable laser spectrometer to measure volatiles in the atmosphere and released from rock powders heated up to 1000 C. The measurement of organics in solid samples will be accomplished by three experiments: (1) pyrolysis QMS to identify alkane fragments and simple aromatic compounds; pyrolysis GCMS to separate and identify complex mixtures of larger hydrocarbons; and (3) chemical derivatization and GCMS extract less volatile compounds including amino and carboxylic acids that are not detectable by the other two experiments.

Investigating the Origin of Chlorohydrocarbons Detected by the Sample Analysis at Mars (SAM) Instrument at Rocknest

NASA Technical Reports Server (NTRS)

Glavin, D.; Archer, D.; Brunner, A.; Buch, A.; Cabane, M.; Coll, P.; Conrad, P.; Coscia, D.; Dworkin J.; Eigenbrode, J.;

SAM-Like Evolved Gas Analyses of Phyllosilicate Minerals and Applications to SAM Analyses of the Sheepbed Mudstone, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Franz, H. B.; Mahaffy, P. R.; Eigenbrode, J. L.; Stern, J. C.; Brunner, B.; Sutter, B.; Archer, P. D.; Ming , D. W.; Morris, R. V.;

SAMS-II Requirements and Operations

NASA Technical Reports Server (NTRS)

Wald, Lawrence W.

1998-01-01

The Space Acceleration Measurements System (SAMS) II is the primary instrument for the measurement, storage, and communication of the microgravity environment aboard the International Space Station (ISS). SAMS-II is being developed by the NASA Lewis Research Center Microgravity Science Division to primarily support the Office of Life and Microgravity Science and Applications (OLMSA) Microgravity Science and Applications Division (MSAD) payloads aboard the ISS. The SAMS-II is currently in the test and verification phase at NASA LeRC, prior to its first hardware delivery scheduled for July 1998. This paper will provide an overview of the SAMS-II instrument, including the system requirements and topology, physical and electrical characteristics, and the Concept of Operations for SAMS-II aboard the ISS.

High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suite Gas Processing System (GPS) Carbon Dioxide Scrubber

NASA Technical Reports Server (NTRS)

Hoffman, Christopher; Munoz, Bruno; Gundersen, Cynthia; Thomas, Walter, III; Stephenson, Timothy

2008-01-01

In support of the GPS for the SAM instrument suite built by NASA/GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr alloy wire, 0.0142 cm diameter, for use as a heater element for the carbon dioxide scrubber. The element would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The element also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni- 20Cr in low pressure CO2, coupled with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the element reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber

NASA Technical Reports Server (NTRS)

Gundersen, Cynthia; Hoffman, Christopher; Munoz, Bruno; Steohenson, Timothy; Thomas, Walter

2008-01-01

In support of the GPS for the SAM instrument suite built by GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr wire, 0.0056 inches in diameter, for use as a heater element for the carbon dioxide scrubber. The wire would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The wire also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni-20Cr in low pressure CO2, together with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the wire reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

Fatty Acid Detection in Mars-Analogous Rock Samples with the TMAH Wet Chemistry Experiment on the Sample Analysis at Mars (SAM) Instrument

NASA Astrophysics Data System (ADS)

Williams, A. J.; Eigenbrode, J. L.; Wilhelm, M. B.; Johnson, S. S.; Craft, K.; O'Reilly, S.; Lewis, J. M. T.; Williams, R.; Summons, R. E.; Benison, K. C.; Mahaffy, P. R.

2017-12-01

The Curiosity rover is exploring sedimentary rock sequences in Gale Crater for evidence of habitability and searching for organic compounds using the Sample Analysis at Mars (SAM) instrument suite. SAM includes a gas chromatograph mass spectrometer (GC-MS) and pyrolysis ovens. SAM has the ability to perform wet chemistry experiments, one of which uses tetramethylammonium hydroxide (TMAH) thermochemolysis to liberate bound lipids, making them sufficiently volatile for detection by GC-MS. To determine the effectiveness of the SAM-like TMAH experiment on fatty acid methyl ester (FAME) biomarker identification, rock and sediment samples were collected from a variety of Mars analog environments including iron oxides from a modern mineral precipitate and older surface gossan at Iron Mountain, CA, as well as modern acid salt and neutral lake sediments with mixed iron oxides and clays from Western Australia; siliceous sinter from recently inactive and modern near-vent Icelandic hot springs deposits; modern carbonate ooids from The Bahamas, and organic-rich shale from Germany. Samples underwent pyrolysis with TMAH. Fatty acids were analyzed by pyro-GC-MS using a SAM-like heating ramp (35°C/min) as well as a 500°C flash on a Frontier pyrolyzer and Agilent GC-MS instrument. Results reveal that FAMEs were detectable with the TMAH experiment in nearly all samples. Low molecular weight (MW) C6:0-C10:0 FAMEs were present in all samples, medium MW C11:0-C18:2 FAMEs were present in select samples, and high MW (HMW) C20:0-C30:0 FAMEs were present in the shale sample. Many of these samples exhibited an even-over-odd carbon number preference, indicating biological production. These experiments demonstrate that TMAH thermochemolysis with SAM-like pyro-GC-MS is effective in fatty acid analysis from natural Mars-analog samples that vary in mineralogy, age, and microbial community input. HMW FAMEs are not detected in iron-dominated samples, and may not be detectable at low

Detection of Organic Constituents Including Chloromethylpropene in the Analyses of the ROCKNEST Drift by Sample Analysis at Mars (SAM)

NASA Technical Reports Server (NTRS)

Eigenbrode, J. L.; Glavin, D.; Coll, P.; Summons, R. E.; Mahaffy, P.; Archer, D.; Brunner, A.; Conrad, P.; Freissinet, C.; Martin, M.;

Coordinated Analyses of Antarctic Sediments as Mars Analog Materials Using Reflectance Spectroscopy and Current Flight-Like Instruments for CheMin, SAM and MOMA

NASA Technical Reports Server (NTRS)

Bishop, Janice L.; Franz, Heather B.; Goetz, Walter; Blake, David F.; Freissinet, Caroline; Steininger, Harald; Goesmann, Fred; Brinckerhoff, William B.; Getty, Stephanie; Pinnick, Veronica T.;

PDS4 vs PDS3 - A Comparison of PDS Data for Two Mars Rovers - Existing Mars Curiosity Mission Mass Spectrometer (SAM) PDS3 Data vs Future ExoMars Rover Mass Spectrometer (MOMA) PDS4 Data

NASA Astrophysics Data System (ADS)

Lyness, E.; Franz, H. B.; Prats, B.

2017-12-01

The Sample Analysis at Mars (SAM) instrument is a suite of instruments on Mars aboard the Mars Science Laboratory rover. Centered on a mass spectrometer, SAM delivers its data to the PDS Atmosphere's node in PDS3 format. Over five years on Mars the process of operating SAM has evolved and extended significantly from the plan in place at the time the PDS3 delivery specification was written. For instance, SAM commonly receives double or even triple sample aliquots from the rover's drill. SAM also stores samples in spare cups for long periods of time for future analysis. These unanticipated operational changes mean that the PDS data deliveries are absent some valuable metadata without which the data can be confusing. The Mars Organic Molecule Analyzer (MOMA) instrument is another suite of instruments centered on a mass spectrometer bound for Mars. MOMA is part of the European ExoMars rover mission schedule to arrive on Mars in 2021. While SAM and MOMA differ in some important scientific ways - MOMA uses an linear ion trap compared to the SAM quadropole mass spectrometer and MOMA has a laser desorption experiment that SAM lacks - the data content from the PDS point of view is comparable. Both instruments produce data containing mass spectra acquired from solid samples collected on the surface of Mars. The MOMA PDS delivery will make use of PDS4 improvements to provide a metadata context to the data. The MOMA PDS4 specification makes few assumptions of the operational processes. Instead it provides a means for the MOMA operators to provide the important contextual metadata that was unanticipated during specification development. Further, the software tools being developed for instrument operators will provide a means for the operators to add this crucial metadata at the time it is best know - during operations.

Detecting Organic Compounds Released from Iron Oxidizing Bacteria using Sample Analysis at Mars (SAM) Like Instrument Protocols

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Popa, R.; Martin, M. G.; Freissinet, C.; Fisk, M. R.; Dworkin, J. P.; Mahaffy, P. R.

2012-01-01

Mars is a planet of great interest for Astrobiology since its past environmental conditions are thought to have been favourable for the emergence life. At present, the Red Planet is extremely cold and dry and the surface is exposed to intense UV and ionizing radiation, conditions generally considered to be incompatible with life as we know it on Earth. It was proposed that the shallow subsurface of Mars, where temperatures can be above freezing and liquid water can exist on rock surfaces, could harbor chemolithoautotrophic bacteria such as the iron oxidizing microorganism Pseudomonas sp. HerB. The Mars Science Laboratory (MSL) mission will provide the next opportunity to carry out in situ measurements for organic compounds of possible biological origin on Mars. One instrument onboard MSL, called the Sample Analysis at Mars (SAM) instrument suite, will carry out a broad and sensitive search for organic compounds in surface samples using either high temperature pyrolysis or chemical extraction followed by gas chromatography mass spectrometry. We present gas chromatograph mass spectrometer (GC/MS) data on crushed olivine rock powders that have been inoculated with Pseudomonas sp. HerB at different concentrations ranging from approx 10(exp 2) to 10(exp 7) cells per gram. The inoculated olivine samples were heated under helium carrier gas flow at 500 C and the pyrolysis products concentrated using a SAM-like hydrocarbon trap set at -20 C followed by trap heating and analysis by GC/Ms. In addition, the samples were also extracted using a low temperature "one-pot" chemical extraction technique using N-methyl, N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) as the silylating agent prior to GC/MS analysis. We identified several aldehydes, thiols, and alkene nitriles after pyrolysis GC/MS analysis of the bacteria that were not found in the olivine control samples that had not been inoculated with bacteria. The distribution of pyrolysis products extracted from the

Initial SAM Calibration Gas Experiments on Mars: Quadrupole Mass Spectrometer Results and Implications

NASA Technical Reports Server (NTRS)

Franz, Heather B.; Trainer, Melissa G.; Malespin, Charles A.; Mahaffy, Paul R.; Atreya, Sushil K.; Becker, Richard H,; Benna, Mehdi; Conrad, Pamela G.; Eigenbrode, Jennifer L.; Freissinet, Caroline;

Initial SAM calibration gas experiments on Mars: Quadrupole mass spectrometer results and implications

NASA Astrophysics Data System (ADS)

Franz, Heather B.; Trainer, Melissa G.; Malespin, Charles A.; Mahaffy, Paul R.; Atreya, Sushil K.; Becker, Richard H.; Benna, Mehdi; Conrad, Pamela G.; Eigenbrode, Jennifer L.; Freissinet, Caroline; Manning, Heidi L. K.; Prats, Benito D.; Raaen, Eric; Wong, Michael H.

2017-04-01

The Sample Analysis at Mars (SAM) instrument suite of the Mars Science Laboratory (MSL) Curiosity rover is equipped to analyze both martian atmospheric gases and volatiles released by pyrolysis of solid surface materials, with target measurements including chemical and isotopic composition (Mahaffy et al., 2012). To facilitate assessment of instrument performance and validation of results obtained on Mars, SAM houses a calibration cell containing CO2, Ar, N2, Xe, and several fluorinated hydrocarbon compounds (Franz et al., 2014; Mahaffy et al., 2012). This report describes the first two experiments utilizing this calibration cell on Mars and gives results from analysis of data acquired with the SAM Quadrupole Mass Spectrometer (QMS). These data support the accuracy of isotope ratios obtained with the QMS (Conrad et al., 2016; Mahaffy et al., 2013) and provide ground-truth for reassessment of analytical constants required for atmospheric measurements, which were reported in previous contributions (Franz et al., 2015, 2014). The most significant implication of the QMS data involves reinterpretation of pre-launch contamination previously believed to affect only CO abundance measurements (Franz et al., 2015) to affect N2 abundances, as well. The corresponding adjustment to the N2 calibration constant presented here brings the atmospheric volume mixing ratios for Ar and N2 retrieved by SAM into closer agreement with those reported by the Viking mission (Owen et al., 1977; Oyama and Berdahl, 1977).

Synergy of SAM and ChemCam instruments (Curiosity Rover) to Search for Organic Matter at Mars

NASA Astrophysics Data System (ADS)

Dequaire, T.; Coll, P.; Szopa, C.; Maurice, S.; Mangold, N.

2014-07-01

This work proposes to determine ChemCam capabilities to detect organic molecules in the martian rocks, by coupling LIBS and passive spectroscopy using the ChemCam testbed (IRAP) in order to select at best the samples analyzed by the SAM instrument.

The FIELDS Instrument Suite for Solar Probe Plus

NASA Technical Reports Server (NTRS)

Bale, S. D.; Goetz, K.; Harvey, P. R.; Turin, P.; Bonnell, J. W.; Dudok de Wit, T.; Ergun, R. E.; MacDowall, R. J.; Pulupa, M.; Andre, M.;

The FIELDS Instrument Suite for Solar Probe Plus

PubMed Central

Goetz, K.; Harvey, P.R.; Turin, P.; Bonnell, J.W.; de Wit, T. Dudok; Ergun, R.E.; MacDowall, R.J.; Pulupa, M.; Andre, M.; Bolton, M.; Bougeret, J.-L.; Bowen, T.A.; Burgess, D.; Cattell, C.A.; Chandran, B.D.G.; Chaston, C.C.; Chen, C.H.K.; Choi, M.K.; Connerney, J.E.; Cranmer, S.; Diaz-Aguado, M.; Donakowski, W.; Drake, J.F.; Farrell, W.M.; Fergeau, P.; Fermin, J.; Fischer, J.; Fox, N.; Glaser, D.; Goldstein, M.; Gordon, D.; Hanson, E.; Harris, S.E.; Hayes, L.M.; Hinze, J.J.; Hollweg, J.V.; Horbury, T.S.; Howard, R. A.; Hoxie, V.; Jannet, G.; Karlsson, M.; Kasper, J.C.; Kellogg, P.J.; Kien, M.; Klimchuk, J.A.; Krasnoselskikh, V.V.; Krucker, S.; Lynch, J.J.; Maksimovic, M.; Malaspina, D.M.; Marker, S.; Martin, P.; Martinez-Oliveros, J.; McCauley, J.; McComas, D.J.; McDonald, T.; Meyer-Vernet, N.; Moncuquet, M.; Monson, S.J.; Mozer, F.S.; Murphy, S.D.; Odom, J.; Oliverson, R.; Olson, J.; Parker, E.N.; Pankow, D.; Phan, T.; Quataert, E.; Quinn, T.; Ruplin, S.W.; Salem, C.; Seitz, D.; Sheppard, D.A.; Siy, A.; Stevens, K.; Summers, D.; Szabo, A.; Timofeeva, M.; Vaivads, A.; Velli, M.; Yehle, A.; Werthimer, D.; Wygant, J.R.

2018-01-01

NASA’s Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products. PMID:29755144

[German translation and validation of the Stress Appraisal Measure (SAM)].

PubMed

Delahaye, M; Stieglitz, R D; Graf, M; Keppler, C; Maes, J; Pflueger, M

2015-05-01

In the present study, the German-language version of the Stress Appraisal Measure (SAM) by Peacock and Wong was validated in a student population. SAM is a relatively short questionnaire (28 items) that evaluates a current, stress-triggering event. The theoretical background is provided by the stress model of Lazarus and Folkman. 85 students (age: 23; 59 female, 26 male) were exposed to two stress scenarios in order to test whether they were suited to provoke stress. A factor analysis was performed and the internal consistency of the seven SAM scales was determined. In addition, the convergent validity of SAM with State and Trait Anxiety Inventory (STAI), Coping Inventory for Stressful Situations (CISS) and specific emotion scales was investigated via Pearson's product-moment correlation. The two stress scenarios were suited to evoke stress. The factor structure and the internal consistency of the individual scales, as well as the convergent validity of SAM were replicated with minor limitations in the present German version. Some items (especially from the fifth factor) were only replicated partially. SAM can also be employed in the German language version. © Georg Thieme Verlag KG Stuttgart · New York.

In situ analysis of Mars soil sample with the sam gcms instrumentation onboard Curiosity : interpretation and comparison of measurements done at Rocknest and Yelloknife bay sites

NASA Astrophysics Data System (ADS)

Szopa, Cyril; Coll, Patrice; Cabane, Michel; Coscia, David; Buch, Arnaud; Francois, Pascaline; Millan, Maeva; Teinturier, Sammy; Navarro-Gonzales, Rafael; Glavin, Daniel; Freissinet, Caro; Steele, Andrew; Eigenbrode, Jen; Mahaffy, Paul

2014-05-01

The characterisation of the chemical and mineralogical composition of regolith samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Amongst the SAM suite of instruments [1], SAM-GC (Gas Chromatograph) is devoted to identify and quantify volatiles evolved from the thermal (heating up to about 900°C)/chemical (derivatization procedure) treatment of any soil sample collected by the Curiosity rover. With the aim to search for potential organic molecules outgassed from the samples, a SAM-GC analytical channel composed of thermal-desorption injector and a MXT-CLP chromatographic column was chosen to achieve all the measurements done up today, as it was designed for the separation of a wide range of volatile organic molecules. Three solid samples have been analyzed with GCMS, one sand sample collected at the Rocknest site, and two rock samples (John Klein and Cumberland respectively) collected at the Yellowknife Bay site using the Curiosity driller. All the measurements were successful and they produced complex chromatograms with both detectors used for SAM GC, i.e. a thermal conductivity detector and the SAM quandrupole mass spectrometer. Their interpretation already revealed the presence of an oxychlorine phase present in the sample which is at the origin of chlorohydrocarbons clearly identified [2] but this represents only a fraction of the GCMS signal recorded [3,4]. This work presents a systematic comparison of the GCMS measurements done for the different samples collected, supported by reference data obtained in laboratory with different spare models of the gas chromatograph, with the aim to bring new elements of interpretation of the SAM measurements. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Glavin, D. et al. (2013), JGR. [3] Leshin L. et al. (2013), Science, [4] Ming D. et al. (2013), Science, 32, 64

Evolved Gas Analyses of the Murray Formation in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument

NASA Technical Reports Server (NTRS)

Sutter, B.; McAdam, A. C.; Rampe, E. B.; Thompson, L. M.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

2017-01-01

The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 13 samples from Gale Crater. All SAM-evolved gas analyses have yielded a multitude of volatiles (e.g., H2O, SO2, H2S, CO2, CO, NO, O2, HCl) [1- 6]. The objectives of this work are to 1) Characterize recent evolved SO2, CO2, O2, and NO gas traces of the Murray formation mudstone, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results relative to understanding the geological history of Gale Crater.

Mars Methane Detection and Variability at Gale Crater Measured by the TLS instrument in SAM on the Curiosity Rover

NASA Astrophysics Data System (ADS)

Webster, C. R.; Mahaffy, P. R.; Atreya, S. K.; Flesch, G.

2015-12-01

Over the last several years, Earth-based telescopic and Mars orbit remote sensing instruments have reported significant abundances of methane on Mars ranging to tens of parts-per-billion by volume (ppbv). These observations have reported "plumes" or localized patches of methane with variations on timescales much faster than model predictions, leading to speculation of sources from sub-surface methanogen bacteria, geological water-rock reactions, degassing of infalling comets, or UV degradation of micro-meteorites or interplanetary dust. Using the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on Curiosity, we report in situ detection of methane at background levels of ~0.7 ppbv and also in an episodic release at ten times this value. We will discuss the mechanisms that are believed contributing to these two regimes, report new measurements made since the publication in Science1, and discuss the evidence and implications for seasonal vs. episodic release. Reference 1. "Mars Methane Detection and Variability at Gale Crater", C. R. Webster et al., Science, 347, 415-417 (2015). The research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

Isotopic Composition of Carbon Dioxide Released from Confidence Hills Sediment as Measured by the Sample Analysis at Mars (SAM) Quadrupole Mass Spectrometer

NASA Technical Reports Server (NTRS)

Franz, H. B.; Mahaffy, P. R.; Stern, J.; Archer, P., Jr.; Conrad, P.; Eigenbrode, J.; Freissinet, C.; Glavin, D.; Grotzinger, J. P.; Jones, J.;

Heterotypic Sam-Sam association between Odin-Sam1 and Arap3-Sam: binding affinity and structural insights.

PubMed

Mercurio, Flavia A; Marasco, Daniela; Pirone, Luciano; Scognamiglio, Pasqualina L; Pedone, Emilia M; Pellecchia, Maurizio; Leone, Marilisa

2013-01-02

Arap3 is a phosphatidylinositol 3 kinase effector protein that plays a role as GTPase activator (GAP) for Arf6 and RhoA. Arap3 contains a sterile alpha motif (Sam) domain that has high sequence homology with the Sam domain of the EphA2-receptor (EphA2-Sam). Both Arap3-Sam and EphA2-Sam are able to associate with the Sam domain of the lipid phosphatase Ship2 (Ship2-Sam). Recently, we reported a novel interaction between the first Sam domain of Odin (Odin-Sam1), a protein belonging to the ANKS (ANKyrin repeat and Sam domain containing) family, and EphA2-Sam. In our latest work, we applied NMR spectroscopy, surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) to characterize the association between Arap3-Sam and Odin-Sam1. We show that these two Sam domains interact with low micromolar affinity. Moreover, by means of molecular docking techniques, supported by NMR data, we demonstrate that Odin-Sam1 and Arap3-Sam might bind with a topology that is common to several Sam-Sam complexes. The revealed structural details form the basis for the design of potential peptide antagonists that could be used as chemical tools to investigate functional aspects related to heterotypic Arap3-Sam associations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sample Analysis at Mars Instrument Simulator

NASA Technical Reports Server (NTRS)

Benna, Mehdi; Nolan, Tom

2013-01-01

The Sample Analysis at Mars Instrument Simulator (SAMSIM) is a numerical model dedicated to plan and validate operations of the Sample Analysis at Mars (SAM) instrument on the surface of Mars. The SAM instrument suite, currently operating on the Mars Science Laboratory (MSL), is an analytical laboratory designed to investigate the chemical and isotopic composition of the atmosphere and volatiles extracted from solid samples. SAMSIM was developed using Matlab and Simulink libraries of MathWorks Inc. to provide MSL mission planners with accurate predictions of the instrument electrical, thermal, mechanical, and fluid responses to scripted commands. This tool is a first example of a multi-purpose, full-scale numerical modeling of a flight instrument with the purpose of supplementing or even eliminating entirely the need for a hardware engineer model during instrument development and operation. SAMSIM simulates the complex interactions that occur between the instrument Command and Data Handling unit (C&DH) and all subsystems during the execution of experiment sequences. A typical SAM experiment takes many hours to complete and involves hundreds of components. During the simulation, the electrical, mechanical, thermal, and gas dynamics states of each hardware component are accurately modeled and propagated within the simulation environment at faster than real time. This allows the simulation, in just a few minutes, of experiment sequences that takes many hours to execute on the real instrument. The SAMSIM model is divided into five distinct but interacting modules: software, mechanical, thermal, gas flow, and electrical modules. The software module simulates the instrument C&DH by executing a customized version of the instrument flight software in a Matlab environment. The inputs and outputs to this synthetic C&DH are mapped to virtual sensors and command lines that mimic in their structure and connectivity the layout of the instrument harnesses. This module executes

Carbon and Sulfur Isotopic Composition of Yellowknife Bay Sediments: Measurements by the Sample Analysis at Mars (SAM) Quadrupole Mass Spectrometer

NASA Technical Reports Server (NTRS)

Franz, H. B.; Mahaffy, P. R.; Stern, J. C.; Eigenbrode, J. L.; Steele, A.; Ming, D. W.; McAdam, A. C.; Freissinet, C.; Glavin, D. P.; Archer, P. D.;

The suite of small-angle neutron scattering instruments at Oak Ridge National Laboratory

DOE PAGES

Heller, William T.; Cuneo, Matthew J.; Debeer-Schmitt, Lisa M.; ...

2018-02-21

Oak Ridge National Laboratory is home to the High Flux Isotope Reactor (HFIR), a high-flux research reactor, and the Spallation Neutron Source (SNS), the world's most intense source of pulsed neutron beams. The unique co-localization of these two sources provided an opportunity to develop a suite of complementary small-angle neutron scattering instruments for studies of large-scale structures: the GP-SANS and Bio-SANS instruments at the HFIR and the EQ-SANS and TOF-USANS instruments at the SNS. This article provides an overview of the capabilities of the suite of instruments, with specific emphasis on how they complement each other. As a result, amore » description of the plans for future developments including greater integration of the suite into a single point of entry for neutron scattering studies of large-scale structures is also provided.« less

The suite of small-angle neutron scattering instruments at Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heller, William T.; Cuneo, Matthew J.; Debeer-Schmitt, Lisa M.

Oak Ridge National Laboratory is home to the High Flux Isotope Reactor (HFIR), a high-flux research reactor, and the Spallation Neutron Source (SNS), the world's most intense source of pulsed neutron beams. The unique co-localization of these two sources provided an opportunity to develop a suite of complementary small-angle neutron scattering instruments for studies of large-scale structures: the GP-SANS and Bio-SANS instruments at the HFIR and the EQ-SANS and TOF-USANS instruments at the SNS. This article provides an overview of the capabilities of the suite of instruments, with specific emphasis on how they complement each other. As a result, amore » description of the plans for future developments including greater integration of the suite into a single point of entry for neutron scattering studies of large-scale structures is also provided.« less

The Search for Nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

NASA Technical Reports Server (NTRS)

Navarro-Gonzalez, Rafael; Stern, Jennifer C.; Freissinet, Caroline; McKay, Chirstopher P.; Sutter, Brad; Archer, P. Douglas, Jr.; McAdam, Amy; Franz, Heather; Coll, Partice J.; Glavin, Daniel Patrick;

The Characterization of Biosignatures in Caves Using an Instrument Suite.

PubMed

Uckert, Kyle; Chanover, Nancy J; Getty, Stephanie; Voelz, David G; Brinckerhoff, William B; McMillan, Nancy; Xiao, Xifeng; Boston, Penelope J; Li, Xiang; McAdam, Amy; Glenar, David A; Chavez, Arriana

2017-12-01

The search for life and habitable environments on other Solar System bodies is a major motivator for planetary exploration. Due to the difficulty and significance of detecting extant or extinct extraterrestrial life in situ, several independent measurements from multiple instrument techniques will bolster the community's confidence in making any such claim. We demonstrate the detection of subsurface biosignatures using a suite of instrument techniques including IR reflectance spectroscopy, laser-induced breakdown spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy. We focus our measurements on subterranean calcium carbonate field samples, whose biosignatures are analogous to those that might be expected on some high-interest astrobiology targets. In this work, we discuss the feasibility and advantages of using each of the aforementioned instrument techniques for the in situ search for biosignatures and present results on the autonomous characterization of biosignatures using multivariate statistical analysis techniques. Key Words: Biosignature suites-Caves-Mars-Life detection. Astrobiology 17, 1203-1218.

In Situ Analysis of Mars Soil and Rocks Sample with the Sam Gcms Instrumentation Onboard Curiosity : Interpretation and Comparison of Measurements Done during the First Martian Year of Curiosity on Mars

NASA Astrophysics Data System (ADS)

Szopa, C.; Coll, P. J.; Cabane, M.; Buch, A.; Coscia, D.; Millan, M.; Francois, P.; Belmahadi, I.; Teinturier, S.; Navarro-Gonzalez, R.; Glavin, D. P.; Freissinet, C.; Steele, A.; Eigenbrode, J. L.; Mahaffy, P. R.

2014-12-01

The characterisation of the chemical and mineralogical composition of solid surface samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Amongst the SAM suite of instruments [1], SAM-GC (Gas Chromatograph) is devoted to identify and quantify volatiles evolved from the thermal (heating up to about 900°C)/chemical (derivatization procedure) treatment of any soil sample collected by the Curiosity rover. With the aim to search for potential organic molecules outgassed from the samples, SAM-GC analytical channels composed of thermal-desorption injector, and a MXT-CLP or a MXT-Q chromatographic column was chosen to achieve all the measurements done up today, with the aim to separate of a wide range of volatile inorganic and organic molecules. Four solid samples have been analyzed with GCMS, one sand sample collected at the Rocknest site, two rock samples (John Klein and Cumberland respectively) collected at the Yellowknife Bay site using the Curiosity driller, and one rock sample collected at the Kimberly site. All the measurements were successful and they produced complex chromatograms with both detectors used for SAM GC, i.e. a thermal conductivity detector and the SAM quandrupole mass spectrometer. Their interpretation already revealed the presence of an oxychlorine phase present in the sample which is at the origin of chlorohydrocarbons clearly identified [2] but this represents only a fraction of the GCMS signal recorded [3,4]. This work presents a systematic comparison of the GCMS measurements done for the different samples collected, supported by reference data obtained in laboratory with different spare models of the gas chromatograph, with the aim to bring new elements of interpretation of the SAM measurements. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Glavin, D. et al. (2013), JGR. [3] Leshin L. et al. (2013

Evolved Gas Analyses of Sedimentary Materials in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument from Yellowknife Bay to the Stimson Formation

NASA Technical Reports Server (NTRS)

Sutter, B.; McAdam, A. C.; Rampe, E. B.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

2016-01-01

The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 10 samples from Gale Crater. All SAM evolved gas analyses have yielded a multitude of volatiles (e.g, H2O, SO2, H2S, CO2, CO, NO, O2, HC1). The objectives of this work are to 1) Characterize the evolved H2O, SO2, CO2, and O2 gas traces of sediments analyzed by SAM through sol 1178, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results releative to understanding the geochemical history of Gale Crater.

SAM 2 data user's guide

NASA Technical Reports Server (NTRS)

Chu, W. P.; Osborn, M. T.; Mcmaster, L. R.

1988-01-01

This document is intended to serve as a guide to the use of the data products from the Stratospheric Aerosol Measurement (SAM) 2 experiment for scientific investigations of polar stratospheric aerosols. Included is a detailed description of the Beta and Aerosol Number Density Archive Tape (BANAT), which is the SAM 2 data product containing the aerosol extinction data available for these investigations. Also included are brief descriptions of the instrument operation, data collection, processing and validation, and some of the scientific analyses conducted to date.

Recent Updates to the System Advisor Model (SAM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiOrio, Nicholas A

The System Advisor Model (SAM) is a mature suite of techno-economic models for many renewable energy technologies that can be downloaded for free as a desktop application or software development kit. SAM is used for system-level modeling, including generating performance pro the release of the code as an open source project on GitHub. Other additions that will be covered include the ability to download data directly into SAM from the National Solar Radiation Database (NSRDB) and up- dates to a user-interface macro that assists with PV system sizing. A brief update on SAM's battery model and its integration with themore » detailed photovoltaic model will also be discussed. Finally, an outline of planned work for the next year will be presented, including the addition of a bifacial model, support for multiple MPPT inputs for detailed inverter modeling, and the addition of a model for inverter thermal behavior.« less

Instrument Suite for Vertical Characterization of the Ionosphere-Thermosphere System

NASA Technical Reports Server (NTRS)

Herrero, Federico; Jones, Hollis; Finne, Theodore; Nicholas, Andrew

2012-01-01

A document describes a suite that provides four simultaneous ion and neutral-atom measurements as a function of altitude, with variable sensitivity for neutral atmospheric species. The variable sensitivity makes it possible to extend the measurements over the altitude range of 100 to more than 700 km. The four instruments in the suite are (1) a neutral wind-temperature spectrometer (WTS), (2) an ion-drift ion-temperature spectrometer (IDTS), (3) a neutral mass spectrometer (NMS), and (4) an ion mass spectrometer (IMS).

Selected Analytical Methods for Environmental Remediation and Recovery (SAM) - Home

EPA Pesticide Factsheets

The SAM Home page provides access to all information provided in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM), and includes a query function allowing users to search methods by analyte, sample type and instrumentation.

Possible Detection of Perchlorates by the Sample Analysis at Mars (SAM) Instrument: Comparison with Previous Missions

NASA Technical Reports Server (NTRS)

Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher;

The Inelastic Instrument suite at the SNS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granroth, Garrett E; Abernathy, Douglas L; Ehlers, Georg

2008-01-01

Abstract The instruments in the extensive suite of spectrometers at the SNS are in various stages of installation and commissioning. The Back Scattering Spectrometer (BASIS) is installed and is in commissioning. It's near backscattering analyzer crystals provide the 3 eV resolution as expected. BASIS will enter the user program in the fall of 2007. The ARCS wide angular-range thermal to epithermal neutron spectrometer will come on line in the fall of 2007 followed shortly by the Cold Neutron Chopper Spectrometer. These two direct geometry instruments provide moderate resolution and the ability to trade resolution for flux. In addition both instrumentsmore » have detector coverage out to 140o to provide a large Q range. The SEQUOIA spectrometer, complete in 2008, is the direct geometry instrument that will provide fine resolution in the thermal to epithermal range. The Spin-Echo spectrometer, to be completed on a similar time scale, will provide the finest energy resolution worldwide. The HYSPEC spectrometer, available no later than 2011, will provide polarized capabilities and optimized flux in the thermal energy range. Finally, the Vision chemical spectrometer will use crystal analyzers to study energy transfers into the epithermal range« less

SAM-2 ground-truth plan: Correlative measurements for the Stratospheric Aerosol Measurement-2 (SAM 2) sensor on the Nimbus G satellite

NASA Technical Reports Server (NTRS)

Russell, P. B.; Mccormick, M. P.; Mcmaster, L. R.; Pepin, T. J.; Chu, W. P.; Swissler, T. J.

1978-01-01

The SAM-2 will fly aboard the Nimbus-G satellite for launch in the fall of 1978 and measure stratospheric vertical profiles of aerosol extinction in high latitude bands. The plan gives details of the location and times for the simultaneous satellite/correlative measurements for the nominal launch time, the rationale and choice of the correlative sensors, their characteristics and expected accuracies, and the conversion of their data to extinction profiles. The SAM-2 expected instrument performance and data inversion results are presented. Various atmospheric models representative of polar stratospheric aerosols are used in the SAM-2 and correlative sensor analyses.

Fluorocarbon Contamination from the Drill on the Mars Science Laboratory: Potential Science Impact on Detecting Martian Organics by Sample Analysis at Mars (SAM)

NASA Technical Reports Server (NTRS)

Eigenbrode, J. L.; McAdam, A.; Franz, H.; Freissinet, C.; Bower, H.; Floyd, M.; Conrad, P.; Mahaffy, P.; Feldman, J.; Hurowitz, J.;

Carbon and Sulfur Isotopic Composition of Rocknest Soil as Determined with the Sample Analysis at Mars(SAM) Quadrupole Mass Spectrometer

NASA Technical Reports Server (NTRS)

Franz, H. B.; McAdam, C.; Stern, J. C.; Archer, P. D., Jr.; Sutter, B.; Grotzinger, J. P.; Jones, J. H.; Leshin, L. A.; Mahaffy, P. R.; Ming, D. W.;

Searching for Reduced Carbon on the Surface of Mars: The SAM Combustion Experiment

NASA Technical Reports Server (NTRS)

Stern, J. C.; Malespin, C. A.; Mahaffy, P. R.; Webster, C. R.; Eigenbrode, J. L.; Archer, P. D., Jr.; Brunner, A. E.; Freissinet, C.; Franz, H. B.; Glavin, D. P.;

Thermal and Evolved Gas Analysis of Calcite Under Reduced Operating Pressures: Implications for the 2011 MSL Sample Analysis at Mars (SAM) Instrument

NASA Technical Reports Server (NTRS)

Lauer, H. V. Jr.; Ming, D. W.; Sutter, B.; Mahaffy, P. R.

2010-01-01

The Mars Science Laboratory (MSL) is scheduled for launch in 2011. The science objectives for MSL are to assess the past or present biological potential, to characterize the geology, and to investigate other planetary processes that influence habitability at the landing site. The Sample Analysis at Mars (SAM) is a key instrument on the MSL payload that will explore the potential habitability at the landing site [1]. In addition to searching for organic compounds, SAM will have the capability to characterized evolved gases as a function of increasing temperature and provide information on the mineralogy of volatile-bearing phases such as carbonates, sulfates, phyllosilicates, and Fe-oxyhydroxides. The operating conditions in SAM ovens will be maintained at 30 mb pressure with a He carrier gas flowing at 1 sccm. We have previously characterized the thermal and evolved gas behaviors of volatile-bearing species under reduced pressure conditions that simulated operating conditions of the Thermal and Evolved Gas Analyzer (TEGA) that was onboard the 2007 Mars Phoenix Scout Mission [e.g., 2-8]. TEGA ovens operated at 12 mb pressure with a N2 carrier gas flowing at 0.04 sccm. Another key difference between SAM and TEGA is that TEGA was able to perform differential scanning calorimetry whereas SAM only has a pyrolysis oven. The operating conditions for TEGA and SAM have several key parameter differences including operating pressure (12 vs 30 mb), carrier gas (N2 vs. He), and carrier gas flow rate (0.04 vs 1 sccm). The objectives of this study are to characterize the thermal and evolved gas analysis of calcite under SAM operating conditions and then compare it to calcite thermal and evolved gas analysis under TEGA operating conditions.

The Investigation of Perchlorate/Iron Phase Mixtures as A Possible Source of Oxygen Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.;

Instrumentation at Paranal Observatory: maintaining the instrument suite of five large telescopes and its interferometer alive

NASA Astrophysics Data System (ADS)

Gillet, Gordon; Alvarez, José Luis; Beltrán, Juan; Bourget, Pierre; Castillo, Roberto; Diaz, Álvaro; Haddad, Nicolás; Leiva, Alfredo; Mardones, Pedro; O'Neal, Jared; Ribes, Mauricio; Riquelme, Miguel; Robert, Pascal; Rojas, Chester; Valenzuela, Javier

2010-07-01

This presentation provides interesting miscellaneous information regarding the instrumentation activities at Paranal Observatory. It introduces the suite of 23 instruments and auxiliary systems that are under the responsibility of the Paranal Instrumentation group, information on the type of instruments, their usage and downtime statistics. The data is based on comprehensive data recorded in the Paranal Night Log System and the Paranal Problem Reporting System whose principles are explained as well. The work organization of the 15 team members around the high number of instruments is laid out, which includes: - Maintaining older instruments with obsolete components - Receiving new instruments and supporting their integration and commissioning - Contributing to future instruments in their developing phase. The assignments of the Instrumentation staff to the actual instruments as well as auxiliary equipment (Laser Guide Star Facility, Mask Manufacturing Unit, Cloud Observation Tool) are explained with respect to responsibility and scheduling issues. The essential activities regarding hardware & software are presented, as well as the technical and organizational developments within the group towards its present and future challenges.

Recent select Sample Analysis at Mars (SAM) Testbed analog results

NASA Astrophysics Data System (ADS)

Malespin, C.; McAdam, A.; Teinturier, S.; Eigenbrode, J. L.; Freissinet, C.; Knudson, C. A.; Lewis, J. M.; Millan, M.; Steele, A.; Stern, J. C.; Williams, A. J.

2017-12-01

The Sample Analysis at Mars (SAM) testbed (TB) is a high fidelity replica of the flight instrument currently onboard the Curiosity rover in Gale Crater, Mars1. The SAM testbed is housed in a Mars environment chamber at NASA Goddard Space Flight Center (GSFC), which can replicate both thermal and environmental conditions. The testbed is used to validate and test new experimental procedures before they are implemented on Mars, but it is also used to analyze analog samples which assists in the interpretation of results from the surface. Samples are heated using the same experimental protocol as on Mars to allow for direct comparison with Martian sampling conditions. Here we report preliminary results from select samples that were loaded into the SAM TB, including meteorites, an organically rich iron oxide, and a synthetic analog to the Martian Cumberland sample drilled by the rover at Yellowknife Bay. Each of these samples have been analyzed under SAM-like conditions using breadboard and lab instrument systems. By comparing the data from the lab systems and SAM TB, further insight on results from Mars can be gained. References: [1] Mahaffy, P. R., et al. (2013), Science, 341(6143), 263-266, doi:10.1126/science.1237966.

Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millennium

NASA Astrophysics Data System (ADS)

Dätwyler, Christoph; Neukom, Raphael; Abram, Nerilie J.; Gallant, Ailie J. E.; Grosjean, Martin; Jacques-Coper, Martín; Karoly, David J.; Villalba, Ricardo

2017-11-01

The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects. However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide new austral summer and annual mean SAM index reconstructions over the last millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions point towards changing teleconnection patterns that may be particularly important outside the summer months. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5-95% range of pre-industrial natural variability.

Detection of Nitric Oxide by the Sample Analysis at Mars (SAM) Instrument Implications for the Presence of Nitrates

NASA Technical Reports Server (NTRS)

Navarro-Gonzalez, R.; Stern, J.; Freissinet, C.; Franz, H. B.; Eigenbrode, J. L..; McKay, C. P.; Coll, P.; Sutter, B.; Archer, D.; McAdam, A.;

Oxychlorine and Chloride/Ferrian Saponite Mixtures as a Possible Source of Hydrochloric Acid Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Hogancamp, J. V.; Sutter, B.; Archer, D., Jr.; Ming, D. W.; Mahaffy, P. R.

2017-12-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected HCl gas releases from several analyzed Gale Crater sediments, which are attributed to the presence of perchlorates, chlorates, and/or chlorides in martian sediment. Previous SAM analog laboratory analyses found that most pure perchlorates and chlorates produced HCl at different temperatures than those observed in the SAM data. Subsequent studies examined the effects of perchlorate and chlorate mixtures with Gale Crater analog iron phases, which are known to catalyze oxychlorine decomposition. Several mixtures produced characteristic O2 releases at similar temperatures as Gale Crater materials, but most of these mixtures did not produce HCl releases comparable to those detected by the SAM instrument. Perchlorates, chlorates, and chlorides were mixed with Gale Crater analog ferrian saponite to understand evolved HCl detected by SAM. Evolved water from thermally decomposing saponite is hypothesized to react with residual chloride phases from oxychlorine decomposition to produce high temperature (>700°C) HCl. Mixtures of chlorates, perchlorates, or chlorides with ferrian saponite were heated to 1000 °C in a laboratory analog SAM instrument. Results demonstrated that all chlorate and perchlorate mixtures produce HCl releases below 1000 °C when mixed with ferrian saponite. Mixtures of chlorides with ferrian saponite produced no oxygen releases but did produce HCl releases with peaks below 1000 °C. Ferrian saponite/Mg-chlorate mixtures produced two HCl releases (347 and 820 °C) similar to the Cumberland drilled sample. Additionally, sodium chloride mixed with ferrian saponite produced no oxygen releases and an HCl release (767 °C) similar to the Quela drilled sample. The Marimba drilled sample, which also produced no oxychlorine-derived oxygen, produced a high temperature HCl release that may be the result of chloride(s) reacting with evolved water from thermally decomposing

Integrated Instrument Simulator Suites for Earth Science

NASA Technical Reports Server (NTRS)

Tanelli, Simone; Tao, Wei-Kuo; Matsui, Toshihisa; Hostetler, Chris; Hair, Johnathan; Butler, Carolyn; Kuo, Kwo-Sen; Niamsuwan, Noppasin; Johnson, Michael P.; Jacob, Joseph C.;

Evolved Gas Measurements Planned for the Lower Layers of the Gale Crater Mound with the Sample Analysis at Mars Instrument Suite

NASA Technical Reports Server (NTRS)

Mahaffy, Paul; Brunner, Anna; McAdam, Amy; Franz, Heather; Conrad, Pamela; Webster, Chris; Cabane, Michel

2009-01-01

The lower mound strata of Gale Crater provide a diverse set of chemical environments for exploration by the varied tools of the Curiosity Rover of the Mars Science Laboratory (MSL) Mission. Orbital imaging and spectroscopy clearly reveal distinct layers of hydrated minerals, sulfates, and clays with abundant evidence of a variety of fluvial processes. The three instruments of the MSL Sample Analysis at aMars (SAM) investigation, the Quadrupole Mass Spectrometer (QMS), the Tunable Laser Spectrometer (TLS), and the Gas Chromatograph (GC) are designed to analyze either atmospheric gases or volatiles thermally evolved or chemically extracted from powdered rock or soil. The presence or absence of organic compounds in these layers is of great interest since such an in situ search for this type of record has not been successfully implemented since the mid-60s Viking GCMS experiments. However, regardless of the outcome of the analysis for organics, the abundance and isotopic composition of thermally evolved inorganic compounds should also provide a rich data set to complement the mineralogical and elemental information provided by other MSL instruments. In addition, these evolved gas analysis (EGA) experiments will help test sedimentary models proposed by Malin and Edgett (2000) and then further developed by Milliken et al (2010) for Gale Crater. In the SAM EGA experiments the evolution temperatures of H2O, CO2, SO2, O2, or other simple compounds as the samples are heated in a helium stream to 1000 C provides information on mineral types and their associations. The isotopic composition of O, H, C, and S can be precisely determined in several evolved compounds and compared with the present day atmosphere. Such SAM results might be able to test mineralogical evidence of changing sedimentary and alteration processes over an extended period of time. For example, Bibring et al (2006) have suggested such a major shift from early nonacidic to later acidic alteration. We will

Primordial argon isotope fractionation in the atmosphere of Mars measured by the SAM instrument on Curiosity and implications for atmospheric loss

PubMed Central

Atreya, Sushil K; Trainer, Melissa G; Franz, Heather B; Wong, Michael H; Manning, Heidi L K; Malespin, Charles A; Mahaffy, Paul R; Conrad, Pamela G; Brunner, Anna E; Leshin, Laurie A; Jones, John H; Webster, Christopher R; Owen, Tobias C; Pepin, Robert O; Navarro-González, R

2013-01-01

[1] The quadrupole mass spectrometer of the Sample Analysis at Mars (SAM) instrument on Curiosity rover has made the first high-precision measurement of the nonradiogenic argon isotope ratio in the atmosphere of Mars. The resulting value of 36Ar/38Ar = 4.2 ± 0.1 is highly significant for it provides excellent evidence that “Mars” meteorites are indeed of Martian origin, and it points to a significant loss of argon of at least 50% and perhaps as high as 85–95% from the atmosphere of Mars in the past 4 billion years. Taken together with the isotopic fractionations in N, C, H, and O measured by SAM, these results imply a substantial loss of atmosphere from Mars in the posthydrodynamic escape phase. PMID:25821261

Carbon Isotopic Composition of CO2, Evolved During Perchlorate-Induced Reactions in Mars Analog Materials: Interpreting SAM/MSL Rocknest Data

NASA Technical Reports Server (NTRS)

Stern, J. C.; McAdam, A. C.; Archer, P. D., Jr.; Bower, H.; Buch, A.; Eigenbrode, J.; Freissinet, C.; Franz, H. B.; Glavin, D.; Jones, J. H.;

The Characterization of Biosignatures in Caves Using an Instrument Suite

NASA Astrophysics Data System (ADS)

Uckert, Kyle; Chanover, Nancy J.; Getty, Stephanie; Voelz, David G.; Brinckerhoff, William B.; McMillan, Nancy; Xiao, Xifeng; Boston, Penelope J.; Li, Xiang; McAdam, Amy; Glenar, David A.; Chavez, Arriana

2017-12-01

The search for life and habitable environments on other Solar System bodies is a major motivator for planetary exploration. Due to the difficulty and significance of detecting extant or extinct extraterrestrial life in situ, several independent measurements from multiple instrument techniques will bolster the community's confidence in making any such claim. We demonstrate the detection of subsurface biosignatures using a suite of instrument techniques including IR reflectance spectroscopy, laser-induced breakdown spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy. We focus our measurements on subterranean calcium carbonate field samples, whose biosignatures are analogous to those that might be expected on some high-interest astrobiology targets. In this work, we discuss the feasibility and advantages of using each of the aforementioned instrument techniques for the in situ search for biosignatures and present results on the autonomous characterization of biosignatures using multivariate statistical analysis techniques.

Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2) Sensor Suite

NASA Technical Reports Server (NTRS)

Hwang, Helen; Wright, Henry; Kuhl, Chris; Schoenenberger, Mark; White, Todd; Karlgaard, Chris; Mahzari, Milad; Oishi, Tomo; Pennington, Steve; Trombetta, Nick;

MSL SAM-like Analyses of Hawaiian Altered Basaltic Materials: Implications for Analyses by the Mars Science Laboratory

NASA Astrophysics Data System (ADS)

McAdam, A.; Eigenbrode, J. L.; Young, K. E.; Bleacher, J. E.; Knudson, C. A.; Rogers, D.; Glotch, T. D.; Sutter, B.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Downs, R. T.

2015-12-01

Samples of basaltic materials were collected during several traverses of the Kau Desert on the leeward side of the Kilauea Volcano, Hawaii, conducted by the Remote, In Situ, and Synchrotron Studies for Science and Exploration (RIS4E) team, a node of the Solar System Exploration and Research Virtual Institute (SSERVI) program. Some of these samples had been exposed to circumneutral to slightly acidic alteration conditions from exposure to fog/rain, and acidic fog/rain, while others had been exposed to more acidic conditions due to proximity to fumaroles. The samples consisted of basalts with coatings, sands and soils, and ash, and were collected using organically clean protocols to enable investigation of organic chemistry and organic-mineral associations, in addition to mineralogy. The Mars Science Laboratory (MSL) rover has analyzed basaltic materials inferred to have been altered under conditions ranging from circumneutral to acidic, but several aspects of the Sample Analysis at Mars (SAM) instrument suite results are still being investigated and analyses of relevant terrestrial analogs can play an important role in interpretation of the data. For example, all materials analyzed to date have a significant amorphous component. Comparisons of the mineralogy obtained with the MSL CheMin instrument and volatiles evolved during SAM analyses indicate that, by mass balance, some portion of the volatiles, such as SO2 and H2O, are likely associated with this component. Many of the RIS4E samples also have a significant amorphous component, and field x-ray diffraction (XRD) and x-ray fluorescence (XRF) data indicate differences in the chemistry of this material in samples exposed to different alteration conditions. Preliminary SAM-like analyses indicate that the amorphous materials in some of these samples evolve volatiles such as H2O and SO2 during heating. Here we will discuss these results, and others, obtained through SAM-like analyses of selected samples.

The Detection of Evolved Oxygen from the Rocknest Eolian Bedform Material by the Sample Analysis at Mars(SAM) instrument at the Mars Curiosity Landing Site

NASA Technical Reports Server (NTRS)

Sutter, B.; Archer, D.; Ming, D.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A.; Mahaffy, P.; Stern, J.; Navarro-Gonzalex, R.;

The Investigation of Chlorate/Iron-Phase Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Clark, J.; Sutter, B.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P.; Mahaffy, P.; Navarro-Gonzalez, R.

2016-01-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected oxygen and HCl gas releases from all analyzed Gale Crater sediments. The presence of perchlorate ClO4(sup-) and/or chlorates ClO3(sup-) are potential sources of the aforementioned O2 releases. The detections of O2 and HCl gas releases and chlorinated hydrocarbons by SAM coupled with the detection of perchlorates by Phoenix Lander's 2008 Wet Chemistry Laboratory all suggest that perchlorates, and possibly chorates, may be present in the Gale Crater sediments. Previous laboratory studies have attempted to replicate these O2 releases by heating perchlorates and chlorates in instruments operated similarly to those in the SAM instrument. Early studies found that pure perchlorates release O2 at temperatures higher than those observed in SAM data. Subsequently, studies were done to test the effects of mixing iron-phase minerals, analogous to those detected on Mars by ChemMin, with perchlorates. The iron in these minerals acts as a catalyst and causes O2 to be released from the perchlorate at a lower temperature. These studies found that perchlorate solutions mixed with either Hawaii palagonite or ferrihydrite produce O2 releases at temperatures similar to the Rocknest (RN) windblown deposit and the John Klein (JK) drill sample from the Sheepbed mudstone. The study also determined that perchlorate mixtures with magnetite, hematite, fayalite-magnetite, ilmentite, and pyrrhotite produce O2 releases at temperatures similar to the Confidence Hills (CH) drill sample from the Murray mudstone. Oxygen re-leases from pure chlorates were recently compared with the SAM data. Laboratory analyses determined that Ca-chlorate produces O2 and HCl peaks that are similar to those detected in RN and JK materials. Currently, no perchlorate/chlorate mixture with iron-phase minerals can explain the O2 releases from either the Cumberland (CB) drill sample from the Sheepbed mudstone or Windjana (WJ) drill

Influence of Oxychlorine Phases on the Pyrolysis of Organics Trapped in Jarosite and the Quest of Organics on Mars with the SAM Instrument Onboard Curiosity

NASA Astrophysics Data System (ADS)

Millan, M.; Lewis, J. M. T.; Eigenbrode, J. L.; Freissinet, C.; Szopa, C.; Buch, A.; McAdam, A.; Glavin, D. P.; Navarro-Gonzalez, R.; Johnson, S. S.; Mahaffy, P. R.

2017-12-01

The Curiosity rover is currently analyzing the base of Mt Sharp in Mars' Gale crater to find clues of habitability in the stratigraphic layers of rocks. One of its goal is the search of organic compounds thanks to the Sample Analysis at Mars (SAM) experiment. With this aim, SAM performs in situ molecular analysis of gases evolved from the heat of the solid samples collected by Curiosity. SAM uses a gas-chromatograph mass-spectrometer (GCMS), to detect/identify inorganics and organics present in the samples. During the pyrolysis, chemical reactions can occur between the gases thermally released from minerals and organic molecules SAM is looking for. Beyond the minerals involved, oxychlorines, likely spread at Mars' surface, liberate dioxygen and chlorine species, and sulfates release sulfur-bearing species. The detection of Cl- and S-bearing organics were attributed to reactions between oxychlorines, sulfates and organics. These last were proved to come from SAM instrument background and Mars indigenous organics, proving the presence of organics on Mars. However, the identification of their precursors is complex due to the chemical reactivity in the SAM ovens. Recent studies suggest compounds from various chemical families, as potential precursors of the chlorohydrocarbons detected on Mars, but considered limited parameters and mineralogy. Laboratory experiments have been performed to understand the influence of oxychlorines on organic matter incorporated in sulfates, during pyrolysis. To do so, organics from chemical families potentially present on Mars and synthetized in laboratory within jarosite, a ferric sulfate, were pyrolyzed in presence of oxychlorines. GCMS was used to identify the pyrolysis products and try to correlate them with the organo-chlorinated compounds detected by SAM. This helps discriminate their likely parent organics or chemical families. The work includes the investigation of sulfurized compounds generated from reactions between the organics

Specific Eph receptor-cytoplasmic effector signaling mediated by SAM-SAM domain interactions.

PubMed

Wang, Yue; Shang, Yuan; Li, Jianchao; Chen, Weidi; Li, Gang; Wan, Jun; Liu, Wei; Zhang, Mingjie

2018-05-11

The Eph receptor tyrosine kinase (RTK) family is the largest subfamily of RTKs playing critical roles in many developmental processes such as tissue patterning, neurogenesis and neuronal circuit formation, angiogenesis, etc. How the 14 Eph proteins, via their highly similar cytoplasmic domains, can transmit diverse and sometimes opposite cellular signals upon engaging ephrins is a major unresolved question. Here we systematically investigated the bindings of each SAM domain of Eph receptors to the SAM domains from SHIP2 and Odin, and uncover a highly specific SAM-SAM interaction-mediated cytoplasmic Eph-effector binding pattern. Comparative X-ray crystallographic studies of several SAM-SAM heterodimer complexes, together with biochemical and cell biology experiments, not only revealed the exquisite specificity code governing Eph/effector interactions but also allowed us to identify SAMD5 as a new Eph binding partner. Finally, these Eph/effector SAM heterodimer structures can explain many Eph SAM mutations identified in patients suffering from cancers and other diseases. © 2018, Wang et al.

