scholarly journals Emirates Mars Mission Characterization of Mars Atmosphere Dynamics and Processes

2021 ◽  
Vol 217 (8) ◽  
Author(s):  
Hessa Almatroushi ◽  
Hoor AlMazmi ◽  
Noora AlMheiri ◽  
Mariam AlShamsi ◽  
Eman AlTunaiji ◽  
...  
Keyword(s):  
Physical Models ◽  
Lower Atmosphere ◽  
Imaging Data ◽  
Science Data ◽  
Mars Atmosphere ◽  
Mars Mission ◽  
Atmospheric Escape ◽  
Infrared Wavelengths ◽  
Circulation Dynamics

AbstractThe Emirates Mars Mission (EMM) – Hope Probe – was developed to understand Mars atmospheric circulation, dynamics, and processes through characterization of the Mars atmosphere layers and its interconnections enabled by a unique high-altitude (19,970 km periapse and 42,650 km apoapse) low inclination orbit that will offer an unprecedented local and seasonal time coverage over most of the planet. EMM has three scientific objectives to (A) characterize the state of the Martian lower atmosphere on global scales and its geographic, diurnal and seasonal variability, (B) correlate rates of thermal and photochemical atmospheric escape with conditions in the collisional Martian atmosphere, and (C) characterize the spatial structure and variability of key constituents in the Martian exosphere. The EMM data products include a variety of spectral and imaging data from three scientific instruments measuring Mars at visible, ultraviolet, and infrared wavelengths and contemporaneously and globally sampled on both diurnal and seasonal timescale. Here, we describe our strategies for addressing each objective with these data in addition to the complementary science data, tools, and physical models that will facilitate our understanding. The results will also fill a unique role by providing diagnostics of the physical processes driving atmospheric structure and dynamics, the connections between the lower and upper atmospheres, and the influences of these on atmospheric escape.

Emirates Mars Mission (EMM) 2020 Overview and Status

2021 ◽  
Author(s):  
Omran Sharaf ◽  
Sarah Amiri ◽  
Hessa Almatroushi ◽  
Adnan AlRais ◽  
Mohammad Wali ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Martian Atmosphere ◽  
Space Physics ◽  
Lower Atmosphere ◽  
State University ◽  
Arizona State University ◽  
Transfer Programs ◽  
Mars Mission ◽  
Atmospheric Escape ◽  
The Status

<p>The Emirates Mars Mission (EMM) is the United Arab Emirates’ (UAE) first mission to Mars and is the first Arab mission to another planet. It launched an unmanned observatory called “Hope” into an elliptical orbit around Mars on July 20, 2020  carrying three scientific instruments to study the Martian atmosphere in visible, ultraviolet, and infrared wavelengths. EMM will be the first mission to provide the first truly global picture of the Martian atmosphere, revealing important information about how atmospheric processes drive diurnal variations for a period of one Martian year. This will provide scientists with valuable understanding of the changes to the Martian atmosphere today through the achievement of three scientific objectives:</p><ul><li>Characterize the state of the Martian lower atmosphere on global scales and its geographic, diurnal and seasonal variability.</li> <li>Correlate rates of thermal and photochemical atmospheric escape with conditions in the collisional Martian atmosphere.</li> <li>Characterize the spatial structure and variability of key constituents in the Martian exosphere.</li> </ul><p>The mission is led by Emiratis from Mohammed Bin Rashid Space Centre (MBRSC) and is expanding the nation’s human capital through knowledge transfer programs set with international partners from the University of Colorado Laboratory for Atmospheric and Space Physics (LASP), Arizona State University (ASU) School of Earth and Space Exploration, and University of California Berkeley Space Sciences Laboratory (SSL). The presentation will review the status of the mission up to and beyond a successful Mars Orbit Insertion on Feb 9, 2021, including activities from Mars orbit in preparation for the start of mission science in May 2021.</p>

scholarly journals Genome-wide binding potential and regulatory activity of the glucocorticoid receptor’s monomeric and dimeric forms

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas A. Johnson ◽  
Ville Paakinaho ◽  
Sohyoung Kim ◽  
Gordon L. Hager ◽  
Diego M. Presman
Keyword(s):  
Receptor Binding ◽  
Site Response ◽  
Physiological Role ◽  
Binding Potential ◽  
Open Chromatin ◽  
Imaging Data ◽  
Response Elements ◽  
Genome Wide ◽  
Genomic Studies

AbstractA widely regarded model for glucocorticoid receptor (GR) action postulates that dimeric binding to DNA regulates unfavorable metabolic pathways while monomeric receptor binding promotes repressive gene responses related to its anti-inflammatory effects. This model has been built upon the characterization of the GRdim mutant, reported to be incapable of DNA binding and dimerization. Although quantitative live-cell imaging data shows GRdim as mostly dimeric, genomic studies based on recovery of enriched half-site response elements suggest monomeric engagement on DNA. Here, we perform genome-wide studies on GRdim and a constitutively monomeric mutant. Our results show that impairing dimerization affects binding even to open chromatin. We also find that GRdim does not exclusively bind half-response elements. Our results do not support a physiological role for monomeric GR and are consistent with a common mode of receptor binding via higher order structures that drives both the activating and repressive actions of glucocorticoids.

