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Here we review the origin, evolution, and compositional properties of Saturn's ring moons. This class of eleven small satellites includes objects orbiting near the outer edge of the main rings (Pan, Daphnis, Atlas, Prometheus, Pandora, Janus, Epimetheus) and "ring-embedded" moons (Aegeon, Methone, Anthe, Pallene) orbiting inward of Enceladus and associated with either diffuse or partial rings. We discuss current formation scenarios, according to which ring moons could originate either in the main rings from accretion onto original seeds denser than the ring material, or outside the A ring from spontaneous accretion of ring particles, and then evolve outwards due to gravitational torque from the rings. Remote sensing observations of the ring moons from the Cassini mission are analyzed in the broader context of Saturn's icy moons and main rings observations. Spectroscopic data support a compositional paradigm similar to the main rings, dominated by water ice, and smaller amounts of two separate contaminants, in the form of a UV absorber and a spectrally neutral darkening material. Global radial trends in the spectral properties of the ring moons suggest that the surface composition is significantly affected by a complex interplay of exogenous processes, among which the contamination from nearby A ring particles, meteoritic bombardment, charged particle flux, and E ring particle accumulation, depending on the corresponding magnitude at the ring moon orbital distance and exposure time. These processes modify the original composition inherited by the rings and, coupled with the fact that the surface composition is likely representative only of the ring moon outer layers, make it difficult to trace back the present composition to a given ring moon formation scenario. [ABSTRACT FROM AUTHOR]

This article compares two science advisory organizations: the Intergovernmental Panel for Climate Change (IPCC) and the International Council for the Exploration of the Seas (ICES), with a special focus on how their respective policy systems absorb the knowledge delivered for use in decision processes. The science-policy processes of these two organizations differ in important respects; ICES delivers highly specified knowledge to a specified uptake mechanism, while the IPCC produces unspecified knowledge for an unspecified uptake mechanism. Since both environmental governance areas are criticized for lack of needed action, a comparison is of interest asking how this might relate to the organization of science advice. As theoretical resources for this explorative comparison we utilize two approaches from the field of science and technology studies: the co-production approach, which focuses on the entanglements of scientific and political processes, and the systems-theory-oriented multiple-worlds model, which assumes a clear difference in institutional logics between the scientific and the political field. Since the IPCC has been critically analysed by several studies utilizing resources from the two approaches, we contribute with new insights by bringing in ICES, which is a much less studied organization exposing a different science-policy structure. One important finding is that the two theoretical approaches focus on different aspects, exposing 'links' and 'integration', both of which we argue are important for analysing and assessing science advisory organizations. Moreover, these aspects can be advantageously integrated into a single theoretical framework. [ABSTRACT FROM AUTHOR]

Integrative and conjugative elements (ICEs) are important vectors of lateral gene transfer and contribute to the evolution of bacterial pathogens. However, studies on the transfer among species and the physiological consequences of ICEs are rare. The objective of this study was to investigate the cross-species transferability of newly identified erm(B)-carried ICE in Streptococcus anginosus San95 and its physiological consequences after transfer. The erm(B)-carried ICE, characterized by a triple serine integrase module, integrated into hsdM genes, thus designated ICESan95_hsdM. Analysis of ICESan95_hsdM revealed 32 additional ICESan95-like ICEs in the available NCBI genome (n = 24) and sequence of clinical isolates (n = 8). Polymerase chain reaction (PCR) was used to evaluate the 467 clinical isolates, of which 84 were positive for core genes (integrase, relaxase, and T4SS genes) of ICESan95_hsdM. Cross-species transfer experiments demonstrated that ICESan95_hsdM could transfer from S. anginosus to different streptococcal and enterococcal recipients. Growth and competitive culture assays showed acquisition of ICESan95_hsdM incurred no fitness cost. Our work discovered a group of ICEs in Streptococci and Enterococci. For the first time, we demonstrated the broad cross-species transferability to different species or genera of ICEs with no fitness cost that enables commensal S. anginosus to deliver antimicrobial resistance genes to other streptococci and enterococci. [ABSTRACT FROM AUTHOR]