SAM/SAH Analogs as Versatile Tools for SAM-Dependent Methyltransferases.

PubMed

Zhang, Jing; Zheng, Yujun George

2016-03-18

S-Adenosyl-L-methionine (SAM) is a sulfonium molecule with a structural hybrid of methionine and adenosine. As the second largest cofactor in the human body, its major function is to serve as methyl donor for SAM-dependent methyltransferases (MTases). The resultant transmethylation of biomolecules constitutes a significant biochemical mechanism in epigenetic regulation, cellular signaling, and metabolite degradation. Recently, numerous SAM analogs have been developed as synthetic cofactors to transfer the activated groups on MTase substrates for downstream ligation and identification. Meanwhile, new compounds built upon or derived from the SAM scaffold have been designed and tested as selective inhibitors for important MTase targets. Here, we summarized the recent development and application of SAM analogs as chemical biology tools for MTases.

The Investigation of Chlorates as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Sutter, B.; Archer, D. P.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P; Stern, J. C.;

Common themes and differences in SAM recognition among SAM riboswitches

PubMed Central

Price, Ian R.; Grigg, Jason C.; Ke, Ailong

2014-01-01

The recent discovery of short cis-acting RNA elements termed riboswitches has caused a paradigm shift in our understanding of genetic regulatory mechanisms. The three distinct superfamilies of S-adenosyl-L-methionine (SAM) riboswitches are the most commonly found riboswitch classes in nature. These RNAs represent three independent evolutionary solutions to achieve specific SAM recognition. This review summarizes research on 1) modes of gene regulatory mechanisms, 2) common themes and differences in ligand recognition, and 3) ligand-induced conformational dynamics among SAM riboswitch families. The body of work on the SAM riboswitch families constitutes a useful primer to the topic of gene regulatory RNAs as a whole. PMID:24863160

Measuring Sulfur Isotope Ratios from Solid Samples with the Sample Analysis at Mars Instrument and the Effects of Dead Time Corrections

NASA Technical Reports Server (NTRS)

Franz, H. B.; Mahaffy, P. R.; Kasprzak, W.; Lyness, E.; Raaen, E.

2011-01-01

The Sample Analysis at Mars (SAM) instrument suite comprises the largest science payload on the Mars Science Laboratory (MSL) "Curiosity" rover. SAM will perform chemical and isotopic analysis of volatile compounds from atmospheric and solid samples to address questions pertaining to habitability and geochemical processes on Mars. Sulfur is a key element of interest in this regard, as sulfur compounds have been detected on the Martian surface by both in situ and remote sensing techniques. Their chemical and isotopic composition can belp constrain environmental conditions and mechanisms at the time of formation. A previous study examined the capability of the SAM quadrupole mass spectrometer (QMS) to determine sulfur isotope ratios of SO2 gas from a statistical perspective. Here we discuss the development of a method for determining sulfur isotope ratios with the QMS by sampling SO2 generated from heating of solid sulfate samples in SAM's pyrolysis oven. This analysis, which was performed with the SAM breadboard system, also required development of a novel treatment of the QMS dead time to accommodate the characteristics of an aging detector.

Identification of Phyllosilicates in Mudstone Samples Using Water Releases Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Hogancamp, J. V. (Clark); Ming, D. W.; McAdam, A. C.; Archer, P. D.; Morris, R. V.; Bristow, T. F.; Rampe, E. B.; Mahaffy, P. R.; Gellert, R.

2017-01-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected high temperature water releases from mud-stones in the areas of Yellowknife Bay, Pahrump Hills, Naukluft Plateau, and Murray Buttes in Gale crater. Dehydroxylation of phyllosilicates may have caused the high temperature water releases observed in these samples. Because each type of phyllosilicate undergoes dehydroxylation at distinct temperatures, these water releases can be used to help constrain the type of phyllosilicate present in each sample.

Sam37 is crucial for formation of the mitochondrial TOM-SAM supercomplex, thereby promoting β-barrel biogenesis.

PubMed

Wenz, Lena-Sophie; Ellenrieder, Lars; Qiu, Jian; Bohnert, Maria; Zufall, Nicole; van der Laan, Martin; Pfanner, Nikolaus; Wiedemann, Nils; Becker, Thomas

2015-09-28

Biogenesis of mitochondrial β-barrel proteins requires two preprotein translocases, the general translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). TOM and SAM form a supercomplex that promotes transfer of β-barrel precursors. The SAM core complex contains the channel protein Sam50, which cooperates with Sam35 in precursor recognition, and the peripheral membrane protein Sam37. The molecular function of Sam37 has been unknown. We report that Sam37 is crucial for formation of the TOM-SAM supercomplex. Sam37 interacts with the receptor domain of Tom22 on the cytosolic side of the mitochondrial outer membrane and links TOM and SAM complexes. Sam37 thus promotes efficient transfer of β-barrel precursors to the SAM complex. We conclude that Sam37 functions as a coupling factor of the translocase supercomplex of the mitochondrial outer membrane. © 2015 Wenz et al.

Common themes and differences in SAM recognition among SAM riboswitches.

PubMed

Price, Ian R; Grigg, Jason C; Ke, Ailong

2014-10-01

The recent discovery of short cis-acting RNA elements termed riboswitches has caused a paradigm shift in our understanding of genetic regulatory mechanisms. The three distinct superfamilies of S-adenosyl-l-methionine (SAM) riboswitches are the most commonly found riboswitch classes in nature. These RNAs represent three independent evolutionary solutions to achieve specific SAM recognition. This review summarizes research on 1) modes of gene regulatory mechanisms, 2) common themes and differences in ligand recognition, and 3) ligand-induced conformational dynamics among SAM riboswitch families. The body of work on the SAM riboswitch families constitutes a useful primer to the topic of gene regulatory RNAs as a whole. This article is part of a Special Issue entitled: Riboswitches. Copyright © 2014 Elsevier B.V. All rights reserved.

Evolved Gas Measurements Planned for the Lower Layers of the Gale Crater Mound with the Sample Analysis at Mars Instrument Suite

NASA Astrophysics Data System (ADS)

Mahaffy, P. R.; Franz, H.; McAdam, A.; Conrad, P. G.; Brunner, A.; Cabane, M.; Webster, C. R.

2011-12-01

The lower mound strata of Gale Crater provide a diverse set of chemical environments for exploration by the varied tools of the Curiosity Rover of the Mars Science Laboratory (MSL) Mission. Orbital imaging and spectroscopy clearly reveal distinct layers of hydrated minerals, sulfates, and clays with abundant evidence of a variety of fluvial processes. The three instruments of the MSL Sample Analysis at Mars (SAM) investigation, the Quadrupole Mass Spectrometer (QMS), the Tunable Laser Spectrometer (TLS), and the Gas Chromatograph (GC) are designed to analyze either atmospheric gases or volatiles thermally evolved or chemically extracted from powdered rock or soil. The presence or absence of organic compounds in these layers is of great interest since such an in situ search for this type of record has not been successfully implemented since the mid-70s Viking GCMS experiments. However, regardless of the outcome of the analysis for organics, the abundance and isotopic composition of thermally evolved inorganic compounds should also provide a rich data set to complement the mineralogical and elemental information provided by other MSL instruments. In addition, these evolved gas analysis (EGA) experiments will help test sedimentary models proposed by Malin and Edgett (2000) and then further developed by Milliken et al (2010) for Gale Crater. In the SAM EGA experiments the evolution temperatures of H2O, CO2, SO2, O2, or other simple compounds as the samples are heated in a helium stream to 1000C provides information on mineral types and their associations. The isotopic composition of O, H, C, and S can be precisely determined in several evolved compounds and compared with the present day atmosphere. Such SAM results might be able to test mineralogical evidence of changing sedimentary and alteration processes over an extended period of time. For example, Bibring et al (2006) have suggested such a major shift from early nonacidic to later acidic alteration. We will

SAM Companion Documents

EPA Pesticide Factsheets

SAM Companion Documents and Sample Collection Procedures provide information intended to complement the analytical methods listed in Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

SAM-VI RNAs selectively bind S-adenosylmethionine and exhibit similarities to SAM-III riboswitches.

PubMed

Mirihana Arachchilage, Gayan; Sherlock, Madeline E; Weinberg, Zasha; Breaker, Ronald R

2018-03-04

Five distinct riboswitch classes that regulate gene expression in response to the cofactor S-adenosylmethionine (SAM) or its metabolic breakdown product S-adenosylhomocysteine (SAH) have been reported previously. Collectively, these SAM- or SAH-sensing RNAs constitute the most abundant collection of riboswitches, and are found in nearly every major bacterial lineage. Here, we report a potential sixth member of this pervasive riboswitch family, called SAM-VI, which is predominantly found in Bifidobacterium species. SAM-VI aptamers selectively bind the cofactor SAM and strongly discriminate against SAH. The consensus sequence and structural model for SAM-VI share some features with the consensus model for the SAM-III riboswitch class, whose members are mainly found in lactic acid bacteria. However, there are sufficient differences between the two classes such that current bioinformatics methods separately cluster representatives of the two motifs. These findings highlight the abundance of RNA structures that can form to selectively recognize SAM, and showcase the ability of RNA to utilize diverse strategies to perform similar biological functions.

Possible Detection of Nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

NASA Technical Reports Server (NTRS)

Navarro-Gonzalez, R.; Stern, J.; Sutter, B.; Archer, D.; McAdam, A.; Franz, H. B.; McKay, C. P.; Coll, P.; Cabane, M.; Ming, D. W.;

SAM Photovoltaic Model Technical Reference

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilman, P.

2015-05-27

This manual describes the photovoltaic performance model in the System Advisor Model (SAM). The U.S. Department of Energy’s National Renewable Energy Laboratory maintains and distributes SAM, which is available as a free download from https://sam.nrel.gov. These descriptions are based on SAM 2015.1.30 (SSC 41).

Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

PubMed

Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

2016-09-19

Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Peptide Fragments of Odin-Sam1: Conformational Analysis and Interaction Studies with EphA2-Sam.

PubMed

Mercurio, Flavia A; Di Natale, Concetta; Pirone, Luciano; Scognamiglio, Pasqualina L; Marasco, Daniela; Pedone, Emilia M; Saviano, Michele; Leone, Marilisa

2015-07-27

Odin is a protein belonging to the ANKS family, and has two tandem Sam domains. The first, Odin-Sam1, binds to the Sam domain of the EphA2 receptor (EphA2-Sam); this interaction could be crucial for the regulation of receptor endocytosis and might have an impact on cancer. Odin-Sam1 associates with EphA2-Sam by adopting a "mid-loop/end-helix" model. In this study three peptide sequences, encompassing the mid-loop interacting portion of Odin-Sam1 and its C-terminal α5 helix, were designed. Their conformational properties were analyzed by CD and NMR. In addition, their abilities to interact with EphA2-Sam were investigated by SPR studies. The peptides adopt a predominantly disordered state in aqueous buffer, but a higher helical content is evident in the presence of the cosolvent trifluoroethanol. Dissociation constants towards EphA2-Sam were in the high micromolar range. The structural findings suggest further routes for the design of potential anti-cancer therapeutics as inhibitors of EphA2-Sam heterotypic interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MGGPOD: a Monte Carlo Suite for Modeling Instrumental Line and Continuum Backgrounds in Gamma-Ray Astronomy

NASA Technical Reports Server (NTRS)

Weidenspointner, G.; Harris, M. J.; Sturner, S.; Teegarden, B. J.; Ferguson, C.

2004-01-01

Intense and complex instrumental backgrounds, against which the much smaller signals from celestial sources have to be discerned, are a notorious problem for low and intermediate energy gamma-ray astronomy (approximately 50 keV - 10 MeV). Therefore a detailed qualitative and quantitative understanding of instrumental line and continuum backgrounds is crucial for most stages of gamma-ray astronomy missions, ranging from the design and development of new instrumentation through performance prediction to data reduction. We have developed MGGPOD, a user-friendly suite of Monte Carlo codes built around the widely used GEANT (Version 3.21) package, to simulate ab initio the physical processes relevant for the production of instrumental backgrounds. These include the build-up and delayed decay of radioactive isotopes as well as the prompt de-excitation of excited nuclei, both of which give rise to a plethora of instrumental gamma-ray background lines in addition t o continuum backgrounds. The MGGPOD package and documentation are publicly available for download. We demonstrate the capabilities of the MGGPOD suite by modeling high resolution gamma-ray spectra recorded by the Transient Gamma-Ray Spectrometer (TGRS) on board Wind during 1995. The TGRS is a Ge spectrometer operating in the 40 keV to 8 MeV range. Due to its fine energy resolution, these spectra reveal the complex instrumental background in formidable detail, particularly the many prompt and delayed gamma-ray lines. We evaluate the successes and failures of the MGGPOD package in reproducing TGRS data, and provide identifications for the numerous instrumental lines.

S-adenosyl methionine (SAM) attenuates the development of tolerance to analgesic activity of morphine in rats.

PubMed

Katyal, Jatinder; Kumar, Hemant; Joshi, Dinesh; Gupta, Yogendra Kumar

2017-04-03

Development of tolerance to analgesic effect, on chronic administration of morphine, limits its clinical usefulness in pain management. S-adenosyl methionine (SAM) used for arthritis and approved as a supplement in many countries including United States was evaluated for reducing morphine tolerance. Male 'Wistar' rats were used. The analgesic activity was determined using tail flick analgesiometer (Columbus Instruments, USA). Rats given morphine (7mg/kg), intraperitoneally (i.p.), once daily for 5days developed tolerance to analgesic effect. To evaluate the effect of SAM on morphine tolerance, SAM 800mg/kg was administered orally (p.o.), 45min prior to each dose of morphine. The analgesic activity of SAM and opioidergic component in its activity was also evaluated. Co-administration of morphine and SAM reversed morphine tolerance. SAM exhibited analgesic effect after repeated administration which was reversed by naloxone administration. Since safety of SAM on chronic use is documented it can be a good option in morphine tolerance. Role in drug addiction and withdrawal should also be evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of the Presence of Chlorates and Perchlorates on the Pyrolysis of Organic Compounds: Implications for Measurements Done with the SAM Experiment Onboard the Curiosity Rover

NASA Technical Reports Server (NTRS)

Millan, M.; Szopa, C.; Buch, A.; Belmahdi, I.; Coll, P.; Glavin, D. P.; Freissinet, C.; Archer, P. D., Jr.; Sutter, B.; Summons, R. E.;

The Investigation of Chlorate and Perchlorate/Saponite Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater

NASA Technical Reports Server (NTRS)

Clark, J.; Sutter, B.; Min, D. W.; Mahaffy, P.

2016-01-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected O2 and HCl gas releases from all analyzed Gale Crater sediments, which are attributed to the presence of perchlorates and/or chlorates in martian sediment. Previous SAM analog laboratory analyses found that most pure perchlorates and chlorates release O2 and HCl at different temperatures than those observed in the SAM data. Subsequent studies examined the effects of perchlorate and chlorate mixtures with Gale Crater analog iron phases, which are known to catalyze oxychlorine decomposition. Several mixtures produced O2 releases at similar temperatures as Gale Crater materials, but most of these mixtures did not produce significant HCl releases comparable to those detected by the SAM instrument. In order to better explain the Gale Crater HCl releases, perchlorates and chlorates were mixed with Gale Crater analog saponite, which is found at abundances from 8 to 20 wt % in the John Klein and Cumberland drill samples. Mixtures of chlorates or perchlorates with calcium-saponite or ferrian-saponite were heated to 1000 deg C in a Labsys EVO differential scanning calorimeter/mass spectrometer configured to operate similarly to the SAM oven/quadrupole mass spectrometer system. Our results demonstrate that all chlorate and perchlorate mixtures produce significant HCl releases below 1000 deg C as well as depressed oxygen peak release temperatures when mixed with saponite. The type of saponite (calcium or ferrian saponite) did not affect the evolved gas results significantly. Saponite/Mg-perchlorate mixtures produced two HCl releases similar to the Cumberland drilled sample. Mg-chlorate mixed with saponite produced HCl releases similar to the Big Sky drilled sample in an eolian sandstone. A mixture of Ca-perchlorate and saponite produced HCl and oxygen releases similar to the Buckskin mudstone drilled sample and the Gobabeb 2 eolian dune material. Ca-chlorate mixed with saponite produced both

Human polyhomeotic homolog 3 (PHC3) sterile alpha motif (SAM) linker allows open-ended polymerization of PHC3 SAM.

PubMed

Robinson, Angela K; Leal, Belinda Z; Nanyes, David R; Kaur, Yogeet; Ilangovan, Udayar; Schirf, Virgil; Hinck, Andrew P; Demeler, Borries; Kim, Chongwoo A

2012-07-10

Sterile alpha motifs (SAMs) are frequently found in eukaryotic genomes. An intriguing property of many SAMs is their ability to self-associate, forming an open-ended polymer structure whose formation has been shown to be essential for the function of the protein. What remains largely unresolved is how polymerization is controlled. Previously, we had determined that the stretch of unstructured residues N-terminal to the SAM of a Drosophila protein called polyhomeotic (Ph), a member of the polycomb group (PcG) of gene silencers, plays a key role in controlling Ph SAM polymerization. Ph SAM with its native linker created shorter polymers compared to Ph SAM attached to either a random linker or no linker. Here, we show that the SAM linker for the human Ph ortholog, polyhomeotic homolog 3 (PHC3), also controls PHC3 SAM polymerization but does so in the opposite fashion. PHC3 SAM with its native linker allows longer polymers to form compared to when attached to a random linker. Attaching the PHC3 SAM linker to Ph SAM also resulted in extending Ph SAM polymerization. Moreover, in the context of full-length Ph protein, replacing the SAM linker with PHC3 SAM linker, intended to create longer polymers, resulted in greater repressive ability for the chimera compared to wild-type Ph. These findings show that polymeric SAM linkers evolved to modulate a wide dynamic range of SAM polymerization abilities and suggest that rationally manipulating the function of SAM containing proteins through controlling their SAM polymerization may be possible.

Astronaut Sam Gemar, wearing EMU, prepares for training in WETF

NASA Image and Video Library

1987-03-01

S87-26630 (March 1987) --- Astronaut Charles D. (Sam) Gemar, wearing a training version of the Extravehicular Mobility Unit (EMU) space suit, prepares to be emersed in the 25-ft. deep waters of the Weightless Environment Training Facility (WET-F) at the Johnson Space Center (JSC). Once underwater, Gemar was able to achieve a neutrally buoyant state and to simulate the floating type activities of an astronaut in microgravity. Gemar began training as an astronaut candidate in the summer of 1985.

Constraints on the Mineralogy of Gale Crater Mudstones from MSL SAM Evolved Water

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Sutter, B.; Franz, H. B.; Hogancamp, J. V. (Clark); Knudson, C. A.; Andrejkovicova, S.; Archer, P. D.; Eigenbrode, J. L.; Ming, D. W.; Mahaffy, P. R.

2017-01-01

The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) have analysed more than 150 micron fines from 14 sites at Gale Crater. Here we focus on the mudstone samples. Two were drilled from sites John Klein (JK) and Cumberland (CB) in the Sheepbed mudstone. Six were drilled from Murray Formation mudstone: Confidence Hills (CH), Mojave (MJ), Telegraph Peak (TP), Buckskin (BK), Oudam (OU), Marimba (MB). SAM's evolved gas analysis mass spectrometry (EGA-MS) detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, and other trace gases, including organic fragments. The identity and evolution temperature of evolved gases can support CheMin mineral detection and place constraints on trace volatile-bearing phases or phases difficult to characterize with X-ray diffraction (e.g., amorphous phases). Here we will focus on SAM H2O data and comparisons to SAM-like analyses of key reference materials.

Crystal structures of the SAM-III/SMK riboswitch reveal the SAM-dependent translation inhibition mechanism

PubMed Central

Lu, Changrui; Smith, Angela M; Fuchs, Ryan T; Ding, Fang; Rajashankar, Kanagalaghatta; Henkin, Tina M; Ke, Ailong

2011-01-01

Three distinct classes of S-adenosyl-l-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The SMK box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-Å crystal structure of the Enterococcus faecalis SMK box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti–Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions with the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the SMK box riboswitch sampling the near-cognate ligand S-adenosyl-l-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions. PMID:18806797

The Sam-Sam interaction between Ship2 and the EphA2 receptor: design and analysis of peptide inhibitors.

PubMed

Mercurio, Flavia Anna; Di Natale, Concetta; Pirone, Luciano; Iannitti, Roberta; Marasco, Daniela; Pedone, Emilia Maria; Palumbo, Rosanna; Leone, Marilisa

2017-12-12

The lipid phosphatase Ship2 represents a drug discovery target for the treatment of different diseases, including cancer. Its C-terminal sterile alpha motif domain (Ship2-Sam) associates with the Sam domain from the EphA2 receptor (EphA2-Sam). This interaction is expected to mainly induce pro-oncogenic effects in cells therefore, inhibition of the Ship2-Sam/EphA2-Sam complex may represent an innovative route to discover anti-cancer therapeutics. In the present work, we designed and analyzed several peptide sequences encompassing the interaction interface of EphA2-Sam for Ship2-Sam. Peptide conformational analyses and interaction assays with Ship2-Sam conducted through diverse techniques (CD, NMR, SPR and MST), identified a positively charged penta-amino acid native motif in EphA2-Sam, that once repeated three times in tandem, binds Ship2-Sam. NMR experiments show that the peptide targets the negatively charged binding site of Ship2-Sam for EphA2-Sam. Preliminary in vitro cell-based assays indicate that -at 50 µM concentration- it induces necrosis of PC-3 prostate cancer cells with more cytotoxic effect on cancer cells than on normal dermal fibroblasts. This work represents a pioneering study that opens further opportunities for the development of inhibitors of the Ship2-Sam/EphA2-Sam complex for therapeutic applications.

Major Volatiles Released from the Fourth John Klein Portion

NASA Image and Video Library

2013-04-08

As the Sample Analysis at Mars SAM suite of instruments on NASA Curiosity Mars rover heats a sample, gases are released or evolved from the sample and can be identified using SAM quadrupole mass spectrometer.

Expanding the Chemistry of the Class C Radical SAM Methyltransferase NosN by Using an Allyl Analogue of SAM.

PubMed

Ji, Xinjian; Mandalapu, Dhanaraju; Cheng, Jinduo; Ding, Wei; Zhang, Qi

2018-03-30

The radical S-adenosylmethionine (SAM) superfamily enzymes cleave SAM reductively to generate a highly reactive 5'-deoxyadenosyl (dAdo) radical, which initiates remarkably diverse reactions. Unlike most radical SAM enzymes, the class C radical SAM methyltransferase NosN binds two SAMs in the active site, using one SAM to produce a dAdo radical and the second as a methyl donor. Here, we report a mechanistic investigation of NosN in which an allyl analogue of SAM (allyl-SAM) was used. We show that NosN cleaves allyl-SAM efficiently and the resulting dAdo radical can be captured by the olefin moieties of allyl-SAM or 5'-allylthioadenosine (ATA), the latter being a derivative of allyl-SAM. Remarkably, we found that NosN produced two distinct sets of products in the presence and absence of the methyl acceptor substrate, thus suggesting substrate-triggered production of ATA from allyl-SAM. We also show that NosN produces S-adenosylhomocysteine from 5'-thioadenosine and homoserine lactone. These results support the idea that 5'-methylthioadenosine is the direct methyl donor in NosN reactions, and demonstrate great potential to modulate radical SAM enzymes for novel catalytic activities. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

CSAM: Compressed SAM format.

PubMed

Cánovas, Rodrigo; Moffat, Alistair; Turpin, Andrew

2016-12-15

Next generation sequencing machines produce vast amounts of genomic data. For the data to be useful, it is essential that it can be stored and manipulated efficiently. This work responds to the combined challenge of compressing genomic data, while providing fast access to regions of interest, without necessitating decompression of whole files. We describe CSAM (Compressed SAM format), a compression approach offering lossless and lossy compression for SAM files. The structures and techniques proposed are suitable for representing SAM files, as well as supporting fast access to the compressed information. They generate more compact lossless representations than BAM, which is currently the preferred lossless compressed SAM-equivalent format; and are self-contained, that is, they do not depend on any external resources to compress or decompress SAM files. An implementation is available at https://github.com/rcanovas/libCSAM CONTACT: canovas-ba@lirmm.frSupplementary Information: Supplementary data is available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

SAM Theory Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Rui

The System Analysis Module (SAM) is an advanced and modern system analysis tool being developed at Argonne National Laboratory under the U.S. DOE Office of Nuclear Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM development aims for advances in physical modeling, numerical methods, and software engineering to enhance its user experience and usability for reactor transient analyses. To facilitate the code development, SAM utilizes an object-oriented application framework (MOOSE), and its underlying meshing and finite-element library (libMesh) and linear and non-linear solvers (PETSc), to leverage modern advanced software environments and numerical methods. SAM focuses on modeling advanced reactormore » concepts such as SFRs (sodium fast reactors), LFRs (lead-cooled fast reactors), and FHRs (fluoride-salt-cooled high temperature reactors) or MSRs (molten salt reactors). These advanced concepts are distinguished from light-water reactors in their use of single-phase, low-pressure, high-temperature, and low Prandtl number (sodium and lead) coolants. As a new code development, the initial effort has been focused on modeling and simulation capabilities of heat transfer and single-phase fluid dynamics responses in Sodium-cooled Fast Reactor (SFR) systems. The system-level simulation capabilities of fluid flow and heat transfer in general engineering systems and typical SFRs have been verified and validated. This document provides the theoretical and technical basis of the code to help users understand the underlying physical models (such as governing equations, closure models, and component models), system modeling approaches, numerical discretization and solution methods, and the overall capabilities in SAM. As the code is still under ongoing development, this SAM Theory Manual will be updated periodically to keep it consistent with the state of the development.« less

SAM Photovoltaic Model Technical Reference 2016 Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilman, Paul; DiOrio, Nicholas A; Freeman, Janine M

This manual describes the photovoltaic performance model in the System Advisor Model (SAM) software, Version 2016.3.14 Revision 4 (SSC Version 160). It is an update to the 2015 edition of the manual, which describes the photovoltaic model in SAM 2015.1.30 (SSC 41). This new edition includes corrections of errors in the 2015 edition and descriptions of new features introduced in SAM 2016.3.14, including: 3D shade calculator Battery storage model DC power optimizer loss inputs Snow loss model Plane-of-array irradiance input from weather file option Support for sub-hourly simulations Self-shading works with all four subarrays, and uses same algorithm for fixedmore » arrays and one-axis tracking Linear self-shading algorithm for thin-film modules Loss percentages replace derate factors. The photovoltaic performance model is one of the modules in the SAM Simulation Core (SSC), which is part of both SAM and the SAM SDK. SAM is a user-friedly desktop application for analysis of renewable energy projects. The SAM SDK (Software Development Kit) is for developers writing their own renewable energy analysis software based on SSC. This manual is written for users of both SAM and the SAM SDK wanting to learn more about the details of SAM's photovoltaic model.« less

Outcrop-Scale Hyperspectral Studies of a Lacustrine-Volcanic Mars Analog: Examination with a Mars 2020-like Instrument Suite

NASA Astrophysics Data System (ADS)

Martin, P.; Ehlmann, B. L.; Blaney, D. L.; Bhartia, R.; Allwood, A.

2015-12-01

Using the recently developed Ultra Compact Imaging Spectrometer (UCIS) (0.4-2.5 μm) to generate outcrop-scale infrared images and compositional maps, a Mars-relevant field site near China Ranch in the Mojave Desert has been surveyed and sampled to analyze the synergies between instruments in the Mars 2020 rover instrument suite. The site is broadly comprised of large lacustrine gypsum beds with fine-grained gypsiferous mudstones and interbedded volcanic ashes deposited in the Pleistocene, with a carbonate unit atop the outcrop. Alteration products such as clays and iron oxides are pervasive throughout the sequence. Mineralogical mapping of the outcrop was performed using UCIS. As the 2020 rover will have an onboard multispectral camera and IR point spectrometer, Mastcam-Z and SuperCam, this process of spectral analysis leading to the selection of sites for more detailed investigation is similar to the process by which samples will be selected for increased scrutiny during the 2020 mission. The infrared image is resampled (spatially and spectrally) to the resolutions of Mastcam-Z and SuperCam to simulate data from the Mars 2020 rover. Hand samples were gathered in the field (guided by the prior infrared compositional mapping), capturing samples of spectral and mineralogical variance in the scene. After collection, a limited number of specimens were chosen for more detailed analysis. The hand samples are currently being analyzed using JPL prototypes of the Mars 2020 arm-mounted contact instruments, specifically PIXL (Planetary Instrument for X-ray Lithochemistry) and SHERLOC (Scanning Habitable Environments with Raman & Luminescence). The geologic story as told by the Mars 2020 instrument data will be analyzed and compared to the full suite of data collected by hyperspectral imaging and terrestrial techniques (e.g. XRD) applied to the collected hand samples. This work will shed light on the potential uses and synergies of the Mars 2020 instrument suite, especially

Crystal structures of the SAM-III/S[subscript MK] riboswitch reveal the SAM-dependent translation inhibition mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, C.; Smith, A.M.; Fuchs, R.T.

2010-01-07

Three distinct classes of S-adenosyl-L-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The SMK box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-{angstrom} crystal structure of the Enterococcus faecalis SMK box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti-Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions withmore » the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the SMK box riboswitch sampling the near-cognate ligand S-adenosyl-L-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions.« less

Redox Behavior of the S-Adenosylmethionine (SAM)-Binding Fe-S Cluster in Methylthiotransferase RimO, toward Understanding Dual SAM Activity.

PubMed

Molle, Thibaut; Moreau, Yohann; Clemancey, Martin; Forouhar, Farhad; Ravanat, Jean-Luc; Duraffourg, Nicolas; Fourmond, Vincent; Latour, Jean-Marc; Gambarelli, Serge; Mulliez, Etienne; Atta, Mohamed

2016-10-18

RimO, a radical-S-adenosylmethionine (SAM) enzyme, catalyzes the specific C 3 methylthiolation of the D89 residue in the ribosomal S 12 protein. Two intact iron-sulfur clusters and two SAM cofactors both are required for catalysis. By using electron paramagnetic resonance, Mössbauer spectroscopies, and site-directed mutagenesis, we show how two SAM molecules sequentially bind to the unique iron site of the radical-SAM cluster for two distinct chemical reactions in RimO. Our data establish that the two SAM molecules bind the radical-SAM cluster to the unique iron site, and spectroscopic evidence obtained under strongly reducing conditions supports a mechanism in which the first molecule of SAM causes the reoxidation of the reduced radical-SAM cluster, impeding reductive cleavage of SAM to occur and allowing SAM to methylate a HS - ligand bound to the additional cluster. Furthermore, by using density functional theory-based methods, we provide a description of the reaction mechanism that predicts the attack of the carbon radical substrate on the methylthio group attached to the additional [4Fe-4S] cluster.

Cryo-Vacuum Testing of JWST's Integrated Telescope & Scientific Instrument Suite (OTIS)

NASA Astrophysics Data System (ADS)

Kimble, Randy; Apollo, Peter; Feinberg, Lee; Glazer, Stuart; Hanley, Jeffrey; Keski-Kuha, Ritva; Kirk, Jeffrey; Knight, J. Scott; Lambros, Scott; Lander, Juli; McGuffey, Douglas; Mehalick, Kimberly; Ohl, Raymond; Ousley, Wes; Reis, Carl; Reynolds, Paul; Begoña Vila, Maria; Waldman, Mark; Whitman, Tony

2018-01-01

A year ago we reported on the planning for a major test in the James Webb Space Telescope (JWST) program: cryo-vacuum testing of the combination of the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM). The cryo-vacuum testing of that scientific heart of the JWST observatory, known as OTIS (= OTE + ISIM), has now been completed in historic chamber A at NASA’s Johnson Space Center. From July through October 2017, the flight payload was cooled to its operating temperatures, put through a comprehensive suite of optical, thermal, and operational tests, and then safely warmed back to room temperature. We report here on the execution and top-level results from this milestone event in the JWST program.

Evaluating SAMS in Hong Kong Schools.

ERIC Educational Resources Information Center

Kwok, Lam-for; Lau, Chi-kuen; Fung, Sun-wai

1999-01-01

Describes the School Administration and Management Systems (SAMS) that was developed to support elementary and secondary schools in Hong Kong in administrative and managerial tasks. Reports results of a survey that investigated the impact of SAMS, evaluated its effectiveness, and identified possible areas of improvement to SAMS operation.…

SAM in a Nutshell.

ERIC Educational Resources Information Center

Givens, Larry R.

2000-01-01

Explains what the Association of Higher Education Facilities Officers' Strategic Assessment Model (SAM) is and how to use it to achieve organizational excellence through continuous improvement. Showing features of both the Malcolm Baldrige programs and the Balanced Scorecard, the SAM components are described along with an explanation of the four…

The Investigation of Magnesium Perchlorate/Iron Phase-mineral Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Sutter, B.; Heil, E.; Archer, P. D.; Ming, D. W.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P. R.; Niles, P. B.;

Construction and Resource Utilization Explorer (CRUX): Implementing Instrument Suite Data Fusion to Characterize Regolith Hydrogen Resources

NASA Technical Reports Server (NTRS)

Haldemann, Albert F. C.; Johnson, Jerome B.; Elphic, Richard C.; Boynton, William V.; Wetzel, John

2006-01-01

CRUX is a modular suite of geophysical and borehole instruments combined with display and decision support system (MapperDSS) tools to characterize regolith resources, surface conditions, and geotechnical properties. CRUX is a NASA-funded Technology Maturation Program effort to provide enabling technology for Lunar and Planetary Surface Operations (LPSO). The MapperDSS uses data fusion methods with CRUX instruments, and other available data and models, to provide regolith properties information needed for LPSO that cannot be determined otherwise. We demonstrate the data fusion method by showing how it might be applied to characterize the distribution and form of hydrogen using a selection of CRUX instruments: Borehole Neutron Probe and Thermal Evolved Gas Analyzer data as a function of depth help interpret Surface Neutron Probe data to generate 3D information. Secondary information from other instruments along with physical models improves the hydrogen distribution characterization, enabling information products for operational decision-making.

Variable sequences outside the SAM-binding core critically influence the conformational dynamics of the SAM-III/SMK box riboswitch

PubMed Central

Lu, Changrui; Smith, Angela M; Ding, Fang; Chowdhury, Anirban; Henkin, Tina M; Ke, Ailong

2012-01-01

The SMK box (SAM-III) translational riboswitches were identified in S-adenosyl-L-methionine (SAM) synthetase metK genes in members of the Lactobacillales. This riboswitch switches between two alternative conformations in response to the intracellular SAM concentration and controls metK expression at the level of translation initiation. We previously reported the crystal structure of the SAM-bound SMK box riboswitch. In this study we combined SHAPE chemical probing with mutagenesis to probe the ligand-induced conformational switching mechanism. We revealed that while the majority of the apo SMK box RNA molecules exist in an alternatively base paired (ON) conformation, a subset of them pre-organize into a SAM-bound-like (READY) conformation, which upon SAM exposure is selectively stabilized into the SAM-bound (OFF) conformation through an induced-fit mechanism. Mutagenesis showed that the ON state is only slightly more stable than the READY state, as several single-nucleotide substitutions in a hypervariable region outside the SAM-binding core can alter the folding landscape to favor the READY state. Such SMK variants display a “constitutively-OFF” behavior both in vitro and in vivo. Time-resolved and temperature-dependent SHAPE analyses revealed adaptation of the SMK box RNA to its mesothermal working environment. The latter analysis revealed that the SAM-bound SMK box RNA follows a two-step folding/unfolding process. PMID:21549712

Calibration and Sequence Development Status for the Sample Analysis at Mars Investigation on the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Mahaffy, Paul R.

2012-01-01

The measurement goals of the Sample Analysis at Mars (SAM) instrument suite on the "Curiosity" Rover of the Mars Science Laboratory (MSL) include chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples [1,2]. SAM directly supports the ambitious goals of the MSL mission to provide a quantitative assessment of habitability and preservation in Gale crater by means of a range of chemical and geological measurements [3]. The SAM FM combined calibration and environmental testing took place primarily in 2010 with a limited set of tests implemented after integration into the rover in January 2011. The scope of SAM FM testing was limited both to preserve SAM consumables such as life time of its electromechanical elements and to minimize the level of terrestrial contamination in the SAM instrument. A more comprehensive calibration of a SAM-like suite of instruments will be implemented in 2012 with calibration runs planned for the SAM testbed. The SAM Testbed is nearly identical to the SAM FM and operates in a ambient pressure chamber. The SAM Instrument Suite: SAM's instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). Gas Chromatography Mass Spectrometry is designed for identification of even trace organic compounds. The TLS [5] secures the C, H, and O isotopic composition in carbon dioxide, water, and methane. Sieved materials are delivered from the MSL sample acquisition and processing system to one of68 cups of the Sample Manipulation System (SMS). 59 of these cups are fabricated from inert quartz. After sample delivery, a cup is inserted into one of 2 ovens for evolved gas analysis (EGA ambient to >9500C) by the QMS and TLS. A portion of the gas released can be trapped and subsequently analyzed by GCMS. Nine sealed cups contain liquid solvents and chemical derivatization or thermochemolysis agents to extract and transform polar molecules

Microbial Habitability in Gale Crater: Sample Analysis at Mars (SAM) Instrument Detection of Microbial Essential Carbon and Nitrogen

NASA Technical Reports Server (NTRS)

Sutter, B.; Ming, D. W.; Eigenbrode, J. E.; Steele, A.; Stern, J. C.; Gonzalez, R. N.; McAdam, A. C.; Mahaffy, P. R.

2016-01-01

Chemical analyses of Mars soils and sediments from previous landed missions have demonstrated that Mars surface materials possessed major (e.g., P, K, Ca, Mg, S) and minor (e.g., Fe, Mn, Zn, Ni, Cl) elements essential to support microbial life. However, the detection of microbial essential organic-carbon (C) and nitrate have been more elusive until the Mars Science Laboratory (MSL) rover mission. Nitrate and organic-C in Gale Crater, Mars have been detected by the Sample Analysis at Mars (SAM) instrument onboard the MSL Curiosity rover. Eolian fines and drilled sedimentary rock samples were heated in the SAM oven from approximately 30 to 860 degrees Centigrade where evolved gases (e.g., nitrous oxide (NO) and CO2) were released and analyzed by SAM’s quadrupole mass spectrometer (MS). The temperatures of evolved NO was assigned to nitrate while evolved CO2 was assigned to organic-C and carbonate. The CO2 releases in several samples occurred below 450 degrees Centigrade suggesting organic-C dominated in those samples. As much as 7 micromoles NO3-N per gram and 200 micromoles CO2-C per gram have been detected in the Gale Crater materials. These N and C levels coupled with assumed microbial biomass (9 x 10 (sup -7) micrograms per cell) C (0.5 micrograms C per micrograms cell) and N (0.14 micrograms N per micrograms cell) requirements, suggests that less than 1 percent and less than 10 percent of Gale Crater C and N, respectively, would be required if available, to accommodate biomass requirements of 1 by 10 (sup 5) cells per gram sediment. While nitrogen is the limiting nutrient, the potential exists that sufficient N and organic-C were present to support limited heterotrophic microbial populations that may have existed on ancient Mars.

SAM International Case Studies: DPV Analysis in Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCall, James D

Presentation demonstrates the use of the System Advisor Model (SAM) in international analyses, specifically Mexico. Two analyses are discussed with relation to SAM modelling efforts: 1) Customer impacts from changes to net metering and billing agreements and 2) Potential benefits of PV for Mexican solar customers, the Mexican Treasury, and the environment. Along with the SAM analyses, integration of the International Utility Rate Database (I-URDB) with SAM and future international SAM work are discussed. Presentation was created for the International Solar Energy Society's (ISES) webinar titled 'International use of the NREL System Advisor Model (SAM) with case studies'.

Mars Atmospheric Escape Recorded by H, C and O Isotope Ratios in Carbon Dioxide and Water Measured by the Sam Tunable Laser Spectrometer on the Curiosity Rover

NASA Technical Reports Server (NTRS)

Webster, C. R.; Mahaffy, P. R.; Leshin, L. A.; Atreya, S. K.; Flesch, G. J.; Stern, J.; Christensen, L. E.; Vasavada, A. R.; Owen, T.; Niles, P. B.;

In situ analysis of martian regolith with the SAM experiment during the first mars year of the MSL mission: Identification of organic molecules by gas chromatography from laboratory measurements

NASA Astrophysics Data System (ADS)

Millan, M.; Szopa, C.; Buch, A.; Coll, P.; Glavin, D. P.; Freissinet, C.; Navarro-Gonzalez, R.; François, P.; Coscia, D.; Bonnet, J. Y.; Teinturier, S.; Cabane, M.; Mahaffy, P. R.

2016-09-01

The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover, is specifically designed for in situ molecular and isotopic analyses of martian surface materials and atmosphere. It contributes to the Mars Science Laboratory (MSL) missions primary scientific goal to characterize the potential past, present or future habitability of Mars. In all of the analyses of solid samples delivered to SAM so far, chlorinated organic compounds have been detected above instrument background levels and identified by gas chromatography coupled to mass spectrometry (GC-MS) (Freissinet et al., 2015; Glavin et al., 2013). While some of these may originate from reactions between oxychlorines and terrestrial organic carbon present in the instrument background (Glavin et al., 2013), others have been demonstrated to originate from indigenous organic carbon present in samples (Freissinet et al., 2015). We present here laboratory calibrations that focused on the analyses performed with the MXT-CLP GC column (SAM GC-5 channel) used for nearly all of the GC-MS analyses of the martian soil samples carried out with SAM to date. Complementary to the mass spectrometric data, gas chromatography allows us to separate and identify the species analyzable in a nominal SAM-GC run time of about 21 min. To characterize the analytical capabilities of this channel within the SAM Flight Model (FM) operating conditions on Mars, and their implications on the detection of organic matter, it is required to perform laboratory experimental tests and calibrations on spare model components. This work assesses the SAM flight GC-5 column efficiency, confirms the identification of the molecules based on their retention time, and enables a better understanding of the behavior of the SAM injection trap (IT) and its release of organic molecules. This work will enable further optimization of the SAM-GC runs for additional samples to be analyzed during the MSL mission.

In Situ Analysis of Martian Regolith with the SAM Experiment During the First Mars Year of the MSL Mission: Identification of Organic Molecules by Gas Chromatography from Laboratory Measurements

NASA Technical Reports Server (NTRS)

Millan, M.; Szopa, C.; Buch, A.; Coll, P.; Glavin, D. P.; Freissinet, C.; Navarro-Gonzalez, R.; Francois, P.; Coscia, D.; Bonnet, J. Y.;

Mars Methane at Gale Crater Shows Strong Seasonal Cycle: Updated Results from TLS-SAM on Curiosity

NASA Astrophysics Data System (ADS)

Webster, C. R.; Mahaffy, P. R.; Atreya, S. K.; Flesch, G.; Malespin, C.; McKay, C.; Martinez, G.; Moores, J.; Smith, C. L.; Martin-Torres, F. J.; Gomez-Elvira, J.; Zorzano, M. P.; Wong, M. H.; Trainer, M. G.; Eigenbrode, J. L.; Glavin, D. P.; Steele, A.; Archer, D., Jr.; Sutter, B.; Coll, P. J.; Freissinet, C.; Meslin, P. Y.; Pavlov, A.; Keymeulen, D.; Christensen, L. E.; Gough, R. V.; Schwenzer, S. P.; Navarro-Gonzalez, R.; Pla-García, J.; Rafkin, S. C.; Vicente-Retortillo, Á.; Kahanpää, H.; Viudez-Moreiras, D.; Smith, M. D.; Harri, A. M.; Genzer, M.; Hassler, D.; Lemmon, M. T.; Crisp, J. A.; Zurek, R. W.; Vasavada, A. R.

2017-12-01

In situ measurements of atmospheric methane have been made over a 5-year period at Gale Crater on Mars using the Tunable Laser Spectrometer (TLS) instrument in the Sample Analysis at Mars (SAM) suite on the Curiosity rover. We report two important observations: (i) a background level of mean value of 0.41 ±0.11 (2sem) that is about 5 times lower than some model predictions based on generation from UV degradation of micro-meteorites or interplanetary dust delivered to the martian surface; (ii) "spikes" of elevated levels of 7 ppbv attributed to episodic releases from small local sources, probably to the north of Gale crater1. Reports of plumes, patches or episodic releases of methane in the Martian atmosphere have to date eluded explanation in part because of their lack of repeatability in time or location. Our in situ measurements of the background methane levels exhibit a strong, repeatable seasonal variability. The amplitude of the observed seasonal cycle is 3 times greater than both that expected from the annual sublimation and freezing of polar carbon dioxide and that expected from methane production from ultraviolet (UV) degradation of exogenously-delivered surface material. The observed large seasonal variation in the background, and sporadic observations of higher pulses of 7 ppbv appear consistent with localized small sources of methane release from Martian surface reservoirs that may be occurring throughout the planet. We will present our updated data set, correlations of Mars methane with various other measurements from SAM, REMS, RAD and ChemCam instruments on Curiosity, as well as empirical models of UV surface insolation, and provide preliminary interpretation of results. 1 "Mars Methane Detection and Variability at Gale Crater", C. R. Webster et al., Science, 347, 415-417 (2015) and references therein. The research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the

The SAM-responsive SMK box is a reversible riboswitch

PubMed Central

Smith, Angela M.; Fuchs, Ryan T.; Grundy, Frank J.; Henkin, Tina M.

2010-01-01

The SMK (SAM-III) box is an S-adenosylmethionine (SAM)-responsive riboswitch found in the 5′ untranslated region of metK genes, encoding SAM synthetase, in many members of the Lactobacillales. SAM binding causes a structural rearrangement in the RNA that sequesters the Shine-Dalgarno (SD) sequence by pairing with a complementary anti-SD (ASD) sequence; sequestration of the SD sequence inhibits binding of the 30S ribosomal subunit and prevents translation initiation. We observed a slight increase in the half-life of the metK transcript in vivo when Enterococcus faecalis cells were depleted for SAM, but no significant change in overall transcript abundance, consistent with the model that this riboswitch regulates at the level of translation initiation. The half-life of the SAM-SMK box RNA complex in vitro is shorter than that of the metK transcript in vivo, raising the possibility of reversible binding of SAM. We used a fluorescence assay to directly visualize reversible switching between the SAM-free and SAM-bound conformations. We propose that the SMK box riboswitch can make multiple SAM-dependent regulatory decisions during the lifetime of the transcript in vivo, acting as a reversible switch that allows the cell to respond rapidly to fluctuations in SAM pools by modulating expression of the SAM synthetase gene. PMID:21143313

Detection of Evolved Carbon Dioxide in the Rocknest Eolian Bedform by the Sample Analysis at Mars(SAM) Instrument at the Mars Curiosity Landing Site

NASA Technical Reports Server (NTRS)

Sutter, B.; Archer, D.; McAdam, A.; Franz, H.; Ming, D. W.; Eigenbrode, J. L.; Glavin, D. P.; Mahaffy, P.; Stern, J.; Navarro-Gonzalez, R.

2013-01-01

The Sample Analysis at Mars (SAM) instrument detected four releases of carbon dioxide (CO2) that ranged from 100 to 700 C from the Rocknest eolian bedform material (Fig. 1). Candidate sources of CO2 include adsorbed CO2, carbonate(s), combusted organics that are either derived from terrestrial contamination and/or of martian origin, occluded or trapped CO2, and other sources that have yet to be determined. The Phoenix Lander s Thermal Evolved Gas Analyzer (TEGA) detected two CO2 releases (400-600, 700-840 C) [1,2]. The low temperature release was attributed to Fe- and/or Mg carbonates [1,2], per-chlorate interactions with carbonates [3], nanophase carbonates [4] and/or combusted organics [1]. The high temperature CO2 release was attributed to a calcium bearing carbonate [1,2]. No evidence of a high temperature CO2 release similar to the Phoenix material was detected in the Rocknest materials by SAM. The objectives of this work are to evaluate the temperature and total contribution of each Rocknest CO2 release and their possible sources. Four CO2 releases from the Rocknest material were detected by SAM. Potential sources of CO2 are adsorbed CO2, (peak 1) and Fe/Mg carbonates (peak 4). Only a fraction of peaks 2 and 3 (0.01 C wt.%) may be partially attributed to combustion of organic contamination. Meteoritic organics mixed in the Rocknest bedform could be present, but the peak 2 and 3 C concentration (approx.0.21 C wt. %) is likely too high to be attributed solely to meteoritic organic C. Other inorganic sources of C such as interactions of perchlorates and carbonates and sources yet to be identified will be evaluated to account for CO2 released from the thermal decomposition of Rocknest material.

78 FR 62627 - Sam Rayburn Dam Rate

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

Search for organic matter at Mars with combined measurements of the SAM and ChemCam instruments onboard the Curiosity rover

NASA Astrophysics Data System (ADS)

Dequaire, T.; Meslin, P. Y.; Rapin, W.; Jaber, M.; Maurice, S.; Gasnault, O.; Forni, O.; Coll, P.; Szopa, C.

2015-10-01

Since 2012, he Curiosity rover on Mars seeks clues of habitability in Gale crater. One of these clues is the presence of organic matter. For the moment,only a few traces of organic matter was recently found with the SAM experiment. We propose here to evaluate the capabilities for the ChemCam experiment to detect organic molecules from its elemental analysis of the Mars regolith or rocks. The first results obtained in laboratory with the ChemCam spare model and different samples show that it is possible to detect organic signatures with LIBS,focusing on atomic carbon, hydrogen and nitrogen peaks,and on a C-N molecular peak when the samples areenriched in organic molecules(100-10 wt%). We currently work with Mars representative samples to determine the instrument detection limitfor organics, in order to determine if it can be used to guide Curiosity towards interesting outcrops.

Multiple polymer architectures of human Polyhomeotic homolog 3 (PHC3) SAM

PubMed Central

Nanyes, David R.; Junco, Sarah E.; Taylor, Alexander B.; Robinson, Angela K.; Patterson, Nicolle L.; Shivarajpur, Ambika; Halloran, Jonathan; Hale, Seth M.; Kaur, Yogeet; Hart, P. John; Kim, Chongwoo A.

2014-01-01

The self-association of sterile alpha motifs (SAMs) into a helical polymer architecture is a critical functional component of many different and diverse array of proteins. For the Drosophila Polycomb group (PcG) protein Polyhomeotic (Ph), its SAM polymerization serves as the structural foundation to cluster multiple PcG complexes, helping to maintain a silenced chromatin state. Ph SAM shares 64% sequence identity with its human ortholog, PHC3 SAM, and both SAMs polymerize. However, in the context of their larger protein regions, PHC3 SAM forms longer polymers compared to Ph SAM. Motivated to establish the precise structural basis for the differences, if any, between Ph and PHC3 SAM, we determined the crystal structure of the PHC3 SAM polymer. PHC3 SAM utilizes the same SAM-SAM interaction as the Ph SAM six-fold repeat polymer. Yet, PHC3 SAM polymerizes utilizing just five SAMs per turn of the helical polymer rather than the typical six per turn observed for all SAM polymers reported to date. Structural analysis suggested that malleability of the PHC3 SAM would allow formation of not just the five-fold repeat structure but possibly others. Indeed, a second PHC3 SAM polymer in a different crystal form forms a six-fold repeat polymer. These results suggest that the polymers formed by PHC3 SAM, and likely others, are quite dynamic. The functional consequence of the variable PHC3 SAM polymers may be to create different chromatin architectures. PMID:25044168

The FIELDS Instrument Suite on MMS: Scientific Objectives, Measurements, and Data Products

NASA Astrophysics Data System (ADS)

Torbert, R. B.; Russell, C. T.; Magnes, W.; Ergun, R. E.; Lindqvist, P.-A.; Le Contel, O.; Vaith, H.; Macri, J.; Myers, S.; Rau, D.; Needell, J.; King, B.; Granoff, M.; Chutter, M.; Dors, I.; Olsson, G.; Khotyaintsev, Y. V.; Eriksson, A.; Kletzing, C. A.; Bounds, S.; Anderson, B.; Baumjohann, W.; Steller, M.; Bromund, K.; Le, Guan; Nakamura, R.; Strangeway, R. J.; Leinweber, H. K.; Tucker, S.; Westfall, J.; Fischer, D.; Plaschke, F.; Porter, J.; Lappalainen, K.

2016-03-01

The FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission provides comprehensive measurements of the full vector magnetic and electric fields in the reconnection regions investigated by MMS, including the dayside magnetopause and the night-side magnetotail acceleration regions out to 25 Re. Six sensors on each of the four MMS spacecraft provide overlapping measurements of these fields with sensitive cross-calibrations both before and after launch. The FIELDS magnetic sensors consist of redundant flux-gate magnetometers (AFG and DFG) over the frequency range from DC to 64 Hz, a search coil magnetometer (SCM) providing AC measurements over the full whistler mode spectrum expected to be seen on MMS, and an Electron Drift Instrument (EDI) that calibrates offsets for the magnetometers. The FIELDS three-axis electric field measurements are provided by two sets of biased double-probe sensors (SDP and ADP) operating in a highly symmetric spacecraft environment to reduce significantly electrostatic errors. These sensors are complemented with the EDI electric measurements that are free from all local spacecraft perturbations. Cross-calibrated vector electric field measurements are thus produced from DC to 100 kHz, well beyond the upper hybrid resonance whose frequency provides an accurate determination of the local electron density. Due to its very large geometric factor, EDI also provides very high time resolution (˜1 ms) ambient electron flux measurements at a few selected energies near 1 keV. This paper provides an overview of the FIELDS suite, its science objectives and measurement requirements, and its performance as verified in calibration and cross-calibration procedures that result in anticipated errors less than 0.1 nT in B and 0.5 mV/m in E. Summaries of data products that result from FIELDS are also described, as well as algorithms for cross-calibration. Details of the design and performance characteristics of AFG/DFG, SCM, ADP, SDP, and EDI

Structural basis for diversity in the SAM clan of riboswitches.

PubMed

Trausch, Jeremiah J; Xu, Zhenjiang; Edwards, Andrea L; Reyes, Francis E; Ross, Phillip E; Knight, Rob; Batey, Robert T

2014-05-06

In bacteria, sulfur metabolism is regulated in part by seven known families of riboswitches that bind S-adenosyl-l-methionine (SAM). Direct binding of SAM to these mRNA regulatory elements governs a downstream secondary structural switch that communicates with the transcriptional and/or translational expression machinery. The most widely distributed SAM-binding riboswitches belong to the SAM clan, comprising three families that share a common SAM-binding core but differ radically in their peripheral architecture. Although the structure of the SAM-I member of this clan has been extensively studied, how the alternative peripheral architecture of the other families supports the common SAM-binding core remains unknown. We have therefore solved the X-ray structure of a member of the SAM-I/IV family containing the alternative "PK-2" subdomain shared with the SAM-IV family. This structure reveals that this subdomain forms extensive interactions with the helix housing the SAM-binding pocket, including a highly unusual mode of helix packing in which two helices pack in a perpendicular fashion. Biochemical and genetic analysis of this RNA reveals that SAM binding induces many of these interactions, including stabilization of a pseudoknot that is part of the regulatory switch. Despite strong structural similarity between the cores of SAM-I and SAM-I/IV members, a phylogenetic analysis of sequences does not indicate that they derive from a common ancestor.

