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1. Unambiguous detection of mesospheric CO2 clouds on Mars using 2.7 {\mu}m absorption band from the ACS/TGO solar occultations

Author

Luginin, M., Trokhimovskiy, A., Fedorova, A., Belyaev, D., Ignatiev, N., Korablev, O., Montmessin, F., and Grigoriev, A.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Mesospheric CO2 clouds are one of two types of carbon dioxide clouds known on Mars. We present observations of mesospheric CO2 clouds made by Atmospheric Chemistry Suit (ACS) onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO). We analyzed 1663 solar occultation sessions of Thermal InfraRed (TIRVIM) and Middle InfraRed (MIR) channels of ACS covering more than two Martian years that contain spectra of 2.7 {\mu}m carbon dioxide ice absorption band. That allowed us to unambiguously discriminate carbon dioxide ice aerosols from mineral dust and water ice aerosols, not relying on the information of atmospheric thermal conditions. CO2 clouds were detected in eleven solar occultation observations at altitudes from 39 km to 90 km. In five cases, there were two or three layers of CO2 clouds that were vertically separated by 5-15 km gaps. Effective radius of CO2 aerosol particles is in the range of 0.1-2.2 {\mu}m. Spectra produced by the smallest particles indicate a need for a better resolved CO2 ice refractive index. Nadir optical depth of CO2 clouds is in the range 5*10^{-4}-4*10^{-2} at both 2.7 {\mu}m and 0.8 {\mu}m. Asymmetrical diurnal distribution of detections observed by ACS is potentially due to local time variations of temperature induced by thermal tides. Two out of five cases of carbon dioxide cloud detections made by the TIRVIM instrument reveal the simultaneous presence of CO2 ice and H2O ice aerosols. Temperature profiles measured by the Near InfraRed (NIR) channel of ACS are used to calculate CO2 saturation ratio S at locations of carbon dioxide clouds. Supersaturation S > 1 is detected in only 5 out of 19 cases of CO2 cloud layers; extremely low values of S < 0.1 are found in 9 out of 19 cases., Comment: 29 pages, 10 figures. Submitted to Icarus

Published
2024
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2. Strong Localized Pumping of Water Vapor to High Altitudes on Mars During the Perihelion Season.

Author

Brines, A., López‐Valverde, M. A., Funke, B., González‐Galindo, F., Aoki, S., Villanueva, G. L., Holmes, J. A., Belyaev, D. A., Liuzzi, G., Thomas, I. R., Erwin, J. T., Grabowski, U., Forget, F., Lopez‐Moreno, J. J., Rodriguez‐Gomez, J., Daerden, F., Trompet, L., Ristic, B., Patel, M. R., and Bellucci, G.

Subjects
MARTIAN atmosphere, WATER vapor, WATER vapor transport, MARS (Planet), WATER pumps, ATMOSPHERIC water vapor measurement, ALTITUDES
Abstract

Here we present water vapor vertical profiles observed with the ExoMars Trace Gas Orbiter/Nadir and Occultation for MArs Discovery instrument during the perihelion and Southern summer solstice season (LS = 240°–300°) in three consecutive Martian Years 34, 35, and 36. We show the detailed latitudinal distribution of H2O at tangent altitudes from 10 to 120 km, revealing a vertical plume at 60°S–50°S injecting H2O upward, reaching abundance of about 50 ppmv at 100 km. We have observed this event repeatedly in the three Martian years analyzed, appearing at LS = 260°–280° and showing inter‐annual variations in the magnitude and timing due to long term effects of the Martian Year 34 Global Dust Storm. We provide a rough estimate of projected hydrogen escape of 3.2 × 109 cm−2 s−1 associated to these plumes, adding further evidence of the key role played by the perihelion season in the long term evolution of the planet's climate. Plain Language Summary: Studying the vertical distribution of the Martian atmosphere is crucial to understand what happened to the water presumably present in larger abundance on ancient Mars. We have analyzed the vertical profiles of three Martian Years during the Southern summer, revealing a strong vertical transport of water vapor to the upper atmosphere. This seasonal phenomenon seems to be repeated annually, although with variations in the location and time of the year. Our estimation of the associated upward hydrogen flux represents an important loss which could have contributed to the escape of water to space for at least the period in which Mars had its present orbital inclination. Key Points: Latitudinal distributions of water vapor up to 120 km are analyzed in detail using Nadir and Occultation for MArs Discovery (NOMAD) observations with an improved retrieval schemeWater vapor injection during the perihelion localized around 50°–60°S in three consecutive Martian yearsMartian year 34 Global Dust Storm may have affected the driving mechanisms of the plume, delaying its appearance and reducing its magnitude [ABSTRACT FROM AUTHOR]

Published
2024
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4. ФЛУОРЕСЦЕНТНОЕ ОПРЕДЕЛЕНИЕ ПАРОВ НИТРОБЕНЗОЛА С ИСПОЛЬЗОВАНИЕМ ДОПИРОВАННОГО ФЛУОРОФОРАМИ ПОЛИСТИРОЛА

Author

Chuvashov, R. D., Belyaev, D. V., Khokhlov, K. O., Baranova, A. A., Zen Eddin, M., Milman, I. I., Verbitskiy, E. V., The reported study was funded by RFBR, project number 20-37-90108, and Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 20-37-90108.

Abstract

Integration of fluorescent substances into polymeric matrices can improve their sensory properties and photostability. In this work, fluorescent materials based on fluorophore-doped polystyrene were obtained and characterized as sensors towards the ecotoxicant nitrobenzene in gas phase. Melamine-formaldehyde foam has been proposed as a permeable substrate for the sensor material deposition applicable for gas-phase measurements. The effect on sensor properties of the porous material surface obtained via Breath Figure pore generation technique was investigated. Limits of detection and calibration relationships of obtained materials towards nitrobenzene were evaluated by materials exposure to low concentrations of nitrobenzene vapors. The sorption properties of polystyrene allow the retention of the quencher near the fluorophore, leading to improved detection limits compared with pure fluorophores. Obtaining a porous surface of the polymer material by the Breath Figure technique increases the scale of its fluorescence quenching by vapors. Detection limits (down to 0.45 ppm) and detectable concentration ranges (0.5 - 371.6 ppm) have been experimentally established. The relative standard deviations of the fluorescent signal of polymer materials do not exceed 13.3 % for a number of concentrations in the detectable range. The applicability of the calibration linear relationship of the logarithm of the fluorescent signal on the logarithm of the nitrobenzene vapor concentration is shown. Fluorescence signal measurements were performed using the original sensor element and the luminescence detector employing an array of fluorescent materials. The developed device is simple in application, portable, automated, and in combination with the used polymeric materials allows detection of nitrobenzene vapors in concentrations 2.5 times lower than the maximum permissible level. Keywords: Fluorescence, nitrobenzene, polystyrene, melamine, doping, breath figure, fluorescence reader, Интеграцией флуоресцентных веществ в полимерные матрицы можно улучшить их сенсорные свойства и фотостабильность. В работе получены и исследованы флуоресцентные материалы на основе допированного флуорофорами полистирола в качестве сенсоров на экотоксикант нитробензол в газовой фазе. Меламин-формальдегидная пена предложена в качестве проницаемого субстрата для нанесения сенсорных составов. Исследовано влияние техники создания пористой поверхности материала Breath Figure на сенсорные свойства. Пределы обнаружения нитробензола в газовой фазе с использованием полученных материалов были оценены экспозицией малым концентрациям паров нитробензола. Измерения флуоресцентного сигнала были выполнены с помощью оригинальных сенсорного элемента и регистратора люминесценции, применяющих комбинацию флуоресцентных материалов. Разработанное техническое решение регистратора люминесценции является простым в применении, портативным, автоматизированным и позволяет с использованием полученных полимерных материалов обнаружение паров нитробензола в концентрациях ниже предельно допустимой по гигиеническим нормативам.

Published
2023

5. Fluctuating asymmetry of the needles of Pinus brutia var. pityusa (STEVEN) SILBA, 1985, growing in industrial and recreational areas in Tuapse

Author

Kozlov G, Pushkarev M, Belyaeva I, Maksimova A, Shvidkoy S, and Belyaev D

Subjects
Environmental sciences, GE1-350
Abstract

The paper provides information on the index of fluctuating asymmetry of the Pitsunda pine in industrial and recreational areas in the city of Tuapse (the Russian Black Sea coast of the Caucasus). It is shown that pollution is localized in the port area, and in the city center, the fluctuating asymmetry index is comparable to that for resort areas at a considerable distance from the Tuapse port. The necessity of taking into account the climate when using the coefficient of fluctuating asymmetry of the needles of the Mediterranean (Pitsunda) pine in assessing the degree of ecological well-being of various areas is shown.