Turbulent fluxes of heat, momentum, and humidity in the atmospheric boundary layer are pivotal to the evolution of geology, weather and climate, and the possibility of life. Here we extend recent advances in calculating these near‐surface turbulent fluxes in the Earth's atmospheric boundary layer to any terrestrial planetary body with an atmosphere. These improvements include: (a) incorporating Monin‐Obukhov similarity functions that encompass the entire range of atmospheric stability expected on terrestrial planetary bodies, (b) accounting for the additional shear associated with buoyant plumes under unstable conditions, (c) using surface renewal theory to calculate transfer rates within the interfacial layer adjacent to the surface, and (d) explicitly accounting for key humidity effects that become especially important when a volatile is more buoyant than the ambient gas (e.g., on Mars where H2O is lighter than CO2). We tested and validated our model using in situ data collected on Earth, Mars, and Titan under a wide range of atmospheric stability, pressure, and surface roughness conditions. The model shows up to 71% better agreement with measurements compared to methods commonly used on Mars for evaporation/sublimation. Compared to previous estimates for H2O ice on Mars, our model predicts up to 1.5–190x lower latent heat fluxes under stable atmospheric conditions (depending on the wind speed) and 1.78x higher latent heat fluxes under unstable conditions. Our results provide improved constraints on the stability of ice on Mars and will help determine whether ice can melt under present‐day conditions. Plain Language Summary: As air flows over a surface, the resulting turbulent eddies cause the air to mix. The intensity of turbulence generated dictates the rate at which energy is given to, or taken away from the surface. If there are volatiles such as liquid water at the surface, then the magnitude of the turbulent fluxes determines how long the volatiles will remain stable before evaporating or freezing. We applied recent advances made on Earth to develop a model for predicting turbulent fluxes and evaporation rates on any planetary body with an atmosphere. To check whether our simulations are accurate, we compared them with measurements made on Earth, Mars and Titan. We found that our simulations agreed up to 71% better with measurements compared to previously developed models used for Mars evaporation. Our simulations predict significantly higher or lower rates of evaporation when compared to previous estimates, depending on atmospheric conditions. These results provide improved constraints on the stability of ice on Mars and will help determine whether ice can melt under present‐day conditions. Key Points: We present an improved model to predict atmospheric turbulent fluxes and evaporation/sublimation rates on any terrestrial planetary bodyThe model shows up to 71% better agreement with measurements compared to methods commonly used on Mars for evaporation and sublimationOur results provide improved constraints on the stability of Martian ice and will help determine whether ice can melt on Mars at present [ABSTRACT FROM AUTHOR]

Purpose: The COVID-19 pandemic had innumerable impacts on healthcare delivery. In Canada, this included limitations on inpatient capacity, which resulted in an increased focus on outpatient surgery for non-emergent cases such as joint replacements. The objective of this study was to assess whether the pandemic and the shift towards outpatient surgery had an impact on access to joint replacement for marginalized patients. Methods: Data from Ontario's administrative healthcare databases were obtained for all patients undergoing an elective hip or knee replacement between January 1, 2018 and August 31, 2021. All surgeries performed before March 15, 2020 were classified as "pre-COVID," while all procedures performed after that date were classified as "post-COVID." The Ontario Marginalization Index domains were used to analyze proportion of marginalized patients undergoing surgery pre- and post-COVID. Results: A total of 102,743 patients were included—42,812 hip replacements and 59,931 knee replacements. There was a significant shift towards outpatient surgery during the post-COVID period (1.1% of all cases pre-COVID to 13.2% post-COVID, p < 0.001). In the post-COVID cohort, there were significantly fewer patients from some marginalized groups, as well as fewer patients with certain co-morbidities, such as congestive heart failure and chronic obstructive pulmonary disease. Conclusion: The most important finding of this population-level database study is that, compared to before the COVID-19 pandemic, there has been a change in the profile of patients undergoing hip and knee replacements in Ontario, specifically across a range of indicators. Fewer marginalized patients are undergoing joint replacement surgery since the COVID-19 pandemic. Further monitoring of access to joint replacement surgery is required in order to ensure that surgery is provided to those who are most in need. [ABSTRACT FROM AUTHOR]