Improving methionine and ATP availability by MET6 and SAM2 co-expression combined with sodium citrate feeding enhanced SAM accumulation in Saccharomyces cerevisiae.

PubMed

Chen, Hailong; Wang, Zhou; Wang, Zhilai; Dou, Jie; Zhou, Changlin

2016-04-01

S-adenosyl-L-methionine (SAM), biosynthesized from methionine and ATP, exhibited diverse pharmaceutical applications. To enhance SAM accumulation in S. cerevisiae CGMCC 2842 (wild type), improvement of methionine and ATP availability through MET6 and SAM2 co-expression combined with sodium citrate feeding was investigated here. Feeding 6 g/L methionine at 12 h into medium was found to increase SAM accumulation by 38 % in wild type strain. Based on this result, MET6, encoding methionine synthase, was overexpressed, which caused a 59 % increase of SAM. To redirect intracellular methionine into SAM, MET6 and SAM2 (encoding methionine adenosyltransferase) were co-expressed to obtain the recombinant strain YGSPM in which the SAM accumulation was 2.34-fold of wild type strain. The data obtained showed that co-expression of MET6 and SAM2 improved intracellular methionine availability and redirected the methionine to SAM biosynthesis. To elevate intracellular ATP levels, 6 g/L sodium citrate, used as an auxiliary energy substrate, was fed into the batch fermentation medium, and an additional 19 % increase of SAM was observed after sodium citrate addition. Meanwhile, it was found that addition of sodium citrate improved the isocitrate dehydrogenase activity which was associated with the intracellular ATP levels. The results demonstrated that addition of sodium citrate improved intracellular ATP levels which promoted conversion of methionine into SAM. This study presented a feasible approach with considerable potential for developing highly SAM-productive strains based on improving methionine and ATP availability.

System Advisor Model, SAM 2014.1.14: General Description

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blair, Nate; Dobos, Aron P.; Freeman, Janine

2014-02-01

This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2013.9.20, released on September 9, 2013. SAM is a computer model that calculates performance and financial metrics of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of photovoltaic, concentrating solar power, solar water heating, wind, geothermal, biomass, and conventional power systems. The financial model can represent financial structures for projects thatmore » either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). SAM's advanced simulation options facilitate parametric and sensitivity analyses, and statistical analysis capabilities are available for Monte Carlo simulation and weather variability (P50/P90) studies. SAM can also read input variables from Microsoft Excel worksheets. For software developers, the SAM software development kit (SDK) makes it possible to use SAM simulation modules in their applications written in C/C++, C#, Java, Python, and MATLAB. NREL provides both SAM and the SDK as free downloads at http://sam.nrel.gov. Technical support and more information about the software are available on the website.« less

4-Mercaptophenylboronic acid SAMs on gold: comparison with SAMs derived from thiophenol, 4-mercaptophenol, and 4-mercaptobenzoic acid.

PubMed

Barriet, David; Yam, Chi Ming; Shmakova, Olga E; Jamison, Andrew C; Lee, T Randall

2007-08-14

We report the formation and characterization of self-assembled monolayers (SAMs) derived from the adsorption of 4-mercaptophenylboronic acid (MPBA) on gold. For comparison, SAMs derived from the adsorption of thiophenol (TP), 4-mercaptophenol (MP), and 4-mercaptobenzoic acid (MBA) were also examined. The structure and properties of the SAMs were evaluated by ellipsometry, contact-angle goniometry, polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS). Specifically, ellipsometry was used to assess the formation of monolayer films, and contact angle measurements were used to determine the surface hydrophilicity and homogeneity. Separately, PM-IRRAS was used to evaluate the molecular composition and orientation as well as the intermolecular hydrogen bonding within the SAMs. Finally, XPS was used to evaluate the film composition and surface coverage (i.e., packing density), which was observed to increase in the following order: TP < MP < MPBA < MBA. A rationalization for the observed packing differences is presented. The XPS data indicate further that ultrahigh vacuum conditions induce the partial dehydration of MPBA SAMs with the concomitant formation of surface boronic anhydride species. Overall, the analytical data collectively show that the MPBA moieties in the SAMs exist in the acid form rather than the anhydride form under ambient laboratory conditions. Furthermore, stability studies find that MPBA SAMs are surprisingly labile in basic solution, where the terminal B-C bonds are cleaved by the attack of hydroxide ion and strongly basic amine nucleophiles. The unanticipated lability observed here should be considered by those wishing to use MPBA moieties in carbohydrate-sensing applications.

The Statin-Associated Muscle Symptom Clinical Index (SAMS-CI): Revision for Clinical Use, Content Validation, and Inter-rater Reliability.

PubMed

Rosenson, Robert S; Miller, Kate; Bayliss, Martha; Sanchez, Robert J; Baccara-Dinet, Marie T; Chibedi-De-Roche, Daniela; Taylor, Beth; Khan, Irfan; Manvelian, Garen; White, Michelle; Jacobson, Terry A

2017-04-01

The Statin-Associated Muscle Symptom Clinical Index (SAMS-CI) is a method for assessing the likelihood that a patient's muscle symptoms (e.g., myalgia or myopathy) were caused or worsened by statin use. The objectives of this study were to prepare the SAMS-CI for clinical use, estimate its inter-rater reliability, and collect feedback from physicians on its practical application. For content validity, we conducted structured in-depth interviews with its original authors as well as with a panel of independent physicians. Estimation of inter-rater reliability involved an analysis of 30 written clinical cases which were scored by a sample of physicians. A separate group of physicians provided feedback on the clinical use of the SAMS-CI and its potential utility in practice. Qualitative interviews with providers supported the content validity of the SAMS-CI. Feedback on the clinical use of the SAMS-CI included several perceived benefits (such as brevity, clear wording, and simple scoring process) and some possible concerns (workflow issues and applicability in primary care). The inter-rater reliability of the SAMS-CI was estimated to be 0.77 (confidence interval 0.66-0.85), indicating high concordance between raters. With additional provider feedback, a revised SAMS-CI instrument was created suitable for further testing, both in the clinical setting and in prospective validation studies. With standardized questions, vetted language, easily interpreted scores, and demonstrated reliability, the SAMS aims to estimate the likelihood that a patient's muscle symptoms were attributable to statins. The SAMS-CI may support better detection of statin-associated muscle symptoms in clinical practice, optimize treatment for patients experiencing muscle symptoms, and provide a useful tool for further clinical research.

The Improvement of SAM Accumulation by Integrating the Endogenous Methionine Adenosyltransferase Gene SAM2 in Genome of the Industrial Saccharomyces cerevisiae Strain.

PubMed

Zhao, Weijun; Shi, Feng; Hang, Baojian; Huang, Lei; Cai, Jin; Xu, Zhinan

2016-03-01

S-Adenosyl-L-methionine (SAM) plays important roles in trans-methylation, trans-sulfuration, and polyamine synthesis in all living cells, and it is also an effective cure for liver disease, depressive syndromes, and osteoarthritis. The increased demands of SAM in pharmaceuticals industry have aroused lots of attempts to improve its production. In this study, a multiple-copy integrative plasmid pYMIKP-SAM2 was introduced into the chromosome of wild-type Saccharomyces cerevisiae strain ZJU001 to construct the recombined strain R1-ZJU001. Further studies showed that the recombinant yeast exhibited higher enzymatic activity of methionine adenosyltransferase and improved its SAM biosynthesis. With a three-phase fed-batch strategy in 15-liter bench-top fermentor, 8.81 g/L SAM was achieved after 52 h cultivation of R1-ZJU001, about 27.1 % increase over its parent strain ZJU001, whereas the SAM content was also improved from 64.6 mg/g DCW to 91.0 mg/g DCW. Our results shall provide insights into the metabolic engineering of SAM pathway in yeast for improved productivity of SAM and subsequent industrial applications.

Noncanonical Radical SAM Enzyme Chemistry Learned from Diphthamide Biosynthesis.

PubMed

Dong, Min; Zhang, Yugang; Lin, Hening

2018-05-10

Radical S-adenosylmethionine (SAM) enzymes are a superfamily of enzymes that use SAM and reduced [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical to catalyze numerous challenging reactions. We have reported a type of noncanonical radical SAM enzymes in the diphthamide biosynthesis pathway. These enzymes also use SAM and reduced [4Fe-4S] clusters, but generate a 3-amino-3-carboxypropyl (ACP) radical to modify the substrate protein, translation elongation factor 2. The regioselective cleavage of a different C-S bond of the sulfonium center of SAM in these enzymes comparing to canonical radical SAM enzymes is intriguing. Here, we highlight some recent findings in the mechanism of these types of enzymes, showing that the diphthamide biosynthetic radial SAM enzymes bound SAM with a distinct geometry. In this way, the unique iron of the [4Fe-4S] cluster in the enzyme can only attack the carbon on the ACP group to form an organometallic intermediate. The homolysis of the organometallic intermediate releases the ACP radical and generates the EF2 radial.

Substation alarm multiplexing system (SAMS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

ElBadaly, H.; Gaughan, J.; Ward, G.

1996-03-01

This paper describes an on going R&D project to develop, design, install, and assess the field performance of an advanced substation alarm system. SAMS provides a highly fault-tolerant system for the reporting of equipment alarms. SAMS separates and identifies each of the multiple alarm contacts, transmits an alarm condition over existing substation two-wire system, and displays the alarm source, and its associated technical information, on a touch-screen monitor inside the substation control room, and a remote central location and on a hand held terminal which may be carried anywhere within the substation. SAMS is currently installed at the Sherman Creekmore » substation in the Bronx for the purpose of a three month field evaluation.« less

Evidence for Smectite Clays from MSL SAM Analyses of Mudstone at Yellowknife Bay, Gale Crater, Mars

NASA Astrophysics Data System (ADS)

McAdam, A.; Franz, H.; Mahaffy, P. R.; Eigenbrode, J. L.; Stern, J. C.; Brunner, A.; Sutter, B.; Archer, P. D.; Ming, D. W.; Morris, R. V.; Atreya, S. K.; Team, M.

2013-12-01

Drilled samples of mudstone from the Sheepbed unit at Yellowknife Bay were analyzed by MSL instruments including the Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments in MSL's Analytical Laboratory. CheMin analyses revealed the first in situ X-ray diffraction based evidence of clay minerals on Mars, which are likely trioctahedral smectites (e.g., saponite) and comprise ~20% of the mudstone sample (e.g., Bristow et al., this meeting). SAM analyses, which heated the mudstone samples to 1000oC and monitored volatiles evolved to perform in situ evolved gas analysis mass spectrometry (EGA-MS), resulted in a H2O trace exhibiting a wide evolution at temperatures <500oC, and an evolution peak at higher temperatures near ~750oC. The low temperature H2O evolution has many potential contributors, including adsorbed H2O, smectite interlayer H2O, and structural H2O/OH from bassanite and akaganeite (identified by CheMin) and H2O/OH from amorphous phases in the sample. The high temperature H2O is consistent with the evolution of H2O from the dehydroxylation of the smectite clay mineral. Comparison to EGA-MS data collected under SAM-like conditions on a variety of clay mineral reference materials indicate that a trioctahedral smectite, such as saponite, is most consistent with the high temperature H2O evolution observed. There may also be SAM EGA-MS evidence for a small high temperature H2O evolution from scoop samples from the Yellowknife Bay Rocknest sand shadow bedform. As in the mudstone samples, this evolution may indicate the detection of smectite clays, and the idea that minor clays may be present in Rocknest materials that could be expected to be at least partially derived from local sources is reasonable. But, because smectite clays were not definitively observed in CheMin analyses of Rocknest materials, they must be present at much lower abundances than the ~20% observed in the mudstone samples. This potential detection underscores the

Evidence for Smectite Clays from MSL SAM Analyses of Mudstone at Yellowknife Bay, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

McAdam, Amy; Franz, Heather; Mahaffy, Paul R.; Eigenbrode, Jennifer L.; Stern, Jennifer C.; Brunner, Anna; Archer, Paul Douglas; Ming, Douglas W.; Morris, Richard V.; Atreya, Sushil K.

2013-01-01

Drilled samples of mudstone from the Sheepbed unit at Yellowknife Bay were analyzed by MSL instruments including the Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments in MSL's Analytical Laboratory. CheMin analyses revealed the first in situ X-ray diffraction based evidence of clay minerals on Mars, which are likely trioctahedral smectites (e.g., saponite) and comprise approx 20% of the mudstone sample (e.g., Bristow et al., this meeting). SAM analyses, which heated the mudstone samples to 1000 C and monitored volatiles evolved to perform in situ evolved gas analysis mass spectrometry (EGA-MS), resulted in a H2O trace exhibiting a wide evolution at temperatures < 500 C, and an evolution peak at higher temperatures near approx 750 C. The low temperature H2O evolution has many potential contributors, including adsorbed H2O, smectite interlayer H2O, and structural H2O/OH from bassanite and akaganeite (identified by CheMin) and H2O/OH from amorphous phases in the sample. The high temperature H2O is consistent with the evolution of H2O from the dehydroxylation of the smectite clay mineral. Comparison to EGA-MS data collected under SAM-like conditions on a variety of clay mineral reference materials indicate that a trioctahedral smectite, such as saponite, is most consistent with the high temperature H2O evolution observed. There may also be SAM EGA-MS evidence for a small high temperature H2O evolution from scoop samples from the Yellowknife Bay Rocknest sand shadow bedform. As in the mudstone samples, this evolution may indicate the detection of smectite clays, and the idea that minor clays may be present in Rocknest materials that could be expected to be at least partially derived from local sources is reasonable. But, because smectite clays were not definitively observed in CheMin analyses of Rocknest materials, they must be present at much lower abundances than the approx 20% observed in the mudstone samples. This potential detection

Emerging themes in radical SAM chemistry

PubMed Central

Shisler, Krista A; Broderick, Joan B

2014-01-01

Enzymes in the radical SAM (RS) superfamily catalyze a wide variety of reactions through unique radical chemistry. The characteristic markers of the superfamily include a [4Fe–4S] cluster coordinated to the protein via a cysteine triad motif, typically CX3CX2C, with the fourth iron coordinated by S-adenosylmethionine (SAM). The SAM serves as a precursor for a 5′-deoxyadenosyl radical, the central intermediate in nearly all RS enzymes studied to date. The SAM-bound [4Fe–4S] cluster is located within a partial or full triosephosphate isomerase (TIM) barrel where the radical chemistry occurs protected from the surroundings. In addition to the TIM barrel and a RS [4Fe–4S] cluster, many members of the superfamily contain additional domains and/or additional Fe–S clusters. Recently characterized superfamily members are providing new examples of the remarkable range of reactions that can be catalyzed, as well as new structural and mechanistic insights into these fascinating reactions. PMID:23141873

Structural Basis for Methyl Transfer by a Radical SAM Enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boal, Amie K.; Grove, Tyler L.; McLaughlin, Monica I.

2014-10-02

The radical S-adenosyl-l-methionine (SAM) enzymes RlmN and Cfr methylate 23S ribosomal RNA, modifying the C2 or C8 position of adenosine 2503. The methyl groups are installed by a two-step sequence involving initial methylation of a conserved Cys residue (RlmN Cys{sup 355}) by SAM. Methyl transfer to the substrate requires reductive cleavage of a second equivalent of SAM. Crystal structures of RlmN and RlmN with SAM show that a single molecule of SAM coordinates the [4Fe-4S] cluster. Residue Cys{sup 355} is S-methylated and located proximal to the SAM methyl group, suggesting the SAM that is involved in the initial methyl transfermore » binds at the same site. Thus, RlmN accomplishes its complex reaction with structural economy, harnessing the two most important reactivities of SAM within a single site.« less

Sam's progress with learning mathematics.

PubMed

Haslam, Lynne

2007-07-01

Sam is 18 years old and has Down syndrome. He achieved a grade in the standard assessment of mathematics (GCSE) at 16 years of age. This paper describes the part played in his success in school by the Kumon method of teaching mathematics, identifies the benefits of the small steps and lots of practice built in to the method and illustrates the way Sam applied his Kumon learning in school.

System Advisor Model, SAM 2011.12.2: General Description

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilman, P.; Dobos, A.

2012-02-01

This document describes the capabilities of the U.S. Department of Energy and National Renewable Energy Laboratory's System Advisor Model (SAM), Version 2011.12.2, released on December 2, 2011. SAM is software that models the cost and performance of renewable energy systems. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of solar, wind, geothermal, biomass, and conventional power systems. The financial model can represent financing structures for projects that either buy and sell electricity at retail ratesmore » (residential and commercial) or sell electricity at a price determined in a power purchase agreement (utility). Advanced analysis options facilitate parametric, sensitivity, and statistical analyses, and allow for interfacing SAM with Microsoft Excel or with other computer programs. SAM is available as a free download at http://sam.nrel.gov. Technical support and more information about the software are available on the website.« less

Chromatographic, Spectroscopic and Mass Spectrometric Approaches for Exploring the Habitability of Mars in 2012 and Beyond with the Curiosity Rover

NASA Technical Reports Server (NTRS)

Mahaffy, Paul

2012-01-01

The Sample Analysis at Mars (SAM) suite of instruments on the Curiosity Rover of Mars Science Laboratory Mission is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The goals of the science investigation enabled by the gas chromatograph mass spectrometer and tunable laser spectrometer instruments of SAM are to work together with the other MSL investigations is to quantitatively assess habitability through a series of chemical and geological measurements. We describe the multi-column gas chromatograph system employed on SAM and the approach to extraction and analysis of organic compounds that might be preserved in ancient martian rocks.

Sam Donaldson: Tips From a Cancer Survivor

MedlinePlus

... Home Current Issue Past Issues Special Section Sam Donaldson: Tips From a Cancer Survivor Past Issues / Spring ... courtesy of ABC News For 40 years, Sam Donaldson has worked for ABC News, reporting from virtually ...

Structural insights into SAM domain-mediated tankyrase oligomerization.

PubMed

DaRosa, Paul A; Ovchinnikov, Sergey; Xu, Wenqing; Klevit, Rachel E

2016-09-01

Tankyrase 1 (TNKS1; a.k.a. ARTD5) and tankyrase 2 (TNKS2; a.k.a ARTD6) are highly homologous poly(ADP-ribose) polymerases (PARPs) that function in a wide variety of cellular processes including Wnt signaling, Src signaling, Akt signaling, Glut4 vesicle translocation, telomere length regulation, and centriole and spindle pole maturation. Tankyrase proteins include a sterile alpha motif (SAM) domain that undergoes oligomerization in vitro and in vivo. However, the SAM domains of TNKS1 and TNKS2 have not been structurally characterized and the mode of oligomerization is not yet defined. Here we model the SAM domain-mediated oligomerization of tankyrase. The structural model, supported by mutagenesis and NMR analysis, demonstrates a helical, homotypic head-to-tail polymer that facilitates TNKS self-association. Furthermore, we show that TNKS1 and TNKS2 can form (TNKS1 SAM-TNKS2 SAM) hetero-oligomeric structures mediated by their SAM domains. Though wild-type tankyrase proteins have very low solubility, model-based mutations of the SAM oligomerization interface residues allowed us to obtain soluble TNKS proteins. These structural insights will be invaluable for the functional and biophysical characterization of TNKS1/2, including the role of TNKS oligomerization in protein poly(ADP-ribosyl)ation (PARylation) and PARylation-dependent ubiquitylation. © 2016 The Protein Society.

SJ-3366 Sam Jin Pharmaceutical.

PubMed

Baba, Masanori

2002-08-01

Sam Jin is investigating SJ-3366, a non-nucleoside reverse transcriptase inhibitor (NNRTI), for the potential treatment of HIV infection [302450]. As well as acting as an NNRTI, SJ-3366 also interferes with HIV-1 entry via an intermediate target formed after virus-cell attachment [341146], [363900]. As of June 1998, Sam Jin had been awarded a patent for SJ-3366 in South Africa, with applications pending in 22 other countries [302450].

Crystal structure of SAM-dependent methyltransferase from Pyrococcus horikoshii.

PubMed

Pampa, K J; Madan Kumar, S; Hema, M K; Kumara, Karthik; Naveen, S; Kunishima, Naoki; Lokanath, N K

2017-12-01

Methyltransferases (MTs) are enzymes involved in methylation that are needed to perform cellular processes such as biosynthesis, metabolism, gene expression, protein trafficking and signal transduction. The cofactor S-adenosyl-L-methionine (SAM) is used for catalysis by SAM-dependent methyltransferases (SAM-MTs). The crystal structure of Pyrococcus horikoshii SAM-MT was determined to a resolution of 2.1 Å using X-ray diffraction. The monomeric structure consists of a Rossmann-like fold (domain I) and a substrate-binding domain (domain II). The cofactor (SAM) molecule binds at the interface between adjacent subunits, presumably near to the active site(s) of the enzyme. The observed dimeric state might be important for the catalytic function of the enzyme.

OCAMS: The OSIRIS-REx Camera Suite

NASA Astrophysics Data System (ADS)

Rizk, B.; Drouet d'Aubigny, C.; Golish, D.; Fellows, C.; Merrill, C.; Smith, P.; Walker, M. S.; Hendershot, J. E.; Hancock, J.; Bailey, S. H.; DellaGiustina, D. N.; Lauretta, D. S.; Tanner, R.; Williams, M.; Harshman, K.; Fitzgibbon, M.; Verts, W.; Chen, J.; Connors, T.; Hamara, D.; Dowd, A.; Lowman, A.; Dubin, M.; Burt, R.; Whiteley, M.; Watson, M.; McMahon, T.; Ward, M.; Booher, D.; Read, M.; Williams, B.; Hunten, M.; Little, E.; Saltzman, T.; Alfred, D.; O'Dougherty, S.; Walthall, M.; Kenagy, K.; Peterson, S.; Crowther, B.; Perry, M. L.; See, C.; Selznick, S.; Sauve, C.; Beiser, M.; Black, W.; Pfisterer, R. N.; Lancaster, A.; Oliver, S.; Oquest, C.; Crowley, D.; Morgan, C.; Castle, C.; Dominguez, R.; Sullivan, M.

2018-02-01

The OSIRIS-REx Camera Suite (OCAMS) will acquire images essential to collecting a sample from the surface of Bennu. During proximity operations, these images will document the presence of satellites and plumes, record spin state, enable an accurate model of the asteroid's shape, and identify any surface hazards. They will confirm the presence of sampleable regolith on the surface, observe the sampling event itself, and image the sample head in order to verify its readiness to be stowed. They will document Bennu's history as an example of early solar system material, as a microgravity body with a planetesimal size-scale, and as a carbonaceous object. OCAMS is fitted with three cameras. The MapCam will record color images of Bennu as a point source on approach to the asteroid in order to connect Bennu's ground-based point-source observational record to later higher-resolution surface spectral imaging. The SamCam will document the sample site before, during, and after it is disturbed by the sample mechanism. The PolyCam, using its focus mechanism, will observe the sample site at sub-centimeter resolutions, revealing surface texture and morphology. While their imaging requirements divide naturally between the three cameras, they preserve a strong degree of functional overlap. OCAMS and the other spacecraft instruments will allow the OSIRIS-REx mission to collect a sample from a microgravity body on the same visit during which it was first optically acquired from long range, a useful capability as humanity reaches out to explore near-Earth, Main-Belt and Jupiter Trojan asteroids.

DNA adenine methylation of sams1 gene in symbiont-bearing Amoeba proteus.

PubMed

Jeon, Taeck J

2008-10-01

The expression of amoeba sams genes is switched from sams1 to sams2 when amoebae are infected with Legionella jeonii. To elucidate the mechanism for the inactivation of host sams1 gene by endosymbiotic bacteria, methylation states of the sams1 gene of D and xD amoebae was compared in this study. The sams1 gene of amoebae was methylated at an internal adenine residue of GATC site in symbiont-bearing xD amoebae but not in symbiont-free D amoebae, suggesting that the modification might have caused the inactivation of sams1 in xD amoebae. The sams1 gene of xD amoebae was inactivated at the transcriptional level. Analysis of DNA showed that adenine residues in L. jeonii sams were also methylated, implying that L. jeonii bacteria belong to a Dam methylase-positive strain. In addition, both SAM and Met appeared to act as negative regulators for the expression of sams1 whereas the expression of sams2 was not affected in amoebae.

Characterization of sams genes of Amoeba proteus and the endosymbiotic X-bacteria.

PubMed

Jeon, Taeck J; Jeon, Kwang W

2003-01-01

As a result of harboring obligatory bacterial endosymbionts, the xD strain of Amoeba proteus no longer produces its own S-adenosylmethionine synthetase (SAMS). When symbiont-free D amoebae are infected with symbionts (X-bacteria), the amount of amoeba SAMS decreases to a negligible level within four weeks, but about 47% of the SAMS activity, which apparently comes from another source, is still detected. Complete nucleotide sequences of sams genes of D and xD amoebae are presented and show that there are no differences between the two. Long-established xD amoebae contain an intact sams gene and thus the loss of xD amoeba's SAMS is not due to the loss of the gene itself. The open reading frame of the amoeba's sams gene has 1,281 nucleotides, encoding SAMS of 426 amino acids with a mass of 48 kDa and pI of 6.5. The amino acid sequence of amoeba SAMS is longer than the SAMS of other organisms by having an extra internal stretch of 28 amino acids. The 5'-flanking region of amoeba sams contains consensus-binding sites for several transcription factors that are related to the regulation of sams genes in E. coli and yeast. The complete nucleotide sequence of the symbiont's sams gene is also presented. The open reading frame of X-bacteria sams is 1,146 nucleotides long, encoding SAMS of 381 amino acids with a mass of 41 kDa and pI of 6.0. The X-bacteria SAMS has 45% sequence identity with that of A. proteus.

System Advisor Model (SAM) General Description (Version 2017.9.5)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, Janine M; DiOrio, Nicholas A; Blair, Nathan J

This document describes the capabilities of the System Advisor Model (SAM) developed and distributed by the U.S. Department of Energy's National Renewable Energy Laboratory. The document is for potential users and others wanting to learn about the model's capabilities. SAM is a techno-economic computer model that calculates performance and financial metrics of renewable energy projects. Project developers, policy makers, equipment manufacturers, and researchers use graphs and tables of SAM results in the process of evaluating financial, technology, and incentive options for renewable energy projects. SAM simulates the performance of photovoltaic, concentrating solar power, solar water heating, wind, geothermal, biomass, andmore » conventional power systems. The financial models are for projects that either buy and sell electricity at retail rates (residential and commercial) or sell electricity at a price determined in a power purchase agreement (PPA). SAM's simulation tools facilitate parametric and sensitivity analyses, Monte Carlo simulation and weather variability (P50/P90) studies. SAM can also read input variables from Microsoft Excel worksheets. For software developers, the SAM software development kit (SDK) makes it possible to use SAM simulation modules in their applications written in C/C plus plus, C sharp, Java, Python, MATLAB, and other languages. NREL provides both SAM and the SDK as free downloads at https://sam.nrel.gov. SAM is an open source project, so its source code is available to the public. Researchers can study the code to understand the model algorithms, and software programmers can contribute their own models and enhancements to the project. Technical support and more information about the software are available on the website.« less

Auxiliary iron-sulfur cofactors in radical SAM enzymes.

PubMed

Lanz, Nicholas D; Booker, Squire J

2015-06-01

A vast number of enzymes are now known to belong to a superfamily known as radical SAM, which all contain a [4Fe-4S] cluster ligated by three cysteine residues. The remaining, unligated, iron ion of the cluster binds in contact with the α-amino and α-carboxylate groups of S-adenosyl-l-methionine (SAM). This binding mode facilitates inner-sphere electron transfer from the reduced form of the cluster into the sulfur atom of SAM, resulting in a reductive cleavage of SAM to methionine and a 5'-deoxyadenosyl radical. The 5'-deoxyadenosyl radical then abstracts a target substrate hydrogen atom, initiating a wide variety of radical-based transformations. A subset of radical SAM enzymes contains one or more additional iron-sulfur clusters that are required for the reactions they catalyze. However, outside of a subset of sulfur insertion reactions, very little is known about the roles of these additional clusters. This review will highlight the most recent advances in the identification and characterization of radical SAM enzymes that harbor auxiliary iron-sulfur clusters. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Structural insights into SAM domain‐mediated tankyrase oligomerization

PubMed Central

DaRosa, Paul A.; Ovchinnikov, Sergey

2016-01-01

Abstract Tankyrase 1 (TNKS1; a.k.a. ARTD5) and tankyrase 2 (TNKS2; a.k.a ARTD6) are highly homologous poly(ADP‐ribose) polymerases (PARPs) that function in a wide variety of cellular processes including Wnt signaling, Src signaling, Akt signaling, Glut4 vesicle translocation, telomere length regulation, and centriole and spindle pole maturation. Tankyrase proteins include a sterile alpha motif (SAM) domain that undergoes oligomerization in vitro and in vivo. However, the SAM domains of TNKS1 and TNKS2 have not been structurally characterized and the mode of oligomerization is not yet defined. Here we model the SAM domain‐mediated oligomerization of tankyrase. The structural model, supported by mutagenesis and NMR analysis, demonstrates a helical, homotypic head‐to‐tail polymer that facilitates TNKS self‐association. Furthermore, we show that TNKS1 and TNKS2 can form (TNKS1 SAM‐TNKS2 SAM) hetero‐oligomeric structures mediated by their SAM domains. Though wild‐type tankyrase proteins have very low solubility, model‐based mutations of the SAM oligomerization interface residues allowed us to obtain soluble TNKS proteins. These structural insights will be invaluable for the functional and biophysical characterization of TNKS1/2, including the role of TNKS oligomerization in protein poly(ADP‐ribosyl)ation (PARylation) and PARylation‐dependent ubiquitylation. PMID:27328430

The Mars Science Laboratory Organic Check Material

NASA Technical Reports Server (NTRS)

Conrad, Pamela G.; Eigenbrode, J. E.; Mogensen, C. T.; VonderHeydt, M. O.; Glavin, D. P.; Mahaffy, P. M.; Johnson, J. A.

2011-01-01

The Organic Check Material (OCM) has been developed for use on the Mars Science Laboratory mission to serve as a sample standard for verification of organic cleanliness and characterization of potential sample alteration as a function of the sample acquisition and portioning process on the Curiosity rover. OCM samples will be acquired using the same procedures for drilling, portioning and delivery as are used to study martian samples with The Sample Analysis at Mars (SAM) instrument suite during MSL surface operations. Because the SAM suite is highly sensitive to organic molecules, the mission can better verify the cleanliness of Curiosity's sample acquisition hardware if a known material can be processed through SAM and compared with the results obtained from martian samples.

Sample Analysis at Mars (SAM) and Mars Organic Molecule Analyzer (MOMA) as Critical In Situ Investigation for Targeting Mars Returned Samples

NASA Astrophysics Data System (ADS)

Freissinet, C.; Glavin, D. P.; Mahaffy, P. R.; Szopa, C.; Buch, A.; Goesmann, F.; Goetz, W.; Raulin, F.; SAM Science Team; MOMA Science Team

2018-04-01

SAM (Curiosity) and MOMA (ExoMars) Mars instruments, seeking for organics and biosignatures, are essential to establish taphonomic windows of preservation of molecules, in order to target the most interesting samples to return from Mars.

The FIELDS Instrument Suite for Solar Probe Plus Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients

NASA Technical Reports Server (NTRS)

Bale, S. D.; Goetz, K.; Harvey, P. R.; Turin, P.; Bonnell, J. W.; Dudok de Wit, T.; Ergun, R. E.; MacDowall, R. J.; Pulupa, M.; Choi, M. K.;

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients.

PubMed

Bale, S D; Goetz, K; Harvey, P R; Turin, P; Bonnell, J W; de Wit, T Dudok; Ergun, R E; MacDowall, R J; Pulupa, M; Andre, M; Bolton, M; Bougeret, J-L; Bowen, T A; Burgess, D; Cattell, C A; Chandran, B D G; Chaston, C C; Chen, C H K; Choi, M K; Connerney, J E; Cranmer, S; Diaz-Aguado, M; Donakowski, W; Drake, J F; Farrell, W M; Fergeau, P; Fermin, J; Fischer, J; Fox, N; Glaser, D; Goldstein, M; Gordon, D; Hanson, E; Harris, S E; Hayes, L M; Hinze, J J; Hollweg, J V; Horbury, T S; Howard, R A; Hoxie, V; Jannet, G; Karlsson, M; Kasper, J C; Kellogg, P J; Kien, M; Klimchuk, J A; Krasnoselskikh, V V; Krucker, S; Lynch, J J; Maksimovic, M; Malaspina, D M; Marker, S; Martin, P; Martinez-Oliveros, J; McCauley, J; McComas, D J; McDonald, T; Meyer-Vernet, N; Moncuquet, M; Monson, S J; Mozer, F S; Murphy, S D; Odom, J; Oliverson, R; Olson, J; Parker, E N; Pankow, D; Phan, T; Quataert, E; Quinn, T; Ruplin, S W; Salem, C; Seitz, D; Sheppard, D A; Siy, A; Stevens, K; Summers, D; Szabo, A; Timofeeva, M; Vaivads, A; Velli, M; Yehle, A; Werthimer, D; Wygant, J R

2016-12-01

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

The FIELDS Instrument Suite for Solar Probe Plus. Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients

NASA Astrophysics Data System (ADS)

Bale, S. D.; Goetz, K.; Harvey, P. R.; Turin, P.; Bonnell, J. W.; Dudok de Wit, T.; Ergun, R. E.; MacDowall, R. J.; Pulupa, M.; Andre, M.; Bolton, M.; Bougeret, J.-L.; Bowen, T. A.; Burgess, D.; Cattell, C. A.; Chandran, B. D. G.; Chaston, C. C.; Chen, C. H. K.; Choi, M. K.; Connerney, J. E.; Cranmer, S.; Diaz-Aguado, M.; Donakowski, W.; Drake, J. F.; Farrell, W. M.; Fergeau, P.; Fermin, J.; Fischer, J.; Fox, N.; Glaser, D.; Goldstein, M.; Gordon, D.; Hanson, E.; Harris, S. E.; Hayes, L. M.; Hinze, J. J.; Hollweg, J. V.; Horbury, T. S.; Howard, R. A.; Hoxie, V.; Jannet, G.; Karlsson, M.; Kasper, J. C.; Kellogg, P. J.; Kien, M.; Klimchuk, J. A.; Krasnoselskikh, V. V.; Krucker, S.; Lynch, J. J.; Maksimovic, M.; Malaspina, D. M.; Marker, S.; Martin, P.; Martinez-Oliveros, J.; McCauley, J.; McComas, D. J.; McDonald, T.; Meyer-Vernet, N.; Moncuquet, M.; Monson, S. J.; Mozer, F. S.; Murphy, S. D.; Odom, J.; Oliverson, R.; Olson, J.; Parker, E. N.; Pankow, D.; Phan, T.; Quataert, E.; Quinn, T.; Ruplin, S. W.; Salem, C.; Seitz, D.; Sheppard, D. A.; Siy, A.; Stevens, K.; Summers, D.; Szabo, A.; Timofeeva, M.; Vaivads, A.; Velli, M.; Yehle, A.; Werthimer, D.; Wygant, J. R.

2016-12-01

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

SAM syndrome is characterized by extensive phenotypic heterogeneity.

PubMed

Taiber, Shahar; Samuelov, Liat; Mohamad, Janan; Cohen Barak, Eran; Sarig, Ofer; Shalev, Stavit Allon; Lestringant, Gilles; Sprecher, Eli

2018-03-31

Severe skin dermatitis, multiple allergies and metabolic wasting (SAM) syndrome is a rare life-threatening inherited condition caused by bi-allelic mutations in DSG1 encoding desmoglein 1. The disease was initially reported to manifest with severe erythroderma, failure to thrive, atopic manifestations, recurrent infections, hypotrichosis and palmoplantar keratoderma. We present 3 new cases of SAM syndrome in 2 families and review the cases published so far. Whole exome and direct sequencing were used to identify SAM syndrome-causing mutations. Consistent with previous data, SAM syndrome was found in all 3 patients to result from homozygous mutations in DSG1 predicted to result in premature termination of translation. In contrast, as compared with patients previously reported, the present cases were found to display a wide range of clinical presentations of variable degrees of severity. The present data emphasizes the fact that SAM syndrome is characterized by extensive phenotypic heterogeneity, suggesting the existence of potent modifier traits. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Evidence for Perchlorates and the Origin of Chlorinated Hydrocarbons Detected by SAM at the Rocknest Aeolian Deposit in Gale Crater

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.;

The nuclear protein Sam68 is cleaved by the FMDV 3C protease redistributing Sam68 to the cytoplasm during FMDV infection of host cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, Paul; Schafer, Elizabeth A.; Rieder, Elizabeth, E-mail: elizabeth.rieder@ars.usda.gov

2012-03-30

Picornavirus infection can lead to disruption of nuclear pore traffic, shut-off of cell translation machinery, and cleavage of proteins involved in cellular signal transduction and the innate response to infection. Here, we demonstrated that the FMDV 3C{sup pro} induced the cleavage of nuclear RNA-binding protein Sam68 C-terminus containing the nuclear localization sequence (NLS). Consequently, it stimulated the redistribution of Sam68 to the cytoplasm. The siRNA knockdown of Sam68 resulted in a 1000-fold reduction in viral titers, which prompted us to study the effect of Sam68 on FMDV post-entry events. Interestingly, Sam68 interacts with the internal ribosomal entry site within themore » 5 Prime non-translated region of the FMDV genome, and Sam68 knockdown decreased FMDV IRES-driven activity in vitro suggesting that it could modulate translation of the viral genome. The results uncover a novel role for Sam68 in the context of picornaviruses and the proteolysis of a new cellular target of the FMDV 3C{sup pro}.« less

SAM Gcms Chromatography Performed at Mars : Elements of Interpretation

NASA Astrophysics Data System (ADS)

Szopa, C.; Coll, P. J.; Buch, A.; François, P.; Cabane, M.; Coscia, D.; Teinturier, S.; Navarro-Gonzalez, R.; Glavin, D. P.; Freissinet, C.; Mahaffy, P. R.

2013-12-01

The characterisation of the chemical and mineralogical composition of regolith samples collected with the Curiosity rover is a primary objective of the SAM experiment. These data should provide essential clues on the past habitability of Gale crater. Interpretation of the data collected after SAM pyrolysis evolved gas analysis (EGA) and gas chromatography mass spectrometry (GC-MS) experiments on the first soil samples collected by MSL at the Rocknest Aeolian Deposit in Gale Crater has been challenging due to the concomitant presence in the ovens of an oxychlorine phase present in the samples, and a derivatization agent coming from the SAM wet chemistry experiment (Glavin et al., 2013). Moreover, accurate identification and quantification, in the SAM EGA mode, of volatiles released from the heated sample, or generated by reactions occurring in the SAM pyrolysis oven, is also difficult for a few compounds due to evolution over similar temperature ranges and overlap of their MS signatures. Hence, the GC analyses, coupled with MS, enabled the separation and identification and quantification of most of the volatile compounds detected. These results can have been obtained through tests and calibration done with GC individual spare components and with the SAM testbed. This paper will present a view of the interpretation of the chromatograms obtained when analyzing the Rocknest and John Klein solid samples delivered to SAM, on sols 96 and 199 respectively, supported by laboratory calibrations.

Technical Manual for the SAM Physical Trough Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, M. J.; Gilman, P.

2011-06-01

NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field,more » power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.« less

Atomic-level insights into metabolite recognition and specificity of the SAM-II riboswitch

PubMed Central

Doshi, Urmi; Kelley, Jennifer M.; Hamelberg, Donald

2012-01-01

Although S-adenosylhomocysteine (SAH), a metabolic by-product of S-adenosylmethionine (SAM), differs from SAM only by a single methyl group and an overall positive charge, SAH binds the SAM-II riboswitch with more than 1000-fold less affinity than SAM. Using atomistic molecular dynamics simulations, we investigated the molecular basis of such high selectivity in ligand recognition by SAM-II riboswitch. The biosynthesis of SAM exclusively generates the (S,S) stereoisomer, and (S,S)-SAM can spontaneously convert to the (R,S) form. We, therefore, also examined the effects of (R,S)-SAM binding to SAM-II and its potential biological function. We find that the unfavorable loss in entropy in SAM-II binding is greater for (S,S)- and (R,S)-SAM than SAH, which is compensated by stabilizing electrostatic interactions with the riboswitch. The positively charged sulfonium moiety on SAM acts as the crucial anchor point responsible for the formation of key ionic interactions as it fits favorably in the negatively charged binding pocket. In contrast, SAH, with its lone pair of electrons on the sulfur, experiences repulsion in the binding pocket of SAM-II and is enthalpically destabilized. In the presence of SAH, similar to the unbound riboswitch, the pseudoknot structure of SAM-II is not completely formed, thus exposing the Shine-Dalgarno sequence. Unlike SAM, this may further facilitate ribosomal assembly and translation initiation. Our analysis of the conformational ensemble sampled by SAM-II in the absence of ligands and when bound to SAM or SAH reveals that ligand binding follows a combination of conformational selection and induced-fit mechanisms. PMID:22194311

Atomic-level insights into metabolite recognition and specificity of the SAM-II riboswitch.

PubMed

Doshi, Urmi; Kelley, Jennifer M; Hamelberg, Donald

2012-02-01

Although S-adenosylhomocysteine (SAH), a metabolic by-product of S-adenosylmethionine (SAM), differs from SAM only by a single methyl group and an overall positive charge, SAH binds the SAM-II riboswitch with more than 1000-fold less affinity than SAM. Using atomistic molecular dynamics simulations, we investigated the molecular basis of such high selectivity in ligand recognition by SAM-II riboswitch. The biosynthesis of SAM exclusively generates the (S,S) stereoisomer, and (S,S)-SAM can spontaneously convert to the (R,S) form. We, therefore, also examined the effects of (R,S)-SAM binding to SAM-II and its potential biological function. We find that the unfavorable loss in entropy in SAM-II binding is greater for (S,S)- and (R,S)-SAM than SAH, which is compensated by stabilizing electrostatic interactions with the riboswitch. The positively charged sulfonium moiety on SAM acts as the crucial anchor point responsible for the formation of key ionic interactions as it fits favorably in the negatively charged binding pocket. In contrast, SAH, with its lone pair of electrons on the sulfur, experiences repulsion in the binding pocket of SAM-II and is enthalpically destabilized. In the presence of SAH, similar to the unbound riboswitch, the pseudoknot structure of SAM-II is not completely formed, thus exposing the Shine-Dalgarno sequence. Unlike SAM, this may further facilitate ribosomal assembly and translation initiation. Our analysis of the conformational ensemble sampled by SAM-II in the absence of ligands and when bound to SAM or SAH reveals that ligand binding follows a combination of conformational selection and induced-fit mechanisms.

Preparation for Analytical Measurements on Mars

NASA Image and Video Library

2015-03-31

A Sample Analysis at Mars (SAM) team member at NASA's Goddard Space Flight Center, Greenbelt, Maryland, prepares the SAM testbed for an experiment. This test copy of the SAM suite of instruments is inside a chamber that, when closed, can model the pressure and temperature environment that SAM sees inside NASA's Curiosity rover on Mars. Many weeks of testing are often needed to develop and refine sequences of operations that SAM uses for making specific measurements on Mars. This was the case with preparation to pull a volume of gas from the atmosphere and extract the heavy noble gas xenon. SAM's measurements of different types of xenon in the Martian atmosphere provide clues about the planet's history. http://photojournal.jpl.nasa.gov/catalog/PIA19149

Evidence for Perchlorates and the Origin of Chlorinated Hydrocarbons Detected by SAM at the Rocknest Aeolian Deposit in Gale Crater

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Freissinet, Caroline; Miller, Kristen E.; Eigenbrode, Jennifer L.; Brunner, Anna E.; Buch, Arnaud; Sutter, Brad; Archer, P. Douglas, Jr.; Atreya, Sushil K.; Brinckerhoff, William B.;

Modulation of Conformational Equilibria in the S-Adenosylmethionine (SAM) II Riboswitch by SAM, Mg(2+), and Trimethylamine N-Oxide.

PubMed

McPhie, Peter; Brown, Patrick; Chen, Bin; Dayie, Theodore K; Minton, Allen P

2016-09-13

The dependence of the conformation of the S-adenosylmethionine (SAM) II riboswitch on the concentration of added Mg(2+) ions and SAM, individually and in mixtures, was monitored by circular dichroism (CD) spectroscopy and by measurement of the diffusion coefficient. The results are analyzed in the context of two complementary quantitative models, both of which are consistent with a single underlying physical model. Magnesium binding sites in the open state have an affinity on average higher than the affinity of those in the compact state, but formation of the compact state is accompanied by an increase in the number of binding sites. Consequently, at low Mg(2+) concentrations, Mg(2+) binds preferentially to the open state, favoring its formation, but at high concentrations, Mg(2+) binds preferentially to the compact state. The affinity of the riboswitch for SAM increases drastically with an increased level of binding of Mg(2+) to the compact pseudoknot conformation. The effect of increasing concentrations of trimethylamine N-oxide (TMAO), a well-studied molecular crowding agent, on the conformation of the riboswitch and its affinity for SAM were also monitored by CD spectroscopy and measurement of diffusion. In the absence of added Mg(2+), high concentrations of TMAO were found to induce a conformational change compatible with the formation of the pseudoknot form but have only a small effect on the affinity of the RNA for SAM.

Major Volatiles from MSL SAM Evolved Gas Analyses: Yellowknife Bay Through Lower Mount Sharp

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Archer, P. D., Jr.; Sutter, B.; Franz, H. B.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Niles, P. B.; Stern, J. C.; Freissinet, C.;

Information System through ANIS at CeSAM

NASA Astrophysics Data System (ADS)

Moreau, C.; Agneray, F.; Gimenez, S.

2015-09-01

ANIS (AstroNomical Information System) is a web generic tool developed at CeSAM to facilitate and standardize the implementation of astronomical data of various kinds through private and/or public dedicated Information Systems. The architecture of ANIS is composed of a database server which contains the project data, a web user interface template which provides high level services (search, extract and display imaging and spectroscopic data using a combination of criteria, an object list, a sql query module or a cone search interfaces), a framework composed of several packages, and a metadata database managed by a web administration entity. The process to implement a new ANIS instance at CeSAM is easy and fast : the scientific project has to submit data or a data secure access, the CeSAM team installs the new instance (web interface template and the metadata database), and the project administrator can configure the instance with the web ANIS-administration entity. Currently, the CeSAM offers through ANIS a web access to VO compliant Information Systems for different projects (HeDaM, HST-COSMOS, CFHTLS-ZPhots, ExoDAT,...).

Simulation of a suite of generic long-pulse neutron instruments to optimize the time structure of the European Spallation Source.

PubMed

Lefmann, Kim; Klenø, Kaspar H; Birk, Jonas Okkels; Hansen, Britt R; Holm, Sonja L; Knudsen, Erik; Lieutenant, Klaus; von Moos, Lars; Sales, Morten; Willendrup, Peter K; Andersen, Ken H

2013-05-01

We here describe the result of simulations of 15 generic neutron instruments for the long-pulsed European Spallation Source. All instruments have been simulated for 20 different settings of the source time structure, corresponding to pulse lengths between 1 ms and 2 ms; and repetition frequencies between 10 Hz and 25 Hz. The relative change in performance with time structure is given for each instrument, and an unweighted average is calculated. The performance of the instrument suite is proportional to (a) the peak flux and (b) the duty cycle to a power of approximately 0.3. This information is an important input to determining the best accelerator parameters. In addition, we find that in our simple guide systems, most neutrons reaching the sample originate from the central 3-5 cm of the moderator. This result can be used as an input in later optimization of the moderator design. We discuss the relevance and validity of defining a single figure-of-merit for a full facility and compare with evaluations of the individual instrument classes.

Summary Status of the Space Acceleration Measurement System (SAMS), September 1993

NASA Technical Reports Server (NTRS)

DeLombard, Richard

1993-01-01

The Space Acceleration Measurement System (SAMS) was developed to measure the microgravity acceleration environment to which NASA science payloads are exposed during microgravity science missions on the shuttle. Six flight units have been fabricated to date. The inaugural flight of a SAMS unit was on STS-40 in June 1991 as part of the flrst Spacelab Life Sciences mission. Since that time, SAMS has flown on six additional missions and gathered 18 gigabytes of data representing 68 days of microgravity environment. The SAMS units have been flown in the shuttle middeck and cargo bay, in the Spacelab module, and in the Spacehab module. This paper summarizes the missions and experiments which SAMS has supported. The quantity of data and the utilization of the SAMS data is described. Future activities are briefly described for the SAMS project and.the Microgravity Measurement and Analysis Project (MMAP) to support science experiments and scientists with microgravity environment measurement and analysis.

Summary Status of the Space Acceleration Measurement System (SAMS), September 1993

NASA Technical Reports Server (NTRS)

DeLombard, Richard

1994-01-01

The Space Acceleration Measurement System (SAMS) was developed to measure the microgravity acceleration environment to which NASA science payloads are exposed during microgravity science missions on the shuttle. Six flight units have been fabricated to date. The inaugural flight of a SAMS unit was on STS-40 in June 1991 as part of the First Spacelab Life Sciences mission. Since that time, SAMS has flown on six additional missions and gathered eighteen gigabytes of data representing sixty-eight days of microgravity environment. The SAMS units have been flown in the shuttle middeck and cargo bay, in the Spacelab module, and in the Spacehab module. This paper summarizes the missions and experiments which SAMS has supported. The quantity of data and the utilization of the SAMS data is described. Future activities are briefly described for the SAMS project and the Microgravity Measurement and Analysis project (MMAP) to support science experiments and scientists with microgravity environment measurement and analysis.

The instrument control software package for the Habitable-Zone Planet Finder spectrometer

NASA Astrophysics Data System (ADS)

Bender, Chad F.; Robertson, Paul; Stefansson, Gudmundur Kari; Monson, Andrew; Anderson, Tyler; Halverson, Samuel; Hearty, Frederick; Levi, Eric; Mahadevan, Suvrath; Nelson, Matthew; Ramsey, Larry; Roy, Arpita; Schwab, Christian; Shetrone, Matthew; Terrien, Ryan

2016-08-01

We describe the Instrument Control Software (ICS) package that we have built for The Habitable-Zone Planet Finder (HPF) spectrometer. The ICS controls and monitors instrument subsystems, facilitates communication with the Hobby-Eberly Telescope facility, and provides user interfaces for observers and telescope operators. The backend is built around the asynchronous network software stack provided by the Python Twisted engine, and is linked to a suite of custom hardware communication protocols. This backend is accessed through Python-based command-line and PyQt graphical frontends. In this paper we describe several of the customized subsystem communication protocols that provide access to and help maintain the hardware systems that comprise HPF, and show how asynchronous communication benefits the numerous hardware components. We also discuss our Detector Control Subsystem, built as a set of custom Python wrappers around a C-library that provides native Linux access to the SIDECAR ASIC and Hawaii-2RG detector system used by HPF. HPF will be one of the first astronomical instruments on sky to utilize this native Linux capability through the SIDECAR Acquisition Module (SAM) electronics. The ICS we have created is very flexible, and we are adapting it for NEID, NASA's Extreme Precision Doppler Spectrometer for the WIYN telescope; we will describe this adaptation, and describe the potential for use in other astronomical instruments.

SAM 2 and SAGE data management and processing

NASA Technical Reports Server (NTRS)

Osborn, M. T.; Trepte, C. R.

1987-01-01

The data management and processing supplied by ST Systems Corporation (STX) for the Stratospheric Aerosol Measurement 2 (SAM 2) and Stratospheric Aerosol and Gas Experiment (SAGE) experiments for the years 1983 to 1986 are described. Included are discussions of data validation, documentation, and scientific analysis, as well as the archival schedule met by the operational reduction of SAM 2 and SAGE data. Work under this contract resulted in the archiving of the first seven years of SAM 2 data and all three years of SAGE data. A list of publications and presentations supported was also included.

Combustion of organic matter in Mars analogs using SAM-like techniques

NASA Astrophysics Data System (ADS)

Stern, J. C.; McAdam, A.; Mahaffy, P. R.; Steele, A.

2012-12-01

The combustion experiment on the Sample Analysis at Mars (SAM) suite on Curiosity will heat a sample of Mars regolith in the presence of oxygen and measure the carbon isotopic composition (δ13C) of the evolved CO2 using the Tunable Laser Spectrometer (TLS). The degree to which the δ13C of the sample is representative of any organic carbon present depends on a) whether complete combustion has been achieved, and b) the simultaneous presence of inorganic, or mineralogical carbon in the sample, and our ability to quantify its contribution to the bulk δ13C. To optimize and characterize combustion of a variety of organic molecules in a range of rock matrices, combustion experiments simulating those to be performed on SAM were conducted at NASA Goddard. CO2 gas generated by heating Mars analogs in a SAM-like oven in the presence of oxygen on a laboratory breadboard was captured and analyzed via IRMS for δ13C. These values were compared to bulk and total organic carbon (TOC) abundance and δ13C values using commercial flash combustion EA- IRMS techniques to determine whether quantitative conversion of reduced carbon to CO2 was achieved. Factors contributing to incomplete combustion and isotopic fractionation include structural complexity of reduced organics, their thermal decomposition temperatures, and mineral-organic associations. An additional consideration must be made for unintentional combustion by oxidizing salts (perchlorates), which may partially or totally oxidize reduced organic compounds to CO2, depending on soil perchlorate concentration, sample matrix, and how refractory the organics are. Thus, to investigate the oxidizing potential of a salt known to exist on the Martian surface, laboratory breadboard experiments heating simple and complex organics in the presence of Mg perchlorate were performed using a SAM-like oven coupled to a Hiden Mass Spectrometer and gas collection manifold. Samples were heated in the absence and presence of Mg perchlorate to

SAMS Acceleration Measurements on MIR

NASA Technical Reports Server (NTRS)

Moskowitz, Milton E.; Hrovat, Kenneth; Finkelstein, Robert; Reckart, Timothy

1997-01-01

During NASA Increment 3 (September 1996 to January 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 11 optical disks and were returned to Earth on STS-81. During this time, SAMS data were collected in the Priroda module to support the following experiments: the Mir Structural Dynamics Experiment (MiSDE) and Binary Colloidal Alloy Tests (BCAT). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-81 operations, a Progress engine burn, attitude control thruster operation, and crew exercise. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

MSL SAM-Like Evolved Gas Analyses of Si-rich Amorphous Materials

NASA Technical Reports Server (NTRS)

McAdam, Amy; Knudson, Christine; Sutter, Brad; Andrejkovicova, Slavka; Archer, P. Douglas; Franz, Heather; Eigenbrode, Jennifer; Morris, Richard; Ming, Douglas; Sun, Vivian;

Sam, Brookhaven, and the Physical Review

NASA Astrophysics Data System (ADS)

Blume, Martin

2010-03-01

Sam Goudsmit came to Brookhaven National Laboratory in 1948, just after the first year of operation of the new institution, and after a year of his postwar appointment as Professor of Physics at Northwestern University. He was named an associate editor of the Physical Review at that time, under the then Managing Editor John T. Tate of the University of Minnesota. Tate had been Editor since 1926, and had presided over the growth of Physical Review to leadership of publication in the world of physics. Tate died in 1950, and after a search under an interim Editor Sam was, in 1951, named Managing Editor. In 1952 he became Chair of the Brookhaven Physics Department, founded Physical Review Letters, and served as department chair until 1960, when he stepped down but remained an Associate Chair. I will discuss my own interactions with Sam during this later period, when I learned of his many faceted talents and accomplishments.