Published
2020
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9. Production of Fluorescent Sensors by the Breath Figure Method for Environmental Assessment

Author

Belyaev, D., Chuvashov, R., and Baranova, A.

Subjects
BREATH FIGURE ARRAYS, ОЦЕНКА СОСТОЯНИЯ ОКРУЖАЮЩЕЙ СРЕДЫ, POROUS FILM, BREATH FIGURE, НИТРОБЕНЗОЛ, NITROBENZENE, FLUOROPHORE, ENVIRONMENTAL ASSESSMENT, ФЛУОРЕСЦЕНТНЫЕ ВЕЩЕСТВА, ПОРИСТАЯ ПЛЕНКА
Abstract

В работе предложено использование сенсорных материалов, изготовленных методом breath figure (BF), для обнаружения и идентификации отравляющих, ядовитых и взрывчатых веществ и газовой фазе. Данный метод основан на формировании пористой поверхности вследствие конденсации капель воды на поверхности раствора полистирола и хлороформа при окружающей влажности. В качестве чувствительного элемента были использованы флуорофор 1,3,6,8-Тетракис(триметилсилилэтинил)пирен. В качестве подложки для формирования пористой структуры использовалась меламиновая губка. Приведены результаты определения LOD для нитробензола сенсоров, синтезированных при разной влажности: 1) при влажности ~80%; 2) при влажности ~40%. The use of sensor materials made by the breath figure (BF) method for the detection and identification of toxic and explosive substances in the gas phase is proposed in the work. This method is based on the formation of a porous surface due to condensation of water droplets on the surface of a solution of polystyrene and chloroform at ambient humidity. The fluorophore 1,3,6,8-Tetrakis (trimethylsilylethynyl) pyrene was used as a sensitive element. A melamine sponge was used as a substrate to form the porous structure. The results of LOD determination for nitrobenzene sensors synthesized at different humidity levels are presented: 1) at a humidity of ~ 80%; 2) at a humidity of ~ 40%.

Published
2021

11. Isotopes of chlorine from HCl in the Martian atmosphere

Author

Trokhimovskiy, A., primary, Fedorova, A. A., additional, Olsen, K. S., additional, Alday, J., additional, Korablev, O., additional, Montmessin, F., additional, Lefèvre, F., additional, Patrakeev, A., additional, Belyaev, D., additional, and Shakun, A. V., additional

Published
2021
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13. Upper limits for phosphine (PH3) in the atmosphere of Mars

Author

Olsen, K. S., primary, Trokhimovskiy, A., additional, Braude, A. S., additional, Korablev, O. I., additional, Fedorova, A. A., additional, Wilson, C. F., additional, Patel, M. R., additional, Irwin, P. G. J., additional, Montmessin, F., additional, Lefèvre, F., additional, Baggio, L., additional, Alday, J., additional, Belyaev, D. A., additional, Patrakeev, A., additional, and Shakun, A., additional

Published
2021
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14. Seasonal reappearance of HCl in the atmosphere of Mars during the Mars year 35 dusty season

Author

Olsen, K. S., primary, Trokhimovskiy, A., additional, Montabone, L., additional, Fedorova, A. A., additional, Luginin, M., additional, Lefèvre, F., additional, Korablev, O. I., additional, Montmessin, F., additional, Forget, F., additional, Millour, E., additional, Bierjon, A., additional, Baggio, L., additional, Alday, J., additional, Wilson, C. F., additional, Irwin, P. G. J., additional, Belyaev, D. A., additional, Patrakeev, A., additional, and Shakun, A., additional

Published
2021
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17. ИСПОЛЬЗОВАНИЕ ТЕХНОЛОГИИ 3D ПЕЧАТИ ДЛЯ ИЗГОТОВЛЕНИЯ ПЕРСОНАЛИЗИРОВАННЫХ БОЛЮСОВ ДЛЯ ОПТИМИЗАЦИИ КУРСОВ ЛУЧЕВОЙ ТЕРАПИИ

Author

Gasilova, E. K., Belyaev, D. V., and Vazirov, R. A.

Subjects
sense organs
Abstract

This work is aimed at studying the use of 3D printing technology for the manufacture of personalized boluses in order to change the distribution of the absorbed dose for various types of radiation therapy.

Published
2020

19. Evaluation of 3d Printing Materials as Tissue Equivalent Materials for Phantom Manufacturing

Author

Belyaev, D., Gasilova, E., and Vazirov, R.

Subjects
ТКАНЕЭКВИВАЛЕНТНОСТЬ, КЛИНИЧЕСКАЯ ДОЗИМЕТРИЯ, 3D ПЕЧАТЬ, CLINICAL DOSIMETRY, PHANTOMS, RADIATION THERAPY, ФАНТОМЫ, АДДИТИВНЫЕ ТЕХНОЛОГИИ, ADDITIVE TECHNOLOGIES, TISSUE EQUIVALENCE, ЛУЧЕВАЯ ТЕРАПИЯ, 3D PRINTING
Abstract

Развитие технологии 3D-печати стимулирует активный поиск новых способов ее применения. Создание фантомов с помощью 3D-принтера – одно из перспективных направлений. Такой подход позволит проводить более точный и индивидуальный дозиметрический контроль перед прохождением курса лучевой терапии. Основная цель этого исследования - изучить тканеэквивалентность пластиков, применяемых в 3D печати. Массовый коэффициент ослабления фотонного излучения был определен на основе химического состава путем расчета в базе данных XCom, которая представлена и поддерживается национальным институтом стандартов и технологий (NIST). Затем был осуществлен расчет линейных коэффициентов ослабления. Сравнение линейных коэффициентов ослабления проводилось с 4 тканями человека (печень, кожа, почки и грудь). Численные значения ослабления фотонного излучения тканями были получены из отчета №44 Международной комиссии по радиационным единицам и измерениям (report №44 ICRU). Среднее отношение пластик / ткань было рассчитано для выбранного диапазона энергий (10–150 кэВ). На основании экспериментальных данных получено, что наиболее тканеэквивалентным пластиком из рассмотренных является PETG. Наилучшее соответствие наблюдается с почкой и кожей. Это исследование показывает, что существующие материалы, используемые в 3D-печати, можно использовать для создания индивидуальных фантомов. The development of 3D printing technology stimulates an active search for new methods of its application. Creating phantoms using a 3D printer is one of the promising areas. This will allow for more accurate and individual dosimetric monitoring during radiation therapy. The purpose of this work is to study the tissue equivalence of plastics used in 3D printing. The mass attenuation coefficient was determined based on chemical composition by calculation in the XCom database, which is presented and maintained by the National Institute of Standards and Technology (NIST). Then the linear attenuation factors were calculated. Linear attenuation coefficients were compared with 4 human tissues (liver, skin, kidney, and breast). Tissue attenuation values for photon radiation were obtained from International Commission on Radiation Units and Measurements report №44 (ICRU report №44). The average plastic / tissue ratio was calculated for the selected energy range (10–150 keV). Based on experimental data, it was found that PETG plastic is the best for imitating kidney and skin. This study shows that existing materials used in 3D printing can be used to create customized phantoms.

Published
2020

20. Structure of a shell made from uranium alloyed with iron and germanium after explosive loading.

Author

Gálvez Díaz-Rubio, F., Cendón Franco, D. A., Belyaev, D. A., Aleksandrov, A. S., Zuev, Yu. N., Kozlov, E. A., Shestakov, A. E., Lekomtsev, S. A., Nedosviti, A. S., Svyatov, I. L., and Levi, E. A.

Subjects
GERMANIUM, URANIUM alloys, SCANNING electron microscopy, X-ray diffraction, METALLOGRAPHY
Abstract

This paper presents results of metallographic examination of a thick-wall spherical shell from uranium alloyed with iron and germanium. This shell is recovered after low-level explosive loading. Light microscopy, hardness measurement, scanning electron microscopy and X-Ray diffraction study were used to investigate the meridional section of the test shell as this section most completely exhibits the whole variety of structural features associated with explosive loading of the material. Processing, presentation, and analysis of experimental data on volumetric distribution of studied physical quantities were performed with the help of digital panning and color mapping. [ABSTRACT FROM AUTHOR]

Published
2021
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21. Исследование тканеэквивалентности пластиков, применяемых в 3D печати, для изготовления фантомов

Author

Беляев, Д. В., Гасилова, Е. К., Вазиров, Р. А., Belyaev, D., Gasilova, E., Vazirov, R., Беляев, Д. В., Гасилова, Е. К., Вазиров, Р. А., Belyaev, D., Gasilova, E., and Vazirov, R.

