Emergence of Intermediate Range Order in Jammed Packings.

We perform a structural analysis of large scale jammed packings of monodisperse, frictionless and frictional spheres to elucidate structural signatures of the static structure factor in the low-to-intermediate wave number region. We employ discrete element method simulations containing up to 8×10^{7} particles, in which the particle friction coefficient(s), including sliding, rolling, and twisting interactions, are varied. At intermediate wave number values, corresponding to length scales that lie between that of the nearest neighbor primary peak and the system size, we find the emergence of a prepeak-a signature of intermediate range order-that grows with increasing friction.

UVC-Intense Exoplanets May Not Be Uninhabitable: Evidence from a Desert Lichen.

Many of the recently discovered Earth-like exoplanets are hosted by M and F stars, stars that emit intense UVC, especially during a flare. We studied whether such planets are nevertheless habitable by irradiating a desert lichen, with 254-nm 55 W/m UVC nonstop for 3 months in the laboratory. Only 50% of its algal photobiont cells were inactivated.

Simulated microgravity triggers a membrane adaptation to stress in E. coli REL606.

Investigating the evolution of Escherichia coli in microgravity offers valuable insights into microbial adaptation to extreme environments. Here the effects of simulated microgravity (SµG) on gene expression and genome evolution of E. coli REL606, a strain evolved terrestrially for 35 years, is explored.

Structural Enzymology, Phylogenetics, Differentiation, and Symbolic Reflexivity at the Dawn of Biology.

Translation of symbols in one chemical language into another defined genetics. Yet, the co-linearity of codons and amino acids is so commonplace an idea that few even ask how it arose. Readout is done by two distinct sets of proteins, called aminoacyl-tRNA synthetases.

No dewfall or frost in the Antarctic Dry Valley summers: Comment on Büdel et al. (2008).

Microbial communities within porous rocks in the upper elevations of the McMurdo Dry Valleys of Antarctica are an interesting analog for life on Mars. The primary source of moisture for this community is summer snowmelt adsorbed by the porous stone. Büdel et al.

StableTiCT MXene Ink Formulation and High-Resolution Aerosol Jet Printing for High-Performance MXene Supercapacitors.

Lightweight energy storage devices are essential for developing compact wearable and distributed electronics, and additive manufacturing offers a scalable, low-cost approach to fabricating such devices with complex geometries. However, additive manufacturing of high-performance, on-demand energy storage devices remains challenging due to the need for stable, multifunctional nanomaterial inks. Herein, the development of 2-dimensional (2D) titanium carbide (TiCT MXene) ink that is compatible with aerosol jet printing for energy storage applications is demonstrated.

RNA-DNA Differences: Mechanisms, Oxidative Stress, Transcriptional Fidelity, and Health Implications.

RNA-DNA differences (RDDs) challenge the traditional view of RNA as a faithful copy of DNA, arising through RNA editing, transcriptional errors, and oxidative damage. Reactive oxygen species (ROS) play a central role, inducing lesions like 8-oxo-guanine that compromise transcription and translation, leading to dysfunctional proteins. This review explores the biochemical basis of RDDs, their exacerbation under oxidative stress, and their dual roles in cellular adaptation and disease.

Characterization of the murine spine for spaceflight studies.

Rodents provide a useful analog for understanding the effects of spaceflight on the human body, offering opportunities for investigations into the relationship between microgravity and the musculoskeletal system. In particular, rodents have often been utilized to improve our understanding of the effects of spaceflight on the spine, including intervertebral disc and vertebral body health. However, there are a number of experimental factors that differ between existing works, including mission duration, animal housing, and anatomical location of interest, making it difficult to draw holistic conclusions.

Scaling Advantage in Approximate Optimization with Quantum Annealing.

Quantum annealing is a heuristic optimization algorithm that exploits quantum evolution to find low-energy states. Quantum annealers have scaled up in recent years to tackle increasingly larger and more highly connected discrete optimization and quantum simulation problems. Nevertheless, a computational quantum advantage in exact optimization using quantum annealing hardware has so far remained elusive.

Polycyclic (anti)aromatic hydrocarbons: interstellar formation and spectroscopic characterization of biphenylene and benzopentalene.