Background: Mepolizumab, the first widely available anti-interleukin 5 biologic, targets eosinophilic inflammation and has been shown in clinical trials to reduce exacerbations, oral corticosteroid dependence, and healthcare utilization in patients with severe asthma. The impact of mepolizumab in a real-world, publicly funded healthcare setting is unknown. The objective of this study was to describe the demographics and clinical characteristics of real-world patients receiving mepolizumab, and to compare asthma-related outcomes and associated asthma-related costs before and during mepolizumab use. Methods: This retrospective, observational study in Ontario, Canada, included patients initiating mepolizumab between February 2016 and March 2019. Patients were identified using the mepolizumab patient support program and linked to the Institute for Clinical Evaluative Sciences database of publicly accessed healthcare. Patient outcomes were obtained for 12 months pre- and post-mepolizumab initiation and compared. Results: A total of 275 patients were enrolled in the overall patient support program cohort (mean [standard deviation] age 57.6 [13.5] years, mean [standard deviation] of the median per-patient eosinophil count 540.4 [491.9] cells/μL). Mepolizumab was associated with reductions in asthma exacerbations (46.1%, P < 0.001) and in the number of asthma-related visits to general practitioners (40.2%, P < 0.001), specialists (27.2%, P < 0.001), and emergency departments (52.1%, P < 0.001). Associated costs were significantly lower post- versus pre-mepolizumab for asthma-related general practitioner and specialist visits, and for all-cause emergency department visits and hospital admissions. Conclusions: In a real-world population of Canadian patients with severe asthma with an eosinophilic phenotype, the use of mepolizumab within a patient support program reduced asthma exacerbations and decreased asthma-related healthcare resource utilization and associated costs. [ABSTRACT FROM AUTHOR]

Introduction: Streptococcus suis is a major pathogen for swine and human. Here we aimed to know the rates of antimicrobial resistance (AMR) in invasive S. suis isolates recovered along Spain between 2016 - 2021 and elucidate their genetic origin. Methods: Antibiotic susceptibility testing was performed for 116 isolates of different genetic backgrounds and geographic origins against 18 antibiotics of 9 families. The association between AMR and genotypes and the origin of the isolates were statistically analyzed using Pearson's chi-square test and the likelihood ratio. The antimicrobial resistant genes were identified by whole genome sequencing analysis and PCR screenings. Results: High AMR rates (>80%) were detected for tetracyclines, spectinomycin, lincosamides, and marbofloxacin, medium (20-40%) for sulphonamides/trimethoprim, tiamulin, penicillin G, and enrofloxacin, and low (< 20%) for florfenicol, and four additional β-lactams. The occurrence of multidrug resistance was observed in 90% of isolates. For certain antibiotics (penicillin G, enrofloxacin, marbofloxacin, tilmicosin, and erythromycin), AMR was significantly associated with particular sequence types (STs), geographic regions, age of pigs, and time course. Whole genome sequencing comparisons and PCR screenings identified 23 AMR genes, of which 19 were previously reported in S. suis (aph(3')-IIIa, sat4, aadE, spw, aac(6')-Ie-aph(2")-Ia, fexA, optrA, erm(B), mef(A/E), mrs(D), mph(C), lnu(B), lsa(E), vga(F), tet(M), tet(O), tet(O/W/32/O), tet(W)), and 4 were novel (aph(2")-IIIa, apmA, erm(47), tet(T)). These AMR genes explained the AMR to spectinomycin, macrolides, lincosamides, tiamulin, and tetracyclines. Several genes were located on mobile genetic elements which showed a variable organization and composition. As AMR gene homologs were identified in many human and animal pathogens, the resistome of S. suis has a different phylogenetic origin. Moreover, AMR to penicillin G, fluoroquinolones, and trimethoprim related to mutations in genes coding for target enzymes (pbp1a, pbp2b, pbp2x, mraY, gyrA, parC, and dhfr). Bioinformatic analysis estimated traits of recombination on target genes, also indicative of gene transfer events. Conclusions: Our work evidences that S. suis is a major contributor to AMR dissemination across veterinary and human pathogens. Therefore, control of AMR in S. suis should be considered from a One Health approach in regions with high pig production to properly tackle the issue of antimicrobial drug resistance. [ABSTRACT FROM AUTHOR]