Abstract

Развитие технологии 3D-печати стимулирует активный поиск новых способов ее применения. Создание фантомов с помощью 3D-принтера – одно из перспективных направлений. Такой подход позволит проводить более точный и индивидуальный дозиметрический контроль перед прохождением курса лучевой терапии. Основная цель этого исследования - изучить тканеэквивалентность пластиков, применяемых в 3D печати. Массовый коэффициент ослабления фотонного излучения был определен на основе химического состава путем расчета в базе данных XCom, которая представлена и поддерживается национальным институтом стандартов и технологий (NIST). Затем был осуществлен расчет линейных коэффициентов ослабления. Сравнение линейных коэффициентов ослабления проводилось с 4 тканями человека (печень, кожа, почки и грудь). Численные значения ослабления фотонного излучения тканями были получены из отчета №44 Международной комиссии по радиационным единицам и измерениям (report №44 ICRU). Среднее отношение пластик / ткань было рассчитано для выбранного диапазона энергий (10–150 кэВ). На основании экспериментальных данных получено, что наиболее тканеэквивалентным пластиком из рассмотренных является PETG. Наилучшее соответствие наблюдается с почкой и кожей. Это исследование показывает, что существующие материалы, используемые в 3D-печати, можно использовать для создания индивидуальных фантомов., The development of 3D printing technology stimulates an active search for new methods of its application. Creating phantoms using a 3D printer is one of the promising areas. This will allow for more accurate and individual dosimetric monitoring during radiation therapy. The purpose of this work is to study the tissue equivalence of plastics used in 3D printing. The mass attenuation coefficient was determined based on chemical composition by calculation in the XCom database, which is presented and maintained by the National Institute of Standards and Technology (NIST). Then the linear attenuation factors were calculated. Linear attenuation coefficients were compared with 4 human tissues (liver, skin, kidney, and breast). Tissue attenuation values for photon radiation were obtained from International Commission on Radiation Units and Measurements report №44 (ICRU report №44). The average plastic / tissue ratio was calculated for the selected energy range (10–150 keV). Based on experimental data, it was found that PETG plastic is the best for imitating kidney and skin. This study shows that existing materials used in 3D printing can be used to create customized phantoms.

Published
2020

23. The Atmospheric Chemistry Suite (ACS) of three spectrometers for the ExoMars 2016 Trace Gas Orbiter

Author

Korablev, O., Montmessin, F., Trokhimovskiy, A., Fedorova, A. A., Shakun, A. V., Grigoriev, A. V., Moshkin, B. E., Ignatiev, N. I., Forget, F., Lefèvre, F., Anufreychik, K., Dzuban, I., Ivanov, Y. S., Kalinnikov, Y. K., Kozlova, T. O., Kungurov, A., Makarov, V., Martynovich, F., Maslov, I., Merzlyakov, D., Moiseev, P. P., Nikolskiy, Y., Patrakeev, A., Patsaev, D., Santos-Skripko, A., Sazonov, O., Semena, N., Semenov, A., Shashkin, V., Sidorov, A., Stepanov, A. V., Stupin, I., Timonin, D., Titov, A. Y., Viktorov, A., Zharkov, A., Altieri, F., Arnold, G., Belyaev, D. A., Bertaux, J. L., Betsis, D. S., Duxbury, N., Encrenaz, T., Fouchet, T., Gérard, J.-C., Grassi, D., Guerlet, S., Hartogh, P., Kasaba, Y., Khatuntsev, I., Krasnopolsky, V. A., Kuzmin, R. O., Lellouch, E., Lopez-Valverde, M. A., Luginin, M., Määttänen, A., Marcq, E., Martin Torres, J., Medvedev, A. S., Millour, E., Olsen, K. S., Patel, M. R., Quantin-Nataf, C., Rodin, A. V., Shematovich, V. I., Thomas, I., Thomas, N., Vazquez, L., Vincendon, M., Wilquet, V., Wilson, C. F., Zasova, L. V., Zelenyi, L. M., Zorzano, M. P., Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Main Astronomical Observatory of NAS of Ukraine (MAO), National Academy of Sciences of Ukraine (NASU), National Research Institute for Physical-technical and Radiotechnical Measurements (VNIIFTRI), Scientific Production Enterprise Astron Electronics, Faculty of Physics [MSU, Moscow], Lomonosov Moscow State University (MSU), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Tohoku University [Sendai], Moscow Institute of Physics and Technology [Moscow] (MIPT), Catholic University of America, Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Department of Computer Science [Kiruna], Luleå University of Technology (LUT), Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Universidad de Granada (UGR), The Open University [Milton Keynes] (OU), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Institute of Astronomy of the Russian Academy of Sciences (INASAN), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Universität Bern [Bern], Facultad de Informática [Madrid], Universidad Complutense de Madrid [Madrid] (UCM), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Oxford], University of Oxford [Oxford], Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), PLANETO - LATMOS, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad de Granada (UGR), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad de Granada = University of Granada (UGR), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of Oxford, and Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)

Subjects
Cross-dispersion, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Atmosphere, 520 Astronomy, Mars, Echelle, Fourier-spectrometer, 620 Engineering, High-resolution spectrometer, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph]
Abstract

International audience; The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described.

Published
2018
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25. Oxygen isotopic ratios in Martian water vapour observed by ACS MIR on board the ExoMars Trace Gas Orbiter

Author

Alday, J., primary, Wilson, C. F., additional, Irwin, P. G. J., additional, Olsen, K. S., additional, Baggio, L., additional, Montmessin, F., additional, Trokhimovskiy, A., additional, Korablev, O., additional, Fedorova, A. A., additional, Belyaev, D. A., additional, Grigoriev, A., additional, Patrakeev, A., additional, and Shakun, A., additional

Published
2019
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26. Comprehensive and Integrated Genomic Characterization of Adult Soft Tissue Sarcomas