Formation of biphenylene (CH) and its isomer benzopentalene, CH, may act as a consumption route for -benzyne (-CH) in interstellar clouds such as TMC-1. MRCI-F12 and CCSD(T)-F12 potential energy surfaces show that -CH dimerization is possible through a -symmetry single-bond association to a (CH) precursor before isomerization to (CH) and subsequently CH. Formation of a bimolecular product set from either species is energetically hindered, allowing (CH) and CH to stabilize radiatively.

Airborne imaging spectroscopy surveys of Arctic and boreal Alaska and northwestern Canada 2017-2023.

Since 2015, NASA's Arctic Boreal Vulnerability Experiment (ABoVE) has investigated how climate change impacts the vulnerability and/or resilience of the permafrost-affected ecosystems of Alaska and northwestern Canada. ABoVE conducted extensive surveys with the Next Generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) during 2017, 2018, 2019, and 2022 and with AVIRIS-3 in 2023 to characterize tundra, taiga, peatlands, and wetlands in unprecedented detail. The ABoVE AVIRIS dataset comprises ~1700 individual flight lines covering ~120,000 km with nominal 5 m × 5 m spatial resolution.

Non-DNA radiosensitive targets that initiate persistent behavioral deficits in rats exposed to space radiation.

Predicting future CNS risks for astronauts during deep-space missions will rely substantially on ground-based rodent data with space-relevant ions and behaviors. For rats, the accumulated evidence indicates that less densely ionizing radiation, such as He and C ions, induce behavior deficits at lower doses than densely ionizing ions, such as Ti and Fe. However, this observation conflicts with standard somatic radiobiology, in which densely ionizing ions are generally more effective than less densely ionizing ions, and where the DNA/nucleus is the accepted target for radiation-induced tumorigenesis, cytogenetic aberrations, genetic mutations, and reproductive cell death.

Human de novo mutation rates from a four-generation pedigree reference.

Understanding the human de novo mutation (DNM) rate requires complete sequence information. Here using five complementary short-read and long-read sequencing technologies, we phased and assembled more than 95% of each diploid human genome in a four-generation, twenty-eight-member family (CEPH 1463). We estimate 98-206 DNMs per transmission, including 74.

Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars.

Ancient Mars had surface liquid water and a dense carbon dioxide (CO)-rich atmosphere. Such an atmosphere would interact with crustal rocks, potentially leaving a mineralogical record of its presence. We analyzed the composition of an 89-meter stratigraphic section of Gale crater, Mars, using data collected by the Curiosity rover.

Priority research directions for wildfire science: views from a historically fire-prone and an emerging fire-prone country.

Fire regimes are changing across the globe, with new wildfire behaviour phenomena and increasing impacts felt, especially in ecosystems without clear adaptations to wildfire. These trends pose significant challenges to the scientific community in understanding and communicating these changes and their implications, particularly where we lack underlying scientific evidence to inform decision-making. Here, we present a perspective on priority directions for wildfire science research-through the lens of academic and government wildfire scientists from a historically wildfire-prone (USA) and emerging wildfire-prone (UK) country.

Classical Preoptimization Approach for ADAPT-VQE: Maximizing the Potential of High-Performance Computing Resources to Improve Quantum Simulation of Chemical Applications.

The ADAPT-VQE algorithm is a promising method for generating a compact ansatz based on derivatives of the underlying cost function, and it yields accurate predictions of electronic energies for molecules. In this work, we report the implementation and performance of ADAPT-VQE with our recently developed sparse wave function circuit solver (SWCS) in terms of accuracy and efficiency for molecular systems with up to 52 spin orbitals. The SWCS can be tuned to balance computational cost and accuracy, which extends the application of ADAPT-VQE for molecular electronic structure calculations to larger basis sets and a larger number of qubits.

Segmentation of dense and multi-species bacterial colonies using models trained on synthetic microscopy images.

The spread of microbial infections is governed by the self-organization of bacteria on surfaces. Bacterial interactions in clinically relevant settings remain challenging to quantify, especially in systems with multiple species or varied material properties. Quantitative image analysis methods based on machine learning show promise to overcome this challenge and support the development of novel antimicrobial treatments, but are limited by a lack of high-quality training data.