SAM-FS: LSC's New Solaris-Based Storage Management Product

NASA Technical Reports Server (NTRS)

Angell, Kent

1996-01-01

SAM-FS is a full featured hierarchical storage management (HSM) device that operates as a file system on Solaris-based machines. The SAM-FS file system provides the user with all of the standard UNIX system utilities and calls, and adds some new commands, i.e. archive, release, stage, sls, sfind, and a family of maintenance commands. The system also offers enhancements such as high performance virtual disk read and write, control of the disk through an extent array, and the ability to dynamically allocate block size. SAM-FS provides 'archive sets' which are groupings of data to be copied to secondary storage. In practice, as soon as a file is written to disk, SAM-FS will make copies onto secondary media. SAM-FS is a scalable storage management system. The system can manage millions of files per system, though this is limited today by the speed of UNIX and its utilities. In the future, a new search algorithm will be implemented that will remove logical and performance restrictions on the number of files managed.

Emerging roles for Sam68 in adipogenesis and neuronal development.

PubMed

Vogel, Gillian; Richard, Stéphane

2012-09-01

Sam68, the Src-associated substrate during mitosis of 68 kDa, belongs to the large class of heteronuclear ribonucleoprotein particle K (hnRNP K) homology (KH) domain family of RNA-binding proteins. Sam68 contains a single KH domain harboring conserved N- and C-terminal sequences required for RNA binding and homodimerization. The KH domain is one of the most prevalent RNA binding domains that directly contacts single-stranded RNA. Sam68 has been implicated in numerous aspects of RNA metabolism including alternative splicing and polysomal recruitment of mRNAs. Studies in mice have revealed physiological roles linking Sam68 to osteoporosis, obesity, cancer, infertility and ataxia. Recent publications have greatly enhanced our understanding of Sam68 mechanism of action in addition to its cellular role. Herein, we will discuss the latest advances in the literature pertaining to obesity and neuronal development.

Argon Isotopes Provide Robust Signature of Atmospheric Loss

NASA Image and Video Library

2013-04-08

This image, made by the quadrupole mass spectrometer in the SAM suite of instruments in NASA Curiosity Mars rover. shows the ratio of the argon isotope argon-36 to the heavier argon isotope argon-38, in various measurements.

Discrimination between Closely Related Cellular Metabolites by the SAM-I Riboswitch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montange, R.; Mondragon, E; van Tyne, D

2010-01-01

The SAM-I riboswitch is a cis-acting element of genetic control found in bacterial mRNAs that specifically binds S-adenosylmethionine (SAM). We previously determined the 2.9-{angstrom} X-ray crystal structure of the effector-binding domain of this RNA element, revealing details of RNA-ligand recognition. To improve this structure, variations were made to the RNA sequence to alter lattice contacts, resulting in a 0.5-{angstrom} improvement in crystallographic resolution and allowing for a more accurate refinement of the crystallographic model. The basis for SAM specificity was addressed by a structural analysis of the RNA complexed to S-adenosylhomocysteine (SAH) and sinefungin and by measuring the affinity ofmore » SAM and SAH for a series of mutants using isothermal titration calorimetry. These data illustrate the importance of two universally conserved base pairs in the RNA that form electrostatic interactions with the positively charged sulfonium group of SAM, thereby providing a basis for discrimination between SAM and SAH.« less

Probing the nature and resistance of the molecule-electrode contact in SAM-based junctions.

PubMed

Sangeeth, C S Suchand; Wan, Albert; Nijhuis, Christian A

2015-07-28

It is challenging to quantify the contact resistance and to determine the nature of the molecule-electrode contacts in molecular two-terminal junctions. Here we show that potentiodynamic and temperature dependent impedance measurements give insights into the nature of the SAM-electrode interface and other bottlenecks of charge transport (the capacitance of the SAM (C(SAM)) and the resistance of the SAM (R(SAM))), unlike DC methods, independently of each other. We found that the resistance of the top-electrode-SAM contact for junctions with the form of Ag(TS)-SC(n)//GaO(x)/EGaIn with n = 10, 12, 14, 16 or 18 is bias and temperature independent and hence Ohmic (non-rectifying) in nature, and is orders of magnitude smaller than R(SAM). The C(SAM) and R(SAM) are independent of the temperature, indicating that the mechanism of charge transport in these SAM-based junctions is coherent tunneling and the charge carrier trapping at the interfaces is negligible.

Other Resources Related to SAM

EPA Pesticide Factsheets

Learn more about websites and information related to EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM), including key EPA collaborators, laboratories, and research centers.

Radical-mediated enzymatic methylation: a tale of two SAMS.

PubMed

Zhang, Qi; van der Donk, Wilfred A; Liu, Wen

2012-04-17

Methylation is an essential and ubiquitous reaction that plays an important role in a wide range of biological processes. Most biological methylations use S-adenosylmethionine (SAM) as the methyl donor and proceed via an S(N)2 displacement mechanism. However, researchers have discovered an increasing number of methylations that involve radical chemistry. The enzymes known to catalyze these reactions all belong to the radical SAM superfamily. This family of enzymes utilizes a specialized [4Fe-4S] cluster for reductive cleavage of SAM to yield a highly reactive 5'-deoxyadenosyl (dAdo) radical. Radical chemistry is then imposed on a variety of organic substrates, leading to a diverse array of transformations. Until recently, researchers had not fully understood how these enzymes employ radical chemistry to mediate a methyl transfer reaction. Sequence analyses reveal that the currently identified radical SAM methyltransferases (RSMTs) can be grouped into three classes, which appear distinct in protein architecture and mechanism. Class A RSMTs mainly include the rRNA methyltransferases RlmN and Cfr from various origins. As exemplified by Escherichia coli RlmN, these proteins have a single canonical radical SAM core domain that includes an (βα)(6) partial barrel most similar to that of pyruvate formate lyase-activase. The exciting recent studies on RlmN and Cfr are beginning to provide insights into the intriguing chemistry of class A RSMTs. These enzymes utilize a methylene radical generated on a unique methylated cysteine residue. However, based on the variety of substrates used by the other classes of RSMTs, alternative mechanisms are likely to be discovered. Class B RSMTs contain a proposed N-terminal cobalamin binding domain in addition to a radical SAM domain at the C-terminus. This class of proteins methylates diverse substrates at inert sp(3) carbons, aromatic heterocycles, and phosphinates, possibly involving a cobalamin-mediated methyl transfer process. Class

Sam2bam: High-Performance Framework for NGS Data Preprocessing Tools

PubMed Central

Cheng, Yinhe; Tzeng, Tzy-Hwa Kathy

2016-01-01

This paper introduces a high-throughput software tool framework called sam2bam that enables users to significantly speed up pre-processing for next-generation sequencing data. The sam2bam is especially efficient on single-node multi-core large-memory systems. It can reduce the runtime of data pre-processing in marking duplicate reads on a single node system by 156–186x compared with de facto standard tools. The sam2bam consists of parallel software components that can fully utilize multiple processors, available memory, high-bandwidth storage, and hardware compression accelerators, if available. The sam2bam provides file format conversion between well-known genome file formats, from SAM to BAM, as a basic feature. Additional features such as analyzing, filtering, and converting input data are provided by using plug-in tools, e.g., duplicate marking, which can be attached to sam2bam at runtime. We demonstrated that sam2bam could significantly reduce the runtime of next generation sequencing (NGS) data pre-processing from about two hours to about one minute for a whole-exome data set on a 16-core single-node system using up to 130 GB of memory. The sam2bam could reduce the runtime of NGS data pre-processing from about 20 hours to about nine minutes for a whole-genome sequencing data set on the same system using up to 711 GB of memory. PMID:27861637

The radical SAM protein HemW is a heme chaperone.

PubMed

Haskamp, Vera; Karrie, Simone; Mingers, Toni; Barthels, Stefan; Alberge, François; Magalon, Axel; Müller, Katrin; Bill, Eckhard; Lubitz, Wolfgang; Kleeberg, Kirstin; Schweyen, Peter; Bröring, Martin; Jahn, Martina; Jahn, Dieter

2018-02-16

Radical S -adenosylmethionine (SAM) enzymes exist in organisms from all kingdoms of life, and all of these proteins generate an adenosyl radical via the homolytic cleavage of the S-C(5') bond of SAM. Of particular interest are radical SAM enzymes, such as heme chaperones, that insert heme into respiratory enzymes. For example, heme chaperones insert heme into target proteins but have been studied only for the formation of cytochrome c -type hemoproteins. Here, we report that a radical SAM protein, the heme chaperone HemW from bacteria, is required for the insertion of heme b into respiratory chain enzymes. As other radical SAM proteins, HemW contains three cysteines and one SAM coordinating an [4Fe-4S] cluster, and we observed one heme per subunit of HemW. We found that an intact iron-sulfur cluster was required for HemW dimerization and HemW-catalyzed heme transfer but not for stable heme binding. A bacterial two-hybrid system screen identified bacterioferritins and the heme-containing subunit NarI of the respiratory nitrate reductase NarGHI as proteins that interact with HemW. We also noted that the bacterioferritins potentially serve as heme donors for HemW. Of note, heme that was covalently bound to HemW was actively transferred to a heme-depleted, catalytically inactive nitrate reductase, restoring its nitrate-reducing enzyme activity. Finally, the human HemW orthologue radical SAM domain-containing 1 (RSAD1) stably bound heme. In conclusion, our findings indicate that the radical SAM protein family HemW/RSAD1 is a heme chaperone catalyzing the insertion of heme into hemoproteins. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Cooperation between Magnesium and Metabolite Controls Collapse of the SAM-I Riboswitch.

PubMed

Roy, Susmita; Onuchic, José N; Sanbonmatsu, Karissa Y

2017-07-25

The S-adenosylmethionine (SAM)-I riboswitch is a noncoding RNA that regulates the transcription termination process in response to metabolite (SAM) binding. The aptamer portion of the riboswitch may adopt an open or closed state depending on the presence of metabolite. Although the transition between the open and closed states is critical for the switching process, its atomistic details are not well understood. Using atomistic simulations, we calculate the effect of SAM and magnesium ions on the folding free energy landscape of the SAM-I riboswitch. These molecular simulation results are consistent with our previous wetlab experiments and aid in interpreting the SHAPE probing measurements. Here, molecular dynamics simulations explicitly identify target RNA motifs sensitive to magnesium ions and SAM. In the simulations, we observe that, whereas the metabolite mostly stabilizes the P1 and P3 helices, magnesium serves an important role in stabilizing a pseudoknot interaction between the P2 and P4 helices, even at high metabolite concentrations. The pseudoknot stabilization by magnesium, in combination with P1 stabilization by SAM, explains the requirement of both SAM and magnesium to form the fully collapsed metabolite-bound closed state of the SAM-I riboswitch. In the absence of SAM, frequent open-to-closed conformational transitions of the pseudoknot occur, akin to breathing. These pseudoknot fluctuations disrupt the binding site by facilitating fluctuations in the 5'-end of helix P1. Magnesium biases the landscape toward a collapsed state (preorganization) by coordinating pseudoknot and 5'-P1 fluctuations. The cooperation between SAM and magnesium in stabilizing important tertiary interactions elucidates their functional significance in transcription regulation. Published by Elsevier Inc.

Organic molecules on Mars

NASA Astrophysics Data System (ADS)

ten Kate, Inge Loes

2018-06-01

On 6 August 2012, the Sample Analysis at Mars (SAM) instrument suite (1) arrived on Mars onboard the Curiosity rover. SAM's main aim was to search for organic molecules on the martian surface. On page 1096 of this issue, Eigenbrode et al. (2) report SAM data that provide conclusive evidence for the presence of organic compounds—thiophenic, aromatic, and aliphatic compounds—in drill samples from Mars' Gale crater. In a related paper on page 1093, Webster et al. (3) report a strong seasonal variation in atmospheric methane, the simplest organic molecule, in the martian atmosphere. Both these finding are breakthroughs in astrobiology.

SAMS Acceleration Measurements on Mir from June to November 1995

NASA Technical Reports Server (NTRS)

DeLombard, Richard; Hrovat, Ken; Moskowitz, Milton; McPherson, Kevin

1996-01-01

The NASA Microgravity Science and Applications Division (MSAD) sponsors science experiments on a variety of microgravity carriers, including sounding rockets, drop towers, parabolic aircraft, and Orbiter missions. The MSAD sponsors the Space Acceleration Measurement System (SAMS) to support microgravity science experiments with acceleration measurements to characterize the microgravity environment to which the experiments were exposed. The Principal Investigator Microgravity Services project at the NASA Lewis Research Center supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. In 1993, a cooperative effort was started between the United States and Russia involving science utilization of the Russian Mir space station by scientists from the United States and Russia. MSAD is currently sponsoring science experiments participating in the Shuttle-Mir Science Program in cooperation with the Russians on the Mir space station. Included in the complement of MSAD experiments and equipment is a SAMS unit In a manner similar to Orbiter mission support, the SAMS unit supports science experiments from the U.S. and Russia by measuring the microgravity environment during experiment operations. The initial SAMS supported experiment was a Protein Crystal Growth (PCG) experiment from June to November 1995. SAMS data were obtained during the PCG operations on Mir in accordance with the PCG Principal Investigator's requirements. This report presents an overview of the SAMS data recorded to support this PCG experiment. The report contains plots of the SAMS 100 Hz sensor head data as an overview of the microgravity environment, including the STS-74 Shuttle-Mir docking.

Practical aspects in the management of statin-associated muscle symptoms (SAMS).

PubMed

Laufs, Ulrich; Filipiak, Krysztof J; Gouni-Berthold, Ioanna; Catapano, Alberico L

2017-04-01

Statin-associated muscle symptoms (SAMS) frequently cause statin non-adherence, switching and discontinuation, contributing to adverse cardiovascular (CV) outcomes. Therefore, the management of SAMS is key in the effective treatment of patients with cardiovascular disease (CVD), through achievement of maximum-tolerated statin dosing and other practical aspects. The aim of this article is to provide practical, focused advice for healthcare professionals on the management of patients with SAMS. An expert working group combined current evidence, published guidelines and experiences surrounding a number of topics concerning SAMS to provide recommendations on how to best assess and manage this condition and reach the highest tolerated dose of statin for each individual patient. The group collaborated to provide guidance on definitions in the SAMS field, psychological issues, re-challenging and switching treatments, as well as interpretation of current guidelines and optimal treatment of SAMS in different patient populations. An algorithm was developed to guide the management of patients with SAMS. In addition, the expert working group considered some of the more complex scenarios in a series of frequently asked questions and suggested answers. The expert working group gave recommendations for healthcare professionals on the management of SAMS but highlighted the importance of tailoring the treatment approach to each individual patient. Evidence supporting the role of nutraceuticals and complementary therapies, such as vitamin D, was lacking, however the majority of the group favoured combination therapy with ezetimibe and the addition of PCSK9 inhibitors in high-risk patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatial Analysis and Modeling Systems (SAMS)

NASA Technical Reports Server (NTRS)

Vermillion, Charles; Chan, Paul; Hill, John; Jaske, Robert; Rochon, Gilbert; Stetina, Fran

1991-01-01

The objective is to develop a uniform environmental data gathering and distribution system to support (1) emergency management for environmental disasters, and (2) the calibration and validation of remotely sensed data. Initial activities will be to select a data test site and to demonstrate multi-discipline applications using simulated or satellite data in a non real-time mode. Rainfall and flooding are chosen as the testbeds for the SAMS concept because of the abundance of data and the availability of models. The capability to display and process GOES data and analyze GOES generated rain-rate maps will be integrated into SAMS.

Validation of SAM 2 and SAGE satellite

NASA Technical Reports Server (NTRS)

Kent, G. S.; Wang, P.-H.; Farrukh, U. O.; Yue, G. K.

1987-01-01

Presented are the results of a validation study of data obtained by the Stratospheric Aerosol and Gas Experiment I (SAGE I) and Stratospheric Aerosol Measurement II (SAM II) satellite experiments. The study includes the entire SAGE I data set (February 1979 - November 1981) and the first four and one-half years of SAM II data (October 1978 - February 1983). These data sets have been validated by their use in the analysis of dynamical, physical and chemical processes in the stratosphere. They have been compared with other existing data sets and the SAGE I and SAM II data sets intercompared where possible. The study has shown the data to be of great value in the study of the climatological behavior of stratospheric aerosols and ozone. Several scientific publications and user-oriented data summaries have appeared as a result of the work carried out under this contract.

Two Dual Ion Spectrometer Flight Units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS)

NASA Technical Reports Server (NTRS)

Adams, Mitzi

2014-01-01

Two Dual Ion Spectrometer flight units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS) have returned to MSFC for flight testing. Anticipated to begin on June 30, tests will ensue in the Low Energy Electron and Ion Facility of the Heliophysics and Planetary Science Office (ZP13), managed by Dr. Victoria Coffey of the Natural Environments Branch of the Engineering Directorate (EV44). The MMS mission consists of four identical spacecraft, whose purpose is to study magnetic reconnection in the boundary regions of Earth's magnetosphere.

Structure-guided discovery of the metabolite carboxy-SAM that modulates tRNA function.

PubMed

Kim, Jungwook; Xiao, Hui; Bonanno, Jeffrey B; Kalyanaraman, Chakrapani; Brown, Shoshana; Tang, Xiangying; Al-Obaidi, Nawar F; Patskovsky, Yury; Babbitt, Patricia C; Jacobson, Matthew P; Lee, Young-Sam; Almo, Steven C

2013-06-06

The identification of novel metabolites and the characterization of their biological functions are major challenges in biology. X-ray crystallography can reveal unanticipated ligands that persist through purification and crystallization. These adventitious protein-ligand complexes provide insights into new activities, pathways and regulatory mechanisms. We describe a new metabolite, carboxy-S-adenosyl-l-methionine (Cx-SAM), its biosynthetic pathway and its role in transfer RNA modification. The structure of CmoA, a member of the SAM-dependent methyltransferase superfamily, revealed a ligand consistent with Cx-SAM in the catalytic site. Mechanistic analyses showed an unprecedented role for prephenate as the carboxyl donor and the involvement of a unique ylide intermediate as the carboxyl acceptor in the CmoA-mediated conversion of SAM to Cx-SAM. A second member of the SAM-dependent methyltransferase superfamily, CmoB, recognizes Cx-SAM and acts as a carboxymethyltransferase to convert 5-hydroxyuridine into 5-oxyacetyl uridine at the wobble position of multiple tRNAs in Gram-negative bacteria, resulting in expanded codon-recognition properties. CmoA and CmoB represent the first documented synthase and transferase for Cx-SAM. These findings reveal new functional diversity in the SAM-dependent methyltransferase superfamily and expand the metabolic and biological contributions of SAM-based biochemistry. These discoveries highlight the value of structural genomics approaches in identifying ligands within the context of their physiologically relevant macromolecular binding partners, and in revealing their functions.

Current status of the facility instrumentation suite at the Large Binocular Telescope Observatory

NASA Astrophysics Data System (ADS)

Rothberg, Barry; Kuhn, Olga; Edwards, Michelle L.; Hill, John M.; Thompson, David; Veillet, Christian; Wagner, R. Mark

2016-07-01

The current status of the facility instrumentation for the Large Binocular Telescope (LBT) is reviewed. The LBT encompasses two 8.4 meter primary mirrors on a single mount yielding an effective collecting area of 11.8 meters or 23 meters when interferometrically combined. The three facility instruments at LBT include: 1) the Large Binocular Cameras (LBCs), each with a 23'× 25' field of view (FOV). The blue optimized and red optimized optical wavelength LBCs are mounted at the prime focus of the SX (left) and DX (right) primary mirrors, respectively. Combined, the filter suite of the two LBCs cover 0.3-1.1 μm, including the addition of new medium-band filters centered on TiO (0.78 μm) and CN (0.82 μm) 2) the Multi-Object Double Spectrograph (MODS), two identical optical spectrographs each mounted at the straight through f/15 Gregorian focus of the primary mirrors. The capabilities of MODS-1 and -2 include imaging with Sloan filters (u, g, r, i, and z) and medium resolution (R ˜ 2000) spectroscopy, each with 24 interchangeable masks (multi-object or longslit) over a 6'× 6' FOV. Each MODS is capable of blue (0.32-0.6 μm) and red (0.5-1.05 μm) wavelength only spectroscopy coverage or both can employ a dichroic for 0.32-1.05 μm wavelength coverage (with reduced coverage from 0.56- 0.57 μm) and 3) the two LBT Utility Camera in the Infrared instruments (LUCIs), are each mounted at a bent-front Gregorian f/15 focus of a primary mirror. LUCI-1 and 2 are designed for seeing-limited (4'× 4' FOV) and active optics using thin-shell adaptive secondary mirrors (0.5'× 0.5' FOV) imaging and spectroscopy over the wavelength range of 0.95-2.5 μm and spectroscopic resolutions of 400 <= R <= 11000 (depending on the combination of grating, slits, and cameras used). The spectroscopic capabilities also include 32 interchangeable multi-object or longslit masks which are cryogenically cooled. Currently all facility instruments are in-place at the LBT and, for the first time

Structural analysis of a putative SAM-dependent methyltransferase, YtqB, from Bacillus subtilis.

PubMed

Park, Sun Cheol; Song, Wan Seok; Yoon, Sung-il

2014-04-18

S-adenosyl-L-methionine (SAM)-dependent methyltransferases (MTases) methylate diverse biological molecules using a SAM cofactor. The ytqB gene of Bacillus subtilis encodes a putative MTase and its biological function has never been characterized. To reveal the structural features and the cofactor binding mode of YtqB, we have determined the crystal structures of YtqB alone and in complex with its cofactor, SAM, at 1.9 Å and 2.2 Å resolutions, respectively. YtqB folds into a β-sheet sandwiched by two α-helical layers, and assembles into a dimeric form. Each YtqB monomer contains one SAM binding site, which shapes SAM into a slightly curved conformation and exposes the reactive methyl group of SAM potentially to a substrate. Our comparative structural analysis of YtqB and its homologues indicates that YtqB is a SAM-dependent class I MTase, and provides insights into the substrate binding site of YtqB. Copyright © 2014 Elsevier Inc. All rights reserved.

The vesicle protein SAM-4 regulates the processivity of synaptic vesicle transport.

PubMed

Zheng, Qun; Ahlawat, Shikha; Schaefer, Anneliese; Mahoney, Tim; Koushika, Sandhya P; Nonet, Michael L

2014-10-01

Axonal transport of synaptic vesicles (SVs) is a KIF1A/UNC-104 mediated process critical for synapse development and maintenance yet little is known of how SV transport is regulated. Using C. elegans as an in vivo model, we identified SAM-4 as a novel conserved vesicular component regulating SV transport. Processivity, but not velocity, of SV transport was reduced in sam-4 mutants. sam-4 displayed strong genetic interactions with mutations in the cargo binding but not the motor domain of unc-104. Gain-of-function mutations in the unc-104 motor domain, identified in this study, suppress the sam-4 defects by increasing processivity of the SV transport. Genetic analyses suggest that SAM-4, SYD-2/liprin-α and the KIF1A/UNC-104 motor function in the same pathway to regulate SV transport. Our data support a model in which the SV protein SAM-4 regulates the processivity of SV transport.

The Vesicle Protein SAM-4 Regulates the Processivity of Synaptic Vesicle Transport

PubMed Central

Zheng, Qun; Ahlawat, Shikha; Schaefer, Anneliese; Mahoney, Tim; Koushika, Sandhya P.; Nonet, Michael L.

2014-01-01

Axonal transport of synaptic vesicles (SVs) is a KIF1A/UNC-104 mediated process critical for synapse development and maintenance yet little is known of how SV transport is regulated. Using C. elegans as an in vivo model, we identified SAM-4 as a novel conserved vesicular component regulating SV transport. Processivity, but not velocity, of SV transport was reduced in sam-4 mutants. sam-4 displayed strong genetic interactions with mutations in the cargo binding but not the motor domain of unc-104. Gain-of-function mutations in the unc-104 motor domain, identified in this study, suppress the sam-4 defects by increasing processivity of the SV transport. Genetic analyses suggest that SAM-4, SYD-2/liprin-α and the KIF1A/UNC-104 motor function in the same pathway to regulate SV transport. Our data support a model in which the SV protein SAM-4 regulates the processivity of SV transport. PMID:25329901

Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase.

PubMed

Fenwick, Michael K; Mehta, Angad P; Zhang, Yang; Abdelwahed, Sameh H; Begley, Tadhg P; Ealick, Steven E

2015-03-27

Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

DOE PAGES

Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; ...

2015-03-27

Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active sitemore » metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.« less

Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

NASA Technical Reports Server (NTRS)

Hock, R. A.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Chamberlin, P. C.; Woods, E. C.

2010-01-01

The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. . In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

A role of the SAM domain in EphA2 receptor activation.

PubMed

Shi, Xiaojun; Hapiak, Vera; Zheng, Ji; Muller-Greven, Jeannine; Bowman, Deanna; Lingerak, Ryan; Buck, Matthias; Wang, Bing-Cheng; Smith, Adam W

2017-03-24

Among the 20 subfamilies of protein receptor tyrosine kinases (RTKs), Eph receptors are unique in possessing a sterile alpha motif (SAM domain) at their C-terminal ends. However, the functions of SAM domains in Eph receptors remain elusive. Here we report on a combined cell biology and quantitative fluorescence study to investigate the role of the SAM domain in EphA2 function. We observed elevated tyrosine autophosphorylation levels upon deletion of the EphA2 SAM domain (EphA2ΔS) in DU145 and PC3 prostate cancer cells and a skin tumor cell line derived from EphA1/A2 knockout mice. These results suggest that SAM domain deletion induced constitutive activation of EphA2 kinase activity. In order to explain these effects, we applied fluorescence correlation spectroscopy to investigate the lateral molecular organization of EphA2. Our results indicate that SAM domain deletion (EphA2ΔS-GFP) increases oligomerization compared to the full length receptor (EphA2FL-GFP). Stimulation with ephrinA1, a ligand for EphA2, induced further oligomerization and activation of EphA2FL-GFP. The SAM domain deletion mutant, EphA2ΔS-GFP, also underwent further oligomerization upon ephrinA1 stimulation, but the oligomers were larger than those observed for EphA2FL-GFP. Based on these results, we conclude that the EphA2 SAM domain inhibits kinase activity by reducing receptor oligomerization.

Lunar Reference Suite to Support Instrument Development and Testing

NASA Technical Reports Server (NTRS)

Allen, Carlton; Sellar, Glenn; Nunez, Jorge I.; Winterhalter, Daniel; Farmer, Jack

2010-01-01

Astronauts on long-duration lunar missions will need the capability to "high-grade" their samples - to select the highest value samples for transport to Earth - and to leave others on the Moon. Instruments that may be useful for such high-grading are under development. Instruments are also being developed for possible use on future lunar robotic landers, for lunar field work, and for more sophisticated analyses at a lunar outpost. The Johnson Space Center Astromaterials acquisition and Curation Office (JSC Curation) wll support such instrument testing by providing lunar sample "ground truth".

MSL/SAM Measurements of Non Condensable Volatiles, Comparison with Viking Lander, and Implications for Seasonal Cycle

NASA Astrophysics Data System (ADS)

Atreya, Sushil; Squyres, Steve; Mahaffy, Paul; Leshin, Laurie; Franz, Heather; Trainer, Melissa; Wong, Michael; McKay, Christopher; Navarro-Gonzalez, Rafael; ScienceTeam, MarsScienceLab

2013-04-01

The first measurements of the composition of the Martian atmosphere above Gale Crater by the Sample Analysis at Mars (SAM) instrument on Curiosity Rover revealed that although the volume mixing ratios (vmr) of the gases are generally similar to those measured by the Viking Lander 2 (VL2) thirty five years ago [2], they are notably different for N2 and 40Ar [1]. SAM finds a vmr of 1.9% each for N2 and Ar, so that N2 is 30% lower while Ar is 21% greater than the corresponding VL2 values, resulting in a 40% lower N2/Ar ratio compared to the VL2 result. The Ar/N ratio is used to assess the degree of mixing between the Martian atmosphere and the internal gas component of Mars meteorites due to the shock of impact ejection [e.g. 3]. The above differences in N2 and 40Ar seem to result either from different instrument characteristics or time variable atmospheric phenomena or both. The VL2 data were taken during northern summer (48°N, Ls=135°), whereas the SAM measurements correspond to the beginning of spring season (4.5°S, Ls=182-190°). Previous observations by Mars Odyssey Gamma Ray Spectrometer over three years have shown that the Ar mixing ratio increased by a factor of 6 over the south polar region in the winter [4]. However, the data are controversial for the equatorial region, ranging from no seasonal change [4] to as much as a 35% change [5]. No significant change was seen between the equator (SAM) and the midlatitude northern summer (VL2), however [4]. Thus the difference between the SAM and VL2 Ar does not appear to be related to different seasons. On the other hand, the vmr's of non-condensable volatiles (NCV), N2, Ar and CO, at any latitude are expected to vary seasonally due to the annual, global CO2 cycle. Diurnal changes are not expected, considering the long lifetimes of NCV's that exceed the martian year [6]. In addition to Ar, seasonal changes have been recorded in CO from ground-based [7] and MRO/CRISM observations [8], but show a much smaller

The SAM domain inhibits EphA2 interactions in the plasma membrane.

PubMed

Singh, Deo R; Ahmed, Fozia; Paul, Michael D; Gedam, Manasee; Pasquale, Elena B; Hristova, Kalina

2017-01-01

All members of the Eph receptor family of tyrosine kinases contain a SAM domain near the C terminus, which has been proposed to play a role in receptor homotypic interactions and/or interactions with binding partners. The SAM domain of EphA2 is known to be important for receptor function, but its contribution to EphA2 lateral interactions in the plasma membrane has not been determined. Here we use a FRET-based approach to directly measure the effect of the SAM domain on the stability of EphA2 dimers on the cell surface in the absence of ligand binding. We also investigate the functional consequences of EphA2 SAM domain deletion. Surprisingly, we find that the EphA2 SAM domain inhibits receptor dimerization and decreases EphA2 tyrosine phosphorylation. This role is dramatically different from the role of the SAM domain of the related EphA3 receptor, which we previously found to stabilize EphA3 dimers and increase EphA3 tyrosine phosphorylation in cells in the absence of ligand. Thus, the EphA2 SAM domain likely contributes to a unique mode of EphA2 interaction that leads to distinct signaling outputs. Copyright © 2016 Elsevier B.V. All rights reserved.

Motor coordination defects in mice deficient for the Sam68 RNA-binding protein.

PubMed

Lukong, Kiven E; Richard, Stéphane

2008-06-03

The role of RNA-binding proteins in the central nervous system and more specifically their role in motor coordination and learning are poorly understood. We previously reported that ablation of RNA-binding protein Sam68 in mice results in male sterility and delayed mammary gland development and protection against osteoporosis in females. Sam68 however is highly expressed in most regions of the brain especially the cerebellum and thus we investigated the cerebellar-related manifestations in Sam68-null mice. We analyzed the mice for motor function, sensory function, and learning and memory abilities. Herein, we report that Sam68-null mice have motor coordination defects as assessed by beam walking and rotorod performance. Forty-week-old Sam68-null mice (n=12) were compared to their wild-type littermates (n=12). The Sam68-null mice exhibited more hindpaw faults in beam walking tests and fell from the rotating drum at lower speeds and prematurely compared to the wild-type controls. The Sam68-null mice were, however, normal for forelimb strength, tail-hang reflex, balance test, grid walking, the Morris water task, recognition memory, visual discrimination, auditory stimulation and conditional taste aversion. Our findings support a role for Sam68 in the central nervous system in the regulation of motor coordination.

Scaling functional status within the interRAI suite of assessment instruments

PubMed Central

2013-01-01

Background As one ages, physical, cognitive, and clinical problems accumulate and the pattern of loss follows a distinct progression. The first areas requiring outside support are the Instrumental Activities of Daily Living and over time there is a need for support in performing the Activities of Daily Living. Two new functional hierarchies are presented, an IADL hierarchical capacity scale and a combination scale integrating both IADL and ADL hierarchies. Methods A secondary analyses of data from a cross-national sample of community residing persons was conducted using 762,023 interRAI assessments. The development of the new IADL Hierarchy and a new IADL-ADL combined scale proceeded through a series of interrelated steps first examining individual IADL and ADL item scores among persons receiving home care and those living independently without services. A factor analysis demonstrated the overall continuity across the IADL-ADL continuum. Evidence of the validity of the scales was explored with associative analyses of factors such as a cross-country distributional analysis for persons in home care programs, a count of functional problems across the categories of the hierarchy, an assessment of the hours of informal and formal care received each week by persons in the different categories of the hierarchy, and finally, evaluation of the relationship between cognitive status and the hierarchical IADL-ADL assignments. Results Using items from interRAI’s suite of assessment instruments, two new functional scales were developed, the interRAI IADL Hierarchy Scale and the interRAI IADL-ADL Functional Hierarchy Scale. The IADL Hierarchy Scale consisted of 5 items, meal preparation, housework, shopping, finances and medications. The interRAI IADL-ADL Functional Hierarchy Scale was created through an amalgamation of the ADL Hierarchy (developed previously) and IADL Hierarchy Scales. These scales cover the spectrum of IADL and ADL challenges faced by persons in the community

75 FR 4579 - Certificate of Alternative Compliance for the Tugboat MR SAM

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-28

... Compliance for the Tugboat MR SAM AGENCY: Coast Guard, DHS. ACTION: Notice. SUMMARY: The Coast Guard announces that a Certificate of Alternative Compliance was issued for the tugboat MR SAM as required by 33 U... Title 33, Code of Federal Regulations, Parts 81 and 89, has been issued for the tugboat MR SAM, O.N...

The Development, Validation, and Reliability of SAM: A Tool for Measurement of Moderate to Vigorous Physical Activity in School Physical Education

ERIC Educational Resources Information Center

Surapiboonchai, Kampol

2010-01-01

There is a lack of valid and reliable low cost observational instruments to measure moderate to vigorous physical activity (MVPA) in school physical education (PE). The participants in this study were third to tenth grade boys and girls from a south Texas school district. The SAM (Simple Activity Measurement) activity levels were compared with…

Comparison of air exhausts for surgical body suits (space suits) and the potential for periprosthetic joint infection.

PubMed

Ling, F; Halabi, S; Jones, C

2018-07-01

Periprosthetic joint infection is a major complication of total joint replacement surgery and is associated with significant morbidity, mortality and financial burden. Surgical body suits (space suits), originally designed to reduce the incidence of infection, have paradoxically been implicated in increased periprosthetic joint infection rates recently. Air exhausted from space suits may contribute to this increased rate of periprosthetic joint infection. To investigate the flow of air exhausted from space suits commonly used in modern operating theatres. The exhaust airflow patterns of four commercially available space suit systems were compared using a fog machine and serial still photographs. The space suit systems tested all air exhausted into the operating room. The single fan systems with a standard surgical gown exhausted air laterally from the posterior gown fold at approximately the level of the surgical field. The single fan system with a dedicated zippered suit exhausted air at a level below the surgical field. The dual fan system exhausted air out of the top of the helmet at a level above the surgical field. Space suit systems currently in use in joint replacement surgery differ significantly from traditional body exhaust systems; rather than removing contaminated air from the operating environment, modern systems exhaust this air into the operating room, in some cases potentially towards the sterile instrument tray and the surgical field. Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Theodore Roosevelt Chloroforming Uncle Sam "In the Hopeless Ward".

PubMed

Drew, Benjamin A; Bause, George S

2016-10-01

In March of 1905 in Judge magazine, Louis Dalrymple published his political cartoon of Theodore Roosevelt chloroforming "Uncle Sam." Having sampled a host of Democratic remedies, the 125-year-old Sam can expect that Roosevelt's chloroform will either cure him with major Republican surgery or kill him with Osler-linked euthanasia. Copyright © 2016 Elsevier Inc. All rights reserved.

SSCR Automated Manager (SAM) release 1. 1 reference manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1988-10-01

This manual provides instructions for using the SSCR Automated Manager (SAM) to manage System Software Change Records (SSCRs) online. SSCRs are forms required to document all system software changes for the Martin Marietta Energy Systems, Inc., Central computer systems. SAM, a program developed at Energy Systems, is accessed through IDMS/R (Integrated Database Management System) on an IBM system.

Systematic biochemical characterization of the SAM domains in Eph receptor family from Mus Musculus.

PubMed

Wang, Yue; Li, Qingxia; Zheng, Yunhua; Li, Gang; Liu, Wei

2016-05-13

The Eph receptor family is the largest subfamily of receptor tyrosine kinases and well-known for their pivotal roles in axon guidance, synaptogenesis, artery/venous differentiation and tumorigenesis, etc. Activation of the Eph receptor needs multimerization of the receptors. The intracellular C-terminal SAM domain of Eph receptor was reported to mediate self-association of Eph receptors via the homo SAM-SAM interaction. In this study, we systematically expressed and purified the SAM domain proteins of all fourteen Eph receptors of Mus musculus in Escherichia coli. The FPLC (fast protein liquid chromatography) results showed the recombinant SAM domains were highly homogeneous. Using CD (circular dichroism) spectrometry, we found that the secondary structure of all the SAM domains was typically alpha helical folded and remarkably similar. The thermo-stability tests showed that they were quite stable in solution. SEC-MALS (size exclusion chromatography coupled with multiple angle light scattering) results illustrated 200 μM Eph SAM domains behaved as good monomers in the size-exclusion chromatography. More importantly, DLS (dynamic light scattering) results revealed the overwhelming majority of SAM domains was not multimerized in solution either at 200 μM or 2000 μM protein concentration, which indicating the SAM domain alone was not sufficient to mediate the polymerization of Eph receptor. In summary, our studies provided the systematic biochemical characterizations of the Eph receptor SAM domains and implied their roles in Eph receptor mediated signaling pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

The Information System at CeSAM

NASA Astrophysics Data System (ADS)

Agneray, F.; Gimenez, S.; Moreau, C.; Roehlly, Y.

2012-09-01

Modern large observational programmes produce important amounts of data from various origins, and need high level quality control, fast data access via easy-to-use graphic interfaces, as well as possibility to cross-correlate informations coming from different observations. The Centre de donnéeS Astrophysique de Marseille (CeSAM) offer web access to VO compliant Information Systems to access data of different projects (VVDS, HeDAM, EXODAT, HST-COSMOS,…), including ancillary data obtained outside Laboratoire d'Astrophysique de Marseille (LAM) control. The CeSAM Information Systems provides download of catalogues and some additional services like: search, extract and display imaging and spectroscopic data by multi-criteria and Cone Search interfaces.

A paradigm shift for radical SAM reactions: The organometallic intermediate Ω is central to catalysis.

PubMed

Byer, Amanda S; Yang, Hao; McDaniel, Elizabeth C; Kathiresan, Venkatesan; Impano, Stella; Pagnier, Adrien; Watts, Hope; Denler, Carly; Vagstad, Anna; Piel, Jörn; Duschene, Kaitlin S; Shepard, Eric M; Shields, Thomas P; Scott, Lincoln G; Lilla, Edward A; Yokoyama, Kenichi; Broderick, William E; Hoffman, Brian M; Broderick, Joan B

2018-06-28

Radical S-adenosyl-L-methionine (SAM) en-zymes comprise a vast superfamily catalyzing diverse reactions essential to all life through ho-molytic SAM cleavage to liberate the highly-reactive 5-deoxyadenosyl radical (5-dAdo•). Our recent observation of a catalytically compe-tent organometallic intermediate Ω that forms dur-ing reaction of the radical SAM (RS) enzyme py-ruvate formate-lyase activating-enzyme (PFL-AE) was therefore quite surprising, and led to the question of its broad relevance in the superfamily. We now show that Ω in PFL-AE forms as an in-termediate under a variety of mixing order condi-tions, suggesting it is central to catalysis in this enzyme. We further demonstrate that Ω forms in a suite of RS enzymes chosen to span the totality of superfamily reaction types, implicating Ω as essential in catalysis across the RS superfamily. Finally, EPR and electron nuclear double reso-nance spectroscopy establish that Ω involves an Fe-C5 bond between 5-dAdo• and the [4Fe-4S] cluster. An analogous organometallic bond is found in the well-known adenosylcobalamin (co-enzyme B12) cofactor used to initiate radical reac-tions via a 5'-dAdo• intermediate. Generation of a 5'-dAdo• intermediate via homolytic metal-carbon bond cleavage thus appears to be similar for Ω and coenzyme B12. However coenzyme B12 is involved in enzymes catalyzing of only a small number (~12) of distinct reactions, while the RS superfamily has more than 100,000 distinct se-quences and over 80 reaction types character-ized to date. The appearance of Ω across the RS superfamily therefore dramatically enlarges the sphere of bio-organometallic chemistry in Nature.

On LAM's and SAM's for Halley's rotation

NASA Technical Reports Server (NTRS)

Peale, Stanton J.

1992-01-01

Non principal axis rotation for comet Halley is inferred from dual periodicities evident in the observations. The modes where the spin axis precesses around the axis of minimum moment of inertia (long axis mode or LAM) and where it precesses around the axis of maximum moment of inertia (short axis mode or SAM) are described from an inertial point of view. The currently favored LAM model for Halley's rotation state satisfies observational and dynamical constraints that apparently no SAM can satisfy. But it cannot reproduce the observed post perihelion brightening through seasonal illumination of localized sources on the nucleus, whereas a SAM can easily produce post or pre perihelion brightening by this mechanism. However, the likelihood of a LAM rotation for elongated nuclei of periodic comets such as Halley together with Halley's extreme post perihelion behavior far from the Sun suggest that Halley's post perihelion brightening may be due to effects other than seasonal illumination of localized sources, and therefore such brightening may not constrain its rotation state.

Single-molecule FRET reveals the energy landscape of the full-length SAM-I riboswitch.

PubMed

Manz, Christoph; Kobitski, Andrei Yu; Samanta, Ayan; Keller, Bettina G; Jäschke, Andres; Nienhaus, G Ulrich

2017-11-01

S-adenosyl-L-methionine (SAM) ligand binding induces major structural changes in SAM-I riboswitches, through which gene expression is regulated via transcription termination. Little is known about the conformations and motions governing the function of the full-length Bacillus subtilis yitJ SAM-I riboswitch. Therefore, we have explored its conformational energy landscape as a function of Mg 2+ and SAM ligand concentrations using single-molecule Förster resonance energy transfer (smFRET) microscopy and hidden Markov modeling analysis. We resolved four conformational states both in the presence and the absence of SAM and determined their Mg 2+ -dependent fractional populations and conformational dynamics, including state lifetimes, interconversion rate coefficients and equilibration timescales. Riboswitches with terminator and antiterminator folds coexist, and SAM binding only gradually shifts the populations toward terminator states. We observed a pronounced acceleration of conformational transitions upon SAM binding, which may be crucial for off-switching during the brief decision window before expression of the downstream gene.

Ablation of the Sam68 RNA Binding Protein Protects Mice from Age-Related Bone Loss

PubMed Central

Richard, Stéphane; Torabi, Nazi; Franco, Gladys Valverde; Tremblay, Guy A; Chen, Taiping; Vogel, Gillian; Morel, Mélanie; Cléroux, Patrick; Forget-Richard, Alexandre; Komarova, Svetlana; Tremblay, Michel L; Li, Wei; Li, Ailian; Gao, Yun Jing; Henderson, Janet E

2005-01-01

The Src substrate associated in mitosis of 68 kDa (Sam68) is a KH-type RNA binding protein that has been shown to regulate several aspects of RNA metabolism; however, its physiologic role has remained elusive. Herein we report the generation of Sam68-null mice by homologous recombination. Aged Sam68−/− mice preserved their bone mass, in sharp contrast with 12-month-old wild-type littermates in which bone mass was decreased up to approximately 75%. In fact, the bone volume of the 12-month-old Sam68−/− mice was virtually indistinguishable from that of 4-month-old wild-type or Sam68−/− mice. Sam68−/− bone marrow stromal cells had a differentiation advantage for the osteogenic pathway. Moreover, the knockdown of Sam68 using short hairpin RNA in the embryonic mesenchymal multipotential progenitor C3H10T1/2 cells resulted in more pronounced expression of the mature osteoblast marker osteocalcin when differentiation was induced with bone morphogenetic protein-2. Cultures of mouse embryo fibroblasts generated from Sam68+/+ and Sam68−/− littermates were induced to differentiate into adipocytes with culture medium containing pioglitazone and the Sam68−/− mouse embryo fibroblasts shown to have impaired adipocyte differentiation. Furthermore, in vivo it was shown that sections of bone from 12-month-old Sam68−/− mice had few marrow adipocytes compared with their age-matched wild-type littermate controls, which exhibited fatty bone marrow. Our findings identify endogenous Sam68 as a positive regulator of adipocyte differentiation and a negative regulator of osteoblast differentiation, which is consistent with Sam68 being a modulator of bone marrow mesenchymal cell differentiation, and hence bone metabolism, in aged mice. PMID:16362077

Selective Plasma Deposition of Fluorocarbon Films on SAMs

NASA Technical Reports Server (NTRS)

Crain, Mark M., III; Walsh, Kevin M.; Cohn, Robert W.

2006-01-01

A dry plasma process has been demonstrated to be useful for the selective modification of self-assembled monolayers (SAMs) of alkanethiolates. These SAMs are used, during the fabrication of semiconductor electronic devices, as etch masks on gold layers that are destined to be patterned and incorporated into the devices. The selective modification involves the formation of fluorocarbon films that render the SAMs more effective in protecting the masked areas of the gold against etching by a potassium iodide (KI) solution. This modification can be utilized, not only in the fabrication of single electronic devices but also in the fabrication of integrated circuits, microelectromechanical systems, and circuit boards. In the steps that precede the dry plasma process, a silicon mold in the desired pattern is fabricated by standard photolithographic techniques. A stamp is then made by casting polydimethylsiloxane (commonly known as silicone rubber) in the mold. The stamp is coated with an alkanethiol solution, then the stamp is pressed on the gold layer of a device to be fabricated in order to deposit the alkanethiol to form an alkanethiolate SAM in the desired pattern (see figure). Next, the workpiece is exposed to a radio-frequency plasma generated from a mixture of CF4 and H2 gases. After this plasma treatment, the SAM is found to be modified, while the exposed areas of gold remain unchanged. This dry plasma process offers the potential for forming masks superior to those formed in a prior wet etching process. Among the advantages over the wet etching process are greater selectivity, fewer pin holes in the masks, and less nonuniformity of the masks. The fluorocarbon films formed in this way may also be useful as intermediate layers for subsequent fabrication steps and as dielectric layers to be incorporated into finished products.

Self-organizing map (SOM) of space acceleration measurement system (SAMS) data.

PubMed

Sinha, A; Smith, A D

1999-01-01

In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions.

Self-organizing map (SOM) of space acceleration measurement system (SAMS) data

NASA Technical Reports Server (NTRS)

Sinha, A.; Smith, A. D.

1999-01-01

In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions.

Surface adhesion and confinement variation of Staphylococcus aurius on SAM surfaces

NASA Astrophysics Data System (ADS)

Amroski, Alicia; Olsen, Morgan; Calabrese, Joseph; Senevirathne, Reshani; Senevirathne, Indrajith

2012-02-01

Controlled surface adhesion of non - pathogenic gram positive strain, Staphylococcus aureus is interesting as a model system due to possible development of respective biosensors for prevention and detection of the pathogenic strain methicillin resistant Staphylococcus aureus (MRSA) and further as a study for bio-machine interfacing. Self Assembled Monolayers (SAM) with engineered surfaces of linear thiols on Au(111) were used as the substrate. Sub cultured S. aureus were used for the analysis. The SAM layered surfaces were dipped in 2 -- 4 Log/ml S. aureus solution. Subsequent surface adhesion at different bacterial dilutions on surfaces will be discussed, and correlated with quantitative and qualitative adhesion properties of bacteria on the engineered SAM surfaces. The bacteria adhered SAM surfaces were investigated using intermittent contact, noncontact, lateral force and contact modes of Atomic Force Microscopy (AFM).

SAM Works! A Systems Approach Model for Adult Education Programming.

ERIC Educational Resources Information Center

Murk, Peter J.; Wells, John H.

The Systems Approach Model (SAM) is a dynamic approach to planning adult and continuing education that is intended to provide the flexibility, creativity, and meaningfulness necessary to meet the needs and interests of an ever-expanding and ever-aging student population. The SAM model consists of the following dynamically interrelated and…

Identification of trans-acting factors regulating SamDC expression in Oryza sativa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, Supratim, E-mail: supratim_genetics@yahoo.co.in; Division of Plant Biology, Bose Institute, Kolkata; Roychoudhury, Aryadeep

2014-03-07

Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In ourmore » present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.« less

Unanticipated coordination of tris buffer to the Radical SAM cluster of the RimO methylthiotransferase.

PubMed

Molle, Thibaut; Clémancey, Martin; Latour, Jean-Marc; Kathirvelu, Velavan; Sicoli, Giuseppe; Forouhar, Farhad; Mulliez, Etienne; Gambarelli, Serge; Atta, Mohamed

2016-07-01

Radical SAM enzymes generally contain a [4Fe-4S](2+/1+) (RS cluster) cluster bound to the protein via the three cysteines of a canonical motif CxxxCxxC. The non-cysteinyl iron is used to coordinate SAM via its amino-carboxylate moiety. The coordination-induced proximity between the cluster acting as an electron donor and the adenosyl-sulfonium bond of SAM allows for the homolytic cleavage of the latter leading to the formation of the reactive 5'-deoxyadenosyl radical used for substrate activation. Most of the structures of Radical SAM enzymes have been obtained in the presence of SAM, and therefore, little is known about the situation when SAM is not present. In this report, we show that RimO, a methylthiotransferase belonging to the radical SAM superfamily, binds a Tris molecule in the absence of SAM leading to specific spectroscopic signatures both in Mössbauer and pulsed EPR spectroscopies. These data provide a cautionary note for researchers who work with coordinative unsaturated iron sulfur clusters.

Isotopic and Geochemical Investigation of Two Distinct Mars Analog Environments Using Evolved Gas Techniques in Svalbard, Norway

NASA Technical Reports Server (NTRS)

Stern, Jennifer Claire; Mcadam, Amy Catherine; Ten Kate, Inge L.; Bish, David L.; Blake, David F.; Morris, Richard V.; Bowden, Roxane; Fogel, Marilyn L.; Glamoclija, Mihaela; Mahaffy, Paul R.;

RHESUS MONKEY - SAM - POSTFLIGHT - LITTLE JOE II (LJ-2) SPACECRAFT

NASA Image and Video Library

1963-10-23

S63-19199 (4 Dec. 1959) --- Sam, the Rhesus monkey, and his handler after his ride in the Little Joe 2 (LJ-2) spacecraft. He is still encased in his contour couch. A U.S. Navy destroyer safely recovered Sam after he experienced three minutes of weightlessness during the flight. Photo credit: NASA

The Sam Domain of EphA2 Receptor and its Relevance to Cancer: A Novel Challenge for Drug Discovery?

PubMed

Mercurio, Flavia A; Leone, Marilisa

2016-01-01

Eph receptors play important functions in developmental processes and diseases and among them EphA2 is well known for its controversial role in cancer. Drug discovery strategies are mainly centered on EphA2 extracellular ligand-binding domain however, the receptor also contains a largely unexplored cytosolic Sam (Sterile alpha motif) domain at the C-terminus. EphA2-Sam binds the Sam domain from the lipid phosphatase Ship2 and the first Sam domain of Odin. Sam-Sam interactions may be important to regulate ligand-induced receptor endocytosis and degradation i.e., processes that could be engaged against tumor malignancy. We critically analyzed literature related to a) Eph receptors with particular emphasis on EphA2 and its role in cancer, b) Sam domains, c) heterotypic Sam-Sam interactions involving EphA2-Sam. While literature data indicate that binding of EphA2-Sam to Ship2-Sam should largely generate pro-oncogenic effects in cancer cells, the correlation between EphA2- Sam/Odin-Sam1 complex and the disease is unclear. Recently a few linear peptides encompassing binding interfaces from either Ship2-Sam and Odin-Sam1 have been characterized but failed to efficiently block heterotypic Sam-Sam interactions involving EphA2-Sam due to the lack of a native like fold. Molecule antagonists of heterotypic EphA2-Sam associations could work as potential anticancer agents or be implemented as tools to further clarify receptor functions and eventually validate its role as a novel target in the field of anti-cancer drug discovery. Due to the failure of linear peptides there is a crucial need for novel approaches, based on cyclic or helical molecules, to target Sam-Sam interfaces.

Enhancing Student Altruism Using Secure Attachment Messages (SAM) in Lecture

ERIC Educational Resources Information Center

Campbell, Kelly; Ramos, Stephany

2017-01-01

In this brief report, we examine whether students' (N = 230) willingness to help individuals in distress (altruism) would be augmented after viewing Secure Attachment Messages (SAM) during lecture in a college racism course. Students were presented with SAM in alternating weeks as part of the PowerPoint presentation slides. In each of the weeks,…

Mechanistic studies of the radical SAM enzyme spore photoproduct lyase (SPL).

PubMed

Li, Lei

2012-11-01

Spore photoproduct lyase (SPL) repairs a special thymine dimer 5-thyminyl-5,6-dihydrothymine, which is commonly called spore photoproduct or SP at the bacterial early germination phase. SP is the exclusive DNA photo-damage product in bacterial endospores; its generation and swift repair by SPL are responsible for the spores' extremely high UV resistance. The early in vivo studies suggested that SPL utilizes a direct reversal strategy to repair the SP in the absence of light. The research in the past decade further established SPL as a radical SAM enzyme, which utilizes a tri-cysteine CXXXCXXC motif to harbor a [4Fe-4S] cluster. At the 1+ oxidation state, the cluster provides an electron to the S-adenosylmethionine (SAM), which binds to the cluster in a bidentate manner as the fourth and fifth ligands, to reductively cleave the CS bond associated with the sulfonium ion in SAM, generating a reactive 5'-deoxyadenosyl (5'-dA) radical. This 5'-dA radical abstracts the proR hydrogen atom from the C6 carbon of SP to initiate the repair process; the resulting SP radical subsequently fragments to generate a putative thymine methyl radical, which accepts a back-donated H atom to yield the repaired TpT. SAM is suggested to be regenerated at the end of each catalytic cycle; and only a catalytic amount of SAM is needed in the SPL reaction. The H atom source for the back donation step is suggested to be a cysteine residue (C141 in Bacillus subtilis SPL), and the H-atom transfer reaction leaves a thiyl radical behind on the protein. This thiyl radical thus must participate in the SAM regeneration process; however how the thiyl radical abstracts an H atom from the 5'-dA to regenerate SAM is unknown. This paper reviews and discusses the history and the latest progress in the mechanistic elucidation of SPL. Despite some recent breakthroughs, more questions are raised in the mechanistic understanding of this intriguing DNA repair enzyme. This article is part of a Special Issue

An adaptor role for cytoplasmic Sam68 in modulating Src activity during cell polarization.