Author

Lazar, AJ, McLellan, MD, Bailey, MH, Miller, CA, Appelbaum, EL, Cordes, MG, Fronick, CC, Fulton, LA, Fulton, RS, Mardis, ER, Schmidt, HK, Wong, W, Wilson, RK, Yellapantula, V, Radenbaugh, AJ, Hoadley, KA, Hayes, DN, Parker, JS, Wilkerson, MD, Auman, JT, Balu, S, Bodenheimer, T, Hoyle, AP, Jefferys, SR, Jones, CD, Lehmann, K-V, Meng, S, Mieczkowski, PA, Mose, LE, Perou, CM, Roach, J, Senbabaoglu, Y, Shi, Y, Simons, JV, Skelly, T, Soloway, MG, Tan, D, Veluvolu, U, Davis, IJ, Hepperla, AJ, Brohl, AS, Kasaian, K, Mungall, K, Sadeghi, S, Barthel, FP, Verhaak, R, Hu, X, Chibon, F, Cherniack, AD, Shih, J, Beroukhim, R, Meyerson, M, Cibulskis, C, Gabriel, SB, Saksena, G, Schumacher, SE, Gao, Q, Wyczalkowski, M, Bowlby, R, Robertson, AG, Ally, A, Balasundaram, M, Brooks, D, Carlsen, R, Chuah, E, Dhalla, N, Holt, RA, Jones, SJM, Lee, D, Li, I, Ma, Y, Marra, MA, Mayo, M, Moore, RA, Mungall, AJ, Schein, JE, Sipahimalani, P, Tam, A, Thiessen, N, Wong, T, Danilova, L, Cope, L, Baylin, SB, Bootwalla, MS, Lai, PH, Laird, PW, Maglinte, DT, Van Den Berg, DJ, Weisenberger, DJ, Wrangle, J, Drill, E, Shen, R, Iype, L, Reynolds, SM, Shmulevich, I, Yau, C, Armenia, J, Liu, EM, Benz, C, Pastore, A, Sanchez-Vega, F, Schultz, N, Akbani, R, Hegde, AM, Liu, W, Lu, Y, Mills, GB, Weinstein, JN, Roszik, J, Anur, P, Spellman, P, Abeshouse, A, Chen, H-W, Gao, J, Heins, Z, Kundra, R, Larsson, E, Ochoa, A, Sander, C, Socci, N, Zhang, H, Noble, MS, Heiman, DI, Kim, J, Chin, L, Getz, G, Cho, J, Defreitas, T, Frazer, S, Gehlenborg, N, Lawrence, MS, Lin, P, Meier, S, Voet, D, Byers, L, Diao, L, Gay, CM, Wang, J, Newton, Y, Cooper, LAD, Gutman, DA, Lee, S, Nalisnik, M, Bowen, J, Gastier-Foster, JM, Gerken, M, Helsel, C, Hobensack, S, Leraas, KM, Lichtenberg, TM, Ramirez, NC, Wise, L, Zmuda, E, Anderson, ML, Castro, P, Ittmann, M, Gordienko, E, Paklina, O, Setdikova, G, Raut, CP, Karlan, BY, Lester, J, Belyaev, D, Fulidou, V, Potapova, O, Voronina, O, Demetri, GD, Ramalingam, SS, Behera, M, Delman, K, Owonikoko, TK, Sica, GL, Boyd, J, Magliocco, A, Salner, A, Bennett, J, Iacocca, M, Swanson, P, Dottino, P, Kalir, T, Pereira, E, Akeredolu, T, Crain, D, Curley, E, Gardner, J, Mallery, D, Morris, S, Paulauskis, J, Penny, R, Shelton, C, Shelton, T, Thompson, E, Hoon, DB, Parfitt, J, Birrer, M, Karseladze, A, Mariamidze, A, Dao, F, Levine, DA, Olvera, N, Maki, RG, Bartlett, J, Eschbacher, J, Dubina, M, Mozgovoy, E, Fedosenko, K, Manikhas, G, Sekhon, H, Ramirez, N, Ingram, DR, Torres, KE, DiSaia, P, Godwin, AK, Godwin, EM, Kuo, H, Madan, R, Reilly, C, Adebamowo, C, Adebamowo, SN, Bocklage, T, Higgins, K, Martinez, C, Boice, L, Grilley-Olson, JE, Huang, M, Perou, AH, Thorne, LB, Rathmell, WK, Gutmann, DH, Singer, S, Chudamani, S, Liu, J, Lolla, L, Naresh, R, Pihl, T, Sun, Q, Wan, Y, Wu, Y, Felau, I, Zenklusen, JC, Demchok, JA, Ferguson, ML, Hutter, CM, Sofia, HJ, Tarnuzzer, R, Wang, Z, Yang, L, Zhang, JJ, Demicco, EG, Doyle, LA, Hornick, JL, Rubin, BP, de Rijn, MV, Baker, L, Riedel, RF, Ding, L, Ladanyi, M, Novak, JE, Van Tine, BA, Davis, LE, Grilley-Olsen, JE, Pollock, RE, Jones, KB, Martignetti, JA, Tong, P, and Network, CGAR

Subjects
0301 basic medicine, Leiomyosarcoma, Adult, Epigenomics, DNA Copy Number Variations, Genomics, Biology, General Biochemistry, Genetics and Molecular Biology, Undifferentiated Pleomorphic Sarcoma, Article, 03 medical and health sciences, Young Adult, 0302 clinical medicine, medicine, Cluster Analysis, Humans, ATRX, Aged, Comparative genomics, Aged, 80 and over, Genome, Human, Sarcoma, Middle Aged, medicine.disease, Synovial sarcoma, 030104 developmental biology, 030220 oncology & carcinogenesis, Immunology, DNA methylation, Mutation, Cancer research, Genome-Wide Association Study
Abstract

Summary Sarcomas are a broad family of mesenchymal malignancies exhibiting remarkable histologic diversity. We describe the multi-platform molecular landscape of 206 adult soft tissue sarcomas representing 6 major types. Along with novel insights into the biology of individual sarcoma types, we report three overarching findings: (1) unlike most epithelial malignancies, these sarcomas (excepting synovial sarcoma) are characterized predominantly by copy-number changes, with low mutational loads and only a few genes ( TP53 , ATRX , RB1 ) highly recurrently mutated across sarcoma types; (2) within sarcoma types, genomic and regulomic diversity of driver pathways defines molecular subtypes associated with patient outcome; and (3) the immune microenvironment, inferred from DNA methylation and mRNA profiles, associates with outcome and may inform clinical trials of immune checkpoint inhibitors. Overall, this large-scale analysis reveals previously unappreciated sarcoma-type-specific changes in copy number, methylation, RNA, and protein, providing insights into refining sarcoma therapy and relationships to other cancer types.

Published
2017
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30. Construction of quasi-structured locally modified grids for solving problems of high current electronics

Author

Sveshnikov, V. M. and Belyaev, D. O.

Subjects
boundary value problems, локальная модификация, метод декомпозиции области, local modification, сильноточная электроника, УДК 519.632.4, quasi-structured grids, УДК 537.533, квазиструктурированная сетка, high-current electronics, краевые задачи, domain decomposition method
Abstract

Рассматривается алгоритм построения квазиструктурированных сеток, которые состоят из равномерных прямоугольных подсеток и строятся в два этапа. На первом из них расчетная область покрывается равномерной прямоугольной макросеткой, а на втором в каждом макроэлементе задается своя прямоугольная равномерная подсетка. Существенным является то, что подсетки могут быть несогласованными. За счет регулировки плотности узлов подсеток достигается адаптация квазиструктурированной сетки к неоднородностям внутри области. Для адаптации сетки к внешней границе подсетки подвергаются локальной модификации, состоящей в сдвиге приграничных узлов на границу. Излагается алгоритм локальной модификации для построения качественной квазиструктурированной сетки, который не нарушает структурированности подсеток. Предлагаемые квазиструктурированные сетки выгодно отличаются от структурированных сеток тем, что не требуют введения лишних узлов, которые необ- ходимы лишь для поддержки структурированности, и от неструктурированных сеток тем, что не требуют хранения большого объема информации. Решение краевых задач на квазиструктурированных сетках ищется методом декомпозиции расчетной области на подобласти, сопрягаемые без наложения. Данный метод легко распараллеливается и поэтому может быть применим для проведения расчетов на многопроцессорных суперЭВМ. An algorithm for constructing quasi-structured grids, which consist of the uniform rectangular subgrids and are built in two stages, is considered. At first, the computational domain is covered by a uniform rectangular macrogrid, and then an original uniform rectangular subgrid is set for each macroelement. It is essential that subgrids can be inconsistent. By adjusting a density of the subgrid nodes an adaptation of the quasistructured grid to inhomogeneities within the domain is achieved. To adapt the grid to the exterior boundary we make local modifications consisting in a shift of the near boundary nodes to the boundary. Here we propose the algorithm of the local modification to construct a quasi-structured grid of high quality which does not break a subgrid structuring. The suggested quasi-structured grids profitably differ from structured grids in that they do not require extra nodes to support structuring and, also, storing a large amount of information as for unstructured ones. The solution of boundary value problems for quasi-structured grids is found by a decomposition of the computational domain into subdomains without overlapping. This method can be easily parallelized and, therefore, used to carry out calculations on multiprocessor supercomputers. Виктор Митрофанович Свешников, доктор физико-математических наук, заведующий лабораторией вычислительной физики, Институт вычислительной математики и математической геофизики СО РАН (Новосибирск, Российская Федерация), victor@lapasrv.sscc.ru. V.M. Sveshnikov, Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk, Russian Federation), Дмитрий Олегович Беляев, аспирант, Институт вычислительной математики и математической геофизики СО РАН (Новосибирск, Российская Федерация), victor@lapasrv.sscc.ru. D.O. Belyaev, Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk, Russian Federation)

Published
2012

31. Thermal structure of Venus nightside upper atmosphere measured by stellar occultations with SPICAV/Venus Express

Author

Piccialli, A., Montmessin, F., Belyaev, D., Mahieux, A., Fedorova, A., Marcq, E., Bertaux, J. -L., Tellmann, S., Vandaele, A. C., Korablev, O., Piccialli, A., Montmessin, F., Belyaev, D., Mahieux, A., Fedorova, A., Marcq, E., Bertaux, J. -L., Tellmann, S., Vandaele, A. C., and Korablev, O.