scholarly journals Molecular characterization of human coronaviruses and their circulation dynamics in Kenya, 2009–2012

2016 ◽  
Vol 13 (1) ◽  
Author(s):  
Lenata A. Sipulwa ◽  
Juliette R. Ongus ◽  
Rodney L. Coldren ◽  
Wallace D. Bulimo
Keyword(s):  
Molecular Characterization ◽  
Human Coronaviruses ◽  
Circulation Dynamics

Hydrogen escape from Mars is driven by seasonal and dust storm transport of water

Science ◽  
2020 ◽  
Vol 370 (6518) ◽  
pp. 824-831
Author(s):  
Shane W. Stone ◽  
Roger V. Yelle ◽  
Mehdi Benna ◽  
Daniel Y. Lo ◽  
Meredith K. Elrod ◽  
...  
Keyword(s):  
Dust Storm ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Dust Storms ◽  
Upper Atmosphere ◽  
Lower Atmosphere ◽  
Mars Atmosphere ◽  
Water Abundance ◽  
Neutral Gas ◽  
Standard Models

Mars has lost most of its once-abundant water to space, leaving the planet cold and dry. In standard models, molecular hydrogen produced from water in the lower atmosphere diffuses into the upper atmosphere where it is dissociated, producing atomic hydrogen, which is lost. Using observations from the Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution spacecraft, we demonstrate that water is instead transported directly to the upper atmosphere, then dissociated by ions to produce atomic hydrogen. The water abundance in the upper atmosphere varied seasonally, peaking in southern summer, and surged during dust storms, including the 2018 global dust storm. We calculate that this transport of water dominates the present-day loss of atomic hydrogen to space and influenced the evolution of Mars’ climate.

scholarly journals Atmospheric implications of the lack of H 3 + detection at Neptune

2020 ◽  
Vol 378 (2187) ◽  
pp. 20200100 ◽  
Author(s):  
L. Moore ◽  
J. I. Moses ◽  
H. Melin ◽  
T. S. Stallard ◽  
J. O’Donoghue
Keyword(s):  
Giant Planet ◽  
Atmospheric Temperature ◽  
Upper Atmosphere ◽  
Lower Atmosphere ◽  
Observational Constraints ◽  
Atmospheric Conditions ◽  
Atmospheric Escape ◽  
Upper Limits ◽  
Voyager 2 ◽  
The Impact

H 3 + has been detected at all of the solar system giant planets aside from Neptune. Current observational upper limits imply that there is far less H 3 + emission at Neptune than rudimentary modelling would suggest. Here, we explore via modelling a range of atmospheric conditions in order to find some that could be consistent with observational constraints. In particular, we consider that the upper atmosphere might be much cooler than it was during the 1989 Voyager 2 encounter, and we examine the impact of an enhanced influx of external material that could act to reduce H 3 + density. Resulting ionosphere models that are consistent with existing H 3 + observational constraints have an exospheric temperature of 450 K or less, 300 K lower than the Voyager 2 value. Alternatively, if a topside CO influx of 2 × 10 8  cm −2  s −1 is imposed, the upper atmospheric temperature can be higher, up to 550 K. The potential cooling of Neptune’s atmosphere is relevant for poorly understood giant planet thermospheric energetics, and would also impact aerobreaking manoeuvers for any future spacecraft. Such a large CO influx, if present, could imply Triton is a very active moon with prominent atmospheric escape, and/or that Neptune’s rings significantly modify its upper atmosphere, and the introduction of so much exogenic material would complicate interpretation of the origin of species observed in Neptune’s lower atmosphere. This article is part a discussion meeting issue ‘Future exploration of ice giant systems’.

Modeling the Atmospheric Contribution to the Interior Characterization of sub-Neptunes and its Effect on Habitability

2020 ◽  
Author(s):  
Jasmine MacKenzie ◽  
Philipp Baumeister ◽  
Mareike Godolt ◽  
Nicola Tosi ◽  
Daria Kubyshkina ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Physical Parameters ◽  
Habitable Zone ◽  
Calculated Density ◽  
Atmospheric Escape ◽  
Dense Cores ◽  
Solar Composition ◽  
Primary Composition ◽  
Low Mass