PubMed

Huot, Marc-Etienne; Brown, Claire M; Lamarche-Vane, Nathalie; Richard, Stéphane

2009-04-01

The Src-associated substrate during mitosis with a molecular mass of 68 kDa (Sam68) is predominantly nuclear and is known to associate with proteins containing the Src homology 3 (SH3) and SH2 domains. Although Sam68 is a Src substrate, little is known about the signaling pathway that link them. Src is known to be activated transiently after cell spreading, where it modulates the activity of small Rho GTPases. Herein we report that Sam68-deficient cells exhibit loss of cell polarity and cell migration. Interestingly, Sam68-deficient cells exhibited sustained Src activity after cell attachment, resulting in the constitutive tyrosine phosphorylation and activation of p190RhoGAP and its association with p120rasGAP. Consistently, we observed that Sam68-deficient cells exhibited deregulated RhoA and Rac1 activity. By using total internal reflection fluorescence microscopy, we observed Sam68 near the plasma membrane after cell attachment coinciding with phosphorylation of its C-terminal tyrosines and association with Csk. These findings show that Sam68 localizes near the plasma membrane during cell attachment and serves as an adaptor protein to modulate Src activity for proper signaling to small Rho GTPases.

CD and NMR conformational studies of a peptide encompassing the Mid Loop interface of Ship2-Sam.

PubMed

Mercurio, Flavia A; Scognamiglio, Pasqualina L; Di Natale, Concetta; Marasco, Daniela; Pellecchia, Maurizio; Leone, Marilisa

2014-11-01

The lipid phosphatase Ship2 is a protein that intervenes in several diseases such as diabetes, cancer, neurodegeneration, and atherosclerosis. It is made up of a catalytic domain and several protein docking modules such as a C-terminal Sam (Sterile alpha motif) domain. The Sam domain of Ship2 (Ship2-Sam) binds to the Sam domains of the EphA2 receptor (EphA2-Sam) and the PI3K effector protein Arap3 (Arap3-Sam). These heterotypic Sam-Sam interactions occur through formation of dimers presenting the canonical "Mid Loop/End Helix" binding mode. The central region of Ship2-Sam, spanning the C-terminal end of α2, the α3 and α4 helices together with the α2α3 and α3α4 interhelical loops, forms the Mid Loop surface that is needed to bind partners Sam domains. A peptide encompassing most of the Ship2-Sam Mid Loop interface (Shiptide) capable of binding to both EphA2-Sam and Arap3-Sam, was previously identified. Here we investigated the conformational features of this peptide, through solution CD and NMR studies in different conditions. These studies reveal that the peptide is highly flexible in aqueous buffer, while it adopts a helical conformation in presence of 2,2,2-trifluoroethanol. The discovered structural insights and in particular the identification of a helical motif, may lead to the design of more constrained and possibly cell permeable Shiptide analogs that could work as efficient antagonists of Ship2-Sam heterotypic interactions and embrace therapeutic applications. © 2014 Wiley Periodicals, Inc.

Influence of Oxychlorine Phases During the Pyrolysis of Organic Molecules: Implications for the Quest of Organics on Mars with the SAM Experiment Onboard the Curiosity Rover

NASA Technical Reports Server (NTRS)

Millan, M.; Szopa, C.; Buch, A.; Belmahdi, I.; Glavin, D. P.; Freissinet, C.; Eigenbrode, J. L.; Archer, P. D., Jr,; Sutter, B.; Mahaffy, P.

2017-01-01

One among the main objectives of the Sample Analysis at Mars (SAM) experiment is the in situ molecular analysis of gases evolving from solid samples heated up to approximately 850 degrees Centigrade, and collected by Curiosity on Mars surface/sub-surface in Gale crater. With this aim, SAM uses a gas-chromatograph coupled to a quadrupole mass spectrometer (GC-QMS) devoted to separate, detect and identify both volatile inorganic and organic compounds. SAM detected chlorinated organic molecules produced in evolved gas analysis (EGA) experiments. Several of these were also detected by the Viking experiments in 1976. SAM also detected oxychlorine compounds that were present at the Phoenix landing site. The oxychlorines may be prevelant over much of the martian surface. The C1 to C3 aliphatic chlorohydrocarbons (chloromethane and di- and trichloromethane) detected by SAM were attributed to reaction products occurring between the oxychlorines phases and the organic compounds coming from SAM instrument background. But SAM also showed the presence of a large excess of chlorobenzene and C2 to C4 dichloroalkanes among the volatile species released by the Cumberland sample of the Sheepbed mudstone. For the first time in the history of the Mars exploration, this proved the presence of Mars indigenous organic material at the Mars' surface. However, the identification of the precursor organic compounds of these chlorohydrocarbons is difficult due to the complexity of the reactions occurring during the sample pyrolysis. Laboratory pyrolysis experiments have demonstrated that oxychlorines phases such as perchlorates and chlorates, decomposed into dioxygen and volatile chlorine bearing molecules (HCl and/or Cl2) during the pyrolysis. These chemical species can then react with the organic molecules present in the martian solid samples through oxidation, chlorination and oxychlorination processes.

The SAMS: Smartphone Addiction Management System and verification.

PubMed

Lee, Heyoung; Ahn, Heejune; Choi, Samwook; Choi, Wanbok

2014-01-01

While the popularity of smartphones has given enormous convenience to our lives, their pathological use has created a new mental health concern among the community. Hence, intensive research is being conducted on the etiology and treatment of the condition. However, the traditional clinical approach based surveys and interviews has serious limitations: health professionals cannot perform continual assessment and intervention for the affected group and the subjectivity of assessment is questionable. To cope with these limitations, a comprehensive ICT (Information and Communications Technology) system called SAMS (Smartphone Addiction Management System) is developed for objective assessment and intervention. The SAMS system consists of an Android smartphone application and a web application server. The SAMS client monitors the user's application usage together with GPS location and Internet access location, and transmits the data to the SAMS server. The SAMS server stores the usage data and performs key statistical data analysis and usage intervention according to the clinicians' decision. To verify the reliability and efficacy of the developed system, a comparison study with survey-based screening with the K-SAS (Korean Smartphone Addiction Scale) as well as self-field trials is performed. The comparison study is done using usage data from 14 users who are 19 to 50 year old adults that left at least 1 week usage logs and completed the survey questionnaires. The field trial fully verified the accuracy of the time, location, and Internet access information in the usage measurement and the reliability of the system operation over more than 2 weeks. The comparison study showed that daily use count has a strong correlation with K-SAS scores, whereas daily use times do not strongly correlate for potentially addicted users. The correlation coefficients of count and times with total K-SAS score are CC = 0.62 and CC =0.07, respectively, and the t-test analysis for the

Potential sources of artifacts and backgrounds generated by the sample preparation of the SAM experiment aboard the Curiosity Rover on Mars

NASA Astrophysics Data System (ADS)

Buch, Arnaud; Belmahdi, Imene; Szopa, Cyril; Freissinet, Caroline; Glavin, Daniel P.; Eigenbrode, Jennifer; Summons, Roger; Miller, Kristen; Coll, Patrice; cabane, Michel; Navarro-Gonzalez, Rafael; Stern, Jennifer; Coscia, David; Teinturier, Samuel; Bonnet, Jean-Yves; Dequaire, Tristan; Mahaffy, Paul; MSL Science Team

2016-10-01

Sample Analysis at Mars (SAM) is one of the instruments of the MSL mission. Three analytical devices are onboard SAM: the Tunable Laser Spectrometer (TLS), the Gas Chromatography (GC) and the Mass Spectrometer (MS). To adapt the nature of a sample to the analytical devices used on SAM, a sample preparation and gas processing system is implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) which is employed to concentrate volatiles released from the sample prior to GC-MS analysis [1].Volatile compounds and abundant chlorinated hydrocarbons have been detected with SAM when analyzing samples collected in several sites explored by Curiosity rover. Some volatile compounds (chlorinated and non-chlorinated) come from the degradation of the MTBSTFA under high temperature or by the reaction of Martian oxychlorine compounds (present in the samples) with terrestrial carbon coming from the derivatization agent (MTBSTFA) used in SAM [2,3]. But other chlorinated compounds do not follow this pathway. For example, Chlorobenzene has been detected by SAM but it cannot be formed by the reaction of MTBSTFA and perchlorates. Then, two other reaction pathways for chlorobenzene were therefore proposed: (1) reactions between the volatile thermal degradation products of perchlorates (e.g. O2, Cl2 and HCl) and Tenax® and (2) the interaction of perchlorates (T>200°C) with organic material from Mars's soil such as benzenecarboxylates. However, even if major part of the chlorobenzene detected has been identified as Martian origin [4] it is important to list all the potential byproducts able to be released from the Tenax®.Thus, this study inventory all the possible compounds which are originated from Tenax®, MTBSTFA and their interaction with perchlorate.References: [1] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [2] Glavin, D., A. et al. (2013), LPSC. [3] Eigenbrode, J. et al. (2013), LPSC. [4

SAM-CAAM: A Concept for Acquiring Systematic Aircraft Measurements to Characterize Aerosol Air Masses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahn, Ralph A.; Berkoff, Tim A.; Brock, Charles

A modest operational program of systematic aircraft measurements can resolve key satellite aerosol data record limitations. Satellite observations provide frequent global aerosol amount maps but offer only loose aerosol property constraints needed for climate and air quality applications. In this paper, we define and illustrate the feasibility of flying an aircraft payload to measure key aerosol optical, microphysical, and chemical properties in situ. The flight program could characterize major aerosol airmass types statistically, at a level of detail unobtainable from space. It would 1) enhance satellite aerosol retrieval products with better climatology assumptions and 2) improve translation between satellite-retrieved opticalmore » properties and species-specific aerosol mass and size simulated in climate models to assess aerosol forcing, its anthropogenic components, and other environmental impacts. As such, Systematic Aircraft Measurements to Characterize Aerosol Air Masses (SAM-CAAM) could add value to data records representing several decades of aerosol observations from space; improve aerosol constraints on climate modeling; help interrelate remote sensing, in situ, and modeling aerosol-type definitions; and contribute to future satellite aerosol missions. Fifteen required variables are identified and four payload options of increasing ambition are defined to constrain these quantities. “Option C” could meet all the SAM-CAAM objectives with about 20 instruments, most of which have flown before, but never routinely several times per week, and never as a group. Aircraft integration and approaches to data handling, payload support, and logistical considerations for a long-term, operational mission are discussed. Finally, SAM-CAAM is feasible because, for most aerosol sources and specified seasons, particle properties tend to be repeatable, even if aerosol loading varies.« less

SAM-CAAM: A Concept for Acquiring Systematic Aircraft Measurements to Characterize Aerosol Air Masses

DOE PAGES

Kahn, Ralph A.; Berkoff, Tim A.; Brock, Charles; ...

2017-10-30

A modest operational program of systematic aircraft measurements can resolve key satellite aerosol data record limitations. Satellite observations provide frequent global aerosol amount maps but offer only loose aerosol property constraints needed for climate and air quality applications. In this paper, we define and illustrate the feasibility of flying an aircraft payload to measure key aerosol optical, microphysical, and chemical properties in situ. The flight program could characterize major aerosol airmass types statistically, at a level of detail unobtainable from space. It would 1) enhance satellite aerosol retrieval products with better climatology assumptions and 2) improve translation between satellite-retrieved opticalmore » properties and species-specific aerosol mass and size simulated in climate models to assess aerosol forcing, its anthropogenic components, and other environmental impacts. As such, Systematic Aircraft Measurements to Characterize Aerosol Air Masses (SAM-CAAM) could add value to data records representing several decades of aerosol observations from space; improve aerosol constraints on climate modeling; help interrelate remote sensing, in situ, and modeling aerosol-type definitions; and contribute to future satellite aerosol missions. Fifteen required variables are identified and four payload options of increasing ambition are defined to constrain these quantities. “Option C” could meet all the SAM-CAAM objectives with about 20 instruments, most of which have flown before, but never routinely several times per week, and never as a group. Aircraft integration and approaches to data handling, payload support, and logistical considerations for a long-term, operational mission are discussed. Finally, SAM-CAAM is feasible because, for most aerosol sources and specified seasons, particle properties tend to be repeatable, even if aerosol loading varies.« less

SAM-CAAM: A Concept for Acquiring Systematic Aircraft Measurements to Characterize Aerosol Air Masses.

PubMed

Kahn, Ralph A; Berkoff, Tim A; Brock, Charles; Chen, Gao; Ferrare, Richard A; Ghan, Steven; Hansico, Thomas F; Hegg, Dean A; Martins, J Vanderlei; McNaughton, Cameron S; Murphy, Daniel M; Ogren, John A; Penner, Joyce E; Pilewskie, Peter; Seinfeld, John H; Worsnop, Douglas R

2017-10-01

A modest operational program of systematic aircraft measurements can resolve key satellite-aerosol-data-record limitations. Satellite observations provide frequent, global aerosol-amount maps, but offer only loose aerosol property constraints needed for climate and air quality applications. We define and illustrate the feasibility of flying an aircraft payload to measure key aerosol optical, microphysical, and chemical properties in situ . The flight program could characterize major aerosol air-mass types statistically, at a level-of-detail unobtainable from space. It would: (1) enhance satellite aerosol retrieval products with better climatology assumptions, and (2) improve translation between satellite-retrieved optical properties and species-specific aerosol mass and size simulated in climate models to assess aerosol forcing, its anthropogenic components, and other environmental impacts. As such, Systematic Aircraft Measurements to Characterize Aerosol Air Masses (SAM-CAAM) could add value to data records representing several decades of aerosol observations from space, improve aerosol constraints on climate modeling , help interrelate remote-sensing, in situ, and modeling aerosol-type definitions , and contribute to future satellite aerosol missions. Fifteen Required Variables are identified, and four Payload Options of increasing ambition are defined, to constrain these quantities. "Option C" could meet all the SAM-CAAM objectives with about 20 instruments, most of which have flown before, but never routinely several times per week, and never as a group. Aircraft integration, and approaches to data handling, payload support, and logistical considerations for a long-term, operational mission are discussed. SAM-CAAM is feasible because, for most aerosol sources and specified seasons, particle properties tend to be repeatable , even if aerosol loading varies.

Sulphur-bearing Compounds Detected by MSL SAM Evolved Gas Analysis of Materials from Yellowknife Bay, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Franz, H. B.; Archer, P. D. Jr.; Sutter, B.; Eigenbrode, J. L.; Freissinet, C.; Atreya, S. K.; Bish, D. L.; Blake, D. F.; Brunner, A.;

Design of Test Support Hardware for Advanced Space Suits

NASA Technical Reports Server (NTRS)

Watters, Jeffrey A.; Rhodes, Richard

2013-01-01

As a member of the Space Suit Assembly Development Engineering Team, I designed and built test equipment systems to support the development of the next generation of advanced space suits. During space suit testing it is critical to supply the subject with two functions: (1) cooling to remove metabolic heat, and (2) breathing air to pressurize the space suit. The objective of my first project was to design, build, and certify an improved Space Suit Cooling System for manned testing in a 1-G environment. This design had to be portable and supply a minimum cooling rate of 2500 BTU/hr. The Space Suit Cooling System is a robust, portable system that supports very high metabolic rates. It has a highly adjustable cool rate and is equipped with digital instrumentation to monitor the flowrate and critical temperatures. It can supply a variable water temperature down to 34 deg., and it can generate a maximum water flowrate of 2.5 LPM. My next project was to design and build a Breathing Air System that was capable of supply facility air to subjects wearing the Z-2 space suit. The system intakes 150 PSIG breathing air and regulates it to two operating pressures: 4.3 and 8.3 PSIG. It can also provide structural capabilities at 1.5x operating pressure: 6.6 and 13.2 PSIG, respectively. It has instrumentation to monitor flowrate, as well as inlet and outlet pressures. The system has a series of relief valves to fully protect itself in case of regulator failure. Both projects followed a similar design methodology. The first task was to perform research on existing concepts to develop a sufficient background knowledge. Then mathematical models were developed to size components and simulate system performance. Next, mechanical and electrical schematics were generated and presented at Design Reviews. After the systems were approved by the suit team, all the hardware components were specified and procured. The systems were then packaged, fabricated, and thoroughly tested. The next step

Iron-Rich Carbonates as the Potential Source of Evolved CO2 Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater

NASA Technical Reports Server (NTRS)

Sutter, B.; Heil, E.; Rampe, E. B.; Morris, R. V.; Ming, D. W.; Archer, P. D.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A. C.;

Investigations Using Laboratory Testbeds to Interpret Flight Instrument Datasets from Mars Robotic Missions

NASA Technical Reports Server (NTRS)

Ming, D. W.; Morris, R. V.; Sutter, B.; Archer, P. D., Jr.; Achilles, C. N.

2012-01-01

The Astromaterials Research and Exploration Science Directorate at the NASA Johnson Space Center (JSC) has laboratory instrumentation that mimic the capabilities of corresponding flight instruments to enable interpretation of datasets returned from Mars robotic missions. The lab instruments have been and continue to be applied to datasets for the Moessbauer Spectrometer (MB) on the Mars Exploration Rovers (MER), the Thermal & Evolved Gas Analyzer (TEGA) on the Mars Phoenix Scout, the CRISM instrument on the Mars Reconnaissance Orbiter Missions and will be applied to datasets for the Sample Analysis at Mars (SAM), Chemistry and Mineralogy (CheMin) and Chemistry & Camera (ChemCam) instruments onboard the Mars Science Laboratory (MSL). The laboratory instruments can analyze analog samples at costs that are substantially lower than engineering models of flight instruments, but their success to enable interpretation of flight data depends on how closely their capabilities mimic those of the flight instrument. The JSC lab MB instruments are equivalent to the MER instruments except without flight qualified components and no reference channel Co-57 source. Data from analog samples were critical for identification of Mg-Fe carbonate at Gusev crater. Fiber-optic VNIR spectrometers are used to obtain CRISM-like spectral data over the range 350-2500 nm, and data for Fephyllosilicates show irreversible behavior in the electronic transition region upon dessication. The MB and VNIR instruments can be operated within chambers where, for example, the absolute H2O concentration can be measured and controlled. Phoenix's TEGA consisted of a calorimeter coupled to a mass spectrometer (MS). The JSC laboratory testbed instrument consisted of a differential scanning calorimeter (DSC) coupled to a MS configured to operate under total pressure (12 mbar), heating rate (20 C/min), and purge gas composition (N2) analogous to the flight TEGA. TEGA detected CO2 release at both low (400-680 C

Sam68 Allows Selective Targeting of Human Cancer Stem Cells.

PubMed

Benoit, Yannick D; Mitchell, Ryan R; Risueño, Ruth M; Orlando, Luca; Tanasijevic, Borko; Boyd, Allison L; Aslostovar, Lili; Salci, Kyle R; Shapovalova, Zoya; Russell, Jennifer; Eguchi, Masakatsu; Golubeva, Diana; Graham, Monica; Xenocostas, Anargyros; Trus, Michael R; Foley, Ronan; Leber, Brian; Collins, Tony J; Bhatia, Mickie

2017-07-20

Targeting of human cancer stem cells (CSCs) requires the identification of vulnerabilities unique to CSCs versus healthy resident stem cells (SCs). Unfortunately, dysregulated pathways that support transformed CSCs, such as Wnt/β-catenin signaling, are also critical regulators of healthy SCs. Using the ICG-001 and CWP family of small molecules, we reveal Sam68 as a previously unappreciated modulator of Wnt/β-catenin signaling within CSCs. Disruption of CBP-β-catenin interaction via ICG-001/CWP induces the formation of a Sam68-CBP complex in CSCs that alters Wnt signaling toward apoptosis and differentiation induction. Our study identifies Sam68 as a regulator of human CSC vulnerability. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Benchmark Simulation of Natural Circulation Cooling System with Salt Working Fluid Using SAM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, K. K.; Scarlat, R. O.; Hu, R.

Liquid salt-cooled reactors, such as the Fluoride Salt-Cooled High-Temperature Reactor (FHR), offer passive decay heat removal through natural circulation using Direct Reactor Auxiliary Cooling System (DRACS) loops. The behavior of such systems should be well-understood through performance analysis. The advanced system thermal-hydraulics tool System Analysis Module (SAM) from Argonne National Laboratory has been selected for this purpose. The work presented here is part of a larger study in which SAM modeling capabilities are being enhanced for the system analyses of FHR or Molten Salt Reactors (MSR). Liquid salt thermophysical properties have been implemented in SAM, as well as properties ofmore » Dowtherm A, which is used as a simulant fluid for scaled experiments, for future code validation studies. Additional physics modules to represent phenomena specific to salt-cooled reactors, such as freezing of coolant, are being implemented in SAM. This study presents a useful first benchmark for the applicability of SAM to liquid salt-cooled reactors: it provides steady-state and transient comparisons for a salt reactor system. A RELAP5-3D model of the Mark-1 Pebble-Bed FHR (Mk1 PB-FHR), and in particular its DRACS loop for emergency heat removal, provides steady state and transient results for flow rates and temperatures in the system that are used here for code-to-code comparison with SAM. The transient studied is a loss of forced circulation with SCRAM event. To the knowledge of the authors, this is the first application of SAM to FHR or any other molten salt reactors. While building these models in SAM, any gaps in the code’s capability to simulate such systems are identified and addressed immediately, or listed as future improvements to the code.« less

Wind Technology Modeling Within the System Advisor Model (SAM) (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blair, N.; Dobos, A.; Ferguson, T.

This poster provides detail for implementation and the underlying methodology for modeling wind power generation performance in the National Renewable Energy Laboratory's (NREL's) System Advisor Model (SAM). SAM's wind power model allows users to assess projects involving one or more large or small wind turbines with any of the detailed options for residential, commercial, or utility financing. The model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs, and provides analysis to compare the absolute or relative impact of these inputs. SAM is a system performance and economic model designed to facilitate analysismore » and decision-making for project developers, financers, policymakers, and energy researchers. The user pairs a generation technology with a financing option (residential, commercial, or utility) to calculate the cost of energy over the multi-year project period. Specifically, SAM calculates the value of projects which buy and sell power at retail rates for residential and commercial systems, and also for larger-scale projects which operate through a power purchase agreement (PPA) with a utility. The financial model captures complex financing and rate structures, taxes, and incentives.« less

Magnetospheric Multiscale Instrument Suite Operations and Data System

NASA Technical Reports Server (NTRS)

Baker, D. N.; Riesberg, L.; Pankratz, C. K.; Panneton, R. S.; Giles, B. L.; Wilder, F. D.; Ergun, R. E.

2015-01-01

The four Magnetospheric Multiscale (MMS) spacecraft will collect a combined volume of approximately 100 gigabits per day of particle and field data. On average, only 4 gigabits of that volume can be transmitted to the ground. To maximize the scientific value of each transmitted data segment, MMS has developed the Science Operations Center (SOC) to manage science operations, instrument operations, and selection, downlink, distribution, and archiving of MMS science data sets. The SOC is managed by the Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado and serves as the primary point of contact for community participation in the mission. MMS instrument teams conduct their operations through the SOC, and utilize the SOC's Science Data Center (SOC) for data management and distribution. The SOC provides a single mission data archive for the housekeeping and science data, calibration data, ephemerides, attitude and other ancillary data needed to support the scientific use and interpretation. All levels of data products will reside at and be publicly disseminated from the SDC. Documentation and metadata describing data products, algorithms, instrument calibrations, validation, and data quality will be provided. Arguably, the most important innovation developed by the SOC is the MMS burst data management and selection system. With nested automation and 'Scientist-in-the-Loop' (SITL) processes, these systems are designed to maximize the value of the burst data by prioritizing the data segments selected for transmission to the ground. This paper describes the MMS science operations approach, processes and data systems, including the burst system and the SITL concept.

Magnetospheric Multiscale Instrument Suite Operations and Data System

NASA Astrophysics Data System (ADS)

Baker, D. N.; Riesberg, L.; Pankratz, C. K.; Panneton, R. S.; Giles, B. L.; Wilder, F. D.; Ergun, R. E.

2016-03-01

The four Magnetospheric Multiscale (MMS) spacecraft will collect a combined volume of ˜100 gigabits per day of particle and field data. On average, only 4 gigabits of that volume can be transmitted to the ground. To maximize the scientific value of each transmitted data segment, MMS has developed the Science Operations Center (SOC) to manage science operations, instrument operations, and selection, downlink, distribution, and archiving of MMS science data sets. The SOC is managed by the Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado and serves as the primary point of contact for community participation in the mission. MMS instrument teams conduct their operations through the SOC, and utilize the SOC's Science Data Center (SDC) for data management and distribution. The SOC provides a single mission data archive for the housekeeping and science data, calibration data, ephemerides, attitude and other ancillary data needed to support the scientific use and interpretation. All levels of data products will reside at and be publicly disseminated from the SDC. Documentation and metadata describing data products, algorithms, instrument calibrations, validation, and data quality will be provided. Arguably, the most important innovation developed by the SOC is the MMS burst data management and selection system. With nested automation and "Scientist-in-the-Loop" (SITL) processes, these systems are designed to maximize the value of the burst data by prioritizing the data segments selected for transmission to the ground. This paper describes the MMS science operations approach, processes and data systems, including the burst system and the SITL concept.

Alternative function for the mitochondrial SAM complex in biogenesis of alpha-helical TOM proteins.

PubMed

Stojanovski, Diana; Guiard, Bernard; Kozjak-Pavlovic, Vera; Pfanner, Nikolaus; Meisinger, Chris

2007-12-03

The mitochondrial outer membrane contains two preprotein translocases: the general translocase of outer membrane (TOM) and the beta-barrel-specific sorting and assembly machinery (SAM). TOM functions as the central entry gate for nuclear-encoded proteins. The channel-forming Tom40 is a beta-barrel protein, whereas all Tom receptors and small Tom proteins are membrane anchored by a transmembrane alpha-helical segment in their N- or C-terminal portion. Synthesis of Tom precursors takes place in the cytosol, and their import occurs via preexisting TOM complexes. The precursor of Tom40 is then transferred to SAM for membrane insertion and assembly. Unexpectedly, we find that the biogenesis of alpha-helical Tom proteins with a membrane anchor in the C-terminal portion is SAM dependent. Each SAM protein is necessary for efficient membrane integration of the receptor Tom22, whereas assembly of the small Tom proteins depends on Sam37. Thus, the substrate specificity of SAM is not restricted to beta-barrel proteins but also includes the majority of alpha-helical Tom proteins.

A classification model of Hyperion image base on SAM combined decision tree

NASA Astrophysics Data System (ADS)

Wang, Zhenghai; Hu, Guangdao; Zhou, YongZhang; Liu, Xin

2009-10-01

Monitoring the Earth using imaging spectrometers has necessitated more accurate analyses and new applications to remote sensing. A very high dimensional input space requires an exponentially large amount of data to adequately and reliably represent the classes in that space. On the other hand, with increase in the input dimensionality the hypothesis space grows exponentially, which makes the classification performance highly unreliable. Traditional classification algorithms Classification of hyperspectral images is challenging. New algorithms have to be developed for hyperspectral data classification. The Spectral Angle Mapper (SAM) is a physically-based spectral classification that uses an ndimensional angle to match pixels to reference spectra. The algorithm determines the spectral similarity between two spectra by calculating the angle between the spectra, treating them as vectors in a space with dimensionality equal to the number of bands. The key and difficulty is that we should artificial defining the threshold of SAM. The classification precision depends on the rationality of the threshold of SAM. In order to resolve this problem, this paper proposes a new automatic classification model of remote sensing image using SAM combined with decision tree. It can automatic choose the appropriate threshold of SAM and improve the classify precision of SAM base on the analyze of field spectrum. The test area located in Heqing Yunnan was imaged by EO_1 Hyperion imaging spectrometer using 224 bands in visual and near infrared. The area included limestone areas, rock fields, soil and forests. The area was classified into four different vegetation and soil types. The results show that this method choose the appropriate threshold of SAM and eliminates the disturbance and influence of unwanted objects effectively, so as to improve the classification precision. Compared with the likelihood classification by field survey data, the classification precision of this model

The Canadian space agency planetary analogue materials suite

NASA Astrophysics Data System (ADS)

Cloutis, Edward A.; Mann, Paul; Izawa, Matthew R. M.; Applin, Daniel M.; Samson, Claire; Kruzelecky, Roman; Glotch, Timothy D.; Mertzman, Stanley A.; Mertzman, Karen R.; Haltigin, Timothy W.; Fry, Christopher

2015-12-01

The Canadian Space Agency (CSA) recently commissioned the development of a suite of over fifty well-characterized planetary analogue materials. These materials are terrestrial rocks and minerals that are similar to those known or suspected to occur on the lunar or martian surfaces. These include: Mars analogue sedimentary, hydrothermal, igneous and low-temperature alteration rock suites; lunar analogue basaltic and anorthositic rock suites; and a generic impactite rock suite from a variety of terrestrial impact structures. Representative thin sections of the materials have been characterized by optical microscopy and electron probe microanalysis (EPMA). Reflectance spectra have been collected in the ultraviolet, visible, near-infrared and mid-infrared, covering 0.2-25 μm. Thermal infrared emission spectra were collected from 5 to 50 μm. Raman spectra with 532 nm excitation, and laser-induced fluorescence spectra with 405 nm excitation were also measured. Bulk chemical analysis was carried out using X-ray fluorescence, with Fe valence determined by wet chemistry. Chemical and mineralogical data were collected using a field-portable Terra XRD-XRF instrument similar to CheMin on the MSL Curiosity rover. Laser-induced breakdown spectroscopy (LIBS) data similar to those measured by ChemCam on MSL were collected for powdered samples, cut slab surfaces, and as depth profiles into weathered surfaces where present. Three-dimensional laser camera images of rock textures were collected for selected samples. The CSA intends to make available sample powders (<45 μm and 45-1000 μm grain sizes), thin sections, and bulk rock samples, and all analytical data collected in the initial characterisation study to the broader planetary science community. Aiming to complement existing planetary analogue rock and mineral libraries, the CSA suite represents a new resource for planetary scientists and engineers. We envision many potential applications for these materials in the

Quality Control Guidelines for SAM Chemical Methods

EPA Pesticide Factsheets

Learn more about quality control guidelines and recommendations for the analysis of samples using the chemistry methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Radiochemical Methods

EPA Pesticide Factsheets

Learn more about quality control guidelines and recommendations for the analysis of samples using the radiochemistry methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Biotoxin Methods

EPA Pesticide Factsheets

Learn more about quality control guidelines and recommendations for the analysis of samples using the pathogen methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Quality Control Guidelines for SAM Pathogen Methods

EPA Pesticide Factsheets

Learn more about quality control guidelines and recommendations for the analysis of samples using the biotoxin methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Engineering of Neuron Growth and Enhancing Cell-Chip Communication via Mixed SAMs.

PubMed

Markov, Aleksandr; Maybeck, Vanessa; Wolf, Nikolaus; Mayer, Dirk; Offenhäusser, Andreas; Wördenweber, Roger

2018-06-06

The interface between cells and inorganic surfaces represents one of the key elements for bioelectronics experiments and applications ranging from cell cultures and bioelectronics devices to medical implants. In the present paper, we describe a way to tailor the biocompatibility of substrates in terms of cell growth and to significantly improve cell-chip communication, and we also demonstrate the reusability of the substrates for cell experiments. All these improvements are achieved by coating the substrates or chips with a self-assembled monolayer (SAM) consisting of a mixture of organic molecules, (3-aminopropyl)-triethoxysilane and (3-glycidyloxypropyl)-trimethoxysilane. By varying the ratio of these molecules, we are able to tune the cell density and live/dead ratios of rat cortical neurons cultured directly on the mixed SAM as well as neurons cultured on protein-coated SAMs. Furthermore, the use of the SAM leads to a significant improvement in cell-chip communications. Action potential signals of up to 9.4 ± 0.6 mV (signal-to-noise ratio up to 47) are obtained for HL-1 cells on microelectrode arrays. Finally, we demonstrate that the SAMs facilitate a reusability of the samples for all cell experiments with little re-processing.

Standardized added metabolic activity (SAM): a partial volume independent marker of total lesion glycolysis in liver metastases.

PubMed

Mertens, Jeroen; Dobbeleir, André; Ham, Hamphrey; D'Asseler, Yves; Goethals, Ingeborg; Van de Wiele, Christophe

2012-09-01

The standardized added metabolic activity (SAM) is a new marker of total lesion glycolysis that avoids partial volume effect (PVE) and thresholding. SAM is calculated by drawing a volume of interest (VOI(1)) around the tumour and a larger VOI (VOI(2)) around VOI(1). Subtracting the background activity in VOI(2)-VOI(1) from VOI(1) yields SAM. If VOI(1) is set at a reasonable distance from the tumour, PVE are avoided. Phantom and initial clinical validation data are presented. Spheres of a Jaszczak phantom were filled with a 5.4, 3.64 and 2.0 times higher concentration relative to background activity and positron emission tomography (PET) data were acquired during 10 min. SAM of all spheres was expressed as a percentage of the expected value (the actual activity ratio minus 1). In 15 patients a 10-min list-mode acquisition PET study centred on their primary squamous cell carcinoma (PSCC) was performed and images of 1-10 min reconstructed. SAM1-9min values of PSCC were expressed as a percentage of SAM10min. Nineteen patients suffering from liver metastases treated with chemotherapy underwent PET/CT prior to (scan 1) and after 3-6 cycles of chemotherapy (scan 2). SAM and maximum standardized uptake values (SUV(max)) of the liver lesions on scan 1 (SAM1 and SUV(max)1) and the percentage reduction between both ΔSAM and ΔSUV(max) were related to Response Evaluation Criteria in Solid Tumors (RECIST) response. For the phantom acquisitions, the mean normalized SAM/sphere volume calculated was 94.9 % (SD 5.9 %) of the expected value. In the PSCC patients, the mean difference between SAM1min and SAM10min was only 4 % (SD 5 %). SUV(max)1min and SUV(max)10min proved to be not significantly different, but the variability was slightly larger than that of SAM (SD 6.4 %). SAM1 and ΔSAM values for responders versus non-responders were, respectively, 57 (SD 119) versus 297 (SD 625) for SAM1 (p = 0.2) and 99 % (SD 3 %) versus 32 % (SD 44 %) for ΔSAM (p = 0.001). SUV(max)1 and �

Reactions Involving Calcium and Magnesium Sulfates as Potential Sources of Sulfur Dioxide During MSL SAM Evolved Gas Analyses

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Knudson, C. A.; Sutter, B.; Franz, H. B.; Archer, P. D., Jr.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Hurowitz, J. A.; Mahaffy, P. R.;

Possible Origin of Chlorobenzene Detected by SAM Instrument at Gale Crater, Mars: Synergy of Iron Oxides and Perchlorate and Consequences for Organic Matter Analysis

NASA Astrophysics Data System (ADS)

Francois, P.; Coll, P.; Szopa, C.; Georgelin, T.; Buch, A.; Freissinet, C.; Belmahdi, I.; McAdam, A.; Eigenbrode, J.; Glavin, D.; Kashyap, S.; Navarro-Gonzalez, A. R.; Mahaffy, P.; Cabane, M.

2014-07-01

Chlorobenzene, potentially of martian origin, has been detected by the SAM experiment onboard Curiosity rover. We explore its potential formation by a synergy between oxychlorine phases and iron oxides in the presence of a carbon source.

Conformational heterogeneity of the SAM-I riboswitch transcriptional ON state: a chaperone-like role for S-adenosyl methionine.

PubMed

Huang, Wei; Kim, Joohyun; Jha, Shantenu; Aboul-Ela, Fareed

2012-05-18

Riboswitches are promising targets for the design of novel antibiotics and engineering of portable genetic regulatory elements. There is evidence that variability in riboswitch properties allows tuning of expression for genes involved in different stages of biosynthetic pathways by mechanisms that are not currently understood. Here, we explore the mechanism for tuning of S-adenosyl methionine (SAM)-I riboswitch folding. Most SAM-I riboswitches function at the transcriptional level by sensing the cognate ligand SAM. SAM-I riboswitches orchestrate the biosynthetic pathways of cysteine, methionine, SAM, and so forth. We use base-pair probability predictions to examine the secondary-structure folding landscape of several SAM-I riboswitch sequences. We predict different folding behaviors for different SAM-I riboswitch sequences. We identify several "decoy" base-pairing interactions involving 5' riboswitch residues that can compete with the formation of a P1 helix, a component of the ligand-bound "transcription OFF" state, in the absence of SAM. We hypothesize that blockage of these interactions through SAM contacts contributes to stabilization of the OFF state in the presence of ligand. We also probe folding patterns for a SAM-I riboswitch RNA using constructs with different 3' truncation points experimentally. Folding was monitored through fluorescence, susceptibility to base-catalyzed cleavage, nuclear magnetic resonance, and indirectly through SAM binding. We identify key decision windows at which SAM can affect the folding pathway towards the OFF state. The presence of decoy conformations and differential sensitivities to SAM at different transcript lengths is crucial for SAM-I riboswitches to modulate gene expression in the context of global cellular metabolism. Copyright © 2012 Elsevier Ltd. All rights reserved.

Martian Chlorobenzene Identified by Curiosity in Yellowknife Bay: Evidence for the Preservation of Organics in a Mudstone on Mars

NASA Technical Reports Server (NTRS)

Glavin, D.; Freissinet, C.; Mahaffy, P.; Miller, K.; Eigenbrode, J.; Summons, R.; Martin, M.; Franz, H.; Steele, A.; Archer, D.;

Characterization of a S-adenosyl-l-methionine (SAM)-accumulating strain of Scheffersomyces stipitis.

PubMed

Križanović, Stela; Butorac, Ana; Mrvčić, Jasna; Krpan, Maja; Cindrić, Mario; Bačun-Družina, Višnja; Stanzer, Damir

2015-06-01

S-adenosyl-l-methionine (SAM) is an important molecule in the cellular metabolism of mammals. In this study, we examined several of the physiological characteristics of a SAM-accumulating strain of the yeast Scheffersomyces stipitis (M12), including SAM production, ergosterol content, and ethanol tolerance. S. stipitis M12 accumulated up to 52.48 mg SAM/g dry cell weight. Proteome analyses showed that the disruption of C-24 methylation in ergosterol biosynthesis, a step mediated by C-24 sterol methyltransferase (Erg6p), results in greater SAM accumulation by S. stipitis M12 compared to the wild-type strain. A comparative proteome-wide analysis identified 25 proteins that were differentially expressed by S. stipitis M12. These proteins are involved in ribosome biogenesis, translation, the stress response, ubiquitin-dependent catabolic processes, the cell cycle, ethanol tolerance, posttranslational modification, peroxisomal membrane stability, epigenetic regulation, the actin cytoskeleton and cell morphology, iron and copper homeostasis, cell signaling, and energy metabolism. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

Sam68 Is Required for DNA Damage Responses via Regulating Poly(ADP-ribosyl)ation

PubMed Central

Hodgson, Andrea; Wier, Eric M.; Wen, Matthew G.; Kamenyeva, Olena; Xia, Xue; Koo, Lily Y.

2016-01-01

The rapid and robust synthesis of polymers of adenosine diphosphate (ADP)-ribose (PAR) chains, primarily catalyzed by poly(ADP-ribose) polymerase 1 (PARP1), is crucial for cellular responses to DNA damage. However, the precise mechanisms through which PARP1 is activated and PAR is robustly synthesized are not fully understood. Here, we identified Src-associated substrate during mitosis of 68 kDa (Sam68) as a novel signaling molecule in DNA damage responses (DDRs). In the absence of Sam68, DNA damage-triggered PAR production and PAR-dependent DNA repair signaling were dramatically diminished. With serial cellular and biochemical assays, we demonstrated that Sam68 is recruited to and significantly overlaps with PARP1 at DNA lesions and that the interaction between Sam68 and PARP1 is crucial for DNA damage-initiated and PARP1-conferred PAR production. Utilizing cell lines and knockout mice, we illustrated that Sam68-deleted cells and animals are hypersensitive to genotoxicity caused by DNA-damaging agents. Together, our findings suggest that Sam68 plays a crucial role in DDR via regulating DNA damage-initiated PAR production. PMID:27635653

Winning Attitude & Dedication to Physical Therapy Keep Sam Schmidt on Track

ERIC Educational Resources Information Center

Bosley, Nikki Prevenslik

2006-01-01

This article relates how Sam Schmidt returned to living a productive life after an accident left him with spinal cord injury. Schmidt was a former Indy Racing League driver who founded Sam Schmidt Motorsports after his accident in 2000. Schmidt's car hit the wall as he exited turn two during a practice session at Walt Disney World Speedway in…

Characterization of the SAM domain of the PKD-related protein ANKS6 and its interaction with ANKS3.

PubMed

Leettola, Catherine N; Knight, Mary Jane; Cascio, Duilio; Hoffman, Sigrid; Bowie, James U

2014-07-07

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disorder leading to end-stage renal failure in humans. In the PKD/Mhm(cy/+) rat model of ADPKD, the point mutation R823W in the sterile alpha motif (SAM) domain of the protein ANKS6 is responsible for disease. SAM domains are known protein-protein interaction domains, capable of binding each other to form polymers and heterodimers. Despite its physiological importance, little is known about the function of ANKS6 and how the R823W point mutation leads to PKD. Recent work has revealed that ANKS6 interacts with a related protein called ANKS3. Both ANKS6 and ANKS3 have a similar domain structure, with ankyrin repeats at the N-terminus and a SAM domain at the C-terminus. The SAM domain of ANKS3 is identified as a direct binding partner of the ANKS6 SAM domain. We find that ANKS3-SAM polymerizes and ANKS6-SAM can bind to one end of the polymer. We present crystal structures of both the ANKS3-SAM polymer and the ANKS3-SAM/ANKS6-SAM complex, revealing the molecular details of their association. We also learn how the R823W mutation disrupts ANKS6 function by dramatically destabilizing the SAM domain such that the interaction with ANKS3-SAM is lost. ANKS3 is a direct interacting partner of ANKS6. By structurally and biochemically characterizing the interaction between the ANKS3 and ANKS6 SAM domains, our work provides a basis for future investigation of how the interaction between these proteins mediates kidney function.

Characterization of the SAM domain of the PKD-related protein ANKS6 and its interaction with ANKS3

PubMed Central

2014-01-01

Background Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disorder leading to end-stage renal failure in humans. In the PKD/Mhm(cy/+) rat model of ADPKD, the point mutation R823W in the sterile alpha motif (SAM) domain of the protein ANKS6 is responsible for disease. SAM domains are known protein-protein interaction domains, capable of binding each other to form polymers and heterodimers. Despite its physiological importance, little is known about the function of ANKS6 and how the R823W point mutation leads to PKD. Recent work has revealed that ANKS6 interacts with a related protein called ANKS3. Both ANKS6 and ANKS3 have a similar domain structure, with ankyrin repeats at the N-terminus and a SAM domain at the C-terminus. Results The SAM domain of ANKS3 is identified as a direct binding partner of the ANKS6 SAM domain. We find that ANKS3-SAM polymerizes and ANKS6-SAM can bind to one end of the polymer. We present crystal structures of both the ANKS3-SAM polymer and the ANKS3-SAM/ANKS6-SAM complex, revealing the molecular details of their association. We also learn how the R823W mutation disrupts ANKS6 function by dramatically destabilizing the SAM domain such that the interaction with ANKS3-SAM is lost. Conclusions ANKS3 is a direct interacting partner of ANKS6. By structurally and biochemically characterizing the interaction between the ANKS3 and ANKS6 SAM domains, our work provides a basis for future investigation of how the interaction between these proteins mediates kidney function. PMID:24998259

Experimental and computational investigation of graphene/SAMs/n-Si Schottky diodes

NASA Astrophysics Data System (ADS)

Aydin, H.; Bacaksiz, C.; Yagmurcukardes, N.; Karakaya, C.; Mermer, O.; Can, M.; Senger, R. T.; Sahin, H.; Selamet, Y.

2018-01-01

We have investigated the effect of two different self-assembled monolayers (SAMs) on electrical characteristics of bilayer graphene (BLG)/n-Si Schottky diodes. Novel 4″bis(diphenylamino)-1, 1‧:3″-terphenyl-5‧ carboxylic acids (TPA) and 4,4-di-9H-carbazol-9-yl-1,1‧:3‧1‧-terphenyl-5‧ carboxylic acid (CAR) aromatic SAMs have been used to modify n-Si surfaces. Cyclic voltammetry (CV) and Kelvin probe force microscopy (KPFM) results have been evaluated to verify the modification of n-Si surface. The current-voltage (I-V) characteristics of bare and SAMs modified devices show rectification behaviour verifying a Schottky junction at the interface. The ideality factors (n) from ln(I)-V dependences were determined as 2.13, 1.96 and 2.07 for BLG/n-Si, BLG/TPA/n-Si and BLG/CAR/n-Si Schottky diodes, respectively. In addition, Schottky barrier height (SBH) and series resistance (Rs) of SAMs modified diodes were decreased compared to bare diode due to the formation of a compatible interface between graphene and Si as well as π-π interaction between aromatic SAMs and graphene. The CAR-based device exhibits better diode characteristic compared to the TPA-based device. Computational simulations show that the BLG/CAR system exhibits smaller energy-level-differences than the BLG/TPA, which supports the experimental findings of a lower Schottky barrier and series resistance in BLG/CAR diode.

Sam's Progress with Learning Mathematics

ERIC Educational Resources Information Center

Haslam, Lynne

2007-01-01

Sam is 18 years old and has Down syndrome. He achieved a grade in the standard assessment of mathematics (GCSE) at 16 years of age. This paper describes the part played in his success in school by the Kumon method of teaching mathematics, identifies the benefits of the small steps and lots of practice built in to the method and illustrates the…

ER residency of the ceramide phosphoethanolamine synthase SMSr relies on homotypic oligomerization mediated by its SAM domain.

PubMed

Cabukusta, Birol; Kol, Matthijs; Kneller, Laura; Hilderink, Angelika; Bickert, Andreas; Mina, John G M; Korneev, Sergei; Holthuis, Joost C M

2017-01-25

SMSr/SAMD8 is an ER-resident ceramide phosphoethanolamine synthase with a critical role in controlling ER ceramides and suppressing ceramide-induced apoptosis in cultured cells. SMSr-mediated ceramide homeostasis relies on the enzyme's catalytic activity as well as on its N-terminal sterile α-motif or SAM domain. Here we report that SMSr-SAM is structurally and functionally related to the SAM domain of diacylglycerol kinase DGKδ, a central regulator of lipid signaling at the plasma membrane. Native gel electrophoresis indicates that both SAM domains form homotypic oligomers. Chemical crosslinking studies show that SMSr self-associates into ER-resident trimers and hexamers that resemble the helical oligomers formed by DGKδ-SAM. Residues critical for DGKδ-SAM oligomerization are conserved in SMSr-SAM and their substitution causes a dissociation of SMSr oligomers as well as a partial redistribution of the enzyme to the Golgi. Conversely, treatment of cells with curcumin, a drug disrupting ceramide and Ca 2+ homeostasis in the ER, stabilizes SMSr oligomers and promotes retention of the enzyme in the ER. Our data provide first demonstration of a multi-pass membrane protein that undergoes homotypic oligomerization via its SAM domain and indicate that SAM-mediated self-assembly of SMSr is required for efficient retention of the enzyme in the ER.

ER residency of the ceramide phosphoethanolamine synthase SMSr relies on homotypic oligomerization mediated by its SAM domain

PubMed Central

Cabukusta, Birol; Kol, Matthijs; Kneller, Laura; Hilderink, Angelika; Bickert, Andreas; Mina, John G. M.; Korneev, Sergei; Holthuis, Joost C. M.

2017-01-01

SMSr/SAMD8 is an ER-resident ceramide phosphoethanolamine synthase with a critical role in controlling ER ceramides and suppressing ceramide-induced apoptosis in cultured cells. SMSr-mediated ceramide homeostasis relies on the enzyme’s catalytic activity as well as on its N-terminal sterile α-motif or SAM domain. Here we report that SMSr-SAM is structurally and functionally related to the SAM domain of diacylglycerol kinase DGKδ, a central regulator of lipid signaling at the plasma membrane. Native gel electrophoresis indicates that both SAM domains form homotypic oligomers. Chemical crosslinking studies show that SMSr self-associates into ER-resident trimers and hexamers that resemble the helical oligomers formed by DGKδ-SAM. Residues critical for DGKδ-SAM oligomerization are conserved in SMSr-SAM and their substitution causes a dissociation of SMSr oligomers as well as a partial redistribution of the enzyme to the Golgi. Conversely, treatment of cells with curcumin, a drug disrupting ceramide and Ca2+ homeostasis in the ER, stabilizes SMSr oligomers and promotes retention of the enzyme in the ER. Our data provide first demonstration of a multi-pass membrane protein that undergoes homotypic oligomerization via its SAM domain and indicate that SAM-mediated self-assembly of SMSr is required for efficient retention of the enzyme in the ER. PMID:28120887

Highlight on the indigenous organic molecules detected on Mars by SAM and potential sources of artifacts and backgrounds generated by the sample preparation

NASA Astrophysics Data System (ADS)

Buch, A.; Belmahdi, I.; Szopa, C.; Freissinet, C.; Glavin, D. P.; Coll, P. J.; Cabane, M.; Millan, M.; Eigenbrode, J. L.; Navarro-Gonzalez, R.; Stern, J. C.; Pinnick, V. T.; Coscia, D.; Teinturier, S.; Stambouli, M.; Dequaire, T.; Mahaffy, P. R.

2015-12-01

Among the experiments which explore the martian soil aboard the Curiosity Rover, SAM experiment is mainly dedicated to the search for indigenous organic compounds. To reach its goals SAM can operate in different analysis modes: Pyrolysis-GC-MS and Pyrolysis-MS (EGA). In addition SAM includes wet chemistry experiments [1] to supports extraction of polar organic compounds from solid samples that improves their detection either by increasing the release of chemical species from solid sample matrices, or by changing their chemical structure to make compounds more amenable to gas chromatography mass spectrometry (GCMS). The two wet chemistry experimental capabilities of SAM provide alternatives to the nominal inert-thermal desorption/pyrolysis analytical protocol and are more aptly suited for polar components: MTBSTFA derivatization [2-3] and TMAH thermochemolysis [4-5]. Here we focus on the MTBSTFA derivatization experiment. In order to build a support used to help the interpretation of SAM results, we have investigated the artifacts and backgrounds sources generated by the all analysis process: Solid sample were heated up to approximately 840°C at a rate of 35°C/min under He flow. For GC analyses, the majority of the gas released was trapped on a hydrocarbon trap (Tenax®) over a specific temperature range. Adsorbed volatiles on the GC injection trap (IT) were then released into the GC column (CLP-MXT 30m x 0.25mm x 0.25μm) by rapidly heating the IT to 300°C. Then, in order better understand the part of compounds detected coming from internal reaction we have performed several lab experiments to mimic the SAM device: Among the sources of artifact, we test: (1) the thermal stability and the organic material released during the degradation of Tenax® and carbosieve, (2) the impact of MTBSTFA and a mixture of DMF and MTBSTFA on the adsorbent, (3) the reaction between the different adsorbents (Tenax® and Carbosieve) and calcium perchlorate and then (4) the sources

pH-Switchable Interaction of a Carboxybetaine Ester-Based SAM with DNA and Gold Nanoparticles.

PubMed

Filip, Jaroslav; Popelka, Anton; Bertok, Tomas; Holazova, Alena; Osicka, Josef; Kollar, Jozef; Ilcikova, Marketa; Tkac, Jan; Kasak, Peter

2017-07-11

We describe a self-assembled monolayer (SAM) on a gold surface with a carboxybetaine ester functionality to control the interaction between DNA and gold nanoparticles via pH. The negatively charged phosphate backbone of DNA interacts with and adsorbs to the positively charged carboxybetaine esters on the SAM. DNA release can be achieved by the hydrolysis of carboxybetaine ester (CBE) to a zwitterionic carboxybetaine state. Furthermore, the adsorption of negatively charged citrate-capped gold nanoparticles to a SAM-modified plain gold surface can be controlled by the pH. The SAM based on carboxybetaine ester allows for the homogeneous adsorption of particles, whereas the SAM after hydrolysis at high pH repels AuNP adsorption. The antifouling surface properties of the surface modified with carboxybetaine were investigated with protein samples.

Radical SAM catalysis via an organometallic intermediate with an Fe-[5'-C]-deoxyadenosyl bond.

PubMed

Horitani, Masaki; Shisler, Krista; Broderick, William E; Hutcheson, Rachel U; Duschene, Kaitlin S; Marts, Amy R; Hoffman, Brian M; Broderick, Joan B

2016-05-13

Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to cleave SAM to initiate diverse radical reactions. These reactions are thought to involve the 5'-deoxyadenosyl radical intermediate, which has not yet been detected. We used rapid freeze-quenching to trap a catalytically competent intermediate in the reaction catalyzed by the radical SAM enzyme pyruvate formate-lyase activating enzyme. Characterization of the intermediate by electron paramagnetic resonance and (13)C, (57)Fe electron nuclear double-resonance spectroscopies reveals that it contains an organometallic center in which the 5' carbon of a SAM-derived deoxyadenosyl moiety forms a bond with the unique iron site of the [4Fe-4S] cluster. Discovery of this intermediate extends the list of enzymatic bioorganometallic centers to the radical SAM enzymes, the largest enzyme superfamily known, and reveals intriguing parallels to B12 radical enzymes. Copyright © 2016, American Association for the Advancement of Science.

Ectopic shoot meristem generation in monocotyledonous rpk1 mutants is linked to SAM loss and altered seedling morphology.

PubMed

Fiesselmann, Birgit S; Luichtl, Miriam; Yang, Xiaomeng; Matthes, Michaela; Peis, Ottilie; Torres-Ruiz, Ramon A

2015-07-07

In dicot Arabidopsis thaliana embryos two cotyledons develop largely autonomously from the shoot apical meristem (SAM). Recessive mutations in the Arabidopsis receptor-like kinase RPK1 lead to monocotyledonous seedlings, with low (10 %) penetrance due to complex functional redundancy. In strong rpk1 alleles, about 10 % of these (i. e. 1 % of all homozygotes) did not develop a SAM. We wondered whether RPK1 might also control SAM gene expression and SAM generation in addition to its known stochastic impact on cell division and PINFORMED1 (PIN1) polarity in the epidermis. SAM-less seedlings developed a simple morphology with a straight and continuous hypocotyl-cotyledon structure lacking a recognizable epicotyl. According to rpk1's auxin-related PIN1 defect, the seedlings displayed defects in the vascular tissue. Surprisingly, SAM-less seedlings variably expressed essential SAM specific genes along the hypocotyl-cotyledon structure up into the cotyledon lamina. Few were even capable of developing an ectopic shoot meristem (eSM) on top of the cotyledon. The results highlight the developmental autonomy of the SAM vs. cotyledons and suggest that the primary rpk1 defect does not lie in the seedling's ability to express SAM genes or to develop a shoot meristem. Rather, rpk1's known defects in cell division and auxin homeostasis, by disturbed PIN1 polarity, impact on SAM and organ generation. In early embryo stages this failure generates a simplified monocotyledonous morphology. Once generated, this likely entails a loss of positional information that in turn affects the spatiotemporal development of the SAM. SAM-bearing and SAM-less monocotyledonous phenotypes show morphological similarities either to real monocots or to dicot species, which only develop one cotyledon. The specific cotyledon defect in rpk1 mutants thus sheds light upon the developmental implications of the transition from two cotyledons to one.