Abstract

The thermal structure of Venus upper atmosphere (90-140 km) was investigated using stellar occultation measurements acquired by the SPICAV experiment on board Venus Express. The SPICAV ultraviolet channel provides CO2 local density and temperature vertical profiles with a vertical resolution of <7 km of both the southern and the northern hemispheres on the nightside (18:00-06:00 h local time). A permanent layer of warm air is observed at the mesopause in the altitude range 90-100 km. Temperature then decreases with increasing altitude reaching a minimum value around 125 km. Spatial and temporal changes in the thermal structure have been analyzed. Local time variations dominate the structure of Venus atmosphere at these altitudes: temperatures show an increase of similar to 20 K on the morning side compared to the evening side. The homopause altitude was also determined; it varies between 119 and 138 km of altitude, increasing from the evening side to the morning side. SPICAV temperature profiles were compared to several literature results from ground-based observations, previous spacecraft missions and the Venus Express mission. (C) 2014 Elsevier Ltd. All rights reserved.

Published
2015

32. Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

Author

Borrmann, Stephan, Kunkel, Daniel, Weigel, Ralf, Minikin, Andreas, Deshler, Terry, Wilson, J. C., Curtius, Joachim, Shur, G., Belyaev, D., Law, K. S., and Cairo, F.

Subjects
010504 meteorology & atmospheric sciences, 13. Climate action, aerosol, ddc:550, Atmosphärische Spurenstoffe, AMMA, 010502 geochemistry & geophysics, UT/LS, 01 natural sciences, TROCCINOX, 0105 earth and related environmental sciences
Abstract

Processes occurring in the tropical upper troposphere and lower stratosphere (UT/LS) are of importance for the global climate, for the stratospheric dynamics and air chemistry, and they influence the global distribution of water vapour, trace gases and aerosols. The mechanisms underlying cloud formation and variability in the UT/LS are of scientific concern as these still are not adequately described and quantified by numerical models. Part of the reasons for this is the scarcity of detailed in-situ measurements in particular from the Tropical Transition Layer (TTL) within the UT/LS. In this contribution we provide measurements of particle number densities and the amounts of non-volatile particles in the submicron size range present in the UT/LS over Southern Brazil, West Africa, and Northern Australia. The data were collected in-situ on board of the Russian high altitude research aircraft M-55 "Geophysica" using the specialised COPAS (COndensation PArticle counting System) instrument during the TROCCINOX (Araçatuba, Brazil, February 2005), the SCOUT-O3 (Darwin, Australia, December 2005), and SCOUT-AMMA (Ouagadougou, Burkina Faso, August 2006) campaigns. The vertical profiles obtained are compared to those from previous measurements from the NASA DC-8 and NASA WB-57F over Costa Rica and other tropical locations between 1999 and 2007. The number density of the submicron particles as function of altitude was found to be remarkably constant (even back to 1987) over the tropical UT/LS altitude band such that a parameterisation suitable for models can be extracted from the measurements. At altitudes corresponding to potential temperatures above 430 K a slight increase of the number densities from 2005/2006 results from the data in comparison to the 1987 to 2007 measurements. The origins of this increase are unknown. By contrast the data from Northern hemispheric mid latitudes do not exhibit such an increase between 1999 and 2006. Vertical profiles of the non-volatile fraction of the submicron particles were also measured by a COPAS channel and are presented here. The resulting profiles of the non-volatile number density fraction show a pronounced maximum of 50% in the tropical TTL over Australia and West Africa. Below and above this fraction is much lower attaining values of 10% and smaller. In the lower stratosphere the fine particles mostly consist of sulphuric acid which is reflected in the low numbers of non-volatile residues measured by COPAS. Without detailed chemical composition measurements the reason for the increase of non-volatile particle fractions cannot yet be given. The long distance transfer flights to Brazil, Australia and West-Africa were executed during a time window of 17 months within a period of relative volcanic quiescence. Thus the data measured during these transfers represent a "snapshot picture" documenting the status of a significant part of the global UT/LS aerosol (with sizes below 1 μm) at low concentration levels 15 years after the last major (i.e., the 1991 Mount Pinatubo) eruption. The corresponding latitudinal distributions of the measured particle number densities are also presented in this paper in order to provide input on the UT/LS background aerosol for modelling purposes.