Atmospheric photochemistry on Titan continuously transforms methane and nitrogen gases into various organic compounds. This study explores the fate of these molecules when they land on Titan's surface. Our analytical exploration reveals that most simple organics found in Titan's atmosphere, including all nitriles, triple‐bonded hydrocarbons, and benzene, land as solids. Only a few compounds are in the liquid phase, while only ethylene remains gaseous. For the simple organics that land as solids, we further examine their interactions with Titan's lake liquids. Utilizing principles of buoyancy, we found that flotation can be achieved via porosity‐induced (25%–60% porosity) or capillary force‐induced buoyancy for hydrogen cyanide ices on ethane‐rich lakes. Otherwise, these ices would sink and become lakebed sediments. By evaluating the timescale of flotation, our findings suggest that porosity‐induced flotation of millimeter‐sized and larger sediments is the only plausible mechanism for floating solids to explain the transient "magic islands" phenomena on Titan's lakes. Plain Language Summary: Titan, Saturn's largest moon, has a unique atmosphere that transforms simple gases like methane and nitrogen into more complex organic compounds. In this study, we explored what happens to these organic compounds when they reach Titan's surface. We find that most molecules would land as solids. We also looked at what happens when these solids land on Titan's hydrocarbon lakes. Imagine a sponge, full of holes; if the solids are like this, with 25%–60% of their volume being empty space, they can float. Some solids, like hydrogen cyanide ice, can also float due to surface tension effects. If these conditions are not met, they sink into the lake liquids, adding to the lakebed sediments. We examine whether floating rafts can explain a mysterious feature on Titan's lakes known as the "magic islands." These are temporary bright spots seen by radar. By looking at how long the materials will float for each scenario, our study suggests that the magic islands might be made of large chunks of porous organic solids. Key Points: Most simple organics land as solids on Titan's surface, including all nitriles, triple‐bonded hydrocarbons, and benzeneOrganics may float on Titan's lakes via porosity or capillary force‐induced flotation, the latter is unique to hydrogen cyanide ice on ethane‐rich lakesPorosity‐induced flotation of millimeter‐sized and larger particles may explain the transient radar‐bright magic islands on Titan's lakes [ABSTRACT FROM AUTHOR]

Abstract Atmospheric photochemistry on Titan continuously transforms methane and nitrogen gases into various organic compounds. This study explores the fate of these molecules when they land on Titan's surface. Our analytical exploration reveals that most simple organics found in Titan's atmosphere, including all nitriles, triple‐bonded hydrocarbons, and benzene, land as solids. Only a few compounds are in the liquid phase, while only ethylene remains gaseous. For the simple organics that land as solids, we further examine their interactions with Titan's lake liquids. Utilizing principles of buoyancy, we found that flotation can be achieved via porosity‐induced (25%–60% porosity) or capillary force‐induced buoyancy for hydrogen cyanide ices on ethane‐rich lakes. Otherwise, these ices would sink and become lakebed sediments. By evaluating the timescale of flotation, our findings suggest that porosity‐induced flotation of millimeter‐sized and larger sediments is the only plausible mechanism for floating solids to explain the transient “magic islands” phenomena on Titan's lakes.

IntroductionStreptococcus suis is a major pathogen for swine and human. Here we aimed to know the rates of antimicrobial resistance (AMR) in invasive S. suis isolates recovered along Spain between 2016 – 2021 and elucidate their genetic origin.MethodsAntibiotic susceptibility testing was performed for 116 isolates of different genetic backgrounds and geographic origins against 18 antibiotics of 9 families. The association between AMR and genotypes and the origin of the isolates were statistically analyzed using Pearson´s chi-square test and the likelihood ratio. The antimicrobial resistant genes were identified by whole genome sequencing analysis and PCR screenings.ResultsHigh AMR rates (>80%) were detected for tetracyclines, spectinomycin, lincosamides, and marbofloxacin, medium (20-40%) for sulphonamides/trimethoprim, tiamulin, penicillin G, and enrofloxacin, and low (< 20%) for florfenicol, and four additional β-lactams. The occurrence of multidrug resistance was observed in 90% of isolates. For certain antibiotics (penicillin G, enrofloxacin, marbofloxacin, tilmicosin, and erythromycin), AMR was significantly associated with particular sequence types (STs), geographic regions, age of pigs, and time course. Whole genome sequencing comparisons and PCR screenings identified 23 AMR genes, of which 19 were previously reported in S. suis (aph(3’)-IIIa, sat4, aadE, spw, aac(6’)-Ie-aph(2’’)-Ia, fexA, optrA, erm(B), mef(A/E), mrs(D), mph(C), lnu(B), lsa(E), vga(F), tet(M), tet(O), tet(O/W/32/O), tet(W)), and 4 were novel (aph(2’’)-IIIa, apmA, erm(47), tet(T)). These AMR genes explained the AMR to spectinomycin, macrolides, lincosamides, tiamulin, and tetracyclines. Several genes were located on mobile genetic elements which showed a variable organization and composition. As AMR gene homologs were identified in many human and animal pathogens, the resistome of S. suis has a different phylogenetic origin. Moreover, AMR to penicillin G, fluoroquinolones, and trimethoprim related to mutations in genes coding for target enzymes (pbp1a, pbp2b, pbp2x, mraY, gyrA, parC, and dhfr). Bioinformatic analysis estimated traits of recombination on target genes, also indicative of gene transfer events.ConclusionsOur work evidences that S. suis is a major contributor to AMR dissemination across veterinary and human pathogens. Therefore, control of AMR in S. suis should be considered from a One Health approach in regions with high pig production to properly tackle the issue of antimicrobial drug resistance.