Mitigation of the impact of terrestrial contamination on organic measurements from the Mars Science Laboratory.

PubMed

ten Kate, Inge L; Canham, John S; Conrad, Pamela G; Errigo, Therese; Katz, Ira; Mahaffy, Paul R

2008-06-01

The objective of the 2009 Mars Science Laboratory (MSL), which is planned to follow the Mars Exploration Rovers and the Phoenix lander to the surface of Mars, is to explore and assess quantitatively a site on Mars as a potential habitat for present or past life. Specific goals include an assessment of the past or present biological potential of the target environment and a characterization of its geology and geochemistry. Included in the 10 investigations of the MSL rover is the Sample Analysis at Mars (SAM) instrument suite, which is designed to obtain trace organic measurements, measure water and other volatiles, and measure several light isotopes with experiment sequences designed for both atmospheric and solid-phase samples. SAM integrates a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer supported by sample manipulation tools both within and external to the suite. The sub-part-per-billion sensitivity of the suite for trace species, particularly organic molecules, along with a mobile platform that will contain many kilograms of organic materials, presents a considerable challenge due to the potential for terrestrial contamination to mask the signal of martian organics. We describe the effort presently underway to understand and mitigate, wherever possible within the resource constraints of the mission, terrestrial contamination in MSL and SAM measurements.

Detection of Organics at Mars: How Wet Chemistry Onboard SAM Helps

NASA Technical Reports Server (NTRS)

Buch, A.; Freissinet, Caroline; Szopa, C.; Glavin, D.; Coll, P.; Cabane, M.; Eigenbrode, J.; Navarro-Gonzalez, R.; Coscia, D.; Teinturier, S.;

Using a Multiwavelength Suite of Microwave Instruments to Investigate the Microphysical Structure of Deep Convective Cores

NASA Technical Reports Server (NTRS)

Battaglia, A.; Mroz, K.; Lang, Tim; Tridon, F.; Tanelli, S.; Tian, Lin; Heymsfield, Gerald M.

2016-01-01

Due to the large natural variability of its microphysical properties, the characterization of solid precipitation is a longstanding problem. Since in situ observations are unavailable in severe convective systems, innovative remote sensing retrievals are needed to extend our understanding of such systems. This study presents a novel technique able to retrieve the density, mass, and effective diameter of graupel and hail in severe convection through the combination of airborne microwave remote sensing instruments. The retrieval is applied to measure solid precipitation properties within two convective cells observed on 2324 May 2014 over North Carolina during the IPHEx campaign by the NASA ER-2 instrument suite. Between 30 and 40 degrees of freedom of signal are associated with the measurements, which is insufficient to provide full microphysics profiling. The measurements have the largest impact on the retrieval of ice particle sizes, followed by ice water contents. Ice densities are mainly driven by a priori assumptions, though low relative errors in ice densities suggest that in extensive regions of the convective system, only particles with densities larger than 0.4 gcm3 are compatible with the observations. This is in agreement with reports of large hail on the ground and with hydrometeor classification derived from ground-based polarimetric radars observations. This work confirms that multiple scattering generated by large ice hydrometeors in deep convection is relevant for airborne radar systems already at Ku band. A fortiori, multiple scattering will play a pivotal role in such conditions also for Ku band spaceborne radars (e.g., the GPM Dual Precipitation Radar).

Evaluation of the Sensor Data Record from the Nadir Instruments of the Ozone Mapping Profiler Suite (OMPS)

NASA Technical Reports Server (NTRS)

Wu, Xiangqian; Liu, Quanhua; Zeng, Jian; Grotenhuis, Michael; Qian, Haifeng; Caponi, Maria; Flynn, Larry; Jaross, Glen; Sen, Bhaswar; Buss, Richard H., Jr.;

S-adenosyl-methionine (SAM) alters the transcriptome and methylome and specifically blocks growth and invasiveness of liver cancer cells.

PubMed

Wang, Yan; Sun, ZhongSheng; Szyf, Moshe

2017-12-19

S-adenosyl methionine (SAM) is a ubiquitous methyl donor that was reported to have chemo- protective activity against liver cancer, however the molecular footprint of SAM is unknown. We show here that SAM selectively inhibits growth, transformation and invasiveness of hepatocellular carcinoma cell lines but not normal primary liver cells. Analysis of the transcriptome of SAM treated and untreated liver cancer cell lines HepG2 and SKhep1 and primary liver cells reveals pathways involved in cancer and metastasis that are upregulated in cancer cells and are downregulated by SAM. Analysis of the methylome using bisulfite mapping of captured promoters and enhancers reveals that SAM hyper-methylates and downregulates genes in pathways of growth and metastasis that are upregulated in liver cancer cells. Depletion of two SAM downregulated genes STMN1 and TAF15 reduces cellular transformation and invasiveness, providing evidence that SAM targets are genes important for cancer growth and invasiveness. Taken together these data provide a molecular rationale for SAM as an anticancer agent.

Carbon-sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE.

PubMed

Rohac, Roman; Amara, Patricia; Benjdia, Alhosna; Martin, Lydie; Ruffié, Pauline; Favier, Adrien; Berteau, Olivier; Mouesca, Jean-Marie; Fontecilla-Camps, Juan C; Nicolet, Yvain

2016-05-01

Carbon-sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5'-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate.

Carbon-sulfur bond-forming reaction catalysed by the radical SAM enzyme HydE

NASA Astrophysics Data System (ADS)

Rohac, Roman; Amara, Patricia; Benjdia, Alhosna; Martin, Lydie; Ruffié, Pauline; Favier, Adrien; Berteau, Olivier; Mouesca, Jean-Marie; Fontecilla-Camps, Juan C.; Nicolet, Yvain

2016-05-01

Carbon-sulfur bond formation at aliphatic positions is a challenging reaction that is performed efficiently by radical S-adenosyl-L-methionine (SAM) enzymes. Here we report that 1,3-thiazolidines can act as ligands and substrates for the radical SAM enzyme HydE, which is involved in the assembly of the active site of [FeFe]-hydrogenase. Using X-ray crystallography, in vitro assays and NMR spectroscopy we identified a radical-based reaction mechanism that is best described as the formation of a C-centred radical that concomitantly attacks the sulfur atom of a thioether. To the best of our knowledge, this is the first example of a radical SAM enzyme that reacts directly on a sulfur atom instead of abstracting a hydrogen atom. Using theoretical calculations based on our high-resolution structures we followed the evolution of the electronic structure from SAM through to the formation of S-adenosyl-L-cysteine. Our results suggest that, at least in this case, the widely proposed and highly reactive 5‧-deoxyadenosyl radical species that triggers the reaction in radical SAM enzymes is not an isolable intermediate.

Celiac Disease in Children with Severe Acute Malnutrition (SAM): A Hospital Based Study.

PubMed

Beniwal, Neetu; Ameta, Gaurav; Chahar, Chandra Kumar

2017-05-01

To evaluate the prevalence and clinical features of Celiac disease among children with severe acute malnutrition (SAM). This prospective observational study was conducted in PBM Children Hospital, Bikaner from July 2012 through December 2013. All consecutively admitted children with SAM were recruited. All subjects were screened for Celiac disease by serological test for IgA-anti tissue Transglutaminase (IgA tTG) antibodies. All seropositive children underwent upper gastrointestinal endoscopy for small bowel biopsy for the confirmation. Clinical features of patients with and without celiac disease were compared. The sero-prevalence (IgA tTg positivity) of Celiac disease was found to be 15.38% while prevalence of biopsy confirmed Celiac disease was 14.42% among SAM children. Abdominal distension, diarrhea, anorexia, constipation, pain in abdomen, vitamin deficiencies, edema, clubbing and mouth ulcers were more common in patients of Celiac disease compared to patients without Celiac disease but the difference was statistically significant only for abdominal distension and pain abdomen. There is a high prevalence of Celiac disease in SAM. Screening for Celiac disease (especially in presence of pain abdomen and abdominal distension) should be an essential part of work-up in all children with SAM.

Technoeconomic Modeling of Battery Energy Storage in SAM

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiOrio, Nicholas; Dobos, Aron; Janzou, Steven

Detailed comprehensive lead-acid and lithium-ion battery models have been integrated with photovoltaic models in an effort to allow System Advisor Model (SAM) to offer the ability to predict the performance and economic benefit of behind the meter storage. In a system with storage, excess PV energy can be saved until later in the day when PV production has fallen, or until times of peak demand when it is more valuable. Complex dispatch strategies can be developed to leverage storage to reduce energy consumption or power demand based on the utility rate structure. This document describes the details of the batterymore » performance and economic models in SAM.« less

Structural studies of viperin, an antiviral radical SAM enzyme.

PubMed

Fenwick, Michael K; Li, Yue; Cresswell, Peter; Modis, Yorgo; Ealick, Steven E

2017-06-27

Viperin is an IFN-inducible radical S -adenosylmethionine (SAM) enzyme that inhibits viral replication. We determined crystal structures of an anaerobically prepared fragment of mouse viperin (residues 45-362) complexed with S -adenosylhomocysteine (SAH) or 5'-deoxyadenosine (5'-dAdo) and l-methionine (l-Met). Viperin contains a partial (βα) 6 -barrel fold with a disordered N-terminal extension (residues 45-74) and a partially ordered C-terminal extension (residues 285-362) that bridges the partial barrel to form an overall closed barrel structure. Cys84, Cys88, and Cys91 located after the first β-strand bind a [4Fe-4S] cluster. The active site architecture of viperin with bound SAH (a SAM analog) or 5'-dAdo and l-Met (SAM cleavage products) is consistent with the canonical mechanism of 5'-deoxyadenosyl radical generation. The viperin structure, together with sequence alignments, suggests that vertebrate viperins are highly conserved and that fungi contain a viperin-like ortholog. Many bacteria and archaebacteria also express viperin-like enzymes with conserved active site residues. Structural alignments show that viperin is similar to several other radical SAM enzymes, including the molybdenum cofactor biosynthetic enzyme MoaA and the RNA methyltransferase RlmN, which methylates specific nucleotides in rRNA and tRNA. The viperin putative active site contains several conserved positively charged residues, and a portion of the active site shows structural similarity to the GTP-binding site of MoaA, suggesting that the viperin substrate may be a nucleoside triphosphate of some type.

SAM-dependent enzyme-catalysed pericyclic reactions in natural product biosynthesis

NASA Astrophysics Data System (ADS)

Ohashi, Masao; Liu, Fang; Hai, Yang; Chen, Mengbin; Tang, Man-Cheng; Yang, Zhongyue; Sato, Michio; Watanabe, Kenji; Houk, K. N.; Tang, Yi

2017-09-01

Pericyclic reactions—which proceed in a concerted fashion through a cyclic transition state—are among the most powerful synthetic transformations used to make multiple regioselective and stereoselective carbon-carbon bonds. They have been widely applied to the synthesis of biologically active complex natural products containing contiguous stereogenic carbon centres. Despite the prominence of pericyclic reactions in total synthesis, only three naturally existing enzymatic examples (the intramolecular Diels-Alder reaction, and the Cope and the Claisen rearrangements) have been characterized. Here we report a versatile S-adenosyl-L-methionine (SAM)-dependent enzyme, LepI, that can catalyse stereoselective dehydration followed by three pericyclic transformations: intramolecular Diels-Alder and hetero-Diels-Alder reactions via a single ambimodal transition state, and a retro-Claisen rearrangement. Together, these transformations lead to the formation of the dihydropyran core of the fungal natural product, leporin. Combined in vitro enzymatic characterization and computational studies provide insight into how LepI regulates these bifurcating biosynthetic reaction pathways by using SAM as the cofactor. These pathways converge to the desired biosynthetic end product via the (SAM-dependent) retro-Claisen rearrangement catalysed by LepI. We expect that more pericyclic biosynthetic enzymatic transformations remain to be discovered in naturally occurring enzyme ‘toolboxes’. The new role of the versatile cofactor SAM is likely to be found in other examples of enzyme catalysis.

Great Lakes Hyperspectral Water Quality Instrument Suite for Airborne Monitoring of Algal Blooms

NASA Technical Reports Server (NTRS)

Lekki, John; Leshkevich, George; Nguyen, Quang-Viet; Flatico, Joseph; Prokop, Norman; Kojima, Jun; Anderson, Robert; Demers, James; Krasowski, Michael

2007-01-01

NASA Glenn Research Center and NOAA Great Lakes Environmental Research Lab are collaborating to utilize an airborne hyperspectral imaging sensor suite to monitor Harmful Algal Blooms (HABs) in the western basin of Lake Erie. The HABs are very dynamic events as they form, spread and then disappear within a 4 to 8 week time period in late summer. They are a concern for human health, fish and wildlife because they can contain blue green toxic algae. Because of this toxicity there is a need for the blooms to be continually monitored. This situation is well suited for aircraft based monitoring because the blooms are a very dynamic event and they can spread over a large area. High resolution satellite data is not suitable by itself because it will not give the temporal resolution due to the infrequent overpasses of the quickly changing blooms. A custom designed hyperspectral imager and a point spectrometer mounted on aT 34 aircraft have been used to obtain data on an algal bloom that formed in the western basin of Lake Erie during September 2006. The sensor suite and operations will be described and preliminary hyperspectral data of this event will be presented

SAMS Acceleration Measurements on Mir (NASA Increment 4)

NASA Technical Reports Server (NTRS)

DeLombard, Richard

1998-01-01

During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFr), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine bum, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

Basis for ligand discrimination between ON and OFF state riboswitch conformations: the case of the SAM-I riboswitch.

PubMed

Boyapati, Vamsi Krishna; Huang, Wei; Spedale, Jessica; Aboul-Ela, Fareed

2012-06-01

Riboswitches are RNA elements that bind to effector ligands and control gene expression. Most consist of two domains. S-Adenosyl Methionine (SAM) binds the aptamer domain of the SAM-I riboswitch and induces conformational changes in the expression domain to form an intrinsic terminator (transcription OFF state). Without SAM the riboswitch forms the transcription ON state, allowing read-through transcription. The mechanistic link between the SAM/aptamer recognition event and subsequent secondary structure rearrangement by the riboswitch is unclear. We probed for those structural features of the Bacillus subtilis yitJ SAM-I riboswitch responsible for discrimination between the ON and OFF states by SAM. We designed SAM-I riboswitch RNA segments forming "hybrid" structures of the ON and OFF states. The choice of segment constrains the formation of a partial P1 helix, characteristic of the OFF state, together with a partial antiterminator (AT) helix, characteristic of the ON state. For most choices of P1 vs. AT helix lengths, SAM binds with micromolar affinity according to equilibrium dialysis. Mutational analysis and in-line probing confirm that the mode of SAM binding by hybrid structures is similar to that of the aptamer. Altogether, binding measurements and in-line probing are consistent with the hypothesis that when SAM is present, stacking interactions with the AT helix stabilize a partially formed P1 helix in the hybrids. Molecular modeling indicates that continuous stacking between the P1 and the AT helices is plausible with SAM bound. Our findings raise the possibility that conformational intermediates may play a role in ligand-induced aptamer folding.

General Quality Control (QC) Guidelines for SAM Methods

EPA Pesticide Factsheets

Learn more about quality control guidelines and recommendations for the analysis of samples using the methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

S-adenosyl-methionine (SAM) alters the transcriptome and methylome and specifically blocks growth and invasiveness of liver cancer cells

PubMed Central

Wang, Yan; Sun, ZhongSheng; Szyf, Moshe

2017-01-01

S-adenosyl methionine (SAM) is a ubiquitous methyl donor that was reported to have chemo- protective activity against liver cancer, however the molecular footprint of SAM is unknown. We show here that SAM selectively inhibits growth, transformation and invasiveness of hepatocellular carcinoma cell lines but not normal primary liver cells. Analysis of the transcriptome of SAM treated and untreated liver cancer cell lines HepG2 and SKhep1 and primary liver cells reveals pathways involved in cancer and metastasis that are upregulated in cancer cells and are downregulated by SAM. Analysis of the methylome using bisulfite mapping of captured promoters and enhancers reveals that SAM hyper-methylates and downregulates genes in pathways of growth and metastasis that are upregulated in liver cancer cells. Depletion of two SAM downregulated genes STMN1 and TAF15 reduces cellular transformation and invasiveness, providing evidence that SAM targets are genes important for cancer growth and invasiveness. Taken together these data provide a molecular rationale for SAM as an anticancer agent. PMID:29340097

Data handling with SAM and art at the NO vA experiment

DOE PAGES

Aurisano, A.; Backhouse, C.; Davies, G. S.; ...

2015-12-23

During operations, NOvA produces between 5,000 and 7,000 raw files per day with peaks in excess of 12,000. These files must be processed in several stages to produce fully calibrated and reconstructed analysis files. In addition, many simulated neutrino interactions must be produced and processed through the same stages as data. To accommodate the large volume of data and Monte Carlo, production must be possible both on the Fermilab grid and on off-site farms, such as the ones accessible through the Open Science Grid. To handle the challenge of cataloging these files and to facilitate their off-line processing, we havemore » adopted the SAM system developed at Fermilab. SAM indexes files according to metadata, keeps track of each file's physical locations, provides dataset management facilities, and facilitates data transfer to off-site grids. To integrate SAM with Fermilab's art software framework and the NOvA production workflow, we have developed methods to embed metadata into our configuration files, art files, and standalone ROOT files. A module in the art framework propagates the embedded information from configuration files into art files, and from input art files to output art files, allowing us to maintain a complete processing history within our files. Embedding metadata in configuration files also allows configuration files indexed in SAM to be used as inputs to Monte Carlo production jobs. Further, SAM keeps track of the input files used to create each output file. Parentage information enables the construction of self-draining datasets which have become the primary production paradigm used at NOvA. In this study we will present an overview of SAM at NOvA and how it has transformed the file production framework used by the experiment.« less

Thermal Reactivity of Organic Molecules in the Presence of Chlorates and Perchlorates and the Quest for Organics on Mars with the SAM Experiment Onboard the Curiostiy Rover

NASA Astrophysics Data System (ADS)

Szopa, Cyril; Millan, Maeva; Buch, Arnaud; Belmahdi, Imene; Coll, Patrice; Glavin, Daniel P.; Freissinet, Caroline; Eigenbrode, Jennifer; archer, doug; sutter, brad; Summons, Roger; Navarro-Gonzalez, Rafael; Mahaffy, Paul; cabane, Michel

2016-10-01

One of the main objectives of the Sample Analysis at Mars (SAM) experiment is the in situ molecular analysis of gases evolving from solid samples collected by Curiosity when they are heated up to ~850°C. With this aim SAM uses a gas-chromatograph coupled to a mass spectrometer (GC-MS) able to detect and identify both inorganic and organic molecules released by the samples.During the pyrolysis, chemical reactions occur between oxychlorines, probably homogeneously distributed at Mars's surface, and organic compounds SAM seeks for. This was confirmed by the first chlorohydrocarbons (chloromethane and di- and trichloromethane) detected by SAM that were entirely attributed to reaction products occurring between these oxychlorines and organics from instrument background. But SAM also detected in the Sheepbed mudstone of Gale crater, chloroalkanes produced by reaction between oxychlorines and Mars indigenous organics, proving for the first time the presence of organics in the soil of Mars. However, the identification of the molecules at the origin of these chloroalkanes is much more difficult due to the complexity of the reactivity occurring during the sample pyrolysis. If a first study has already been done recently with this aim, it was relatively limited in terms of parameters investigated.This is the reason why, we performed a systematic study in the laboratory to help understanding the influence of oxychlorines on organic matter during pyrolysis. With this aim, different organic compounds from various chemical families (e.g. amino and carboxylic acids) mixed with different perchlorates and chlorates, in concentrations compatible with the Mars soil from estimations done with SAM measurements, were pyrolyzed under SAM like conditions. The products of reaction were analyzed and identified by GC-MS in order to show a possible correlation between them and the parent molecule. Different parameters were tested for the pyrolysis to evaluate their potential influence on the

Basis for ligand discrimination between ON and OFF state riboswitch conformations: The case of the SAM-I riboswitch

PubMed Central

Boyapati, Vamsi Krishna; Huang, Wei; Spedale, Jessica; Aboul-ela, Fareed

2012-01-01

Riboswitches are RNA elements that bind to effector ligands and control gene expression. Most consist of two domains. S-Adenosyl Methionine (SAM) binds the aptamer domain of the SAM-I riboswitch and induces conformational changes in the expression domain to form an intrinsic terminator (transcription OFF state). Without SAM the riboswitch forms the transcription ON state, allowing read-through transcription. The mechanistic link between the SAM/aptamer recognition event and subsequent secondary structure rearrangement by the riboswitch is unclear. We probed for those structural features of the Bacillus subtilis yitJ SAM-I riboswitch responsible for discrimination between the ON and OFF states by SAM. We designed SAM-I riboswitch RNA segments forming “hybrid” structures of the ON and OFF states. The choice of segment constrains the formation of a partial P1 helix, characteristic of the OFF state, together with a partial antiterminator (AT) helix, characteristic of the ON state. For most choices of P1 vs. AT helix lengths, SAM binds with micromolar affinity according to equilibrium dialysis. Mutational analysis and in-line probing confirm that the mode of SAM binding by hybrid structures is similar to that of the aptamer. Altogether, binding measurements and in-line probing are consistent with the hypothesis that when SAM is present, stacking interactions with the AT helix stabilize a partially formed P1 helix in the hybrids. Molecular modeling indicates that continuous stacking between the P1 and the AT helices is plausible with SAM bound. Our findings raise the possibility that conformational intermediates may play a role in ligand-induced aptamer folding. PMID:22543867

Origin of Chlorobenzene Detected by the Curiosity Rover in Yellowknife Bay: Evidence for Martian Organics in the Sheepbed Mudstone?

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Freissinet, Caroline; Eigenbrode, J.; Miller, K.; Martin, M.; Summons, R.; Steele, A.; Franz, H.; Archer, D.; Brinkerhoff, W.;

Safety and Waste Management for SAM Pathogen Methods

EPA Pesticide Factsheets

The General Safety and Waste Management page offers section-specific safety and waste management details for the pathogens included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Safety and Waste Management for SAM Biotoxin Methods

EPA Pesticide Factsheets

The General Safety and Waste Management page offers section-specific safety and waste management details for the biotoxins included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Denitrification of the polar winter stratosphere - Implications of SAM II cloud formation temperatures

NASA Technical Reports Server (NTRS)

Hamill, Patrick; Toon, O. B.

1990-01-01

The SAM II extinction profiles and the associated temperature profiles are used to determine the amount of denitrification of the winter polar stratospheres. Clear evidence of the denitrification process in the Antarctic data is seen. There are indications in the Arctic data that denitrification mechanisms may be at work there also. At the latitudes observed by the SAM II satellite system, denitrification begins before the formation of extensive ice clouds and may be due to sedimentation of nitric acid particles. However, the possibility of dinitrification by type II PSCs at latitudes not observed by SAM II cannot be excluded.

Jeffries Matusita-Spectral Angle Mapper (JM-SAM) spectral matching for species level mapping at Bhitarkanika, Muthupet and Pichavaram mangroves

NASA Astrophysics Data System (ADS)

Padma, S.; Sanjeevi, S.

2014-12-01

This paper proposes a novel hyperspectral matching algorithm by integrating the stochastic Jeffries-Matusita measure (JM) and the deterministic Spectral Angle Mapper (SAM), to accurately map the species and the associated landcover types of the mangroves of east coast of India using hyperspectral satellite images. The JM-SAM algorithm signifies the combination of a qualitative distance measure (JM) and a quantitative angle measure (SAM). The spectral capabilities of both the measures are orthogonally projected using the tangent and sine functions to result in the combined algorithm. The developed JM-SAM algorithm is implemented to discriminate the mangrove species and the landcover classes of Pichavaram (Tamil Nadu), Muthupet (Tamil Nadu) and Bhitarkanika (Odisha) mangrove forests along the Eastern Indian coast using the Hyperion image dat asets that contain 242 bands. The developed algorithm is extended in a supervised framework for accurate classification of the Hyperion image. The pixel-level matching performance of the developed algorithm is assessed by the Relative Spectral Discriminatory Probability (RSDPB) and Relative Spectral Discriminatory Entropy (RSDE) measures. From the values of RSDPB and RSDE, it is inferred that hybrid JM-SAM matching measure results in improved discriminability of the mangrove species and the associated landcover types than the individual SAM and JM algorithms. This performance is reflected in the classification accuracies of species and landcover map of Pichavaram mangrove ecosystem. Thus, the JM-SAM (TAN) matching algorithm yielded an accuracy better than SAM and JM measures at an average difference of 13.49 %, 7.21 % respectively, followed by JM-SAM (SIN) at 12.06%, 5.78% respectively. Similarly, in the case of Muthupet, JM-SAM (TAN) yielded an increased accuracy than SAM and JM measures at an average difference of 12.5 %, 9.72 % respectively, followed by JM-SAM (SIN) at 8.34 %, 5.55% respectively. For Bhitarkanika, the combined

Safety and Waste Management for SAM Chemistry Methods

EPA Pesticide Factsheets

The General Safety and Waste Management page offers section-specific safety and waste management details for the chemical analytes included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Safety and Waste Management for SAM Radiochemical Methods

EPA Pesticide Factsheets

The General Safety and Waste Management page offers section-specific safety and waste management details for the radiochemical analytes included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

SOFIA Science Instruments: Commissioning, Upgrades and Future Opportunities

NASA Technical Reports Server (NTRS)

Smith, Erin C.

2014-01-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is the world's largest airborne observatory, featuring a 2.5 meter telescope housed in the aft section of a Boeing 747sp aircraft. SOFIA's current instrument suite includes: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), a 5-40 µm dual band imager/grism spectrometer developed at Cornell University; HIPO (High-speed Imaging Photometer for Occultations), a 0.3-1.1 micron imager built by Lowell Observatory; FLITECAM (First Light Infrared Test Experiment CAMera), a 1-5 micron wide-field imager/grism spectrometer developed at UCLA; FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), a 42-210 micron IFU grating spectrograph completed by University Stuttgart; and EXES (Echelon-Cross- Echelle Spectrograph), a 5-28 micron high-resolution spectrometer being completed by UC Davis and NASA Ames. A second generation instrument, HAWC+ (Highresolution Airborne Wideband Camera), is a 50-240 micron imager being upgraded at JPL to add polarimetry and new detectors developed at GSFC. SOFIA will continually update its instrument suite with new instrumentation, technology demonstration experiments and upgrades to the existing instrument suite. This paper details instrument capabilities and status as well as plans for future instrumentation, including the call for proposals for 3rd generation SOFIA science instruments.

Targeting EphA2-Sam and Its Interactome: Design and Evaluation of Helical Peptides Enriched in Charged Residues.

PubMed

Mercurio, Flavia A; Marasco, Daniela; Di Natale, Concetta; Pirone, Luciano; Costantini, Susan; Pedone, Emilia M; Leone, Marilisa

2016-11-17

The EphA2 receptor controls diverse physiological and pathological conditions and its levels are often upregulated in cancer. Targeting receptor overexpression, through modulation of endocytosis and consequent degradation, appears to be an appealing strategy for attacking tumor malignancy. In this scenario, the Sam domain of EphA2 plays a pivotal role because it is the site where protein regulators of endocytosis and stability are recruited by means of heterotypic Sam-Sam interactions. Because EphA2-Sam heterotypic complexes are largely based on electrostatic contacts, we have investigated the possibility of attacking these interactions with helical peptides enriched in charged residues. Several peptide sequences with high predicted helical propensities were designed, and detailed conformational analyses were conducted by diverse techniques including NMR, CD, and molecular dynamics (MD) simulations. Interaction studies were also performed by NMR, surface plasmon resonance (SPR), and microscale thermophoresis (MST) and led to the identification of two peptides capable of binding to the first Sam domain of Odin. These molecules represent early candidates for the generation of efficient Sam domain binders and antagonists of Sam-Sam interactions involving EphA2. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

SAMS Acceleration Measurement on Mir From March to September 1996

NASA Technical Reports Server (NTRS)

Moskowitz, Milton E.; Hrovat, Ken; Truong, Duc; Reckart, Timothy

1997-01-01

During NASA Increment 2 (March to September 1996), over 15 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 55 optical disks and were returned to Earth on STS-79. During this time, SAMS data were collected in the Kristall and Kvant modules, and in the Priroda module to support the following experiments: the Queen's University Experiments in Liquid Diffusion (QUELD), the Technological Evaluation of the MIM (TEM), the Forced Flow Flame Spreading Test (FFFT), and Candle Flames in Microgravity (CFM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-76 operations, an extravehicular activity (EVA) to install and deploy solar panels on the Kvant module, a Progress engine burn to raise Mir's altitude, and an on-orbit SAMS calibration procedure. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

SAM-Dependent Enzyme-Catalysed Pericyclic Reactions in Natural Product Biosynthesis

PubMed Central

Ohashi, Masao; Liu, Fang; Hai, Yang; Chen, Mengbin; Tang, Man-cheng; Yang, Zhongyue; Sato, Michio; Watanabe, Kenji; Houk, K. N.; Tang, Yi

2017-01-01

Pericyclic reactions are among the most powerful synthetic transformations to make multiple regioselective and stereoselective carbon-carbon bonds1. These reactions have been widely applied for the synthesis of biologically active complex natural products containing contiguous stereogenic carbon centers2–6. Despite the prominence of pericyclic reactions in total synthesis, only three naturally existing enzymatic examples, intramolecular Diels-Alder (IMDA) reaction7, Cope8 and Claisen rearrangements9, have been characterized. Here, we report the discovery of a S-adenosyl-L-methionine (SAM) dependent enzyme LepI that can catalyse stereoselective dehydration, bifurcating IMDA/hetero-DA (HDA) reactions via an ambimodal transition state, and a [3,3]-sigmatropic retro-Claisen rearrangement leading to the formation of dihydopyran core in the fungal natural product leporin10. Combined in vitro enzymatic characterization and computational studies provide evidence and mechanistic insight about how the O-methyltransferase-like protein LepI regulates the bifurcating biosynthetic reaction pathways (“direct” HDA and “byproduct recycle” IMDA/retro-Claisen reaction pathways) by utilizing SAM as the cofactor in order to converge to the desired biosynthetic end product. This work highlights that LepI is the first example of an enzyme catalysing a (SAM-dependent) retro-Claisen rearrangement. We suggest that more pericyclic biosynthetic enzymatic transformations are yet to be discovered in the intriguing enzyme toolboxes in Nature11, and propose an ever expanding role of the versatile cofactor SAM in enzyme catalysis. PMID:28902839

Sum-frequency generation analyses of the structure of water at amphoteric SAM-liquid water interfaces.

PubMed

Nomura, Kouji; Nakaji-Hirabayashi, Tadashi; Gemmei-Ide, Makoto; Kitano, Hiromi; Noguchi, Hidenori; Uosaki, Kohei

2014-09-01

Surfaces of both a cover glass and the flat plane of a semi-cylindrical quartz prism were modified with a mixture of positively and negatively charged silane coupling reagents (3-aminopropyltriethoxysilane (APTES) and 3-(trihydroxysilyl)propylmethylphosphonate (THPMP), respectively). The glass surface modified with a self-assembled monolayer (SAM) prepared at a mixing ratio of APTES:THPMP=4:6 was electrically almost neutral and was resistant to non-specific adsorption of proteins, whereas fibroblasts gradually adhered to an amphoteric (mixed) SAM surface probably due to its stiffness, though the number of adhered cells was relatively small. Sum frequency generation (SFG) spectra indicated that total intensity of the OH stretching region (3000-3600cm(-1)) for the amphoteric SAM-modified quartz immersed in liquid water was smaller than those for the positively and negatively charged SAM-modified quartz prisms and a bare quartz prism in contact with liquid water. These results suggested that water molecules at the interface of water and an amphoteric SAM-modified quartz prism are not strongly oriented in comparison with those at the interface of a lopsidedly charged SAM-modified quartz prism and bare quartz. The importance of charge neutralization for the anti-biofouling properties of solid materials was strongly suggested. Copyright © 2014 Elsevier B.V. All rights reserved.

A Survey of Educational Activities and Resources Relevant to Mars and Astrobiology

NASA Astrophysics Data System (ADS)

Manning, Heidi L. K.; Bleacher, L.

2009-09-01

Sample Analysis at Mars (SAM) is a suite of instruments that will be onboard the Mars Science Laboratory (MSL) rover, which was recently named Curiosity in a student-naming contest. SAM's three instruments are devoted to studying the chemical composition of the Martian surface and atmosphere and to understanding the planet's past habitability and potential habitability today. Curiosity is scheduled to launch in 2011, however many Education and Public Outreach (EPO) activities supported by the MSL mission are well underway. The SAM EPO plan includes elements of both formal and informal education in addition to outreach, such as incorporating data into the Mars Exploration Student Data Teams program, developing a museum exhibit and associated educational materials about SAM's research, and writing articles about the MSL mission and SAM's findings for ChemMatters magazine. One of the EPO projects currently being carried out by members of the SAM team is training secondary education teachers in Mars geology, astrobiology, and SAM science goals via professional development workshops. Several of the recent Mars missions have had extensive EPO components to them. As a result, numerous educational activities and resources have already been developed relating to understanding Mars and astrobiology. We have conducted a survey of these activities and resources previously created and have compiled those relevant and useful for our SAM teacher training workshops. Resources and activities have been modified as needed. In addition, we have identified areas in which no educational activities exist and are developing new curriculum specifically to address these gaps. This work is funded by the MN Space Grant Consortium and NASA's Science Mission Directorate.

General Safety and Waste Management Related to SAM

EPA Pesticide Factsheets

The General Safety and Waste Management page offers section-specific safety and waste management details for chemicals, radiochemicals, pathogens, and biotoxins included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

PubMed

Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

2017-08-30

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

The Impact of a Ligand Binding on Strand Migration in the SAM-I Riboswitch

PubMed Central

Huang, Wei; Kim, Joohyun; Jha, Shantenu; Aboul-ela, Fareed

2013-01-01

Riboswitches sense cellular concentrations of small molecules and use this information to adjust synthesis rates of related metabolites. Riboswitches include an aptamer domain to detect the ligand and an expression platform to control gene expression. Previous structural studies of riboswitches largely focused on aptamers, truncating the expression domain to suppress conformational switching. To link ligand/aptamer binding to conformational switching, we constructed models of an S-adenosyl methionine (SAM)-I riboswitch RNA segment incorporating elements of the expression platform, allowing formation of an antiterminator (AT) helix. Using Anton, a computer specially developed for long timescale Molecular Dynamics (MD), we simulated an extended (three microseconds) MD trajectory with SAM bound to a modeled riboswitch RNA segment. Remarkably, we observed a strand migration, converting three base pairs from an antiterminator (AT) helix, characteristic of the transcription ON state, to a P1 helix, characteristic of the OFF state. This conformational switching towards the OFF state is observed only in the presence of SAM. Among seven extended trajectories with three starting structures, the presence of SAM enhances the trend towards the OFF state for two out of three starting structures tested. Our simulation provides a visual demonstration of how a small molecule (<500 MW) binding to a limited surface can trigger a large scale conformational rearrangement in a 40 kDa RNA by perturbing the Free Energy Landscape. Such a mechanism can explain minimal requirements for SAM binding and transcription termination for SAM-I riboswitches previously reported experimentally. PMID:23704854

Thermal Reactivity Of Organic Molecules With Perchlorates And The Detection Of Organics In Mars Samples With SAM Onboard Curiosity Rover

NASA Astrophysics Data System (ADS)

Szopa, C.; Millan, M.; Buch, A.; Freissinet, C.; Guzman, M.; Glavin, D. P.; Mahaffy, P. R.; Navarro-Gonzalez, R.

2017-12-01

The search for organic molecules at the Mars surface is a key objective to assess the potential for habitability of the planet and to find biomarkers. Both the past Viking landers and the Curiosity rover of today carry onboard instruments based on gas chromatography coupled to mass spectrometry with the aim to analyze the content of organics present in soil or rock samples. These instruments analyze the volatile compounds released from the samples submitted to thermal or chemical treatments. Even though these sample preparation processes are commonly used on Earth for their efficient extraction of organic materials from mineral matrixes, the presence of oxychlorines recently discovered in the Mars soil [1, 2] makes the process for space applications more complex and the results more difficult to interpret. Indeed, the release of volatile inorganic reactive molecules from oxychlorines during the sample heating process induces reactions of chlorination and oxidation of the organic molecules. For this reason, in an effort to contribute to the interpretation of the results obtained with the Viking/GCMS, and the MSL/SAM experiment our team currently operates on Mars, we started to study systematically the thermal reactivity of a series of organic molecules, of interest for Mars and life purposes, mixed with oxychlorines either detected or potentially present in the soil of Mars [3]. In this presentation, we will mainly focus on two sets of results that were obtained while studying the reactivity of calcium perchlorates with polyaromatic hydrocarbons, amino acids and carboxylic acids under pyrolytic conditions similar to those used in the SAM experiment. First of all, we will show the dependence of reactivity on the temperature of sublimation and decomposition of the individual components in the mixture and, secondly, we will discuss the detection of aromatic chlorinated species by SAM in samples collected at the Cumberland site from the results obtained in this study

The ALICE Glance Shift Accounting Management System (SAMS)

NASA Astrophysics Data System (ADS)

Martins Silva, H.; Abreu Da Silva, I.; Ronchetti, F.; Telesca, A.; Maidantchik, C.

2015-12-01

ALICE (A Large Ion Collider Experiment) is an experiment at the CERN LHC (Large Hadron Collider) studying the physics of strongly interacting matter and the quark-gluon plasma. The experiment operation requires a 24 hours a day and 7 days a week shift crew at the experimental site, composed by the ALICE collaboration members. Shift duties are calculated for each institute according to their correlated members. In order to ensure the full coverage of the experiment operation as well as its good quality, the ALICE Shift Accounting Management System (SAMS) is used to manage the shift bookings as well as the needed training. ALICE SAMS is the result of a joint effort between the Federal University of Rio de Janeiro (UFRJ) and the ALICE Collaboration. The Glance technology, developed by the UFRJ and the ATLAS experiment, sits at the basis of the system as an intermediate layer isolating the particularities of the databases. In this paper, we describe the ALICE SAMS development process and functionalities. The database has been modelled according to the collaboration needs and is fully integrated with the ALICE Collaboration repository to access members information and respectively roles and activities. Run, period and training coordinators can manage their subsystem operation and ensure an efficient personnel management. Members of the ALICE collaboration can book shifts and on-call according to pre-defined rights. ALICE SAMS features a user profile containing all the statistics and user contact information as well as the Institutes profile. Both the user and institute profiles are public (within the scope of the collaboration) and show the credit balance in real time. A shift calendar allows the Run Coordinator to plan data taking periods in terms of which subsystems shifts are enabled or disabled and on-call responsible people and slots. An overview display presents the shift crew present in the control room and allows the Run Coordination team to confirm the presence

An educational laboratory virtual instrumentation suite assisted experiment for studying fundamentals of series resistance-inductance-capacitance circuit

NASA Astrophysics Data System (ADS)

Rana, K. P. S.; Kumar, Vineet; Mendiratta, Jatin

2017-11-01

One of the most elementary concepts in freshmen Electrical Engineering subject comprises the Resistance-Inductance-Capacitance (RLC) circuit fundamentals, that is, their time and frequency domain responses. For a beginner, generally, it is difficult to understand and appreciate the step and the frequency responses, particularly the resonance. This paper proposes a student-friendly teaching and learning approach by inculcating the multifaceted versatile software LabVIEWTM along with the educational laboratory virtual instrumentation suite hardware, for studying the RLC circuit time and frequency domain responses. The proposed approach has offered an interactive laboratory experiment where students can model circuits in simulation and hardware circuits on prototype board, and then compare their performances. The theoretical simulations and the obtained experimental data are found to be in very close agreement, thereby enhancing the conviction of students. Finally, the proposed methodology was also subjected to the assessment of learning outcomes based on student feedback, and an average score of 8.05 out of 10 with a standard deviation of 0.471 was received, indicating the overall satisfaction of the students.

Structure-guided design of fluorescent S-adenosylmethionine analogs for a high-throughput screen to target SAM-I riboswitch RNAs.

PubMed

Hickey, Scott F; Hammond, Ming C

2014-03-20

Many classes of S-adenosylmethionine (SAM)-binding RNAs and proteins are of interest as potential drug targets in diverse therapeutic areas, from infectious diseases to cancer. In the former case, the SAM-I riboswitch is an attractive target because this structured RNA element is found only in bacterial mRNAs and regulates multiple genes in several human pathogens. Here, we describe the synthesis of stable and fluorescent analogs of SAM in which the fluorophore is introduced through a functionalizable linker to the ribose. A Cy5-labeled SAM analog was shown to bind several SAM-I riboswitches via in-line probing and fluorescence polarization assays, including one from Staphylococcus aureus that controls the expression of SAM synthetase in this organism. A fluorescent ligand displacement assay was developed and validated for high-throughput screening of compounds to target the SAM-I riboswitch class. Copyright © 2014 Elsevier Ltd. All rights reserved.

Decarboxylation of Carbon Compounds as a Potential Source for CO2 and CO Observed by SAM at Yellowknife Bay, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Eigenbrode, J. L.; Bower, H.; Archer, P. Jr.

2014-01-01

Martian carbon was detected in the Sheepbed mudtsone at Yellowknife Bay, Gale Crater, Mars by the Sample Analysis at Mars (SAM) instrument onboard Curiosity, the rover of the Mars Science Laboratory missio]. The carbon was detected as CO2 thermally evolved from drilled and sieved rock powder that was delivered to SAM as a <150-micron-particle- size fraction. Most of the CO2 observed in the Cumberland (CB) drill hole evolved between 150deg and 350deg C. In the John Klein (JK) drill hole, the CO2 evolved up to 500deg C. Hypotheses for the source of the the CO2 include the breakdown of carbonate minerals reacting with HCl released from oxychlorine compounds, combustion of organic matter by O2 thermally evolved from the same oxychlorine minerals, and the decarboxylation of organic molecules indigenous to the martian rock sample. Here we explore the potential for the decarboxylation hypothesis.

Quantifying Astronaut Tasks: Robotic Technology and Future Space Suit Design

NASA Technical Reports Server (NTRS)

Newman, Dava

2003-01-01

The primary aim of this research effort was to advance the current understanding of astronauts' capabilities and limitations in space-suited EVA by developing models of the constitutive and compatibility relations of a space suit, based on experimental data gained from human test subjects as well as a 12 degree-of-freedom human-sized robot, and utilizing these fundamental relations to estimate a human factors performance metric for space suited EVA work. The three specific objectives are to: 1) Compile a detailed database of torques required to bend the joints of a space suit, using realistic, multi- joint human motions. 2) Develop a mathematical model of the constitutive relations between space suit joint torques and joint angular positions, based on experimental data and compare other investigators' physics-based models to experimental data. 3) Estimate the work envelope of a space suited astronaut, using the constitutive and compatibility relations of the space suit. The body of work that makes up this report includes experimentation, empirical and physics-based modeling, and model applications. A detailed space suit joint torque-angle database was compiled with a novel experimental approach that used space-suited human test subjects to generate realistic, multi-joint motions and an instrumented robot to measure the torques required to accomplish these motions in a space suit. Based on the experimental data, a mathematical model is developed to predict joint torque from the joint angle history. Two physics-based models of pressurized fabric cylinder bending are compared to experimental data, yielding design insights. The mathematical model is applied to EVA operations in an inverse kinematic analysis coupled to the space suit model to calculate the volume in which space-suited astronauts can work with their hands, demonstrating that operational human factors metrics can be predicted from fundamental space suit information.

The instrument development status of hyper-spectral imager suite (HISUI)

NASA Astrophysics Data System (ADS)

Itoh, Yoshiyuki; Kawashima, Takahiro; Inada, Hitomi; Tanii, Jun; Iwasaki, Akira

2012-11-01

The hyper-multi spectral mission named HISUI (Hyper-spectral Imager SUIte) is the next Japanese earth observation project. This project is the follow up mission of the Advanced Spaceborne Thermal Emission and reflection Radiometer (ASTER) and Advanced Land Imager (ALDS). HISUI is composed of hyperspectral radiometer with higher spectral resolution and multi-spectral radiometer with higher spatial resolution. The development of functional evaluation model was carried out to confirm the spectral and radiometric performance prior to the flight model manufacture phase. This model contains the VNIR and SWIR spectrograph, the VNIR and SWIR detector assemblies with a mechanical cooler for SWIR, signal processing circuit and on-board calibration source.

Sample Manipulation System for Sample Analysis at Mars

NASA Technical Reports Server (NTRS)

Mumm, Erik; Kennedy, Tom; Carlson, Lee; Roberts, Dustyn

2008-01-01

The Sample Analysis at Mars (SAM) instrument will analyze Martian samples collected by the Mars Science Laboratory Rover with a suite of spectrometers. This paper discusses the driving requirements, design, and lessons learned in the development of the Sample Manipulation System (SMS) within SAM. The SMS stores and manipulates 74 sample cups to be used for solid sample pyrolysis experiments. Focus is given to the unique mechanism architecture developed to deliver a high packing density of sample cups in a reliable, fault tolerant manner while minimizing system mass and control complexity. Lessons learned are presented on contamination control, launch restraint mechanisms for fragile sample cups, and mechanism test data.

Stability of Phosphonic Self Assembled Monolayers (SAMs) on Cobalt Chromium (Co-Cr) Alloy under Oxidative conditions

PubMed Central

Bhure, Rahul; Abdel-Fattah, Tarek M.; Bonner, Carl; Hall, Felicia; Mahapatro, Anil

2011-01-01

Cobalt Chromium (Co-Cr) alloys has been widely used in the biomedical arena for cardiovascular, orthopedic and dental applications. Surface modification of the alloy allows us to tailor the interfacial properties to address critical challenges of Co-Cr alloy in medical applications. Self assembled monolayers (SAMs) of Octadecylphosphonic acid (ODPA) have been used to form thin films on the oxide layer of the Co-Cr alloy surface by solution deposition technique. The SAMs formed were investigated for their stability to oxidative conditions of ambient laboratory environment over periods of 1, 3, 7 and 14 days. The samples were then characterized for their stability using X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and Contact Angle Measurements. Detailed high energy XPS elemental scans confirmed the presence of the phosphonic monolayer after oxidative exposure which suggested that the SAMs were firmly attached to the oxide layer of Co-Cr alloy. AFM images gave topographical data of the surface and showed islands of SAMs on Co-Cr alloy surface, before and after SAM formation and also over the duration of the oxidative exposure. Contact angle measurements confirmed the hydrophobicity of the surface over 14 days. Thus the SAMs were found to be stable for the duration of the study. These SAMs could be subsequently tailored by modifying the terminal functional groups and could be used for various potential biomedical applications such as drug delivery, biocompatibility and tissue integration PMID:21603056

Testing the validity, reliability and utility of the Self-Administration of Medication (SAM) tool in patients undergoing rehabilitation.

PubMed

Anderson, Jessica; Manias, Elizabeth; Kusljic, Snezana; Finch, Sue

2014-01-01

Determination of patients' ability to self-administer medications in the hospital has largely been determined using the subjective judgment of health professionals. To examine the validity, reliability and utility of the Self-Administration of Medication (SAM) tool as an objective means to determine patients' ability to self-administer in a rehabilitation unit of a public teaching hospital in Melbourne, Australia. To assess validity of the SAM tool, associations were examined between the total SAM tool score and of the patients' competence to self-administer from the perceptions of the tool administrator, patients and nurses. Validity also was determined from a principal component analysis. Pearson correlations were calculated for how SAM scores related to scores obtained from the Functional Independence Measure (FIM) and Barthel Score Index (BSI). To assess the SAM tool's reliability, a Cronbach's alpha coefficient was calculated. Utility of the SAM tool was evidenced by documenting its administration time. One hundred patients participated in this study. The SAM tool had a Cronbach's alpha coefficient of 0.75 and took a mean time of 5.36 min to complete. The capability to self-medicate section of the SAM tool had strong correlations with the FIM (r = 0.485) and BSI (r = 0.472) data, respectively, and the total SAM tool had moderate and strong correlations with the nurses' (r = 0.315) and tool administrator's (r = 0.632) perceptions of patients' ability to self-administer, respectively. Bland-Altman and ROC curve analyses showed poor agreement between the total SAM tool score and the nurses' perceptions. The SAM tool demonstrated acceptable overall internal consistency. It only requires a short time to be completed and is more objective than seeking out health professionals' perceptions. Additional research is needed to further validate this approach to determining patients' ability to self-medicate. Crown Copyright © 2014. Published by Elsevier Inc. All

Tropical Storm Sam, Eastern Indian Ocean

NASA Image and Video Library

1990-01-20

STS032-80-036 (9-20 Jan. 1990) --- This oblique view of Tropical Storm Sam in the eastern Indian Ocean off the western coast of Australia was photographed with a 70mm camera by the astronauts. Tropical Storm Sam (known as Willy-Willy in Australia) was born in the eastern Indian Ocean near the islands of Timor and Sumba in Indonesia. The storm tracked southwestward attaining sustained winds in excess of 60 knots (70 miles per hour). Other than on Christmas Island and the Cocos (Keeling) Islands south of Java, and for strong swells along the western Australia coast, the storm had little impact on land areas. At the time this photograph was taken, the storm was beginning to dissipate in the south Indian Ocean. The eye of the storm is still visible near center, with the swirling bands of the storm propagating in a clockwise direction toward the center. Winds aloft have begun to shear the tops of thunderstorms associated with the storm, forming a high cirrus cloud cover over the center portions of the storm. This picture was used by the crew at their January 30, 1990 Post-Flight Press Conference (PFPC).

Soft Ultraviolet (UV) Photopatterning and Metallization of Self-Assembled Monolayers (SAMs) Formed from the Lipoic Acid Ester of α-Hydroxy-1-acetylpyrene: The Generality of Acid-Catalyzed Removal of Thiol-on-Gold SAMs using Soft UV Light.

PubMed

Pukenas, Laurynas; Prompinit, Panida; Nishitha, Boda; Tate, Daniel J; Singh, N D Pradeep; Wälti, Christoph; Evans, Stephen D; Bushby, Richard J

2017-05-31

Under a layer of 0.1 M HCl in isopropanol, soft ultraviolet (UV) (365 nm) photolysis of the thiol-on-gold self-assembled monolayer (SAM) derived from the lipoic acid ester of α-hydroxy-1-acetylpyrene results in the expected removal of the acetylpyrene protecting group. When photolyzing through a mask, this can be used to produce a patterned surface and, at a controlled electrochemical potential, it is then possible to selectively and reversibly electrodeposit copper on the photolyzed regions. Rather surprisingly, under these photolysis conditions, there is not only the expected photodeprotection of the ester but also partial removal of the lipoic acid layer which has been formed. In further studies, it is shown that this type of acid-catalyzed photoremoval of SAM layers by soft UV is a rather general phenomenon and results in the partial removal of the thiol-on-gold SAM layers derived from other ω-thiolated carboxylic acids. However, this phenomenon is chain-length dependent. Under conditions in which there is a ∼60% reduction in the thickness of the SAM derived from dithiobutyric acid, the SAM derived from mercaptoundecanoic acid is almost unaffected. The process by which the shorter-chain SAM layers are partially removed is not fully understood because these compounds do not absorb significantly in the 365 nm region of the spectrum! Significantly, this study shows that acid catalysis photolysis of thiol-on-gold SAMs needs to be used with caution.

Hypervirulent Diuraphis noxia (Hemiptera: Aphididae) biotype SAM avoids triggering defenses in its host (Triticum aestivum) (Poales: Poaceae) during feeding.

PubMed

Botha, Anna-Maria; Burger, N Francois V; Van Eck, Leon

2014-06-01

In the molecular arms race between aphids and plants, both organisms rely on adaptive strategies to outcompete their evolutionary rival. In the current study, we investigated the difference in elicited defense responses of wheat (Triticum aestivum L.) near-isogenic lines with different Dn resistance genes, upon feeding by an avirulent and hypervirulent Diuraphis noxia Kurdjumov biotype. After measuring the activity of a suite of enzymes associated with plant defense, it became apparent that the host does not recognize the invasion by the hypervirulent aphid because none of these were induced, while feeding by the avirulent biotype did result in induction of enzyme activity. Genomic plasticity in D. noxia may be a likely explanation for the observed differences in virulence between D. noxia biotype SA1 and SAM, as demonstrated in the current study.

EFFECTS OF POLYCYCLIC AROMATIC HYDROCARBON OF SAM-COATED ELECTRODES USING FERRYICYANIDE AS THE REDOX INDICATOR

EPA Science Inventory

Electrochemical responses on self-assembled monolayer (SAM)-coated polycrystalline gold electrodes were investigated using cyclic voltammetry and square wave voltammetry with a three electrode system. Experimental results show potential in the application of pyrene-imprinted SAM...

Molten Salt Power Tower Cost Model for the System Advisor Model (SAM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turchi, C. S.; Heath, G. A.

2013-02-01

This report describes a component-based cost model developed for molten-salt power tower solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), using data from several prior studies, including a contracted analysis from WorleyParsons Group, which is included herein as an Appendix. The WorleyParsons' analysis also estimated material composition and mass for the plant to facilitate a life cycle analysis of the molten salt power tower technology. Details of the life cycle assessment have been published elsewhere. The cost model provides a reference plant that interfaces with NREL's System Advisor Model or SAM. The referencemore » plant assumes a nominal 100-MWe (net) power tower running with a nitrate salt heat transfer fluid (HTF). Thermal energy storage is provided by direct storage of the HTF in a two-tank system. The design assumes dry-cooling. The model includes a spreadsheet that interfaces with SAM via the Excel Exchange option in SAM. The spreadsheet allows users to estimate the costs of different-size plants and to take into account changes in commodity prices. This report and the accompanying Excel spreadsheet can be downloaded at https://sam.nrel.gov/cost.« less

SAM-based Cell Transfer to Photopatterned Hydrogels for Microengineering Vascular-Like Structures

PubMed Central

Sadr, Nasser; Zhu, Mojun; Osaki, Tatsuya; Kakegawa, Takahiro; Yang, Yunzhi; Moretti, Matteo; Fukuda, Junji; Khademhosseini, Ali

2011-01-01

A major challenge in tissue engineering is to reproduce the native 3D microvascular architecture fundamental for in vivo functions. Current approaches still lack a network of perfusable vessels with native 3D structural organization. Here we present a new method combining self-assembled monolayer (SAM)-based cell transfer and gelatin methacrylate hydrogel photopatterning techniques for microengineering vascular structures. Human umbilical vein cell (HUVEC) transfer from oligopeptide SAM-coated surfaces to the hydrogel revealed two SAM desorption mechanisms: photoinduced and electrochemically triggered. The former, occurs concomitantly to hydrogel photocrosslinking, and resulted in efficient (>97%) monolayer transfer. The latter, prompted by additional potential application, preserved cell morphology and maintained high transfer efficiency of VE-cadherin positive monolayers over longer culture periods. This approach was also applied to transfer HUVECs to 3D geometrically defined vascular-like structures in hydrogels, which were then maintained in perfusion culture for 15 days. As a step toward more complex constructs, a cell-laden hydrogel layer was photopatterned around the endothelialized channel to mimic the vascular smooth muscle structure of distal arterioles. This study shows that the coupling of the SAM-based cell transfer and hydrogel photocrosslinking could potentially open up new avenues in engineering more complex, vascularized tissue constructs for regenerative medicine and tissue engineering applications. PMID:21802723

The Growth-Suppressive Function of the Polycomb Group Protein Polyhomeotic Is Mediated by Polymerization of Its Sterile Alpha Motif (SAM) Domain*

PubMed Central

Robinson, Angela K.; Leal, Belinda Z.; Chadwell, Linda V.; Wang, Renjing; Ilangovan, Udayar; Kaur, Yogeet; Junco, Sarah E.; Schirf, Virgil; Osmulski, Pawel A.; Gaczynska, Maria; Hinck, Andrew P.; Demeler, Borries; McEwen, Donald G.; Kim, Chongwoo A.