Taking the 3Rs to a higher level: replacement and reduction of animal testing in life sciences in space research.

Human settlements on the Moon, crewed missions to Mars and space tourism will become a reality in the next few decades. Human presence in space, especially for extended periods of time, will therefore steeply increase. However, despite more than 60 years of spaceflight, the mechanisms underlying the effects of the space environment on human physiology are still not fully understood.

Dual Function Materials Enabling Human Space Flight: Carbon Dioxide Capture and Conversion for Life Support on Crewed Missions.

Carbon dioxide removal is important for keeping astronauts alive in space, where CO can accumulate to harmful or even deadly levels in cabin air if untreated. Additionally, on Earth, CO direct air capture is an important technology for reversing the harmful impacts of rising anthropogenic atmospheric CO concentrations. In both scenarios, captured CO needs to be dealt with, potentially via reaction into a more desirable final product such as renewable hydrocarbons or water.

Humidity Enhancement in Dry Permafrost: The Effects of Temperature Cycles on Habitability.

The search for life in the solar system often focuses on water and on environments where habitable conditions exist, persistently or occasionally. In this search, dry permafrost (ice-free frozen soil) has received minimal attention. It was previously proposed that within martian dry permafrost the water activity (, an essential property for habitability) could be enhanced by diurnal thermal cycles and water desorption from soil grains, but the details remain unexplored.

37-Day microgravity exposure in 16-Week female C57BL/6J mice is associated with bone loss specific to weight-bearing skeletal sites.

Exposure to weightlessness in microgravity and elevated space radiation are associated with rapid bone loss in mammals, but questions remain about their mechanisms of action and relative importance. In this study, we tested the hypothesis that bone loss during spaceflight in Low Earth Orbit is primarily associated with site-specific microgravity unloading of weight-bearing sites in the skeleton. Microcomputed tomography and histological analyses of bones from mice space flown on ISS for 37 days in the NASA Rodent Research-1 experiment show significant site-specific cancellous and cortical bone loss occurring in the femur, but not in L2 vertebrae.

Effects of Space Flight on Inflammasome Activation in the Brain of Mice.

Space flight exposes astronauts to stressors that alter the immune response, rendering them vulnerable to infections and diseases. In this study, we aimed to determine the levels of inflammasome activation in the brains of mice that were housed in the International Space Station (ISS) for 37 days. C57BL/6 mice were launched to the ISS as part of NASA's Rodent Research 1 Mission on SpaceX-4 CRS-4 Dragon cargo spacecraft from 21 September 2014 to 25 October 2014.

Geochemical Transformations of Gypsum Under Multiple Environmental Settings and Implications for Ca-Sulfate Detection on Mars.

Calcium sulfate minerals are found in multiple environments on Earth and Mars, with chloride (Cl) salts widely distributed on both planets. Low-temperature studies have explored geochemical processes, including the formation of transient liquid water and ion migration on Mars. Some Cl-salts (e.

Evaluating Serpentinization as a Source of Phosphite to Microbial Communities in Hydrothermal Vents.

Previous studies have documented the presence of phosphite, a reduced and highly soluble form of phosphorus, in serpentinites, which has led to the hypothesis that serpentinizing hydrothermal vents could have been an important source of bioavailable phosphorus for early microbial communities in the Archean. Here, we test this hypothesis by evaluating the genomic hallmarks of phosphorus usage in microbial communities living in modern hydrothermal vents with and without influence from serpentinization. These genomic analyses are combined with results from a geochemical model that calculates phosphorus speciation during serpentinization as a function of temperature, water:rock ratio, and lithology at thermodynamic equilibrium.

Heterogeneity of rock-hosted microbial communities in a serpentinizing aquifer of the Coast Range Ophiolite.

The movement of groundwater through fractured bedrock provides favorable conditions for subsurface microbial life, characterized by constrained flow pathways and distinctive local environmental conditions. In this study, we examined a subsurface microbial ecosystem associated with serpentinized rocks recovered from the Coast Range Ophiolite in northern California, USA. The distribution and diversity of microbial communities at various depths within two separate cores reaching up to 45 m below the land surface were investigated with microbiological and geochemical approaches.