Published
2009

34. Comprehensive molecular characterization of gastric adenocarcinoma

Author

Bass, AJ, Thorsson, V, Shmulevich, I, Reynolds, SM, Miller, M, Bernard, B, Hinoue, T, Laird, PW, Curtis, C, Shen, H, Weisenberger, DJ, Schultz, N, Shen, R, Weinhold, N, Keiser, DP, Bowlby, R, Sipahimalani, P, Cherniack, AD, Getz, G, Liu, Y, Noble, MS, Pedamallu, C, Sougnez, C, Taylor-Weiner, A, Akbani, R, Lee, J-S, Liu, W, Mills, GB, Yang, D, Zhang, W, Pantazi, A, Parfenov, M, Gulley, M, Piazuelo, MB, Schneider, BG, Kim, J, Boussioutas, A, Sheth, M, Demchok, JA, Rabkin, CS, Willis, JE, Ng, S, Garman, K, Beer, DG, Pennathur, A, Raphael, BJ, Wu, H-T, Odze, R, Kim, HK, Bowen, J, Leraas, KM, Lichtenberg, TM, Weaver, L, McLellan, M, Wiznerowicz, M, Sakai, R, Lawrence, MS, Cibulskis, K, Lichtenstein, L, Fisher, S, Gabriel, SB, Lander, ES, Ding, L, Niu, B, Ally, A, Balasundaram, M, Birol, I, Brooks, D, Butterfield, YSN, Carlsen, R, Chu, A, Chu, J, Chuah, E, Chun, H-JE, Clarke, A, Dhalla, N, Guin, R, Holt, RA, Jones, SJM, Kasaian, K, Lee, D, Li, HA, Lim, E, Ma, Y, Marra, MA, Mayo, M, Moore, RA, Mungall, AJ, Mungall, KL, Nip, KM, Robertson, AG, Schein, JE, Tam, A, Thiessen, N, Beroukhim, R, Carter, SL, Cho, J, DiCara, D, Frazer, S, Gehlenborg, N, Heiman, DI, Jung, J, Lin, P, Meyerson, M, Ojesina, AI, Pedamallu, CS, Saksena, G, Schumacher, SE, Stojanov, P, Tabak, B, Voet, D, Rosenberg, M, Zack, TI, Zhang, H, Zou, L, Protopopov, A, Santoso, N, Lee, S, Zhang, J, Mahadeshwar, HS, Tang, J, Ren, X, Seth, S, Yang, L, Xu, AW, Song, X, Xi, R, Bristow, CA, Hadjipanayis, A, Seidman, J, Chin, L, Park, PJ, Kucherlapati, R, Ling, S, Rao, A, Weinstein, JN, Kim, S-B, Lu, Y, Mills, G, Bootwalla, MS, Lai, PH, Triche, T, Van Den Berg, DJ, Baylin, SB, Herman, JG, Murray, BA, Askoy, BA, Ciriello, G, Dresdner, G, Gao, J, Gross, B, Jacobsen, A, Lee, W, Ramirez, R, Sander, C, Senbabaoglu, Y, Sinha, R, Sumer, SO, Sun, Y, Iype, L, Kramer, RW, Kreisberg, R, Rovira, H, Tasman, N, Haussler, D, Stuart, JM, Verhaak, RGW, Leiserson, MDM, Taylor, BS, Black, AD, Carney, JA, Gastier-Foster, JM, Helsel, C, McAllister, C, Ramirez, NC, Tabler, TR, Wise, L, Zmuda, E, Penny, R, Crain, D, Gardner, J, Lau, K, Curely, E, Mallery, D, Morris, S, Paulauskis, J, Shelton, T, Shelton, C, Sherman, M, Benz, C, Lee, J-H, Fedosenko, K, Manikhas, G, Voronina, O, Belyaev, D, Dolzhansky, O, Rathmell, WK, Brzezinski, J, Ibbs, M, Korski, K, Kycler, W, Lazniak, R, Leporowska, E, Mackiewicz, A, Murawa, D, Murawa, P, Spychala, A, Suchorska, WM, Tatka, H, Teresiak, M, Abdel-Misih, R, Bennett, J, Brown, J, Iacocca, M, Rabeno, B, Kwon, S-Y, Kemkes, A, Curley, E, Alexopoulou, I, Engel, J, Bartlett, J, Albert, M, Park, D-Y, Dhir, R, Luketich, J, Landreneau, R, Janjigian, YY, Kelsen, DP, Cho, E, Ladanyi, M, Tang, L, McCall, SJ, Park, YS, Cheong, J-H, Ajani, J, Camargo, MC, Alonso, S, Ayala, B, Jensen, MA, Pihl, T, Raman, R, Walton, J, Wan, Y, Eley, G, Shaw, KRM, Tarnuzzer, R, Wang, Z, Zenklusen, JC, Davidsen, T, Hutter, CM, Sofia, HJ, Burton, R, Chudamani, S, Liu, J, Bass, AJ, Thorsson, V, Shmulevich, I, Reynolds, SM, Miller, M, Bernard, B, Hinoue, T, Laird, PW, Curtis, C, Shen, H, Weisenberger, DJ, Schultz, N, Shen, R, Weinhold, N, Keiser, DP, Bowlby, R, Sipahimalani, P, Cherniack, AD, Getz, G, Liu, Y, Noble, MS, Pedamallu, C, Sougnez, C, Taylor-Weiner, A, Akbani, R, Lee, J-S, Liu, W, Mills, GB, Yang, D, Zhang, W, Pantazi, A, Parfenov, M, Gulley, M, Piazuelo, MB, Schneider, BG, Kim, J, Boussioutas, A, Sheth, M, Demchok, JA, Rabkin, CS, Willis, JE, Ng, S, Garman, K, Beer, DG, Pennathur, A, Raphael, BJ, Wu, H-T, Odze, R, Kim, HK, Bowen, J, Leraas, KM, Lichtenberg, TM, Weaver, L, McLellan, M, Wiznerowicz, M, Sakai, R, Lawrence, MS, Cibulskis, K, Lichtenstein, L, Fisher, S, Gabriel, SB, Lander, ES, Ding, L, Niu, B, Ally, A, Balasundaram, M, Birol, I, Brooks, D, Butterfield, YSN, Carlsen, R, Chu, A, Chu, J, Chuah, E, Chun, H-JE, Clarke, A, Dhalla, N, Guin, R, Holt, RA, Jones, SJM, Kasaian, K, Lee, D, Li, HA, Lim, E, Ma, Y, Marra, MA, Mayo, M, Moore, RA, Mungall, AJ, Mungall, KL, Nip, KM, Robertson, AG, Schein, JE, Tam, A, Thiessen, N, Beroukhim, R, Carter, SL, Cho, J, DiCara, D, Frazer, S, Gehlenborg, N, Heiman, DI, Jung, J, Lin, P, Meyerson, M, Ojesina, AI, Pedamallu, CS, Saksena, G, Schumacher, SE, Stojanov, P, Tabak, B, Voet, D, Rosenberg, M, Zack, TI, Zhang, H, Zou, L, Protopopov, A, Santoso, N, Lee, S, Zhang, J, Mahadeshwar, HS, Tang, J, Ren, X, Seth, S, Yang, L, Xu, AW, Song, X, Xi, R, Bristow, CA, Hadjipanayis, A, Seidman, J, Chin, L, Park, PJ, Kucherlapati, R, Ling, S, Rao, A, Weinstein, JN, Kim, S-B, Lu, Y, Mills, G, Bootwalla, MS, Lai, PH, Triche, T, Van Den Berg, DJ, Baylin, SB, Herman, JG, Murray, BA, Askoy, BA, Ciriello, G, Dresdner, G, Gao, J, Gross, B, Jacobsen, A, Lee, W, Ramirez, R, Sander, C, Senbabaoglu, Y, Sinha, R, Sumer, SO, Sun, Y, Iype, L, Kramer, RW, Kreisberg, R, Rovira, H, Tasman, N, Haussler, D, Stuart, JM, Verhaak, RGW, Leiserson, MDM, Taylor, BS, Black, AD, Carney, JA, Gastier-Foster, JM, Helsel, C, McAllister, C, Ramirez, NC, Tabler, TR, Wise, L, Zmuda, E, Penny, R, Crain, D, Gardner, J, Lau, K, Curely, E, Mallery, D, Morris, S, Paulauskis, J, Shelton, T, Shelton, C, Sherman, M, Benz, C, Lee, J-H, Fedosenko, K, Manikhas, G, Voronina, O, Belyaev, D, Dolzhansky, O, Rathmell, WK, Brzezinski, J, Ibbs, M, Korski, K, Kycler, W, Lazniak, R, Leporowska, E, Mackiewicz, A, Murawa, D, Murawa, P, Spychala, A, Suchorska, WM, Tatka, H, Teresiak, M, Abdel-Misih, R, Bennett, J, Brown, J, Iacocca, M, Rabeno, B, Kwon, S-Y, Kemkes, A, Curley, E, Alexopoulou, I, Engel, J, Bartlett, J, Albert, M, Park, D-Y, Dhir, R, Luketich, J, Landreneau, R, Janjigian, YY, Kelsen, DP, Cho, E, Ladanyi, M, Tang, L, McCall, SJ, Park, YS, Cheong, J-H, Ajani, J, Camargo, MC, Alonso, S, Ayala, B, Jensen, MA, Pihl, T, Raman, R, Walton, J, Wan, Y, Eley, G, Shaw, KRM, Tarnuzzer, R, Wang, Z, Zenklusen, JC, Davidsen, T, Hutter, CM, Sofia, HJ, Burton, R, Chudamani, S, and Liu, J

Abstract

Gastric cancer is a leading cause of cancer deaths, but analysis of its molecular and clinical characteristics has been complicated by histological and aetiological heterogeneity. Here we describe a comprehensive molecular evaluation of 295 primary gastric adenocarcinomas as part of The Cancer Genome Atlas (TCGA) project. We propose a molecular classification dividing gastric cancer into four subtypes: tumours positive for Epstein-Barr virus, which display recurrent PIK3CA mutations, extreme DNA hypermethylation, and amplification of JAK2, CD274 (also known as PD-L1) and PDCD1LG2 (also known as PD-L2); microsatellite unstable tumours, which show elevated mutation rates, including mutations of genes encoding targetable oncogenic signalling proteins; genomically stable tumours, which are enriched for the diffuse histological variant and mutations of RHOA or fusions involving RHO-family GTPase-activating proteins; and tumours with chromosomal instability, which show marked aneuploidy and focal amplification of receptor tyrosine kinases. Identification of these subtypes provides a roadmap for patient stratification and trials of targeted therapies.

Published
2014

36. Link graph analysis for adult images classification

Author

Kharitonov, E., Slesarev, A., Muchnik, I., Romanenko, F., Belyaev, D., Kotlyarov, D., Kharitonov, E., Slesarev, A., Muchnik, I., Romanenko, F., Belyaev, D., and Kotlyarov, D.

Abstract

In order to protect an image search engine’s users from undesirable results adult images’ classifier should be built. The information about links from websites to images is employed to create such a classifier. These links are represented as a bipartite website-image graph. Each vertex is equipped with scores of adultness and decentness. The scores for image vertexes are initialized with zero, those for website vertexes are initialized according to a text-based website classifier. An iterative algorithm that propagates scores within a website-image graph is described. The scores obtained are used to classify images by choosing an appropriate threshold. The experiments on Internet-scale data have shown that the algorithm under consideration increases classification recall by 17% in comparison with a simple algorithm which classifies an image as adult if it is connected with at least one adult site (at the same precision level).

Published
2010

39. A warm layer in Venus' cryosphere and high-altitude measurements of HF, HCl, H2O and HDO.

Author

Bertaux, Jean-Loup, Vandaele, Ann-Carine, Korablev, Oleg, Villard, E., Fedorova, A., Fussen, D., Quémerais, E., Belyaev, D., Mahieux, A., Montmessin, F., Muller, C., Neefs, E., Nevejans, D., Wilquet, V., Dubois, J. P., Hauchecorne, A., Stepanov, A., Vinogradov, I., and Rodin, A.

Subjects
VENUS (Planet), INNER planets, CLOUDS, SPECTRUM analysis, SPECTROMETERS, ABSORPTION spectra, AIR, ALTITUDE measurements, ULTRAVIOLET radiation
Abstract

Venus has thick clouds of H2SO4 aerosol particles extending from altitudes of 40 to 60 km. The 60–100 km region (the mesosphere) is a transition region between the 4 day retrograde superrotation at the top of the thick clouds and the solar–antisolar circulation in the thermosphere (above 100 km), which has upwelling over the subsolar point and transport to the nightside. The mesosphere has a light haze of variable optical thickness, with CO, SO2, HCl, HF, H2O and HDO as the most important minor gaseous constituents, but the vertical distribution of the haze and molecules is poorly known because previous descent probes began their measurements at or below 60 km. Here we report the detection of an extensive layer of warm air at altitudes 90–120 km on the night side that we interpret as the result of adiabatic heating during air subsidence. Such a strong temperature inversion was not expected, because the night side of Venus was otherwise so cold that it was named the ‘cryosphere’ above 100 km. We also measured the mesospheric distributions of HF, HCl, H2O and HDO. HCl is less abundant than reported 40 years ago. HDO/H2O is enhanced by a factor of ∼2.5 with respect to the lower atmosphere, and there is a general depletion of H2O around 80–90 km for which we have no explanation. [ABSTRACT FROM AUTHOR]

Published
2007
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41. Immunogenetic study on the polymorphism of serum α2-lipoproteins in mink. I. Identification and genetic control of five Lpm allotypes

Author

Baranov, O. K., Savina, M. A., and Belyaev, D. K.