2012-01-01

Polyhomeotic (Ph), a member of the Polycomb Group (PcG), is a gene silencer critical for proper development. We present a previously unrecognized way of controlling Ph function through modulation of its sterile alpha motif (SAM) polymerization leading to the identification of a novel target for tuning the activities of proteins. SAM domain containing proteins have been shown to require SAM polymerization for proper function. However, the role of the Ph SAM polymer in PcG-mediated gene silencing was uncertain. Here, we first show that Ph SAM polymerization is indeed required for its gene silencing function. Interestingly, the unstructured linker sequence N-terminal to Ph SAM can shorten the length of polymers compared with when Ph SAM is individually isolated. Substituting the native linker with a random, unstructured sequence (RLink) can still limit polymerization, but not as well as the native linker. Consequently, the increased polymeric Ph RLink exhibits better gene silencing ability. In the Drosophila wing disc, Ph RLink expression suppresses growth compared with no effect for wild-type Ph, and opposite to the overgrowth phenotype observed for polymer-deficient Ph mutants. These data provide the first demonstration that the inherent activity of a protein containing a polymeric SAM can be enhanced by increasing SAM polymerization. Because the SAM linker had not been previously considered important for the function of SAM-containing proteins, our finding opens numerous opportunities to manipulate linker sequences of hundreds of polymeric SAM proteins to regulate a diverse array of intracellular functions. PMID:22275371

Roles of Salmonella typhimurium umuDC and samAB in UV mutagenesis and UV sensitivity.

PubMed Central

Nohmi, T; Yamada, M; Watanabe, M; Murayama, S Y; Sofuni, T

1992-01-01

Expression of the umuDC operon is required for UV mutagenesis and most chemical mutagenesis in Escherichia coli. The closely related species Salmonella typhimurium has two sets of umuDC-like operons; the samAB operon is located in a 60-MDa cryptic plasmid, while the S. typhimurium umuDC (umuDCST) operon resides in a chromosome. The roles of these two umuDC-like operons in UV mutagenesis and UV sensitivity of S. typhimurium were investigated. A pBR322-derived plasmid carrying the samAB operon more efficiently restored UV mutability to a umuD44 strain and a umuC122::Tn5 strain of E. coli than a plasmid carrying the umuDCST operon did. When the umuDCST operon was specifically deleted from the chromosome of S. typhimurium TA2659, the resulting strain was not UV mutable and was more sensitive to the killing effect of UV irradiation than the parent strain was. Curing of the 60-MDa cryptic plasmid carrying the samAB operon did not influence the UV mutability of strain TA2659 but did increase its resistance to UV killing. A pSC101-derived plasmid carrying the samAB operon did not restore UV mutability to a umuD44 strain of E. coli, whereas pBR322- or pBluescript-derived plasmids carrying the samAB operon efficiently did restore UV mutability. We concluded that the umuDCST operon plays a major role in UV mutagenesis in S. typhimurium and that the ability of the samAB operon to promote UV mutagenesis is strongly affected by gene dosage. Possible reasons for the poor ability of samAB to promote UV mutagenesis when it is present on low-copy-number plasmids are discussed. Images PMID:1400244

Tandem SAM Domain Structure of Human Caskin1: A Presynaptic, Self-Assembling Scaffold for CASK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stafford, Ryan L.; Hinde, Elizabeth; Knight, Mary Jane

2012-02-07

The synaptic scaffolding proteins CASK and Caskin1 are part of the fibrous mesh of proteins that organize the active zones of neural synapses. CASK binds to a region of Caskin1 called the CASK interaction domain (CID). Adjacent to the CID, Caskin1 contains two tandem sterile a motif (SAM) domains. Many SAM domains form polymers so they are good candidates for forming the fibrous structures seen in the active zone. We show here that the SAM domains of Caskin1 form a new type of SAM helical polymer. The Caskin1 polymer interface exhibits a remarkable segregation of charged residues, resulting in amore » high sensitivity to ionic strength in vitro. The Caskin1 polymers can be decorated with CASK proteins, illustrating how these proteins may work together to organize the cytomatrix in active zones.« less

Optimization of pentacene double floating gate memories based on charge injection regulated by SAM functionalization

NASA Astrophysics Data System (ADS)

Li, S.; Guérin, D.; Lenfant, S.; Lmimouni, K.

2018-02-01

Pentacene based double nano-floating gate memories (NFGM) by using gold nanoparticles (Au NPs) and reduced graphene oxide (rGO) sheets as charge trapping layers are prepared and demonstrated. Particularly, the NFGM chemically treated by 2,3,4,5,6-pentafluorobenzenethiol (PFBT) self-assembled monolayers (SAM) exhibits excellent memory performances, including high mobility of 0.23 cm2V-1s-1, the large memory window of 51 V, and the stable retention property more than 108 s. Comparing the performances of NFGM without treating with PFBT SAM, the improving performances of the memory devices by SAM modification are explained by the increase of charge injection, which could be further investigated by XPS and UPS. In particular, the results highlight the utility of SAM modulations and controlling of charge transport in the development of organic transistor memories.

Possible Detection of Perchlorates by Evolved Gas Analysis of Rocknest Soils: Global Implication

NASA Technical Reports Server (NTRS)

Archer, P. D., Jr.; Sutter, B.; Ming, D. W.; McKay, C. P.; Navarro-Gonzalez, R.; Franz, H. B.; McAdam, A.; Mahaffy, P. R.

2013-01-01

The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. Rocknest was selected as the source of the first samples analyzed because it is representative of both windblown material in Gale crater as well as the globally-distributed dust. The four samples analyzed by SAM were portioned from the fifth scoop at this location. The material delivered to SAM passed through a 150 m sieve and should have been well mixed during the sample acquisition/ preparation/handoff process. Rocknest samples were heated to 835 C at a 35 C/minute ramp rate with a He carrier gas flow rate of 1.5 standard cubic centimeters per minute and at an oven pressure of 30 mbar. Evolved gases were detected by a quadrupole mass spectrometer (QMS).

Evolved Gas Analysis and X-Ray Diffraction of Carbonate Samples from the 2009 Arctic Mars Analog Svalbard Expedition: Implications for Mineralogical Inferences from the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

McAdam, A. C.; Mahaffy, P. R.; Blake, D. F.; Ming, D. W.; Franz, H. B.; Eigenbrode, J. L.; Steele, A.

2010-01-01

The 2009 Arctic Mars Analog Svalbard Expedition (AMASE) investigated several geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return (MSR). AMASE-related research comprises both analyses conducted during the expedition and further analyses of collected samples using laboratory facilities at a variety of institutions. The Sample Analysis at Mars (SAM) instrument suite, which will be part of the Analytical Laboratory on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser spectrometer (TLS). An Evolved Gas Analysis Mass Spectrometer (EGA-MS) was used during AMASE to represent part of the capabilities of SAM. The other instrument included in the MSL Analytical Laboratory is CheMin, which uses X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) to perform quantitative mineralogical characterization of samples. Field-portable versions of CheMin were used during the AMASE 2009. Here, we discuss the preliminary interpretation of EGA and XRD analyses of selected AMASE carbonate samples and implications for mineralogical interpretations from MSL. Though CheMin will be the primary mineralogical tool on MSL, SAM EGA could be used to support XRD identifications or indicate the presence of volatile-bearing minerals which may be near or below XRD detection limits. Data collected with instruments in the field and in comparable laboratory setups (e.g., the SAM breadboard) will be discussed.

A magnesium-induced triplex pre-organizes the SAM-II riboswitch

PubMed Central

Roy, Susmita; Lammert, Heiko; Dayie, T. Kwaku; Sanbonmatsu, Karissa Y.

2017-01-01

Our 13C- and 1H-chemical exchange saturation transfer (CEST) experiments previously revealed a dynamic exchange between partially closed and open conformations of the SAM-II riboswitch in the absence of ligand. Here, all-atom structure-based molecular simulations, with the electrostatic effects of Manning counter-ion condensation and explicit magnesium ions are employed to calculate the folding free energy landscape of the SAM-II riboswitch. We use this analysis to predict that magnesium ions remodel the landscape, shifting the equilibrium away from the extended, partially unfolded state towards a compact, pre-organized conformation that resembles the ligand-bound state. Our CEST and SAXS experiments, at different magnesium ion concentrations, quantitatively confirm our simulation results, demonstrating that magnesium ions induce collapse and pre-organization. Agreement between theory and experiment bolsters microscopic interpretation of our simulations, which shows that triplex formation between helix P2b and loop L1 is highly sensitive to magnesium and plays a key role in pre-organization. Pre-organization of the SAM-II riboswitch allows rapid detection of ligand with high selectivity, which is important for biological function. PMID:28248966

Selection and Characteristics of Fermented Salted Seafood (jeotgal)-Originated Strains with Excellent S-adenosyl-L-methionine (SAM) Production and Probiotics Efficacy.

PubMed

Kim, Min-Jeong; Park, Sunhyun; Lee, Ran-Sook; Lim, Sang-Dong; Kim, Hyo Jin; Lee, Myung-Ki

2014-01-01

This study is executed to develop probiotics which produce S-adenosyl-L-methionine (SAM), a methyl group donor of the 5-methyltetrahydrofolate methylation reaction within the animal cell. SAM is an essential substance for the synthesis, activation, and metabolism of hormones, neurotransmitters, nucleic acids, phospholipids, and cell membranes of animals. The SAM is also known as a nutritional supplement to improve brain functions of the human. In this study, the SAM-producing strains are identified in 18 types of salted fish, and then, the strains with excellent SAM productions are being identified, with 1 strain in the Enterococcus genus and 9 strains in the Bacillus genus. Strains with a large amount of SAM production include the lactic acid bacteria such as En. faecium and En. durans, En. sanguinicola, as well as various strains in the Bacil-lus genus. The SAM-overproducing strains show antibacterial activities with certain harmful microbes in addition to the weak acid resistances and strong bile resistances, indicating characteristics of probiotics. It is possible that the jeotgal-originated beneficial strains with overproducing SAM can be commercially utilized in order to manufacture SAM enriched foods.

Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Weijie, E-mail: 459586768@qq.com; Liu, Yuxi, E-mail: 924013616@qq.com; Wang, Youhua, E-mail: wyouhua1516@163.com

Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwannmore » cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.« less

Regulation of C. elegans presynaptic differentiation and neurite branching via a novel signaling pathway initiated by SAM-10

PubMed Central

Zheng, Qun; Schaefer, Anneliese M.; Nonet, Michael L.

2011-01-01

Little is known about transcriptional control of neurite branching or presynaptic differentiation, events that occur relatively late in neuronal development. Using the Caenorhabditis elegans mechanosensory circuit as an in vivo model, we show that SAM-10, an ortholog of mammalian single-stranded DNA-binding protein (SSDP), functions cell-autonomously in the nucleus to regulate synaptic differentiation, as well as positioning of, a single neurite branch. PLM mechanosensory neurons in sam-10 mutants exhibit abnormal placement of the neurite branch point, and defective synaptogenesis, characterized by an overextended synaptic varicosity, underdeveloped synaptic morphology and disrupted colocalization of active zone and synaptic vesicles. SAM-10 functions coordinately with Lim domain-binding protein 1 (LDB-1), demonstrated by our observations that: (1) mutations in either gene show similar defects in PLM neurons; and (2) LDB-1 is required for SAM-10 nuclear localization. SAM-10 regulates PLM synaptic differentiation by suppressing transcription of prk-2, which encodes an ortholog of the mammalian Pim kinase family. PRK-2-mediated activities of SAM-10 are specifically involved in PLM synaptic differentiation, but not other sam-10 phenotypes such as neurite branching. Thus, these data reveal a novel transcriptional signaling pathway that regulates neuronal specification of neurite branching and presynaptic differentiation. PMID:21115607

Regulation of C. elegans presynaptic differentiation and neurite branching via a novel signaling pathway initiated by SAM-10.

PubMed

Zheng, Qun; Schaefer, Anneliese M; Nonet, Michael L

2011-01-01

Little is known about transcriptional control of neurite branching or presynaptic differentiation, events that occur relatively late in neuronal development. Using the Caenorhabditis elegans mechanosensory circuit as an in vivo model, we show that SAM-10, an ortholog of mammalian single-stranded DNA-binding protein (SSDP), functions cell-autonomously in the nucleus to regulate synaptic differentiation, as well as positioning of, a single neurite branch. PLM mechanosensory neurons in sam-10 mutants exhibit abnormal placement of the neurite branch point, and defective synaptogenesis, characterized by an overextended synaptic varicosity, underdeveloped synaptic morphology and disrupted colocalization of active zone and synaptic vesicles. SAM-10 functions coordinately with Lim domain-binding protein 1 (LDB-1), demonstrated by our observations that: (1) mutations in either gene show similar defects in PLM neurons; and (2) LDB-1 is required for SAM-10 nuclear localization. SAM-10 regulates PLM synaptic differentiation by suppressing transcription of prk-2, which encodes an ortholog of the mammalian Pim kinase family. PRK-2-mediated activities of SAM-10 are specifically involved in PLM synaptic differentiation, but not other sam-10 phenotypes such as neurite branching. Thus, these data reveal a novel transcriptional signaling pathway that regulates neuronal specification of neurite branching and presynaptic differentiation.

cljam: a library for handling DNA sequence alignment/map (SAM) with parallel processing.

PubMed

Takeuchi, Toshiki; Yamada, Atsuo; Aoki, Takashi; Nishimura, Kunihiro

2016-01-01

Next-generation sequencing can determine DNA bases and the results of sequence alignments are generally stored in files in the Sequence Alignment/Map (SAM) format and the compressed binary version (BAM) of it. SAMtools is a typical tool for dealing with files in the SAM/BAM format. SAMtools has various functions, including detection of variants, visualization of alignments, indexing, extraction of parts of the data and loci, and conversion of file formats. It is written in C and can execute fast. However, SAMtools requires an additional implementation to be used in parallel with, for example, OpenMP (Open Multi-Processing) libraries. For the accumulation of next-generation sequencing data, a simple parallelization program, which can support cloud and PC cluster environments, is required. We have developed cljam using the Clojure programming language, which simplifies parallel programming, to handle SAM/BAM data. Cljam can run in a Java runtime environment (e.g., Windows, Linux, Mac OS X) with Clojure. Cljam can process and analyze SAM/BAM files in parallel and at high speed. The execution time with cljam is almost the same as with SAMtools. The cljam code is written in Clojure and has fewer lines than other similar tools.

The U6 snRNA m6A Methyltransferase METTL16 Regulates SAM Synthetase Intron Retention.

PubMed

Pendleton, Kathryn E; Chen, Beibei; Liu, Kuanqing; Hunter, Olga V; Xie, Yang; Tu, Benjamin P; Conrad, Nicholas K

2017-05-18

Maintenance of proper levels of the methyl donor S-adenosylmethionine (SAM) is critical for a wide variety of biological processes. We demonstrate that the N 6 -adenosine methyltransferase METTL16 regulates expression of human MAT2A, which encodes the SAM synthetase expressed in most cells. Upon SAM depletion by methionine starvation, cells induce MAT2A expression by enhanced splicing of a retained intron. Induction requires METTL16 and its methylation substrate, a vertebrate conserved hairpin (hp1) in the MAT2A 3' UTR. Increasing METTL16 occupancy on the MAT2A 3' UTR is sufficient to induce efficient splicing. We propose that, under SAM-limiting conditions, METTL16 occupancy on hp1 increases due to inefficient enzymatic turnover, which promotes MAT2A splicing. We further show that METTL16 is the long-unknown methyltransferase for the U6 spliceosomal small nuclear RNA (snRNA). These observations suggest that the conserved U6 snRNA methyltransferase evolved an additional function in vertebrates to regulate SAM homeostasis. Copyright © 2017 Elsevier Inc. All rights reserved.

Fast and slow responses of Southern Ocean sea surface temperature to SAM in coupled climate models

NASA Astrophysics Data System (ADS)

Kostov, Yavor; Marshall, John; Hausmann, Ute; Armour, Kyle C.; Ferreira, David; Holland, Marika M.

2017-03-01

We investigate how sea surface temperatures (SSTs) around Antarctica respond to the Southern Annular Mode (SAM) on multiple timescales. To that end we examine the relationship between SAM and SST within unperturbed preindustrial control simulations of coupled general circulation models (GCMs) included in the Climate Modeling Intercomparison Project phase 5 (CMIP5). We develop a technique to extract the response of the Southern Ocean SST (55°S-70°S) to a hypothetical step increase in the SAM index. We demonstrate that in many GCMs, the expected SST step response function is nonmonotonic in time. Following a shift to a positive SAM anomaly, an initial cooling regime can transition into surface warming around Antarctica. However, there are large differences across the CMIP5 ensemble. In some models the step response function never changes sign and cooling persists, while in other GCMs the SST anomaly crosses over from negative to positive values only 3 years after a step increase in the SAM. This intermodel diversity can be related to differences in the models' climatological thermal ocean stratification in the region of seasonal sea ice around Antarctica. Exploiting this relationship, we use observational data for the time-mean meridional and vertical temperature gradients to constrain the real Southern Ocean response to SAM on fast and slow timescales.

20. NBS SUIT LAB. TABLE WITH MISCELLANEOUS SUIT PARTS AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. NBS SUIT LAB. TABLE WITH MISCELLANEOUS SUIT PARTS AND TERRY WEST, A SPACE SUIT ASSEMBLY TECHNICIAN LOGGING SUIT PART DATA. PARTS ON THE TABLE ARE A HARD UPPER TORSO (HUT) (REAR LEFT), FULL HELMET (FRONT LEFT), TWO HELMETS WITHOUT PROTECTIVE VISORS, A PAIR OF GLOVES, AND A BACKPACK WITHOUT VOLUMETRIC COVER (REAR RIGHT). THE BACKPACK ATTACHES TO THE HUT TO MAKE-UP THE UPPER TORSO COMPONENTS OF THE SUIT. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

SAM: speech-aware applications in medicine to support structured data entry.

PubMed Central

Wormek, A. K.; Ingenerf, J.; Orthner, H. F.

1997-01-01

In the last two years, improvement in speech recognition technology has directed the medical community's interest to porting and using such innovations in clinical systems. The acceptance of speech recognition systems in clinical domains increases with recognition speed, large medical vocabulary, high accuracy, continuous speech recognition, and speaker independence. Although some commercial speech engines approach these requirements, the greatest benefit can be achieved in adapting a speech recognizer to a specific medical application. The goals of our work are first, to develop a speech-aware core component which is able to establish connections to speech recognition engines of different vendors. This is realized in SAM. Second, with applications based on SAM we want to support the physician in his/her routine clinical care activities. Within the STAMP project (STAndardized Multimedia report generator in Pathology), we extend SAM by combining a structured data entry approach with speech recognition technology. Another speech-aware application in the field of Diabetes care is connected to a terminology server. The server delivers a controlled vocabulary which can be used for speech recognition. PMID:9357730

Background of SAM atom-fraction profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ernst, Frank

Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which ismore » validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition.« less

Search for nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

NASA Astrophysics Data System (ADS)

Navarro-Gonzalez, Rafael; Stern, Jennifer; Freissinet, Caroline; Franz, Heather; McKay, Christopher; Coll, Patrice; Sutter, Brad; Archer, Doug; McAdam, Amy; Cabane, Michel; Ming, Douglas; Glavin, Daniel; Eigenbrode, Jennifer; Leshin, Laurie; Wong, Michael; Atreya, Sushil; Wray, James; Steele, Andrew; Buch, Arnaud; Prats, Benito

2014-05-01

One of the main goals of the Mars Science Laboratory is to determine whether the planet ever had environmental conditions capable of supporting microbial life. Nitrogen is a fundamental element for life, and is present in structural (e.g., proteins), catalytic (e.g., enzymes and ribozymes), energy transfer (e.g., ATP) and information storage (RNA and DNA) bio-molecules. Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as dinitrogen (N2). However, a fraction of N2 has been lost to space by sputtering and photochemical processes [1, 2], impact erosion [3], and chemical oxidation to nitrates [4, 5]. Nitrates produced early in Mars' history by photochemistry may later decompose back into N2 by the current impact flux [6]. It is estimated that the Martian surface could contain soil nitrates at levels of 0.3 wt.% N, if mixed homogenously [6], or a layer of pure NaNO3 of about 3 m thickness [5] distributed globally. Nitrates are a fundamental source for nitrogen for terrestrial microorganisms. Therefore, the detection of soil nitrates is important to assess habitability in the Martian environment. The only previous attempt to search for soil nitrates was by TEGA and the MECA WCL on the Phoenix mission but no evolved N-containing species were detected [7]. Nitrates have been tentatively identified in two Martian meteorites: Nakhla [8] and EETA79001 [9]. SAM is capable of detecting nitrates by their thermal decomposition into nitric oxide, NO. SAM analyzed samples from Rocknest soil and two drill holes located at John Klein (JK) and Cumberland (CB) mudstones in the Sheepbed member of the Yellowknife Bay formation in Gale Crater. There appear to be several peaks associated with the release of m/z 30 in the temperature range from 150° C to 600° C. m/z 30 can be attributed to nitric oxide; however, other possible chemical interferences may be present and are assessed. The origin of nitric oxide is discussed and its thermal evolution is

SAM-based cell transfer to photopatterned hydrogels for microengineering vascular-like structures.

PubMed

Sadr, Nasser; Zhu, Mojun; Osaki, Tatsuya; Kakegawa, Takahiro; Yang, Yunzhi; Moretti, Matteo; Fukuda, Junji; Khademhosseini, Ali

2011-10-01

A major challenge in tissue engineering is to reproduce the native 3D microvascular architecture fundamental for in vivo functions. Current approaches still lack a network of perfusable vessels with native 3D structural organization. Here we present a new method combining self-assembled monolayer (SAM)-based cell transfer and gelatin methacrylate hydrogel photopatterning techniques for microengineering vascular structures. Human umbilical vein cell (HUVEC) transfer from oligopeptide SAM-coated surfaces to the hydrogel revealed two SAM desorption mechanisms: photoinduced and electrochemically triggered. The former, occurs concomitantly to hydrogel photocrosslinking, and resulted in efficient (>97%) monolayer transfer. The latter, prompted by additional potential application, preserved cell morphology and maintained high transfer efficiency of VE-cadherin positive monolayers over longer culture periods. This approach was also applied to transfer HUVECs to 3D geometrically defined vascular-like structures in hydrogels, which were then maintained in perfusion culture for 15 days. As a step toward more complex constructs, a cell-laden hydrogel layer was photopatterned around the endothelialized channel to mimic the vascular smooth muscle structure of distal arterioles. This study shows that the coupling of the SAM-based cell transfer and hydrogel photocrosslinking could potentially open up new avenues in engineering more complex, vascularized tissue constructs for regenerative medicine and tissue engineering applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

SAM68 is a physiological regulator of SMN2 splicing in spinal muscular atrophy

PubMed Central

Pagliarini, Vittoria; Pelosi, Laura; Bustamante, Maria Blaire; Nobili, Annalisa; Berardinelli, Maria Grazia; D’Amelio, Marcello; Musarò, Antonio

2015-01-01

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss of motor neurons in patients with null mutations in the SMN1 gene. The almost identical SMN2 gene is unable to compensate for this deficiency because of the skipping of exon 7 during pre–messenger RNA (mRNA) processing. Although several splicing factors can modulate SMN2 splicing in vitro, the physiological regulators of this disease-causing event are unknown. We found that knockout of the splicing factor SAM68 partially rescued body weight and viability of SMAΔ7 mice. Ablation of SAM68 function promoted SMN2 splicing and expression in SMAΔ7 mice, correlating with amelioration of SMA-related defects in motor neurons and skeletal muscles. Mechanistically, SAM68 binds to SMN2 pre-mRNA, favoring recruitment of the splicing repressor hnRNP A1 and interfering with that of U2AF65 at the 3′ splice site of exon 7. These findings identify SAM68 as the first physiological regulator of SMN2 splicing in an SMA mouse model. PMID:26438828

Smart Anesthesia Manager™ (SAM)--a real-time decision support system for anesthesia care during surgery.

PubMed

Nair, Bala G; Newman, Shu-Fang; Peterson, Gene N; Schwid, Howard A

2013-01-01

Anesthesia information management systems (AIMS) are being increasingly used in the operating room to document anesthesia care. We developed a system, Smart Anesthesia Manager™ (SAM) that works in conjunction with an AIMS to provide clinical and billing decision support. SAM interrogates AIMS database in near real time, detects issues related to clinical care, billing and compliance, and material waste. Issues and the steps for their resolution are brought to the attention of the anesthesia provider in real time through "pop-up" messages overlaid on top of AIMS screens or text pages. SAM improved compliance to antibiotic initial dose and redose to 99.3 ± 0.7% and 83.9 ± 3.4% from 88.5 ± 1.4% and 62.5 ± 1.6%, respectively. Beta-blocker protocol compliance increased to 94.6 ± 3.5% from 60.5 ± 8.6%. Inadvertent gaps (>15 min) in blood pressure monitoring were reduced to 34 ± 30 min/1000 cases from 192 ± 58 min/1000 cases. Additional billing charge capture of invasive lines procedures worth $144,732 per year and 1,200 compliant records were achieved with SAM. SAM was also able to reduce wastage of inhalation anesthetic agents worth $120,168 per year.

The vTAS suite: A simulator for classical and multiplexed three-axis neutron spectrometers

NASA Astrophysics Data System (ADS)

Boehm, M.; Filhol, A.; Raoul, Y.; Kulda, J.; Schmidt, W.; Schmalzl, K.; Farhi, E.

2013-01-01

The vTAS suite provides graphical assistance to prepare and perform inelastic neutron scattering experiments on a TAS instrument, including latest multiplexed instrumental configurations, such as FlatCone, IMPS and UFO. The interactive display allows for flexible translation between instrument positions in real space and neutron scattering conditions represented in reciprocal space. It is a platform independent public domain software tool, available for download from the website of the Institut Laue Langevin (ILL).

Z-2 Suit Support Stand and MKIII Suit Center of Gravity Test

NASA Technical Reports Server (NTRS)

Nguyen, Tuan Q.

2014-01-01

NASA's next generation spacesuits are the Z-Series suits, made for a range of possible exploration missions in the near future. The prototype Z-1 suit has been developed and assembled to incorporate new technologies that has never been utilized before in the Apollo suits and the Extravehicular Mobility Unit (EMU). NASA engineers tested the Z-1 suit extensively in order to developed design requirements for the new Z-2 suit. At the end of 2014, NASA will be receiving the new Z-2 suit to perform more testing and to further develop the new technologies of the suit. In order to do so, a suit support stand will be designed and fabricated to support the Z-2 suit during maintenance, sizing, and structural leakage testing. The Z-2 Suit Support Stand (Z2SSS) will be utilized for these purposes in the early testing stages of the Z-2 suit.

Software Suite to Support In-Flight Characterization of Remote Sensing Systems

NASA Technical Reports Server (NTRS)

Stanley, Thomas; Holekamp, Kara; Gasser, Gerald; Tabor, Wes; Vaughan, Ronald; Ryan, Robert; Pagnutti, Mary; Blonski, Slawomir; Kenton, Ross

2014-01-01

A characterization software suite was developed to facilitate NASA's in-flight characterization of commercial remote sensing systems. Characterization of aerial and satellite systems requires knowledge of ground characteristics, or ground truth. This information is typically obtained with instruments taking measurements prior to or during a remote sensing system overpass. Acquired ground-truth data, which can consist of hundreds of measurements with different data formats, must be processed before it can be used in the characterization. Accurate in-flight characterization of remote sensing systems relies on multiple field data acquisitions that are efficiently processed, with minimal error. To address the need for timely, reproducible ground-truth data, a characterization software suite was developed to automate the data processing methods. The characterization software suite is engineering code, requiring some prior knowledge and expertise to run. The suite consists of component scripts for each of the three main in-flight characterization types: radiometric, geometric, and spatial. The component scripts for the radiometric characterization operate primarily by reading the raw data acquired by the field instruments, combining it with other applicable information, and then reducing it to a format that is appropriate for input into MODTRAN (MODerate resolution atmospheric TRANsmission), an Air Force Research Laboratory-developed radiative transport code used to predict at-sensor measurements. The geometric scripts operate by comparing identified target locations from the remote sensing image to known target locations, producing circular error statistics defined by the Federal Geographic Data Committee Standards. The spatial scripts analyze a target edge within the image, and produce estimates of Relative Edge Response and the value of the Modulation Transfer Function at the Nyquist frequency. The software suite enables rapid, efficient, automated processing of

The New Instrument Suite of the TSU/Fairborn 2m Automatic Spectroscopic Telescope

NASA Astrophysics Data System (ADS)

Muterspaugh, Matthew W.; Maxwell, T.; Williamson, M. W.; Fekel, F. C.; Ge, J.; Kelly, J.; Ghasempour, A.; Powell, S.; Zhao, B.; Varosi, F.; Schofield, S.; Liu, J.; Warner, C.; Jakeman, H.; Avner, L.; Swihart, S.; Harrison, C.; Fishler, D.

2014-01-01

Tied with the Liverpool Telescope as the world's largest fully robotic optical research telescope, Tennessee State University's (TSU) 2m Automatic Spectroscopic Telescope (AST) has recently been upgraded to improve performance and increase versatility by supporting multiple instruments. Its second-generation instrument head enables us to rapidly switch between any of up to twelve fibers optics, each of which can supply light to a different instrument. In 2013 construction was completed on a new temperature-controlled guest instrument building, and two new high resolution spectrographs were commissioned. The current set of instrumentation includes (1) the telescope's original R=30,000 echelle spectrograph (0.38--0.83 microns simultaneous), (2) a single order R=7,000 spectrograph centered at Ca H&K features, (3) a single-mode-fiber fed miniature echelle spectrograph (R=100,000; 0.48--0.62 microns simultaneous), (4) the University of Florida's EXPERT-3 spectrograph (R=100,000; 0.38--0.9 microns simultaneous; vacuum and temperature controlled) and (5) the University of Florida's FIRST spectrograph (R=70,000$; 0.8--1.35 or 1.4--1.8 microns simultaneous; vacuum and temperature controlled). Future instruments include the Externally Dispersed Interferometry (EDI) Testbed, a combination low resolution dispersed spectrograph and Fourier Transform Spectrograph. We welcome inquiries from the community in regards to observing access and/or proposals for future guest instruments.

The transcription factor FBI-1 inhibits SAM68-mediated BCL-X alternative splicing and apoptosis.

PubMed

Bielli, Pamela; Busà, Roberta; Di Stasi, Savino M; Munoz, Manuel J; Botti, Flavia; Kornblihtt, Alberto R; Sette, Claudio

2014-04-01

Alternative splicing (AS) is tightly coupled to transcription for the majority of human genes. However, how these two processes are linked is not well understood. Here, we unveil a direct role for the transcription factor FBI-1 in the regulation of AS. FBI-1 interacts with the splicing factor SAM68 and reduces its binding to BCL-X mRNA. This, in turn, results in the selection of the proximal 5' splice site in BCL-X exon 2, thereby favoring the anti-apoptotic BCL-XL variant and counteracting SAM68-mediated apoptosis. Conversely, depletion of FBI-1, or expression of a SAM68 mutant lacking the FBI-1 binding region, restores the ability of SAM68 to induce BCL-XS splicing and apoptosis. FBI-1's role in splicing requires the activity of histone deacetylases, whose pharmacological inhibition recapitulates the effects of FBI-1 knockdown. Our study reveals an unexpected function for FBI-1 in splicing modulation with a direct impact on cell survival.

The transcription factor FBI-1 inhibits SAM68-mediated BCL-X alternative splicing and apoptosis

PubMed Central

Bielli, Pamela; Busà, Roberta; Di Stasi, Savino M; Munoz, Manuel J; Botti, Flavia; Kornblihtt, Alberto R; Sette, Claudio

2014-01-01

Alternative splicing (AS) is tightly coupled to transcription for the majority of human genes. However, how these two processes are linked is not well understood. Here, we unveil a direct role for the transcription factor FBI-1 in the regulation of AS. FBI-1 interacts with the splicing factor SAM68 and reduces its binding to BCL-X mRNA. This, in turn, results in the selection of the proximal 5′ splice site in BCL-X exon 2, thereby favoring the anti-apoptotic BCL-XL variant and counteracting SAM68-mediated apoptosis. Conversely, depletion of FBI-1, or expression of a SAM68 mutant lacking the FBI-1 binding region, restores the ability of SAM68 to induce BCL-XS splicing and apoptosis. FBI-1's role in splicing requires the activity of histone deacetylases, whose pharmacological inhibition recapitulates the effects of FBI-1 knockdown. Our study reveals an unexpected function for FBI-1 in splicing modulation with a direct impact on cell survival. PMID:24514149

Standardized added metabolic activity (SAM) IN ¹⁸F-FDG PET assessment of treatment response in colorectal liver metastases.

PubMed

Mertens, Jeroen; De Bruyne, S; Van Damme, N; Smeets, P; Ceelen, W; Troisi, R; Laurent, S; Geboes, K; Peeters, M; Goethals, I; Van de Wiele, C

2013-08-01

Standardized added metabolic activity (SAM) is a PET parameter for assessing the total metabolic load of malignant processes, avoiding partial volume effects and lesion segmentation. The potential role of this parameter in the assessment of response to chemotherapy and bevacizumab was tested in patients with metastatic colorectal cancer with potentially resectable liver metastases (mCRC). (18)F-FDG PET/CT was performed in 18 mCRC patients with liver metastases before treatment and after five cycles of FOLFOX/FOLFIRI and bevacizumab. Of the 18 patients, 16 subsequently underwent resection of liver metastases. Baseline and follow-up SUVmax, and SAM as well as reduction in SUVmax (∆SUVmax) and SAM (∆SAM) of all liver metastases were correlated with morphological response, and progression-free and overall survival (PFS and OS). A significant reduction in metabolic activity of the liver metastases was seen after chemotherapy with a median ∆SUVmax of 25.3% and ∆SAM of 94.5% (p = 0.033 and 0.003). Median baseline SUVmax and SAM values were significantly different between morphological responders and nonresponders (3.8 vs. 7.2, p = 0.021; and 34 vs. 211, p = 0.002, respectively), but neither baseline PET parameters nor morphological response was correlated with PFS or OS. Follow-up SUVmax and SAM as well as ∆SAM were found to be prognostic factors. The median PFS and OS in the patient group with a high follow-up SUVmax were 10.4 months and 32 months, compared to a median PFS of 14.7 months and a median OS which had not been reached in the group with a low follow-up SUVmax (p = 0.01 and 0.003, respectively). The patient group with a high follow-up SAM and a low ∆SAM had a median PFS and OS of 9.4 months and 32 months, whereas the other group had a median PFS of 14.7 months and a median OS which had not been reached (p = 0.002 for both PFS and OS). (18)F-FDG PET imaging is a useful tool to assess treatment response and predict clinical outcome in patients with m

Orion ECLSS/Suit System - Ambient Pressure Integrated Suit Test

NASA Technical Reports Server (NTRS)

Barido, Richard A.

2012-01-01

The Ambient Pressure Integrated Suit Test (APIST) phase of the integrated system testing of the Orion Vehicle Atmosphere Revitalization System (ARS) technology was conducted for the Multipurpose Crew Vehicle (MPCV) Program within the National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate. Crew and Thermal Systems Division performed this test in the eleven-foot human-rated vacuum chamber at the NASA Johnson Space Center. This testing is the first phase of suit loop testing to demonstrate the viability of the Environmental Control and Life Support System (ECLSS) being developed for Orion. APIST is the first in a series, which will consist of testing development hardware including the Carbon dioxide and Moisture Removal Amine Swing-bed (CAMRAS) and the air revitalization loop fan with human test subjects in pressure suits at varying suit pressures. Follow-on testing, to be conducted in 2013, will utilize the CAMRAS and a development regulator with human test subjects in pressure suits at varying cabin and suit pressures. This paper will discuss the results and findings of APIST and will also discuss future testing.

Raman mapping and in situ SERS spectroelectrochemical studies of 6-mercaptopurine SAMs on the gold electrode.

PubMed

Yang, Haifeng; Liu, Yanli; Liu, Zhimin; Yang, Yu; Jiang, Jianhui; Zhang, Zongrang; Shen, Guoli; Yu, Ruqin

2005-02-24

The self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) were formed at the roughened polycrystalline gold surfaces in acid and alkaline media. The time-dependent Raman mapping spectral analysis in conjunction with the quantum calculations for the vibrational modes using ab initio BLYP/6-31G method suggested that both of the resulted 6MP SAMs adopted the same adsorption mode through the S atom of pyrimidine moiety and the N7 atom of the imidazole moiety anchoring the gold surface in a vertical way. The in situ surface-enhanced Raman scattering spectroelectrochemical experiment was conducted to examine the stability of the SAMs at various bias potentials. It was found that the detaching process of the 6MP SAMs from the surface involved one electron reduction as the voltage was applied at ca. 0.7 V vs a standard calomel electrode.

Orientation of 6-mercaptopurine SAMs at the silver electrode as studied by Raman mapping and in situ SERS.

PubMed

Chu, Hui; Yang, Haifeng; Huan, Shuangyan; Shen, Guoli; Yu, Ruqin

2006-03-23

Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) on a silver electrode in acid and alkaline media were investigated by a combination protocol of the SERS technique with Raman mapping, and it was found that the adsorption mode of 6MP SAMs changed with the pH value of the environment. Quantum calculations for the vibrational mode were performed by the BLYP/6-31G method. 6MP was adsorbed on the silver electrode with a tilted orientation via S, N1, and N7 atoms in acid medium, while the SAMs adopted head-on adsorption modes with the S atom and the N1 atom anchoring the silver surface in alkaline medium. However, 6MP SAMs turned to the same upright orientation on the electrode through the S and N7 atoms when either acid or basic solution was removed. Stability of 6MP SAMs was observed by in situ SERS spectroelectrochemical measurements. The results reveal that the desorption potentials of 6MP SAMs formed under acid and alkaline conditions from the Ag electrode were at ca. -1.3 V and -1.6 V vs SCE, respectively.

The SAM, not the electrodes, dominates charge transport in metal-monolayer//Ga2O3/gallium-indium eutectic junctions.

PubMed

Reus, William F; Thuo, Martin M; Shapiro, Nathan D; Nijhuis, Christian A; Whitesides, George M

2012-06-26

The liquid-metal eutectic of gallium and indium (EGaIn) is a useful electrode for making soft electrical contacts to self-assembled monolayers (SAMs). This electrode has, however, one feature whose effect on charge transport has been incompletely understood: a thin (approximately 0.7 nm) film-consisting primarily of Ga(2)O(3)-that covers its surface when in contact with air. SAMs that rectify current have been measured using this electrode in Ag(TS)-SAM//Ga(2)O(3)/EGaIn (where Ag(TS) = template-stripped Ag surface) junctions. This paper organizes evidence, both published and unpublished, showing that the molecular structure of the SAM (specifically, the presence of an accessible molecular orbital asymmetrically located within the SAM), not the difference between the electrodes or the characteristics of the Ga(2)O(3) film, causes the observed rectification. By examining and ruling out potential mechanisms of rectification that rely either on the Ga(2)O(3) film or on the asymmetry of the electrodes, this paper demonstrates that the structure of the SAM dominates charge transport through Ag(TS)-SAM//Ga(2)O(3)/EGaIn junctions, and that the electrical characteristics of the Ga(2)O(3) film have a negligible effect on these measurements.

CE-SAM: a conversational interface for ISR mission support

NASA Astrophysics Data System (ADS)

Pizzocaro, Diego; Parizas, Christos; Preece, Alun; Braines, Dave; Mott, David; Bakdash, Jonathan Z.

2013-05-01

There is considerable interest in natural language conversational interfaces. These allow for complex user interactions with systems, such as fulfilling information requirements in dynamic environments, without requiring extensive training or a technical background (e.g. in formal query languages or schemas). To leverage the advantages of conversational interactions we propose CE-SAM (Controlled English Sensor Assignment to Missions), a system that guides users through refining and satisfying their information needs in the context of Intelligence, Surveillance, and Reconnaissance (ISR) operations. The rapidly-increasing availability of sensing assets and other information sources poses substantial challenges to effective ISR resource management. In a coalition context, the problem is even more complex, because assets may be "owned" by different partners. We show how CE-SAM allows a user to refine and relate their ISR information needs to pre-existing concepts in an ISR knowledge base, via conversational interaction implemented on a tablet device. The knowledge base is represented using Controlled English (CE) - a form of controlled natural language that is both human-readable and machine processable (i.e. can be used to implement automated reasoning). Users interact with the CE-SAM conversational interface using natural language, which the system converts to CE for feeding-back to the user for confirmation (e.g. to reduce misunderstanding). We show that this process not only allows users to access the assets that can support their mission needs, but also assists them in extending the CE knowledge base with new concepts.

Characterization of the Candida albicans Amino Acid Permease Family: Gap2 Is the Only General Amino Acid Permease and Gap4 Is an S-Adenosylmethionine (SAM) Transporter Required for SAM-Induced Morphogenesis.

PubMed

Kraidlova, Lucie; Schrevens, Sanne; Tournu, Hélène; Van Zeebroeck, Griet; Sychrova, Hana; Van Dijck, Patrick

2016-01-01

Amino acids are key sources of nitrogen for growth of Candida albicans . In order to detect and take up these amino acids from a broad range of different and changing nitrogen sources inside the host, this fungus must be able to adapt via its expression of genes for amino acid uptake and further metabolism. We analyzed six C. albicans putative general amino acid permeases based on their homology to the Saccharomyces cerevisiae Gap1 general amino acid permease. We generated single- and multiple-deletion strains and found that, based on growth assays and transcriptional or posttranscriptional regulation, Gap2 is the functional orthologue to Sc Gap1, with broad substrate specificity. Expression analysis showed that expression of all GAP genes is under control of the Csy1 amino acid sensor, which is different from the situation in S. cerevisiae , where the expression of ScGAP1 is not regulated by Ssy1. We show that Gap4 is the functional orthologue of Sc Sam3, the only S -adenosylmethionine (SAM) transporter in S. cerevisiae , and we report that Gap4 is required for SAM-induced morphogenesis. IMPORTANCE Candida albicans is a commensal organism that can thrive in many niches in its human host. The environmental conditions at these different niches differ quite a bit, and this fungus must be able to sense these changes and adapt its metabolism to them. Apart from glucose and other sugars, the uptake of amino acids is very important. This is underscored by the fact that the C. albicans genome encodes 6 orthologues of the Saccharomyces. cerevisiae general amino acid permease Gap1 and many other amino acid transporters. In this work, we characterize these six permeases and we show that C. albicans Gap2 is the functional orthologue of Sc Gap1 and that C. albicans Gap4 is an orthologue of Sc Sam3, an S -adenosylmethionine (SAM) transporter. Furthermore, we show that Gap4 is required for SAM-induced morphogenesis, an important virulence factor of C. albicans .

Mars2020 Entry, Descent, and Landing Instrumentation (MEDLI2): Science Objectives and Instrument Requirements

NASA Technical Reports Server (NTRS)

Bose, Deepak; White, Todd; Schoenenberger, Mark; Karlgaard, Chris; Wright, Henry

2015-01-01

NASAs exploration and technology roadmaps call for capability advancements in Mars entry, descent, and landing (EDL) systems to enable increased landed mass, a higher landing precision, and a wider planetary access. It is also recognized that these ambitious EDL performance goals must be met while maintaining a low mission risk in order to pave the way for future human missions. As NASA is engaged in developing new EDL systems and technologies via testing at Earth, instrumentation of existing Mars missions is providing valuable engineering data for performance improvement, risk reduction, and an improved definition of entry loads and environment. The most notable recent example is the Mars Entry, Descent and Landing Instrument (MEDLI) suite hosted by Mars Science Laboratory for its entry in Aug 2012. The MEDLI suite provided a comprehensive dataset for Mars entry aerodynamics, aerothermodynamics and thermal protection system (TPS) performance. MEDLI data has since been used for unprecedented reconstruction of aerodynamic drag, vehicle attitude, in-situ atmospheric density, aerothermal heating, and transition to turbulence, in-depth TPS performance and TPS ablation. [1,2] In addition to validating predictive models, MEDLI data has demonstrated extra margin available in the MSL forebody TPS, which can potentially be used to reduce vehicle parasitic mass. The presentation will introduce a follow-on MEDLI instrumentation suite (called MEDLI2) that is being developed for Mars-2020 mission. MEDLI2 has an enhanced scope that includes backshell instrumentation, a wider forebody coverage, and instruments that specifically target supersonic aerodynamics. Similar to MEDLI, MEDLI2 uses thermal plugs with embedded thermocouples and ports through the TPS to measure surface pressure. MEDLI2, however, also includes heat flux sensors in the backshell and a low range pressure transducer to measure afterbody pressure.

Evidence for S-adenosyl-L-methionine (SAM-e) for the treatment of major depressive disorder.

PubMed

Papakostas, George I

2009-01-01

Despite the increasingly large array of antidepressants available to treat major depressive disorder, patients continue to experience relatively modest response and remission rates. In addition, patients may experience adverse side effects from pharmacotherapy that not only hinder treatment compliance and adherence but, in some cases, may also contribute to increased disability, patient suffering, morbidity, and mortality. In order to enhance treatment efficacy and tolerability, patients and clinicians have become increasingly interested in nonpharmaceutical supplements for treating depression. One of the best-studied of these supplements is S-adenosyl-L-methionine (SAM-e), a naturally occurring molecule present in all living cells and a major methyl group donor in the human body. Controlled trials have found SAM-e to be more efficacious than placebo and equal in efficacy to the tricyclic antidepressants for treating major depressive disorder (MDD) when administered parenterally (either intravenously or intramuscularly). Less evidence supports the use of oral SAM-e, although some trials have demonstrated its efficacy as well. In addition, there is a paucity of evidence examining whether oral forms of SAM-e can be safe, well tolerated, and efficacious when used as adjunctive treatment for antidepressant nonresponders with MDD. Although preliminary data suggest SAM-e may be useful as an adjunctive therapy to antidepressants, controlled studies are needed to confirm or refute these preliminary findings. (c) Copyright 2009 Physicians Postgraduate Press, Inc.

Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurup, Parthiv; Turchi, Craig S.

2015-11-01

This report updates the baseline cost for parabolic trough solar fields in the United States within NREL's System Advisor Model (SAM). SAM, available at no cost at https://sam.nrel.gov/, is a performance and financial model designed to facilitate decision making for people involved in the renewable energy industry. SAM is the primary tool used by NREL and the U.S. Department of Energy (DOE) for estimating the performance and cost of concentrating solar power (CSP) technologies and projects. The study performed a bottom-up build and cost estimate for two state-of-the-art parabolic trough designs -- the SkyTrough and the Ultimate Trough. The SkyTroughmore » analysis estimated the potential installed cost for a solar field of 1500 SCAs as $170/m 2 +/- $6/m 2. The investigation found that SkyTrough installed costs were sensitive to factors such as raw aluminum alloy cost and production volume. For example, in the case of the SkyTrough, the installed cost would rise to nearly $210/m 2 if the aluminum alloy cost was $1.70/lb instead of $1.03/lb. Accordingly, one must be aware of fluctuations in the relevant commodities markets to track system cost over time. The estimated installed cost for the Ultimate Trough was only slightly higher at $178/m 2, which includes an assembly facility of $11.6 million amortized over the required production volume. Considering the size and overall cost of a 700 SCA Ultimate Trough solar field, two parallel production lines in a fully covered assembly facility, each with the specific torque box, module and mirror jigs, would be justified for a full CSP plant.« less

Ultraviolet Testing of Space Suit Materials for Mars

NASA Technical Reports Server (NTRS)

Larson, Kristine; Fries, Marc

2017-01-01

Human missions to Mars may require radical changes in the approach to extra-vehicular (EVA) suit design. A major challenge is the balance of building a suit robust enough to complete multiple EVAs under intense ultraviolet (UV) light exposure without losing mechanical strength or compromising the suit's mobility. To study how the materials degrade on Mars in-situ, the Jet Propulsion Laboratory (JPL) invited the Advanced Space Suit team at NASA's Johnson Space Center (JSC) to place space suit materials on the Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals (SHERLOC) instrument's calibration target of the Mars 2020 rover. In order to select materials for the rover and understand the effects from Mars equivalent UV exposure, JSC conducted ground testing on both current and new space suit materials when exposed to 2500 hours of Mars mission equivalent UV. To complete this testing, JSC partnered with NASA's Marshall Space Flight Center to utilize their UV vacuum chambers. Materials tested were Orthofabric, polycarbonate, Teflon, Dacron, Vectran, spectra, bladder, nGimat coated Teflon, and nGimat coated Orthofabric. All samples were measured for mass, tensile strength, and chemical composition before and after radiation. Mass loss was insignificant (less than 0.5%) among the materials. Most materials loss tensile strength after radiation and became more brittle with a loss of elongation. Changes in chemical composition were seen in all radiated materials through Spectral Analysis. Results from this testing helped select the materials that will fly on the Mars 2020 rover. In addition, JSC can use this data to create a correlation to the chemical changes after radiation-which is what the rover will send back while on Mars-to the mechanical changes, such as tensile strength.

Generation of induced pluripotent stem cells (iPSCs) stably expressing CRISPR-based synergistic activation mediator (SAM).

PubMed

Xiong, Kai; Zhou, Yan; Hyttel, Poul; Bolund, Lars; Freude, Kristine Karla; Luo, Yonglun

2016-11-01

Human fibroblasts were engineered to express the CRISPR-based synergistic activation mediator (SAM) complex: dCas9-VP64 and MS2-P65-HSF1. Two induced pluripotent stem cells (iPSCs) clones expressing SAM were established by transducing these fibroblasts with lentivirus expressing OCT4, SOX2, KLF4 and C-MYC. We have validated that the reprogramming cassette is silenced in the SAM iPSC clones. Expression of pluripotency genes (OCT4, SOX2, LIN28A, NANOG, GDF3, SSEA4, and TRA-1-60), differentiation potential to all three germ layers, and normal karyotypes are validated. These SAM-iPSCs provide a novel, useful tool to investigate genetic regulation of stem cell proliferation and differentiation through CRISPR-mediated activation of endogenous genes. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

Capabilities, performance, and status of the SOFIA science instrument suite

NASA Astrophysics Data System (ADS)

Miles, John W.; Helton, L. Andrew; Sankrit, Ravi; Andersson, B. G.; Becklin, E. E.; De Buizer, James M.; Dowell, C. D.; Dunham, Edward W.; Güsten, Rolf; Harper, Doyal A.; Herter, Terry L.; Keller, Luke D.; Klein, Randolf; Krabbe, Alfred; Marcum, Pamela M.; McLean, Ian S.; Reach, William T.; Richter, Matthew J.; Roellig, Thomas L.; Sandell, Göran; Savage, Maureen L.; Smith, Erin C.; Temi, Pasquale; Vacca, William D.; Vaillancourt, John E.; Van Cleve, Jeffery E.; Young, Erick T.; Zell, Peter T.

2013-09-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airborne observatory, carrying a 2.5 m telescope onboard a heavily modified Boeing 747SP aircraft. SOFIA is optimized for operation at infrared wavelengths, much of which is obscured for ground-based observatories by atmospheric water vapor. The SOFIA science instrument complement consists of seven instruments: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), GREAT (German Receiver for Astronomy at Terahertz Frequencies), HIPO (High-speed Imaging Photometer for Occultations), FLITECAM (First Light Infrared Test Experiment CAMera), FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), EXES (Echelon-Cross-Echelle Spectrograph), and HAWC (High-resolution Airborne Wideband Camera). FORCAST is a 5-40 μm imager with grism spectroscopy, developed at Cornell University. GREAT is a heterodyne spectrometer providing high-resolution spectroscopy in several bands from 60-240 μm, developed at the Max Planck Institute for Radio Astronomy. HIPO is a 0.3-1.1 μm imager, developed at Lowell Observatory. FLITECAM is a 1-5 μm wide-field imager with grism spectroscopy, developed at UCLA. FIFI-LS is a 42-210 μm integral field imaging grating spectrometer, developed at the University of Stuttgart. EXES is a 5-28 μm high-resolution spectrograph, developed at UC Davis and NASA ARC. HAWC is a 50-240 μm imager, developed at the University of Chicago, and undergoing an upgrade at JPL to add polarimetry capability and substantially larger GSFC detectors. We describe the capabilities, performance, and status of each instrument, highlighting science results obtained using FORCAST, GREAT, and HIPO during SOFIA Early Science observations conducted in 2011.

Data from the Mars Science Laboratory CheMin XRD/XRF Instrument

NASA Technical Reports Server (NTRS)

Vaniman, David; Blake, David; Bristow, Tom; DesMarais, David; Achilles, Cherie; Anderson, Robert; Crips, Joy; Morookian, John Michael; Spanovich, Nicole; Vasavada, Ashwin;

The senescence-accelerated mouse prone-8 (SAM-P8) oxidative stress is associated with upregulation of renal NADPH oxidase system.

PubMed

Baltanás, Ana; Solesio, Maria E; Zalba, Guillermo; Galindo, María F; Fortuño, Ana; Jordán, Joaquín

2013-12-01

Herein, we investigate whether the NADPH oxidase might be playing a key role in the degree of oxidative stress in the senescence-accelerated mouse prone-8 (SAM-P8). To this end, the activity and expression of the NADPH oxidase, the ratio of glutathione and glutathione disulfides (GSH/GSSG), and the levels of malonyl dialdehyde (MDA) and nitrotyrosine (NT) were determined in renal tissue from SAM-P8 mice at the age of 1 and 6 months. The senescence-accelerated-resistant mouse (SAM-R1) was used as control. At the age of 1 month, NADPH oxidase activity and Nox2 protein expression were higher in SAM-P8 than in SAM-R1 mice. However, we found no differences in the GSH/GSSG ratio, MDA, NT, and Nox4 levels between both groups of animals. At the age of 6 months, SAM-R1 mice in comparison to SAM-P8 mice showed an increase in NADPH oxidase activity, which is associated with higher levels of NT and increased Nox4 and Nox2 expression levels. Furthermore, we found oxidative stress hallmarks including depletion in GSH/GSSG ratio and increase in MDA levels in the kidney of SAM-P8 mice. Finally, NADPH oxidase activity positively correlated with Nox2 expression in all the animals (r = 0.382, P < 0.05). Taken together, our data allow us to suggest that an increase in NADPH oxidase activity might be an early hallmark to predict future oxidative stress in renal tissue during the aging process that takes place in SAM-P8 mice.

