September 2024 – Page 5 – My WordPress Site

Topological alteration of a state graph. a) A system being coarse-grained and receiving arbitrary labels from an external observer. The example macrostate (u) labels are vectors of three binary-valued microstate variables denoted (v1, v2, v3). Panels b to d display the topologies of the physicallyreachable state graph after constraining a variable of the labeling vector. The nodes and edges that became inaccessible as a consequence of applying a conservation law are displayed with lighter colors. The top row corresponds to setting value 0, while the bottom row corresponds to setting the variable to 1. b) Constraining variable v1. On the one hand (b.1), a conservation law for v1 = 0 leads the system to state u1. On the other hand (b.2), with v1 = 1, the system cannot escape from u2. c) Constraining variable v1. In the case v1 = 1 in c.2), the graph is restricted to u3 and has no possible transitions. The node does exist under a conservation law setting v1 to 1 but there is no way to reach this node due to the topology of the unconstrained graph. d) Constraining variable v3. This variable is constant and equal to 1 in the unconstrained graph in a), so a conservation law setting v3 = 0 such as in panel d.1 is meaningless for this case. -- physics.bio-ph

Biophysics, Biosignatures & Paleobiology, Nanotechnology & SynBio, Origin & Evolution of Life

An Open-Ended Approach to Understanding Local, Emergent Conservation Laws in Biological Evolution

by Keith CowingSeptember 24, 2024September 24, 2024

Supernova -- Astrobiology.com

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Radiation, Stellar Cartography

Sharp Rise in Cosmic Ray Irradiation of Organisms on Earth Caused by a Nearby SN Shockwave Passage

by Keith CowingSeptember 24, 2024September 24, 2024

Pressure-Temperature phase diagram showing Uranus and Neptune adiabats, the fluid-to-superionic transition of pure water (dashed blue) reported in Ref. (Millot et al. 2018), and the melting line of pure SiO2 (dashed red) from Refs. (Millot et al. 2015; Gonz´alez-Cataldo et al. 2016). Simulation performed in this work have been conducted at 3000 K (dotted line). We can observe two phase transitions, the one of pure-water, (blue) which is compatible previous simulations, and another in the 1:4 mixture (purple). The presence of 25% SiO2 molecules delays the superionic water phase by about 70 GPa. The corresponding phase boundary line is sketched (dashed purple) in the vicinity of 3000 K, assuming a temperature dependence similar to the pure-water case (dashed blue). Error bars denote the leftmost (rightmost) point in the pressure line where we observe a fluid (superionic) MD simulation, see Figure. 2. -- astro-ph.EP

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets

The linear-mixing Approximation In Silica-water Mixtures At Planetary Conditions

by Keith CowingSeptember 24, 2024September 24, 2024

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets

Impacting Atmospheres: How Late-Stage Pollution Alters Exoplanet Composition

by Keith CowingSeptember 24, 2024September 24, 2024

Example Tails interface for the scanning of comet candidates. Adapted from Fig. 5 of (Duev et al., 2021) and reproduced with the permission of the authors and AAS Journals. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Astrochemistry, Comets and Asteroids, Imaging & Spectroscopy

Identification and Localization of Cometary Activity in Solar System Objects with Machine Learning

by Keith CowingSeptember 24, 2024September 24, 2024

Relationship between criteria, arguments, and outcome -- Astrobiology via Sage Journals

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Imaging & Spectroscopy, Venus

Venus Phosphine: Updates and Lessons Learned

by Keith CowingSeptember 24, 2024

Modeling and Simulation of SDS and DTMA membranes. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Imaging & Spectroscopy, Origin & Evolution of Life, Planetary Protection & Biosafety, Sample Return, Terraforming & Geoengineering, Venus

Simple Lipids Form Stable Higher-order Structures In Concentrated Sulfuric Acid

by Keith CowingSeptember 23, 2024September 23, 2024

Tardigrade Hypsibius exemplaris. -- Int J Mol Sci.

Cryobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Icy Worlds, Microbiology & Virology, Microgravity, Panspermia, Planetary Protection & Biosafety, Radiation

Antioxidant Defense in the Toughest Animals on the Earth: Its Contribution to the Extreme Resistance of Tardigrades

by Keith CowingSeptember 23, 2024September 23, 2024

Comparing CO2 exosphere to surface properties on Ganymede’s leading hemisphere. A) Vertical CO2 gas column density (unit of 1018 m−2 , this work, see also Fig. O.2); B) Depth of CO2-solid absorption band (Paper I); C) Central wavelength of CO2-solid absorption band (Paper I); D) Reflectance at 3.65 µm (Paper I); E) Central wavelength of H2O Fresnel peak (Paper I); F) Relative amplitude of the maximum reflectance between 3.5 and 4 µm (H2O interband amplitude, Paper I). The north pole of the leading hemisphere possesses the most red-shifted absorption band center of solid CO2, consistent with CO2 trapped in amorphous H2O ice (Paper I). It also has the higher reflectance at 3.65 µm and H2O interband amplitude, indicative of a higher density of facets in H2O ice for the photons (i.e., smaller grains and/or more internal defects and/or higher micro-roughness/porosity), and the most blue-shifted central wavelength of the H2O Fresnel peak due to a higher proportion of amorphous water ice (Mastrapa et al. 2009). -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Cryobiology, Ganymede, Icy Worlds, Jupiter

A Patchy CO2 Exosphere On Ganymede Revealed By The James Webb Space Telescope

by Keith CowingSeptember 23, 2024September 23, 2024

NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership The Suomi NPP satellite acquired this image of a plume of Saharan dust as winds lofted it over the Atlantic Ocean on Aug. 24, 2024. Larger image

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Habitable Zones, Water/Hycean Worlds & Oceanography

Life In The Atlantic Ocean Thrives Due To Windblown Saharan Dust

by Keith CowingSeptember 23, 2024September 23, 2024