Abstract

Five allotypes, Lpm 1, Lpm 2, Lpm 3, Lpm 4, and Lpm 5, were detected by isoimmunization in mink sera. Immunoelectrophoresis, preparative ultracentrifugation, and histochemical tests for lipids and esterase permitted reference of these alloantigenic markers to a very high density a2-lipoprotein. Based on population analysis and breeding tests, five genetic units are postulated: Lpm1, Lpm4, Lpm3,4, Lpm1,2, and Lpm2,4,5. These units determine the polymorphism of the Lpm system and behave as Mendelian alleles.

Published
1976
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42. Immunogenetic study on the polymorphism of serum α2-lipoproteins in mink. II. Identification of allotypes Lpm-7 and Lpm-8 and genetic control of seven markers of the Lpm system

Author

Baranov, O. K., Yermolaev, V. I., and Belyaev, D. K.

Abstract

By means of alloimmunization of mink, two new antigens, Lpm-7 and Lpm-8, were detected in their sera. Lpm-7 and Lpm-8 allospecificities were referred to a very high density a2-lipoprotein (Lpm) by the following criteria: histochemical tests, immunoelectrophoresis, preparative ultracentrifugation, and coalescence of alloprecipitates with heteroprecipitates in double diffusion tests. Genetic analysis indicated that Lpm-7 and Lpm-8, together with the earlier described Lpm-1, Lpm-2, Lpm-3, Lpm-4, and Lpm-5, share a common immunogenetic system. Polymorphism for the seven markers is conditioned by the genetic units Lpm8, Lpm4, Lpm4, 8, Lpm4, 7, Lpm3, 4, 8, Lpm1, 8, Lpm1, 2, 7, and Lpm2, 4, 5, 7, which behave as alleles. Of these units, the latter six are probably haploid sets of closely linked genes.

Published
1978
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43. Thermal Flow Meters

Author

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO, Korotkov,P. A., Belyaev,D. V., Azimov,R. K., FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO, Korotkov,P. A., Belyaev,D. V., and Azimov,R. K.

Abstract

The book describes the principles of operation, circuits and construction of Soviet as well as foreign thermal flow rate meters. The material is arranged according to type, for thermal flow rate meters designed to measure flow rate of liquids, liquid metals and gases. The problems of theory and design of the flow rate meter are discussed. (Author), Edited trans. of mono. Teplovye Raskhodomery, n.p., 1969 p1-175.

Published
1971

44. The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter

Author

Korablev, O., Montmessin, F., Trokhimovskiy, A., Fedorova, A. A., Shakun, A. V., Grigoriev, A. V., Moshkin, B. E., Ignatiev, N. I., Forget, F., Lefèvre, F., Anufreychik, K., Dzuban, I., Ivanov, Y. S., Kalinnikov, Y. K., Kozlova, T. O., Kungurov, A., Makarov, V., Martynovich, F., Maslov, I., Merzlyakov, D., Moiseev, P. P., Nikolskiy, Y., Patrakeev, A., Patsaev, D., Santos-Skripko, A., Sazonov, O., Semena, N., Semenov, A., Shashkin, V., Sidorov, A., Stepanov, A. V., Stupin, I., Timonin, D., Titov, A. Y., Viktorov, A., Zharkov, A., Altieri, F., Arnold, G., Belyaev, D. A., Bertaux, J. L., Betsis, D. S., Duxbury, N., Encrenaz, T., Fouchet, T., Gérard, J.-C., Grassi, D., Guerlet, S., Hartogh, P., Kasaba, Y., Khatuntsev, I., Krasnopolsky, V. A., Kuzmin, R. O., Lellouch, E., Lopez-Valverde, M. A., Luginin, M., Määttänen, A., Marcq, E., Martin Torres, J., Medvedev, A. S., Millour, E., Olsen, K. S., Patel, M. R., Quantin-Nataf, C., Rodin, A. V., Shematovich, V. I., Thomas, I., Thomas, N., Vazquez, L., Vincendon, M., Wilquet, V., Wilson, C. F., Zasova, L. V., Zelenyi, L. M., Zorzano, M. P., Korablev, O., Montmessin, F., Trokhimovskiy, A., Fedorova, A. A., Shakun, A. V., Grigoriev, A. V., Moshkin, B. E., Ignatiev, N. I., Forget, F., Lefèvre, F., Anufreychik, K., Dzuban, I., Ivanov, Y. S., Kalinnikov, Y. K., Kozlova, T. O., Kungurov, A., Makarov, V., Martynovich, F., Maslov, I., Merzlyakov, D., Moiseev, P. P., Nikolskiy, Y., Patrakeev, A., Patsaev, D., Santos-Skripko, A., Sazonov, O., Semena, N., Semenov, A., Shashkin, V., Sidorov, A., Stepanov, A. V., Stupin, I., Timonin, D., Titov, A. Y., Viktorov, A., Zharkov, A., Altieri, F., Arnold, G., Belyaev, D. A., Bertaux, J. L., Betsis, D. S., Duxbury, N., Encrenaz, T., Fouchet, T., Gérard, J.-C., Grassi, D., Guerlet, S., Hartogh, P., Kasaba, Y., Khatuntsev, I., Krasnopolsky, V. A., Kuzmin, R. O., Lellouch, E., Lopez-Valverde, M. A., Luginin, M., Määttänen, A., Marcq, E., Martin Torres, J., Medvedev, A. S., Millour, E., Olsen, K. S., Patel, M. R., Quantin-Nataf, C., Rodin, A. V., Shematovich, V. I., Thomas, I., Thomas, N., Vazquez, L., Vincendon, M., Wilquet, V., Wilson, C. F., Zasova, L. V., Zelenyi, L. M., and Zorzano, M. P.

Abstract

The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrum

45. Upper limits for phosphine (PH3) in the atmosphere of Mars

Author

Olsen, K. S., Trokhimovskiy, A., Braude, A. S., Korablev, O., Fedorova, A., Wilson, C.F., Patel, M. R., Irwin, P. G. J., Montmessin, F., Lefevre, F., Baggio, L., Alday, J., Belyaev, D. A., Patrakeev, A., Shakun, A., Olsen, K. S., Trokhimovskiy, A., Braude, A. S., Korablev, O., Fedorova, A., Wilson, C.F., Patel, M. R., Irwin, P. G. J., Montmessin, F., Lefevre, F., Baggio, L., Alday, J., Belyaev, D. A., Patrakeev, A., and Shakun, A.

Abstract

Phosphine (PH3) is proposed to be a possible biomarker in planetary atmospheres and has been claimed to have been observed in the atmosphere of Venus, sparking interest in the habitability of Venus’s atmosphere. Observations of another biomarker, methane (CH4), have been reported several times in the atmosphere of Mars, hinting at the possibility of a past or present biosphere. The Atmospheric Chemistry Suite on the ExoMars Trace Gas Orbiter has a spectral range that includes several absorption lines of PH3 with line strengths comparable to previously observed CH4 lines. The signature of PH3 was not observed in the 192 observations made over a full Martian year of observations, and here we report upper limits of 0.1–0.6 ppbv.

46. Reappraising the production and transfer of hydrogen atoms from the middle to the upper atmosphere of Mars at times of elevated water vapor

Author

Montmessin, F., Belyaev, D. A., Lefèvre, F., Alday, J., Vals, M., Fedorova, A. A., Korablev, O. I., Trokhimovskiy, A. V., Chaffin, M. S., Schneider, N. M., Montmessin, F., Belyaev, D. A., Lefèvre, F., Alday, J., Vals, M., Fedorova, A. A., Korablev, O. I., Trokhimovskiy, A. V., Chaffin, M. S., and Schneider, N. M.