Consensus Statement National Consensus Workshop on Management of SAM Children through Medical Nutrition Therapy.

PubMed

Sachdev, H P S; Kapil, Umesh; Vir, Sheila

2010-08-01

Severe acute malnutrition (SAM) is an important preventable and treatable cause of morbidity and mortality in children below five years of age in India. The concerned stakeholders are not in agreement about the role of product based medical nutrition therapy in the management of this condition. In November 2009, a National Consensus Workshop was organized by the Department of Human Nutrition, All India Institute of Medical Sciences, New Delhi in collaboration with the Department of Pediatrics and Clinical Epidemiology, Sitaram Bhartia Institute of Science and Research, New Delhi, and the Sub-specialty Chapter on Nutrition, Indian Academy of Pediatrics. Presentations by eminent national and international scientists, the ensuing discussions, and opinions expressed by the participants provided the basic framework for drafting the consensus statement. The draft of the consensus statement was circulated to all the participants; it underwent two revisions after consideration of their comments. (i) Critically appraise the current global evidence on the utility of Medical Nutrition Therapy (MNT) for the management of SAM in under five children; (ii) Formulate a consensus amongst stakeholders regarding the need to introduce product based MNT for the management of SAM in under five children in India; (iii) Identify research priorities for MNT for the management of SAM in under five children in India; and (iv)Ascertain potential challenges for introducing product based MNT in India, if consensus opinion identifies such a need. Guidelines related to the role of MNT in management of children suffering from SAM are presented. Global and regional data document the effectiveness of MNT using ready-to-use therapeutic foods (RUTF) and locally formulated products. Adequate caution should be exercised to ensure that MNT for SAM does not interfere with measures for the holistic prevention of childhood undernutrition. Indian manufacture of RUTF is feasible, and can be scaled up. Product

Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation.

PubMed

Zhang, Hua; Song, Lei; Cong, Haolong; Tien, Po

2015-10-01

Enterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES) trans-acting factor (ITAF) that binds specifically to the EV71 5' untranslated region (5'UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation. The nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection and could potentially

OARE and SAMS on STS-94/MSL-1

NASA Technical Reports Server (NTRS)

Moskowitz, Milton; Hrovat, Kenneth; McPherson, Kevin; Tschen, Peter; DeLombard, Richard; Nati, Maurizio

1998-01-01

Four microgravity acceleration measurement instruments were included on MSL-1 to measure the accelerations and vibrations to which science experiments were exposed during their operation on the mission. The data were processed and presented to the principal investigators in a variety of formats to aid their assessment of the microgravity environment during their experiment operations. Two accelerometer systems managed by the NASA Lewis Research Center (LeRC) supported the MSL-1 mission: the Orbital Acceleration Research Experiment (OARE), and the Space Acceleration Measurement System (SAMS). In addition, the Microgravity Measurement Assembly (MMA) and the Quasi- Steady Acceleration Measurement (QSAM) system, both sponsored by the Microgravity Research Division, collected acceleration data as a part of the MSL-1 mission. The NIMA was funded and designed by the European Space Agency in the Netherlands (ESA/ESTEC), and the QSAM system was funded and designed by the German Space Agency (DLR). The Principal Investigator Microgravity Services (PIMS) project at the NASA Lewis Research Center (LeRC) supports Principal Investigators (PIs) of the Microgravity science community as they evaluate the effects of acceleration on their experiments. PIMS primary responsibility is to support NASA-sponsored investigators in the area of acceleration data analysis and interpretation. A mission summary report was prepared and published by PIMS in order to furnish interested experiment investigators with a guide for evaluating the acceleration environment during the MSL-1 mission.

A Response to Sam McKegney's "Strategies for Ethical Engagement: An Open Letter Concerning Non-Native Scholars of Native Literatures"

ERIC Educational Resources Information Center

Appleford, Rob

2009-01-01

This article presents the author's response to Sam McKegney's "Strategies for Ethical Engagement: An Open Letter Concerning Non-Native Scholars of Native Literatures." In his response to Sam's diagnosis of the malaise currently afflicting non-Aboriginal critics of this literature, the author attempts to consider the "cure" Sam offers (albeit…

Evaluating the effectiveness of self-administration of medication (SAM) schemes in the hospital setting: a systematic review of the literature.

PubMed

Richardson, Suzanna J; Brooks, Hannah L; Bramley, George; Coleman, Jamie J

2014-01-01

Self-administration of medicines is believed to increase patients' understanding about their medication and to promote their independence and autonomy in the hospital setting. The effect of inpatient self-administration of medication (SAM) schemes on patients, staff and institutions is currently unclear. To systematically review the literature relating to the effect of SAM schemes on the following outcomes: patient knowledge, patient compliance/medication errors, success in self-administration, patient satisfaction, staff satisfaction, staff workload, and costs. Keyword and text word searches of online databases were performed between January and March 2013. Included articles described and evaluated inpatient SAM schemes. Case studies and anecdotal studies were excluded. 43 papers were included for final analysis. Due to the heterogeneity of results and unclear findings it was not possible to perform a quantitative synthesis of results. Participation in SAM schemes often led to increased knowledge about drugs and drug regimens, but not side effects. However, the effect of SAM schemes on patient compliance/medication errors was inconclusive. Patients and staff were highly satisfied with their involvement in SAM schemes. SAM schemes appear to provide some benefits (e.g. increased patient knowledge), but their effect on other outcomes (e.g. compliance) is unclear. Few studies of high methodological quality using validated outcome measures exist. Inconsistencies in both measuring and reporting outcomes across studies make it challenging to compare results and draw substantive conclusions about the effectiveness of SAM schemes.

The History of the Austin College Building and Old Main at Sam Houston State University

ERIC Educational Resources Information Center

Singer, Erin; Shields, Samantha

2017-01-01

Austin Hall and Old Main serve as the heart of what is now Sam Houston State University. The buildings' rich histories help one to understand how Sam Houston State University and its proud teacher education heritage came to be. To begin with Austin Hall's story, the University's original building has a unique and interesting tale that journeys…

The SAM domain of ANKS6 has different interacting partners and mutations can induce different cystic phenotypes.

PubMed

Bakey, Zeineb; Bihoreau, Marie-Thérèse; Piedagnel, Rémi; Delestré, Laure; Arnould, Catherine; de Villiers, Alexandre d'Hotman; Devuyst, Olivier; Hoffmann, Sigrid; Ronco, Pierre; Gauguier, Dominique; Lelongt, Brigitte

2015-08-01

The ankyrin repeat and sterile α motif (SAM) domain-containing six gene (Anks6) is a candidate for polycystic kidney disease (PKD). Originally identified in the PKD/Mhm(cy/+) rat model of PKD, the disease is caused by a mutation (R823W) in the SAM domain of the encoded protein. Recent studies support the etiological role of the ANKS6 SAM domain in human cystic diseases, but its function in kidney remains unknown. To investigate the role of ANKS6 in cyst formation, we screened an archive of N-ethyl-N-nitrosourea-treated mice and derived a strain carrying a missense mutation (I747N) within the SAM domain of ANKS6. This mutation is only six amino acids away from the PKD-causing mutation (R823W) in cy/+ rats. Evidence of renal cysts in these mice confirmed the crucial role of the SAM domain of ANKS6 in kidney function. Comparative phenotype analysis in cy/+ rats and our Anks6(I747N) mice further showed that the two models display noticeably different PKD phenotypes and that there is a defective interaction between ANKS6 with ANKS3 in the rat and between ANKS6 and BICC1 (bicaudal C homolog 1) in the mouse. Thus, our data demonstrate the importance of ANKS6 for kidney structure integrity and the essential mediating role of its SAM domain in the formation of protein complexes.

Search for nitrates on Mars by the Sample Analysis at Mars (SAM) Instrument

NASA Astrophysics Data System (ADS)

Navarro-Gonzalez, Rafael

One of the main goals of the Mars Science Laboratory is to determine whether the planet ever had environmental conditions capable of supporting microbial life. Nitrogen is a fundamental element for life, and is present in structural (e.g., proteins), catalytic (e.g., enzymes and ribozymes), energy transfer (e.g., ATP) and information storage (RNA and DNA) bio-molecules. Planetary models suggest that nitrogen was abundant in the early Martian atmosphere as dinitrogen (N _{2}). However, a fraction of N _{2} has been lost to space by sputtering and photochemical processes [1, 2], impact erosion [3], and chemical oxidation to nitrates [4, 5]. Nitrates produced early in Mars’ history by photochemistry may later decompose back into N _{2} by the current impact flux [6]. It is estimated that the Martian surface could contain soil nitrates at levels of 0.3 wt.% N, if mixed homogenously [6], or a layer of pure NaNO _{3} of about 3 m thickness [5] distributed globally. Nitrates are a fundamental source for nitrogen for terrestrial microorganisms. Therefore, the detection of soil nitrates is important to assess habitability in the Martian environment. The only previous attempt to search for soil nitrates was by TEGA and the MECA WCL on the Phoenix mission but no evolved N-containing species were detected [7]. Nitrates have been tentatively identified in two Martian meteorites: Nakhla [8] and EETA79001 [9]. SAM is capable of detecting nitrates by their thermal decomposition into nitric oxide, NO. SAM analyzed samples from Rocknest soil and two drill holes located at John Klein (JK) and Cumberland (CB) mudstones in the Sheepbed member of the Yellowknife Bay formation in Gale Crater. There appear to be several peaks associated with the release of m/z 30 in the temperature range from 150(°) °C to 600(°) °C. M/z 30 can be attributed to nitric oxide; however, other possible chemical interferences may be present, such as ethane (C _{2}H _{6}), formaldehyde (HCHO), diazene (N

A pilot study investigating the feasibility of symptom assessment manager (SAM), a Web-based real-time tool for monitoring challenging behaviors.

PubMed

Loi, Samantha M; Wanasinghage, Sangeeth; Goh, Anita; Lautenschlager, Nicola T; Darby, David G; Velakoulis, Dennis

2018-04-01

Improving and minimizing challenging behaviors seen in psychiatric conditions, including behavioral and psychological symptoms of dementia are important in the care of people with these conditions. Yet there is a lack of systematic evaluation of these as a part of routine clinical care. The Neuropsychiatric Inventory is a validated and reliable tool for rating the severity and disruptiveness of challenging behaviors. We report on the evaluation of a Web-based symptom assessment manager (SAM), designed to address the limitation of previous tools using some of the Neuropsychiatric Inventory functions, to monitor behaviors by staff caring for people with dementia and other psychiatric conditions in inpatient and residential care settings. The SAM was piloted in an 8-bed inpatient neuropsychiatry unit over 5 months. Eleven nurses and 4 clinicians were trained in usage of SAM. Primary outcomes were usage of SAM and perceived usability, utility, and acceptance of SAM. Secondary outcomes were the frequencies of documented behavior. Usage data were analyzed using chi-square and logistic regression analyses. The SAM was used for all admitted patients regardless of diagnosis, with a usage rate of 64% for nurses regularly employed in the unit. Staff provided positive feedback regarding the utility of SAM. The SAM appeared to offer individualized behavior assessment by providing a quick, structured, and standardized platform for assessing behavior in a real-world setting. Further research would involve trialing SAM with more staff in alternative settings such as in home or residential care settings. Copyright © 2017 John Wiley & Sons, Ltd.

Assessing the impact of mineralogy on our ability to detect organic salts in Gale Crater, Mars, through thermal analyses.

NASA Astrophysics Data System (ADS)

Lewis, J. M. T.; Eigenbrode, J. L.; Franz, H. B.; Sutter, B.; Niles, P. B.; McAdam, A.

2016-12-01

Organic matter present in martian sediments analyzed by the Sample Analysis at Mars (SAM) instrument suite on the Curiosity rover and in martian meteorites suggests that there may be a widespread presence of organic molecules on the surface of Mars. This organic pool may be derived from exogenous sources such as interplanetary dust particles and from indigenous processes such as volcanism, serpentinization and life, if it has ever existed on Mars. Direct detection of an ancient organic geochemical record in martian materials is challenged by two issues. First, alteration at the surface can compromise organic matter preservation. It is expected that unprotected organic compounds undergo partial oxidative diagenesis, spurred by ionizing radiation and oxidants, to metastable organic salts (e.g., iron acetate, calcium oxalate, and sodium phthalate). Such organic salts are not directly detectable by pyrolysis, producing only CO2 and CO during heating. Second, exposed organic compounds in the SAM oven, i.e., those available for reaction, are susceptible to oxidation and chlorination by perchlorates, which are thought to be ubiquitous on Mars. In order to assess whether CO2 and CO may be derived from organic salts, as opposed to combustion of other organics or mineral decomposition, a comprehensive understanding of how sample mineralogy influences their decomposition profiles is required. Simplified mineral matrices, consistent with those detected by Curiosity's Chemistry and Mineralogy instrument or inferred from SAM instrument analyses, were prepared and mixed with standards of several organic salts expected to be present on Mars. The mixtures were then analyzed under SAM-like analytical conditions. Results address the influence of iron and sulfur mineralogies and perchlorate salts on the decomposition of metastable organic salts. The results are related to the interpretation of the sub-400 °C CO2 and CO observed by SAM that may be derived from these organic salts.

Curiosity's Sample Analysis at Mars (SAM) Investigation: Overview of Results from the First 120 Sols on Mars

NASA Technical Reports Server (NTRS)

Mahaffy, P. R.; Cabane, M.; Webster, C. R.; Archer, P. D.; Atreya, S. K.; Benna, M.; Brinckerhoff, W. B.; Brunner, A. E.; Buch, A.; Coll, P.;

Ligand-Induced Stabilization of a Duplex-like Architecture Is Crucial for the Switching Mechanism of the SAM-III Riboswitch.

PubMed

Suresh, Gorle; Srinivasan, Harini; Nanda, Shivani; Priyakumar, U Deva

2016-06-21

Riboswitches are structured RNA motifs that control gene expression by sensing the concentrations of specific metabolites and make up a promising new class of antibiotic targets. S-Adenosylmethionine (SAM)-III riboswitch, mainly found in lactic acid bacteria, is involved in regulating methionine and SAM biosynthetic pathways. SAM-III riboswitch regulates the gene expression by switching the translation process on and off with respect to the absence and presence of the SAM ligand, respectively. In this study, an attempt is made to understand the key conformational transitions involved in ligand binding using atomistic molecular dynamics (MD) simulations performed in an explicit solvent environment. G26 is found to recognize the SAM ligand by forming hydrogen bonds, whereas the absence of the ligand leads to opening of the binding pocket. Consistent with experimental results, the absence of the SAM ligand weakens the base pairing interactions between the nucleobases that are part of the Shine-Dalgarno (SD) and anti-Shine-Dalgarno (aSD) sequences, which in turn facilitates recognition of the SD sequence by ribosomes. Detailed analysis reveals that a duplex-like structure formed by nucleotides from different parts of the RNA and the adenine base of the ligand is crucial for the stability of the completely folded state in the presence of the ligand. Previous experimental studies have shown that the SAM-III riboswitch exists in equilibrium between the unfolded and partially folded states in the absence of the ligand, which completely folds upon binding of the ligand. Comparison of the results presented here to the available experimental data indicates the structures obtained using the MD simulations resemble the partially folded state. Thus, this study provides a detailed understanding of the fully and partially folded structures of the SAM-III riboswitch in the presence and absence of the ligand, respectively. This study hypothesizes a dual role for the SAM ligand

Characterization of the near native conformational states of the SAM domain of Ste11 protein by NMR spectroscopy.

PubMed

Gupta, Sebanti; Bhattacharjya, Surajit

2014-11-01

The sterile alpha motif or SAM domain is one of the most frequently present protein interaction modules with diverse functional attributions. SAM domain of the Ste11 protein of budding yeast plays important roles in mitogen-activated protein kinase cascades. In the current study, urea-induced, at subdenaturing concentrations, structural, and dynamical changes in the Ste11 SAM domain have been investigated by nuclear magnetic resonance spectroscopy. Our study revealed that a number of residues from Helix 1 and Helix 5 of the Ste11 SAM domain display plausible alternate conformational states and largest chemical shift perturbations at low urea concentrations. Amide proton (H/D) exchange experiments indicated that Helix 1, loop, and Helix 5 become more susceptible to solvent exchange with increased concentrations of urea. Notably, Helix 1 and Helix 5 are directly involved in binding interactions of the Ste11 SAM domain. Our data further demonstrate that the existence of alternate conformational states around the regions involved in dimeric interactions in native or near native conditions. © 2014 Wiley Periodicals, Inc.

Toposelective electrochemical desorption of thiol SAMs from neighboring polycrystalline gold surfaces.

PubMed

Tencer, Michal; Berini, Pierre

2008-11-04

We describe a method for the selective desorption of thiol self-assembled monolayers from gold surfaces having micrometer-scale separations on a substrate. In an electrolyte solution, the electrical resistance between the adjacent areas can be much lower than the resistance between a surface and the counter electrode. Also, both reductive and oxidative thiol desorption may occur. Therefore, the potentials of the surfaces must be independently controlled with a multichannel potentiostat and operating windows for a given thiol/electrolyte system must be established. In this study operating windows were established for 1-dodecanethiol-based SAMs in phosphate buffer, phosphate-buffered saline, and sodium hydroxide solution, and selective SAM removal was successfully performed in a four-electrode configuration.

Walking a mile in another's shoes: The impact of wearing an Age Suit.

PubMed

Lavallière, Martin; D'Ambrosio, Lisa; Gennis, Angelina; Burstein, Arielle; Godfrey, Kathryn M; Waerstad, Hilde; Puleo, Rozanne M; Lauenroth, Andreas; Coughlin, Joseph F

2017-01-01

The "Age Suit" described in this article was developed to enable future designers, business leaders, and engineers to experience navigating the world as many older adults must. Tools such as this Age Suit offer the opportunity to "walk a mile" in another's shoes to develop empathy that can result in better design of spaces, goods, and services to meet the needs of a rapidly growing older population. This work first examined, through a series of clinical tests, whether younger adults' physical capacities were reduced in a direction consistent with aging by wearing a suit developed by the MIT AgeLab. An experiential learning task was then completed with the suit to understand its impact on completion of an instrumental activity of daily living. Results showed that younger adults wearing the suit experienced changes in task performance consistent with expected changes associated with aging. Participants' self-reports from the experiential learning task indicated that they were able to empathize with older adults regarding some issues they face while completing a grocery shopping task. Future research with the suit should involve a wider range of individuals from the population and examine what effect participants' levels of fitness have on the experience of wearing the suit.

Updates to Selected Analytical Methods for Environmental Remediation and Recovery (SAM)

EPA Pesticide Factsheets

View information on the latest updates to methods included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM), including the newest recommended methods and publications.

The Scintillation and Tomography Receiver in Space (CITRIS) Instrument for Ionospheric Research

DTIC Science & Technology

2008-01-01

Z39-18 220 2008 NRL REVIEW REMOTE SENSING The Scintillation and Tomography Receiver in Space (CITRIS) Instrument for Ionospheric Research P.A...Scintillation and Tomography Receiver in Space (CITRIS) is currently in orbit sam- pling the ionosphere . CITRIS was developed at NRL to (a) permit...Koch, T.L. MacDonald, M.R. Wilkens, and G.P. Landis, “ Ionospheric Applications of the Scintillation and Tomography Receiver in Space (CITRIS

77 FR 67813 - Sam Rayburn Dam Project Power Rate

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-14

... period January 1, 2009, through September 30, 2012. However, the current rate schedule will expire...) prepared a 2012 Current Power Repayment Study using the existing Sam Rayburn Dam Project rate schedule and... because the current rate expires September 30, 2012. Southwestern will reevaluate the ability of the...

The VLF Wave and Particle Precipitation Mapper (VPM) Cubesat Payload Suite

NASA Astrophysics Data System (ADS)

Inan, U.; Linscott, I.; Marshall, R. A.; Lauben, D.; Starks, M. J.; Doolittle, J. H.

2012-12-01

The VLF Wave and Particle Precipitation Mapper (VPM) payload is under development at Stanford University for a Cubesat mission that is planned to fly in low-earth-orbit in 2015. The VPM payload suite includes a 2-meter electric-field dipole antenna; a single-axis magnetic search coil; and a two-channel relativistic electron detector, measuring both trapped and loss-cone electrons. VPM will measure waves and relativistic electrons with the following primary goals: i) develop an improved climatology of plasmaspheric hiss in the L-shell range 1 < L < 3 at all local times; ii) detect VLF waves launched by space-based VLF transmitters, as well as energetic electrons scattered by those in-situ injected waves; iii) develop an improved climatology of lightning-generated whistlers and lightning-induced electron precipitation; iv)measure waves and electron precipitation produced by ground-based VLF transmitters; and v) validate propagation and wave-particle interaction models. In this paper we outline these science objectives of the VPM payload instrument suite, and describe the payload instruments and data products that will meet these science goals.

Human Viperin Causes Radical SAM-Dependent Elongation of Escherichia coli, Hinting at Its Physiological Role.

PubMed

Nelp, Micah T; Young, Anthony P; Stepanski, Branden M; Bandarian, Vahe

2017-08-01

Viperin (virus inhibitory protein, endoplasmic reticulum-associated, interferon-inducible) is a widely distributed protein that is expressed in response to infection and causes antiviral effects against a broad spectrum of viruses. Viperin is a member of the radical S-adenosyl-l-methionine (SAM) superfamily of enzymes, which typically employ a 4Fe-4S cluster to reductively cleave SAM to initiate chemistry. Though the specific reaction catalyzed by viperin remains unknown, it has been shown that expression of viperin causes an increase in the fluidity of lipid membranes, which impedes the budding of nascent viral particles from the membrane inhibiting propagation of the infection. Herein, we show that expression of the human viperin homologue induces a dramatically elongated morphology of the host Escherichia coli cells. Mutation of an essential cysteine that coordinates the radical SAM cluster abrogates this effect. Thus, the native radical SAM activity of viperin is likely occurring in the host bacteria, indicating the elusive substrate is shared between both bacteria and humans, significantly narrowing the range of potential candidate substrates and providing a convenient bacterial platform from which future studies can occur.

Music Education Suites.

ERIC Educational Resources Information Center

Kemp, Wayne

This publication describes options for designing and equipping middle and high school music education suites and suggests means of gaining community support for including full service music suites in new and renovated facilities. It covers the basic music suite, practice rooms, small ensemble rehearsal rooms, recording/MIDI (musical instrument…

Human Cataract Mutations in EPHA2 SAM Domain Alter Receptor Stability and Function

PubMed Central

Park, Jeong Eun; Son, Alexander I.; Hua, Rui; Wang, Lianqing; Zhang, Xue; Zhou, Renping

2012-01-01

The cellular and molecular mechanisms underlying the pathogenesis of cataracts leading to visual impairment remain poorly understood. In recent studies, several mutations in the cytoplasmic sterile-α-motif (SAM) domain of human EPHA2 on chromosome 1p36 have been associated with hereditary cataracts in several families. Here, we have investigated how these SAM domain mutations affect EPHA2 activity. We showed that the SAM domain mutations dramatically destabilized the EPHA2 protein in a proteasome-dependent pathway, as evidenced by the increase of EPHA2 receptor levels in the presence of the proteasome inhibitor MG132. In addition, the expression of wild-type EPHA2 promoted the migration of the mouse lens epithelial αTN4-1 cells in the absence of ligand stimulation, whereas the mutants exhibited significantly reduced activity. In contrast, stimulation of EPHA2 with its ligand ephrin-A5 eradicates the enhancement of cell migration accompanied by Akt activation. Taken together, our studies suggest that the SAM domain of the EPHA2 protein plays critical roles in enhancing the stability of EPHA2 by modulating the proteasome-dependent process. Furthermore, activation of Akt switches EPHA2 from promoting to inhibiting cell migration upon ephrin-A5 binding. Our results provide the first report of multiple EPHA2 cataract mutations contributing to the destabilization of the receptor and causing the loss of cell migration activity. PMID:22570727

Effect of the presence of chlorates and perchlorates on the pyrolysis of organic compounds: implications for measurements done with the SAM experiment onboard the Curiosity rover

NASA Astrophysics Data System (ADS)

Millan, Maeva; Szopa, Cyril; Buch, Arnaud; Belmahdi, Imène; Coll, Patrice; Glavin, Daniel P.; Freissinet, Caroline; Archer, Doug; Sutter, Brad; Summons, Roger E.; Navarro-Gonzalez, Rafael; Cabane, Michel; Mahaffy, Paul

2016-04-01

The Sample Analysis at Mars (SAM) experiment onboard the Curiosity rover of the Mars Science Laboratory mission is partly devoted to the in situ molecular analysis of gases evolving from solid samples collected on Mars surface/sub-surface. SAM has a gas-chromatograph coupled to a quadrupole mass spectrometer (GC-QMS) devoted to the separation and identification of organic and inorganic material [1]. Before proceeding to the GC-QMS analysis, the solid sample collected by Curiosity is subjected to a thermal treatment thanks to the pyrolysis oven to release the volatiles into the gas processing system. As the Viking landers in 1976 [2], SAM detected chlorohydrocarbons with the pyrolysis GC-QMS experiment [3,4]. The detection of perchlorates salts in soil at the Phoenix Landing site [6] suggests that these chlorohydrocarbons could come from the reaction of organics with oxychlorines. Oxychlorines indeed decomposed into molecular oxygen and volatile chlorine when heated and react with the organic matter in the samples by oxidation and/or chlorination processes. [3,5,7,8]. During SAM pyrolysis, samples are heated to 850°C. SAM detected C1 to C3 chloroalkanes, entirely attributed to reaction products occurring during the pyrolysis experiment between oxychlorines and organic carbon from instrument background [3] and chlorobenzene and C2 to C4 dichloroalkanes produced by reaction between Mars endogenous organics with oxychlorines [4]. To help understanding the influence of perchlorate and chlorate salts on organic matter during SAM pyrolysis, we systemically study the reaction products formed during pyrolysis of various organic compounds mixed with various perchlorates and chlorates. We selected organics from simple molecule forms as for instance PAHs and amino acids to complex material (>30 carbon atoms) such as kerogen. The perchlorate and chlorate salts are prepared at 1 wt % concentration in silica and mixed with the organics to study the potential qualitative and

SOFIA science instruments: commissioning, upgrades and future opportunities

NASA Astrophysics Data System (ADS)

Smith, Erin C.; Miles, John W.; Helton, L. Andrew; Sankrit, Ravi; Andersson, B. G.; Becklin, Eric E.; De Buizer, James M.; Dowell, C. D.; Dunham, Edward W.; Güsten, Rolf; Harper, Doyal A.; Herter, Terry L.; Keller, Luke D.; Klein, Randolf; Krabbe, Alfred; Logsdon, Sarah; Marcum, Pamela M.; McLean, Ian S.; Reach, William T.; Richter, Matthew J.; Roellig, Thomas L.; Sandell, Göran; Savage, Maureen L.; Temi, Pasquale; Vacca, William D.; Vaillancourt, John E.; Van Cleve, Jeffrey E.; Young, Erick T.

2014-07-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is the world's largest airborne observatory, featuring a 2.5 meter effective aperture telescope housed in the aft section of a Boeing 747SP aircraft. SOFIA's current instrument suite includes: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), a 5-40 μm dual band imager/grism spectrometer developed at Cornell University; HIPO (High-speed Imaging Photometer for Occultations), a 0.3-1.1μm imager built by Lowell Observatory; GREAT (German Receiver for Astronomy at Terahertz Frequencies), a multichannel heterodyne spectrometer from 60-240 μm, developed by a consortium led by the Max Planck Institute for Radio Astronomy; FLITECAM (First Light Infrared Test Experiment CAMera), a 1-5 μm wide-field imager/grism spectrometer developed at UCLA; FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), a 42-200 μm IFU grating spectrograph completed by University Stuttgart; and EXES (Echelon-Cross-Echelle Spectrograph), a 5-28 μm highresolution spectrometer designed at the University of Texas and being completed by UC Davis and NASA Ames Research Center. HAWC+ (High-resolution Airborne Wideband Camera) is a 50-240 μm imager that was originally developed at the University of Chicago as a first-generation instrument (HAWC), and is being upgraded at JPL to add polarimetry and new detectors developed at Goddard Space Flight Center (GSFC). SOFIA will continually update its instrument suite with new instrumentation, technology demonstration experiments and upgrades to the existing instrument suite. This paper details the current instrument capabilities and status, as well as the plans for future instrumentation.

V-SUIT Model Validation Using PLSS 1.0 Test Results

NASA Technical Reports Server (NTRS)

Olthoff, Claas

2015-01-01

The dynamic portable life support system (PLSS) simulation software Virtual Space Suit (V-SUIT) has been under development at the Technische Universitat Munchen since 2011 as a spin-off from the Virtual Habitat (V-HAB) project. The MATLAB(trademark)-based V-SUIT simulates space suit portable life support systems and their interaction with a detailed and also dynamic human model, as well as the dynamic external environment of a space suit moving on a planetary surface. To demonstrate the feasibility of a large, system level simulation like V-SUIT, a model of NASA's PLSS 1.0 prototype was created. This prototype was run through an extensive series of tests in 2011. Since the test setup was heavily instrumented, it produced a wealth of data making it ideal for model validation. The implemented model includes all components of the PLSS in both the ventilation and thermal loops. The major components are modeled in greater detail, while smaller and ancillary components are low fidelity black box models. The major components include the Rapid Cycle Amine (RCA) CO2 removal system, the Primary and Secondary Oxygen Assembly (POS/SOA), the Pressure Garment System Volume Simulator (PGSVS), the Human Metabolic Simulator (HMS), the heat exchanger between the ventilation and thermal loops, the Space Suit Water Membrane Evaporator (SWME) and finally the Liquid Cooling Garment Simulator (LCGS). Using the created model, dynamic simulations were performed using same test points also used during PLSS 1.0 testing. The results of the simulation were then compared to the test data with special focus on absolute values during the steady state phases and dynamic behavior during the transition between test points. Quantified simulation results are presented that demonstrate which areas of the V-SUIT model are in need of further refinement and those that are sufficiently close to the test results. Finally, lessons learned from the modelling and validation process are given in combination

SAM 2.1—A computer program for plotting and formatting surveying data for estimating peak discharges by the slope-area method

USGS Publications Warehouse

Hortness, J.E.

2004-01-01

The U.S. Geological Survey (USGS) measures discharge in streams using several methods. However, measurement of peak discharges is often impossible or impractical due to difficult access, inherent danger of making measurements during flood events, and timing often associated with flood events. Thus, many peak discharge values often are calculated after the fact by use of indirect methods. The most common indirect method for estimating peak dis- charges in streams is the slope-area method. This, like other indirect methods, requires measuring the flood profile through detailed surveys. Processing the survey data for efficient entry into computer streamflow models can be time demanding; SAM 2.1 is a program designed to expedite that process. The SAM 2.1 computer program is designed to be run in the field on a portable computer. The program processes digital surveying data obtained from an electronic surveying instrument during slope- area measurements. After all measurements have been completed, the program generates files to be input into the SAC (Slope-Area Computation program; Fulford, 1994) or HEC-RAS (Hydrologic Engineering Center-River Analysis System; Brunner, 2001) computer streamflow models so that an estimate of the peak discharge can be calculated.

Music Education Suites

ERIC Educational Resources Information Center

Kemp, Wayne

2009-01-01

This publication describes options for designing and equipping middle and high school music education suites, and suggests ways of gaining community support for including full service music suites in new and renovated school facilities. In addition to basic music suites, and practice rooms, other options detailed include: (1) small ensemble…

Astronaut Ronald Evans is suited up for EVA training

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Ronald E. Evans, command module pilot of the Apollo 17 lunar landing mission, is assisted by technicians in suiting up for extravehicular activity (EVA) training in a water tank in bldg 5 at the Manned Spacecraft Center (49970); Evans participates in EVA training in a water tank in bldg 5 at the Manned Spacecraft Center. The structure in the picture simulates the Scientific Instrument Module (SIM) bay of the Apollo 17 Service Module (49971).

EMU Suit Performance Simulation

NASA Technical Reports Server (NTRS)

Cowley, Matthew S.; Benson, Elizabeth; Harvill, Lauren; Rajulu, Sudhakar

2014-01-01

Introduction: Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. To verify that new suit designs meet requirements, full prototypes must be built and tested with human subjects. However, numerous design iterations will occur before the hardware meets those requirements. Traditional draw-prototype-test paradigms for research and development are prohibitively expensive with today's shrinking Government budgets. Personnel at NASA are developing modern simulation techniques that focus on a human-centric design paradigm. These new techniques make use of virtual prototype simulations and fully adjustable physical prototypes of suit hardware. This is extremely advantageous and enables comprehensive design down-selections to be made early in the design process. Objectives: The primary objective was to test modern simulation techniques for evaluating the human performance component of two EMU suit concepts, pivoted and planar style hard upper torso (HUT). Methods: This project simulated variations in EVA suit shoulder joint design and subject anthropometry and then measured the differences in shoulder mobility caused by the modifications. These estimations were compared to human-in-the-loop test data gathered during past suited testing using four subjects (two large males, two small females). Results: Results demonstrated that EVA suit modeling and simulation are feasible design tools for evaluating and optimizing suit design based on simulated performance. The suit simulation model was found to be advantageous in its ability to visually represent complex motions and volumetric reach zones in three dimensions, giving designers a faster and deeper comprehension of suit component performance vs. human performance. Suit models were able to discern differing movement capabilities between EMU HUT configurations, generic suit fit concerns, and specific suit fit concerns for crewmembers based

Low Background Levels of Mars Methane at Gale Crater Indicate Seasonal Cycle: Updated Results from TLS-SAM on Curiosity

NASA Astrophysics Data System (ADS)

Webster, C. R.; Mahaffy, P. R.; Atreya, S. K.

2016-12-01

In situ measurements of atmospheric methane have been made over a 3-year period at Gale Crater on Mars using the Tunable Laser Spectrometer (TLS) instrument in the Sample Analysis at Mars (SAM) suite on the Curiosity rover. We have reported two important observations: (i) a background level of 0.5 ppbv that is about five times lower than some model predictions based on generation from UV degradation of micro-meteorites or interplanetary dust delivered to the martian surface; (ii) a "spike" of elevated levels of 7 ppbv that were seen1 on four sequential observations over a 2-month period before dropping to background levels. This spike was attributed to an episodic release from a small local source, probably to the north of Gale crater. While the elevated levels of the spike did not return (repeat) one Mars year later, we have seen what appears to be a seasonal variation to the background levels that are all < 1ppbv. The variation ranges from a low of 0.2 ppbv in the northern hemisphere spring to 0.9 ppbv in the northern hemisphere late summer, a change in mixing ratio over a range larger than expected from our current understanding of methane sources and sinks. We will present recent atmospheric methane measurements, and their correlations with a variety of environmental conditions at the location of Curiosity, and discuss the mechanisms that are believed to be contributing to the low background methane signals and their variation. 1 "Mars Methane Detection and Variability at Gale Crater", C. R. Webster et al., Science, 347, 415-417 (2015) and references therein. The research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

NASA Astrophysics Data System (ADS)

Kasper, Justin C.; Abiad, Robert; Austin, Gerry; Balat-Pichelin, Marianne; Bale, Stuart D.; Belcher, John W.; Berg, Peter; Bergner, Henry; Berthomier, Matthieu; Bookbinder, Jay; Brodu, Etienne; Caldwell, David; Case, Anthony W.; Chandran, Benjamin D. G.; Cheimets, Peter; Cirtain, Jonathan W.; Cranmer, Steven R.; Curtis, David W.; Daigneau, Peter; Dalton, Greg; Dasgupta, Brahmananda; DeTomaso, David; Diaz-Aguado, Millan; Djordjevic, Blagoje; Donaskowski, Bill; Effinger, Michael; Florinski, Vladimir; Fox, Nichola; Freeman, Mark; Gallagher, Dennis; Gary, S. Peter; Gauron, Tom; Gates, Richard; Goldstein, Melvin; Golub, Leon; Gordon, Dorothy A.; Gurnee, Reid; Guth, Giora; Halekas, Jasper; Hatch, Ken; Heerikuisen, Jacob; Ho, George; Hu, Qiang; Johnson, Greg; Jordan, Steven P.; Korreck, Kelly E.; Larson, Davin; Lazarus, Alan J.; Li, Gang; Livi, Roberto; Ludlam, Michael; Maksimovic, Milan; McFadden, James P.; Marchant, William; Maruca, Bennet A.; McComas, David J.; Messina, Luciana; Mercer, Tony; Park, Sang; Peddie, Andrew M.; Pogorelov, Nikolai; Reinhart, Matthew J.; Richardson, John D.; Robinson, Miles; Rosen, Irene; Skoug, Ruth M.; Slagle, Amanda; Steinberg, John T.; Stevens, Michael L.; Szabo, Adam; Taylor, Ellen R.; Tiu, Chris; Turin, Paul; Velli, Marco; Webb, Gary; Whittlesey, Phyllis; Wright, Ken; Wu, S. T.; Zank, Gary

2016-12-01

The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on Solar Probe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma. SWEAP consists of the Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SPC is a Faraday Cup that looks directly at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). The SPAN-A ion ESA has a time of flight section that enables it to sort particles by their mass/charge ratio, permitting differentiation of ion species. SPAN-A and -B are rotated relative to one another so their broad fields of view combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield and covered by SPC. Observations by SPC and SPAN produce the combined field of view and measurement capabilities required to fulfill the science objectives of SWEAP and Solar Probe Plus. SWEAP measurements, in concert with magnetic and electric fields, energetic particles, and white light contextual imaging will enable discovery and understanding of solar wind acceleration and formation, coronal and solar wind heating, and particle acceleration in the inner heliosphere of the solar system. SPC and SPAN are managed by the SWEAP Electronics Module (SWEM), which distributes power, formats onboard data products, and serves as a single electrical interface to the spacecraft. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution. Full resolution data are stored within the SWEM, enabling high resolution observations of structures such as shocks, reconnection events, and other transient structures to be selected for download after the fact. This paper describes

Crystal Structure of Bicc1 SAM Polymer and Mapping of Interactions between the Ciliopathy-Associated Proteins Bicc1, ANKS3, and ANKS6.

PubMed

Rothé, Benjamin; Leettola, Catherine N; Leal-Esteban, Lucia; Cascio, Duilio; Fortier, Simon; Isenschmid, Manuela; Bowie, James U; Constam, Daniel B

2018-02-06

Head-to-tail polymers of sterile alpha motifs (SAM) can scaffold large macromolecular complexes. Several SAM-domain proteins that bind each other are mutated in patients with cystic kidneys or laterality defects, including the Ankyrin (ANK) and SAM domain-containing proteins ANKS6 and ANKS3, and the RNA-binding protein Bicc1. To address how their interactions are regulated, we first determined a high-resolution crystal structure of a Bicc1-SAM polymer, revealing a canonical SAM polymer with a high degree of flexibility in the subunit interface orientations. We further mapped interactions between full-length and distinct domains of Bicc1, ANKS3, and ANKS6. Neither ANKS3 nor ANKS6 alone formed macroscopic homopolymers in vivo. However, ANKS3 recruited ANKS6 to Bicc1, and the three proteins together cooperatively generated giant macromolecular complexes. Thus, the giant assemblies are shaped by SAM domains, their flanking sequences, and SAM-independent protein-protein and protein-mRNA interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Abundances of Volatile - Bearing Species from Evolved Gas Analysis of Samples from the Rocknest Aeolian Bedform in Gale Crater

NASA Technical Reports Server (NTRS)

Archer, P. D., Jr.; Franc, H. B.; Sutter, B.; McAdam, A.; Ming, D. W.; Morris, R. V.; Mahaffy, P. R.

2013-01-01

The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. SAM detected the evolution of H2O, CO2, O2, and SO2, indicative of the presence of multiple volatile bearing species (Fig 1). The Rocknest bedform is a windblown deposit selected as representative of both the windblown material in Gale crater as well as the globally-distributed martian dust. Four samples of Rocknest material were analyzed by SAM, all from the fifth scoop taken at this location. The material delivered to SAM passed through a 150 m sieve and is assumed to have been well mixed during the sample acquisition/preparation/handoff process. SAM heated the Rocknest samples to approx.835 C at a ramp rate of 35 C/min with a He carrier gas flow rate of apprx.1.5 standard cubic centimeters per minute and at an oven pressure of 30 mbar [1]. Evolved gases were detected by a quadrupole mass spectrometer (QMS). This abstract presents the molar abundances of H2O, CO2, O2, and SO2 as well as their concentration in rocknest samples using an estimated sample mass.

A Parametric Rosetta Energy Function Analysis with LK Peptides on SAM Surfaces.

PubMed

Lubin, Joseph H; Pacella, Michael S; Gray, Jeffrey J

2018-05-08

Although structures have been determined for many soluble proteins and an increasing number of membrane proteins, experimental structure determination methods are limited for complexes of proteins and solid surfaces. An economical alternative or complement to experimental structure determination is molecular simulation. Rosetta is one software suite that models protein-surface interactions, but Rosetta is normally benchmarked on soluble proteins. For surface interactions, the validity of the energy function is uncertain because it is a combination of independent parameters from energy functions developed separately for solution proteins and mineral surfaces. Here, we assess the performance of the RosettaSurface algorithm and test the accuracy of its energy function by modeling the adsorption of leucine/lysine (LK)-repeat peptides on methyl- and carboxy-terminated self-assembled monolayers (SAMs). We investigated how RosettaSurface predictions for this system compare with the experimental results, which showed that on both surfaces, LK-α peptides folded into helices and LK-β peptides held extended structures. Utilizing this model system, we performed a parametric analysis of Rosetta's Talaris energy function and determined that adjusting solvation parameters offered improved predictive accuracy. Simultaneously increasing lysine carbon hydrophilicity and the hydrophobicity of the surface methyl head groups yielded computational predictions most closely matching the experimental results. De novo models still should be interpreted skeptically unless bolstered in an integrative approach with experimental data.

Methyl donor S-adenosylmethionine (SAM) supplementation attenuates breast cancer growth, invasion, and metastasis in vivo; therapeutic and chemopreventive applications.

PubMed

Mahmood, Niaz; Cheishvili, David; Arakelian, Ani; Tanvir, Imrana; Khan, Haseeb Ahmed; Pépin, Anne-Sophie; Szyf, Moshe; Rabbani, Shafaat A

2018-01-12

DNA hypomethylation coordinately targets various signaling pathways involved in tumor growth and metastasis. At present, there are no approved therapeutic modalities that target hypomethylation. In this regard, we examined the therapeutic plausibility of using universal methyl group donor S-adenosylmethionine (SAM) to block breast cancer development, growth, and metastasis through a series of studies in vitro using two different human breast cancer cell lines (MDA-MB-231 and Hs578T) and in vivo using an MDA-MB-231 xenograft model of breast cancer. We found that SAM treatment caused a significant dose-dependent decrease in cell proliferation, invasion, migration, anchorage-independent growth and increased apoptosis in vitro . These results were recapitulated in vivo where oral administration of SAM reduced tumor volume and metastasis in green fluorescent protein (GFP)-tagged MDA-MB-231 xenograft model. Gene expression analyses validated the ability of SAM to decrease the expression of several key genes implicated in cancer progression and metastasis in both cell lines and breast tumor xenografts. SAM was found to be bioavailable in the serum of experimental animals as determined by enzyme-linked immunosorbent assay and no notable adverse side effects were seen including any change in animal behavior. The results of this study provide compelling evidence to evaluate the therapeutic potential of methylating agents like SAM in patients with breast cancer to reduce cancer-associated morbidity and mortality.

Methyl donor S-adenosylmethionine (SAM) supplementation attenuates breast cancer growth, invasion, and metastasis in vivo; therapeutic and chemopreventive applications

PubMed Central

Mahmood, Niaz; Cheishvili, David; Arakelian, Ani; Tanvir, Imrana; Khan, Haseeb Ahmed; Pépin, Anne-Sophie; Szyf, Moshe; Rabbani, Shafaat A.

2018-01-01

DNA hypomethylation coordinately targets various signaling pathways involved in tumor growth and metastasis. At present, there are no approved therapeutic modalities that target hypomethylation. In this regard, we examined the therapeutic plausibility of using universal methyl group donor S-adenosylmethionine (SAM) to block breast cancer development, growth, and metastasis through a series of studies in vitro using two different human breast cancer cell lines (MDA-MB-231 and Hs578T) and in vivo using an MDA-MB-231 xenograft model of breast cancer. We found that SAM treatment caused a significant dose-dependent decrease in cell proliferation, invasion, migration, anchorage-independent growth and increased apoptosis in vitro. These results were recapitulated in vivo where oral administration of SAM reduced tumor volume and metastasis in green fluorescent protein (GFP)-tagged MDA-MB-231 xenograft model. Gene expression analyses validated the ability of SAM to decrease the expression of several key genes implicated in cancer progression and metastasis in both cell lines and breast tumor xenografts. SAM was found to be bioavailable in the serum of experimental animals as determined by enzyme-linked immunosorbent assay and no notable adverse side effects were seen including any change in animal behavior. The results of this study provide compelling evidence to evaluate the therapeutic potential of methylating agents like SAM in patients with breast cancer to reduce cancer-associated morbidity and mortality. PMID:29435170

Social Activity Method (SAM): A Fractal Language for Mathematics

ERIC Educational Resources Information Center

Dowling, Paul

2013-01-01

In this paper I shall present and develop my organisational language, "social activity method" (SAM), and illustrate some of its applications. I shall introduce a new scheme for "modes of recontextualisation" that enables the analysis of the ways in which one activity--which might be school mathematics or social research or any…

Carbon tax effects on the poor: a SAM-based approach

NASA Astrophysics Data System (ADS)

Chapa, Joana; Ortega, Araceli

2017-09-01

A SAM-based price model for Mexico is developed in order to assess the effects of the carbon tax, which was part of the fiscal reform approved in 2014. The model is formulated based on a social accounting matrix (SAM) that distinguishes households by the official poverty condition and geographical area. The main results are that the sector that includes coke, refined petroleum and nuclear fuel shows the highest price increase due to the direct impact of the carbon tax; in addition, air transport and inland transport are the most affected sectors, in an indirect manner, because both employ inputs from the former sector. Also, it is found that welfare diminishes more in the rural strata than in the urban one. In the urban area, the carbon tax is regressive: the negative impact of carbon tax on family welfare is greater on the poorest families.

Unsupervised classification of Space Acceleration Measurement System (SAMS) data using ART2-A

NASA Technical Reports Server (NTRS)

Smith, A. D.; Sinha, A.

1999-01-01

The Space Acceleration Measurement System (SAMS) has been developed by NASA to monitor the microgravity acceleration environment aboard the space shuttle. The amount of data collected by a SAMS unit during a shuttle mission is in the several gigabytes range. Adaptive Resonance Theory 2-A (ART2-A), an unsupervised neural network, has been used to cluster these data and to develop cause and effect relationships among disturbances and the acceleration environment. Using input patterns formed on the basis of power spectral densities (psd), data collected from two missions, STS-050 and STS-057, have been clustered.

Structural investigation of a C-terminal EphA2 receptor mutant: Does mutation affect the structure and interaction properties of the Sam domain?

PubMed

Mercurio, Flavia A; Costantini, Susan; Di Natale, Concetta; Pirone, Luciano; Guariniello, Stefano; Scognamiglio, Pasqualina L; Marasco, Daniela; Pedone, Emilia M; Leone, Marilisa

2017-09-01

Ephrin A2 receptor (EphA2) plays a key role in cancer, it is up-regulated in several types of tumors and the process of ligand-induced receptor endocytosis, followed by degradation, is considered as a potential path to diminish tumor malignancy. Protein modulators of this mechanism are recruited at the cytosolic Sterile alpha motif (Sam) domain of EphA2 (EphA2-Sam) through heterotypic Sam-Sam associations. These interactions engage the C-terminal helix of EphA2 and close loop regions (the so called End Helix side). In addition, several studies report on destabilizing mutations in EphA2 related to cataract formation and located in/or close to the Sam domain. Herein, we analyzed from a structural point of view, one of these mutants characterized by the insertion of a novel 39 residue long polypeptide at the C-terminus of EphA2-Sam. A 3D structural model was built by computational methods and revealed partial disorder in the acquired C-terminal tail and a few residues participating in an α-helix and two short β-strands. We investigated by CD and NMR studies the conformational properties in solution of two peptides encompassing the whole C-terminal tail and its predicted helical region, respectively. NMR binding experiments demonstrated that these peptides do not interact relevantly with either EphA2-Sam or its interactor Ship2-Sam. Molecular dynamics (MD) simulations further indicated that the EphA2 mutant could be represented only through a conformational ensemble and that the C-terminal tail should not largely wrap the EphA2-Sam End-Helix interface and affect binding to other Sam domains. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of S-adenosyl-L-methionine (SAM), an allosteric activator of cystathionine-β-synthase (CBS) on colorectal cancer cell proliferation and bioenergetics in vitro.

PubMed

Módis, Katalin; Coletta, Ciro; Asimakopoulou, Antonia; Szczesny, Bartosz; Chao, Celia; Papapetropoulos, Andreas; Hellmich, Mark R; Szabo, Csaba

2014-09-15

Recent data show that colon cancer cells selectively overexpress cystathionine-β-synthase (CBS), which produces hydrogen sulfide (H2S), to maintain cellular bioenergetics, support tumor growth and stimulate angiogenesis and vasorelaxation in the tumor microenvironment. The purpose of the current study was to investigate the effect of the allosteric CBS activator S-adenosyl-L-methionine (SAM) on the proliferation and bioenergetics of the CBS-expressing colon cancer cell line HCT116. The non-transformed, non-tumorigenic colon epithelial cell line NCM356 was used as control. For assessment of cell proliferation, the xCELLigence system was used. Bioenergetic function was measured by Extracellular Flux Analysis. Experiments using human recombinant CBS or HCT116 homogenates complemented the cell-based studies. SAM markedly enhanced CBS-mediated H2S production in vitro, especially when a combination of cysteine and homocysteine was used as substrates. Addition of SAM (0.1-3 mM) to HCT116 cells induced a concentration-dependent increase H2S production. SAM exerted time- and concentration-dependent modulatory effects on cell proliferation. At 0.1-1 mM SAM increased HCT116 proliferation between 0 and 12 h, while the highest SAM concentration (3 mM) inhibited proliferation. Over a longer time period (12-24 h), only the lowest concentration of SAM used (0.1 mM) stimulated cell proliferation; higher SAM concentrations produced a concentration-dependent inhibition. The short-term stimulatory effects of SAM were attenuated by the CBS inhibitor aminooxyacetic acid (AOAA) or by stable silencing of CBS. In contrast, the inhibitory effects of SAM on cell proliferation was unaffected by CBS inhibition or CBS silencing. In contrast to HCT116 cells, the lower rate of proliferation of the low-CBS expressor NCM356 cells was unaffected by SAM. Short-term (1 h) exposure of HCT116 cells to SAM induced a concentration-dependent increase in oxygen consumption and bioenergetic function at 0

Mars 2020 Entry, Descent and Landing Instrumentation (MEDLI2)

NASA Technical Reports Server (NTRS)

Bose, Deepak; Wright, Henry; White, Todd; Schoenenberger, Mark; Santos, Jose; Karlgaard, Chris; Kuhl, Chris; Oishi, TOmo; Trombetta, Dominic

2016-01-01

This paper will introduce Mars Entry Descent and Landing Instrumentation (MEDLI2) on NASA's Mars2020 mission. Mars2020 is a flagship NASA mission with science and technology objectives to help answer questions about possibility of life on Mars as well as to demonstrate technologies for future human expedition. Mars2020 is scheduled for launch in 2020. MEDLI2 is a suite of instruments embedded in the heatshield and backshell thermal protection systems of Mars2020 entry vehicle. The objectives of MEDLI2 are to gather critical aerodynamics, aerothermodynamics and TPS performance data during EDL phase of the mission. MEDLI2 builds up the success of MEDLI flight instrumentation on Mars Science Laboratory mission in 2012. MEDLI instrumentation suite measured surface pressure and TPS temperature on the heatshield during MSL entry into Mars. MEDLI data has since been used for unprecedented reconstruction of aerodynamic drag, vehicle attitude, in-situ atmospheric density, aerothermal heating, transition to turbulence, in-depth TPS performance and TPS ablation. [1,2] In addition to validating predictive models, MEDLI data has highlighted extra margin available in the MSL forebody TPS, which can potentially be used to reduce vehicle parasitic mass. MEDLI2 expands the scope of instrumentation by focusing on quantities of interest not addressed in MEDLI suite. The type the sensors are expanded and their layout on the TPS modified to meet these new objectives. The paper will provide key motivation and governing requirements that drive the choice and the implementation of the new sensor suite. The implementation considerations of sensor selection, qualification, and demonstration of minimal risk to the host mission will be described. The additional challenges associated with mechanical accommodation, electrical impact, data storage and retrieval for MEDLI2 system, which extends sensors to backshell will also be described.

The mechanisms of the SAMS experiment flown on Nimbus 7 with particular reference to the 2 axis scanning mirror. [infrared radiometer for stratospheric and mesospheric investigations

NASA Technical Reports Server (NTRS)

Hadley, H.

1980-01-01

The stratospheric and mesospheric sounder (SAMS) experiment on Nimbus 7 includes a 2 axis scanning mirror and 7 pressure modulator cells. The SAMS experiment is a limb sounding instrument to measure the temperature profile and minor constituents of the atmosphere. The limb scan requires small mirror steps over a 3 deg range, while the scan in azimuth is in larger steps over a 15 deg range. The mirror is plane, 20 cm in diameter, and of zero expansion glass-ceramic. It is supported on two tilt tables, fitted one on the other, with the axes at right angles. The angle of tilt is adjusted by means of recirculating ball screws which are ion plated with lead for lubrication and driven by stepper motors. The seven gas filled cells are each pressure modulated by a 3 cm diameter, 0.3 cm stroke piston which is supported by diaphragm springs and driven electromagnetically at the system's mechanical resonant frequency. The mean pressure of the filling gas, which is the atmospheric constituent being measured, is changed by varying the temperature of a suitable molecular sieve.

Space Suit Thermal Dynamics

NASA Technical Reports Server (NTRS)

Campbell, Anthony B.; Nair, Satish S.; Miles, John B.; Iovine, John V.; Lin, Chin H.

1998-01-01

The present NASA space suit (the Shuttle EMU) is a self-contained environmental control system, providing life support, environmental protection, earth-like mobility, and communications. This study considers the thermal dynamics of the space suit as they relate to astronaut thermal comfort control. A detailed dynamic lumped capacitance thermal model of the present space suit is used to analyze the thermal dynamics of the suit with observations verified using experimental and flight data. Prior to using the model to define performance characteristics and limitations for the space suit, the model is first evaluated and improved. This evaluation includes determining the effect of various model parameters on model performance and quantifying various temperature prediction errors in terms of heat transfer and heat storage. The observations from this study are being utilized in two future design efforts, automatic thermal comfort control design for the present space suit and design of future space suit systems for Space Station, Lunar, and Martian missions.