<p>As the number of confirmed exoplanets has increased, so too has the diversity in their physical parameters, namely their mass and radius. A common practice is to place these planets on a Mass-Radius diagram with various calculated density curves corresponding to some bulk composition. However, these lines don’t necessarily correspond to the structure of the planet found using interior models, particularly for low mass planets with masses less than 20 M<sub>⊕</sub> and 4 R<sub>⊕</sub>, which we call “sub-Neptunes.” Planets in this range can have highly degenerate solutions with no solar system analog, from so-called “ocean worlds” to small dense cores with extended primary composition atmospheres. We have created a model that is able to cover the range of solutions possible for sub-Neptunes, with various levels of complexity for both the interior and atmosphere. This includes both an isothermal and semi-grey atmosphere, along with a high-pressure solar composition envelope when atmospheric pressures exceed approximately 1000 bar. We then apply this model to known sub-Neptunes located in the extended habitable zone of their star using a hydrogen-helium dominated atmosphere. An atmospheric escape model is used to investigate the longevity of the atmosphere and its effect on the overall habitability of the planet.</p>

Exoplanet pollution in transit spectroscopy with the next-generation of infrared space telescopes

2020 ◽  
Author(s):  
Giuseppe Morello ◽  
Tiziano Zingales ◽  
Marine Martin-Lagarde ◽  
Rene Gastaud ◽  
Christophe Cossou ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Phase Curve ◽  
Next Generation ◽  
Space Telescopes ◽  
System Parameters ◽  
James Webb Space Telescope ◽  
Infrared Wavelengths ◽  
In Transit ◽  
The Impact

<p>The next generation of space telescopes is expected to deliver transmission spectra of exoplanet atmospheres with precision down to 10 parts per million (ppm). Therefore, it is required to model the astrophysical signals with even greater precision in order not to introduce significant biases for the characterization of the planet and its atmosphere.</p> <p>We discuss, in particular, the contribution of the planetary flux in the analysis of transit observations. Usually, the planetary flux is assumed to be a negligible fraction of the stellar flux, so called <em>dark planet</em> hypothesis. However, this hypothesis is not always valid, especially at the infrared wavelengths, around the peak of thermal emission from the planet. We identify two effects, named <em>self-blend</em> and <em>phase-blend</em>, that tend to bias the measured transit depth in opposite directions (the <em>self-blend</em> effect was already known from Kipping & Tinetti 2010).</p> <p>We introduce a novel sub-package of the software ExoTETHyS that can be used to estimate the amplitude of these two effects depending on the exoplanet system parameters, along with the derivation of the mathematical formulae. In this way, it is possible to identify some priority targets to observe longer transit windows, the secondary eclipse and/or the full phase-curve in order to reduce these potential biases.</p> <p>We also show the impact of the <em>self-</em> and <em>phase-blend</em> effects in the analysis of simulated transit spectra taken with the James Webb Space Telescope (JWST), including the results of the atmospheric retrievals. Our analysis takes into account the possible mitigation depending on the alternative data detrending methods.</p> <p> </p>

scholarly journals 855 Patient Specific Digital Modelling And 3D Printing of Abdominal Anatomy- The Next Frontier in Surgical Simulation?

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
J Fletcher ◽  
C Myles ◽  
D Miskovic ◽  
J Jones ◽  
R Cahill
Keyword(s):  
3D Printing ◽  
Injection Moulding ◽  
Surgical Simulation ◽  
Low Cost ◽  
Physical Models ◽  
Patient Specific ◽  
Phase Imaging ◽  
Imaging Data ◽  
Digital Models ◽  
Operative Planning

Abstract Introduction Innovations in digital technologies afford new opportunities in surgical education. We describe a novel method of combining medical imaging data with virtual 3D modelling and printing techniques that could facilitate patient specific pre-operative planning and rehearsal. Method A series of silicone castings was produced to simulate upper abdominal viscera using a novel polyvinyl alcohol (PVA) injection moulding method. Digital models were generated by segmenting CT dual phase imaging in ITK-SNAP. A 3D polygon mesh was exported and optimised in the computer graphics software: Blender. Two 3D printers were used to manufacture a dissolvable mould of the digital models. Moulds were injected with coloured silicones and dissolved in water to reveal the multicolour/multi-material models. Results The silicone models retained the anatomical detail of the digitally segmented CT data sets. The multi-colour models were achieved with a single print and at very low cost (approx. £248/ model) and possessed varying shore hardness between viscera recreating lifelike fidelity. Conclusions The hybrid 3D printing/injection moulding method offers an avenue to realistic surgical and anatomical simulation. A combination of both virtual models and 3D physical models may provide an enhanced surgical experience for preoperative and intraoperative planning allowing patient specific rehearsal.

scholarly journals Investigation on the low-freauency noise physical models and the defects' characterization of the PbS infrared dectector

2011 ◽  
Vol 60 (10) ◽  
pp. 107202
Author(s):  
Chen Wen-Hao ◽  
Du Lei ◽  
Yin Xue-Song ◽  
Kang Li ◽  
Wang Fang ◽  
...  
Keyword(s):  
Physical Models
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