Abstract

Water escape on Mars has recently undergone a paradigm shift with the discovery of unexpected seasonal variations in the population of hydrogen atoms in the exosphere where thermal escape occurs and results in water lost to space. This discovery led to the hypothesis that, contradicting the accepted pathway, atomic hydrogen in the exosphere was not only produced by molecular hydrogen but mostly by high altitude water vapor. Enhanced presence of water at high altitude during southern spring and summer, due to atmospheric warming and intensified transport, favors production of H through photon-induced ion chemistry of water molecules and thus appears to be the main cause of the observed seasonal variability in escaping hydrogen. This hypothesis is supported by the observation of large concentrations of water vapor between 50 km and 150 km during the southern summer solstice and global dust events. Using a simplified yet representative air parcel transport model, we show that in addition to the formation of atomic hydrogen from water photolysis above 80 km, a major fraction of the exospheric hydrogen is formed at altitudes as low as 60 km and is then directly advected to the upper atmosphere. Comparing the injection modes of a variety of events (global dust storm, perihelion periods, regional storm), we conclude that southern spring/summer controls H production and further ascent into the upper atmosphere on the long term with direct implication for water escape.

47. Seasonal changes in the vertical structure of ozone in the Martian lower atmosphere and its relationship to water vapour

Author

Olsen, K. S., Fedorova, A. A., Trokhimovskiy, A., Montmessin, F., Lefèvre, F., Korablev, O., Baggio, L., Forget, F., Millour, E., Bierjon, A., Alday, J., Wilson, C. F., Irwin, P. G. J., Belyaev, D. A., Patrakeev, A., Shakun, A., Olsen, K. S., Fedorova, A. A., Trokhimovskiy, A., Montmessin, F., Lefèvre, F., Korablev, O., Baggio, L., Forget, F., Millour, E., Bierjon, A., Alday, J., Wilson, C. F., Irwin, P. G. J., Belyaev, D. A., Patrakeev, A., and Shakun, A.

Abstract

The mid-infrared channel of the Atmospheric Chemistry Suite (ACS MIR) onboard the ExoMars Trace Gas Orbiter is capable of observing the infrared absorption of ozone (O3) in the atmosphere of Mars. During solar occulations, the 003←000 band (3000-3060 cm-1) is observed with spectral sampling of ∼0.045 cm-1. Around the equinoxes in both hemispheres and over the southern winters, we regularly observe around 200-500 ppbv of O3 below 30 km. The warm southern summers, near perihelion, produce enough atmospheric moisture that O3 is not detectable at all, and observations are rare even at high northern latitudes. During the northern summers, water vapour is restricted to below 10 km, and an O3 layer (100-300 ppbv) is visible between 20-30 km. At this same time, the aphelion cloud belt forms, condensing water vapour and allowing O3 to build up between 30-40 km. A comparison to vertical profiles of water vapour and temperature in each season reveals that water vapour abundance is controlled by atmospheric temperature, and H2O and O3 are anti-correlated as expected. When the atmosphere cools, over time or over altitude, water vapour condenses (observed as a reduction in its mixing ratio) and the production of odd hydrogen species is reduced, which allows O3 to build up. Conversely, warmer temperatures lead to water vapour enhancements and ozone loss. The LMD Mars Global Climate Model is able to reproduce vertical structure and seasonal changes of temperature, H2O, and O3 that we observe. However, the observed O3 abundance is larger by factors between 2 and 6, indicating important differences in the rate of odd-hydrogen photochemistry.

48. Seasonal changes in the vertical structure of ozone in the Martian lower atmosphere and its relationship to water vapour

Author

Olsen, K. S., Fedorova, A. A., Trokhimovskiy, A., Montmessin, F., Lefèvre, F., Korablev, O., Baggio, L., Forget, F., Millour, E., Bierjon, A., Alday, J., Wilson, C. F., Irwin, P. G. J., Belyaev, D. A., Patrakeev, A., Shakun, A., Olsen, K. S., Fedorova, A. A., Trokhimovskiy, A., Montmessin, F., Lefèvre, F., Korablev, O., Baggio, L., Forget, F., Millour, E., Bierjon, A., Alday, J., Wilson, C. F., Irwin, P. G. J., Belyaev, D. A., Patrakeev, A., and Shakun, A.

Abstract

The mid-infrared channel of the Atmospheric Chemistry Suite (ACS MIR) onboard the ExoMars Trace Gas Orbiter is capable of observing the infrared absorption of ozone (O3) in the atmosphere of Mars. During solar occulations, the 003←000 band (3000-3060 cm-1) is observed with spectral sampling of ∼0.045 cm-1. Around the equinoxes in both hemispheres and over the southern winters, we regularly observe around 200-500 ppbv of O3 below 30 km. The warm southern summers, near perihelion, produce enough atmospheric moisture that O3 is not detectable at all, and observations are rare even at high northern latitudes. During the northern summers, water vapour is restricted to below 10 km, and an O3 layer (100-300 ppbv) is visible between 20-30 km. At this same time, the aphelion cloud belt forms, condensing water vapour and allowing O3 to build up between 30-40 km. A comparison to vertical profiles of water vapour and temperature in each season reveals that water vapour abundance is controlled by atmospheric temperature, and H2O and O3 are anti-correlated as expected. When the atmosphere cools, over time or over altitude, water vapour condenses (observed as a reduction in its mixing ratio) and the production of odd hydrogen species is reduced, which allows O3 to build up. Conversely, warmer temperatures lead to water vapour enhancements and ozone loss. The LMD Mars Global Climate Model is able to reproduce vertical structure and seasonal changes of temperature, H2O, and O3 that we observe. However, the observed O3 abundance is larger by factors between 2 and 6, indicating important differences in the rate of odd-hydrogen photochemistry.

49. Reappraising the production and transfer of hydrogen atoms from the middle to the upper atmosphere of Mars at times of elevated water vapor

Author

Montmessin, F., Belyaev, D. A., Lefèvre, F., Alday, J., Vals, M., Fedorova, A. A., Korablev, O. I., Trokhimovskiy, A. V., Chaffin, M. S., Schneider, N. M., Montmessin, F., Belyaev, D. A., Lefèvre, F., Alday, J., Vals, M., Fedorova, A. A., Korablev, O. I., Trokhimovskiy, A. V., Chaffin, M. S., and Schneider, N. M.

Abstract

Water escape on Mars has recently undergone a paradigm shift with the discovery of unexpected seasonal variations in the population of hydrogen atoms in the exosphere where thermal escape occurs and results in water lost to space. This discovery led to the hypothesis that, contradicting the accepted pathway, atomic hydrogen in the exosphere was not only produced by molecular hydrogen but mostly by high altitude water vapor. Enhanced presence of water at high altitude during southern spring and summer, due to atmospheric warming and intensified transport, favors production of H through photon-induced ion chemistry of water molecules and thus appears to be the main cause of the observed seasonal variability in escaping hydrogen. This hypothesis is supported by the observation of large concentrations of water vapor between 50 km and 150 km during the southern summer solstice and global dust events. Using a simplified yet representative air parcel transport model, we show that in addition to the formation of atomic hydrogen from water photolysis above 80 km, a major fraction of the exospheric hydrogen is formed at altitudes as low as 60 km and is then directly advected to the upper atmosphere. Comparing the injection modes of a variety of events (global dust storm, perihelion periods, regional storm), we conclude that southern spring/summer controls H production and further ascent into the upper atmosphere on the long term with direct implication for water escape.

50. Upper limits for phosphine (PH3) in the atmosphere of Mars

Author

Olsen, K. S., Trokhimovskiy, A., Braude, A. S., Korablev, O., Fedorova, A., Wilson, C.F., Patel, M. R., Irwin, P. G. J., Montmessin, F., Lefevre, F., Baggio, L., Alday, J., Belyaev, D. A., Patrakeev, A., Shakun, A., Olsen, K. S., Trokhimovskiy, A., Braude, A. S., Korablev, O., Fedorova, A., Wilson, C.F., Patel, M. R., Irwin, P. G. J., Montmessin, F., Lefevre, F., Baggio, L., Alday, J., Belyaev, D. A., Patrakeev, A., and Shakun, A.

Abstract

Phosphine (PH3) is proposed to be a possible biomarker in planetary atmospheres and has been claimed to have been observed in the atmosphere of Venus, sparking interest in the habitability of Venus’s atmosphere. Observations of another biomarker, methane (CH4), have been reported several times in the atmosphere of Mars, hinting at the possibility of a past or present biosphere. The Atmospheric Chemistry Suite on the ExoMars Trace Gas Orbiter has a spectral range that includes several absorption lines of PH3 with line strengths comparable to previously observed CH4 lines. The signature of PH3 was not observed in the 192 observations made over a full Martian year of observations, and here we report upper limits of 0.1–0.6 ppbv.

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