The epidemiology of cirrhosis among immigrants to North America has not been described. Using population-level data from Ontario, Canada, recent immigrant and refugees with incident cirrhosis were identified and stratified by World Bank region of origin and cirrhosis etiology. Incidence rates were described based on region of origin and etiology and compared with those in Canadian-born/long-term residents. A total of 25,054 immigrants/refugees were identified with rates of cirrhosis lower compared with those in Canadian-born/long-term residents for all etiologies except hepatitis B virus likely explained by the healthy immigrant effect. Nonalcoholic fatty liver disease was the most common etiology of cirrhosis among immigrants and refugees. [ABSTRACT FROM AUTHOR]

Layers of ice and dust (i.e., "mantle") are found throughout the mid‐latitudes of Mars, where they drape and mute topography and record the recent climate history. Many of the youngest Late Amazonian "latitude‐dependent mantles" have been characterized, but the full range of mantle characteristics, including variations in ice content and age, has not been well documented. To advance our understanding of these ice‐dust units, we use SHAllow RADar (SHARAD) radar sounding data to constrain the subsurface physical properties of a widespread Middle Amazonian mantle unit within Deuteronilus Mensae. This region hosts a high density of glacial landforms, which allows assessment of the stratigraphic relationship between mantle deposits and glacial ice. SHARAD reflectors at the base of the mantle units are used to determine moderate dielectric constants (∼5.75) and high loss tangents (∼0.038). These radar properties imply relatively limited ice content and high‐loss mantling materials with possible enhanced roughness or subsurface scattering. Further, we interpret deeper reflectors that are continuous with glacier basal reflectors and that suggest materials with lower dielectric constants (∼3.2–4.5) and loss tangents (0.0071–0.0120) to be due to extensions of stagnant, possibly lithic‐rich, glacier ice that are buried by a mantle layer. This study demonstrates the high variability in the origins and evolution of mid‐latitude mantling units on Mars. While the most recent latitude‐dependent mantling deposits may still be ice‐rich, older deposits, such as those preserved in Deuteronilus Mensae and elsewhere in the mid‐latitudes of Mars, may be largely desiccated or contain a more heterogeneous and limited distribution of ice. Plain Language Summary: Layers of ice and dust (called "mantle") on Mars are widespread in the middle latitudes. These layers are found to thickly blanket topography and were formed from changes in Mars' climate within the past million to hundreds of millions of years. However, unknown are the complete range of ice content and ages of the mantle layers. To better characterize their properties and relationships with glaciers in the region, we use radar data from the SHAllow RADar instrument, which allows for identification and delineation of the depth and thickness of layers beneath the surface in addition to their material properties. We find that mantle layers have radar characteristics more consistent with low ice content and properties that greatly reduce the strength of the radar signal. Further, we find radar evidence consistent with mantle layers burying the ends of glacial ice. This study demonstrates that mantle layers on Mars have a wide range of ice contents and ages, with some being less ice rich than their surface characteristics alone might imply. Key Points: The subsurface properties of ice‐dust (mantle) layers are characterized with SHAllow RADar radar data in a glaciated mid‐latitude region of MarsMantle layers have moderate dielectric constants and high radar attenuation, indicating lower possible ice content than other mantle unitsRadar properties and surface geomorphology are consistent with mantle burying the termini of glaciers, obscuring boundaries [ABSTRACT FROM AUTHOR]

Landslides are among the most widespread geologic features on Ceres. Using data from Dawn's Framing Camera, landslides were previously classified based upon geomorphologic characteristics into one of three archetypal categories, Type 1(T1), Type 2 (T2), and Type 3 (T3). Due to their geologic context, variation in age, and physical characteristics, most landslides on Ceres are, however, intermediate in their morphology and physical properties between the archetypes of each landslide class. Here we describe the varied morphology of individual intermediate landslides, identify geologic controls that contribute to this variation, and provide first-order quantification of the physical properties of the continuum of Ceres's surface flows. These intermediate flows appear in varied settings and show a range of characteristics, including those found at contacts between craters, those having multiple trunks or lobes; showing characteristics of both T2 and T3 landslides; material slumping on crater rims; very small, ejecta-like flows; and those appearing inside of catenae. We suggest that while their morphologies can vary, the distribution and mechanical properties of intermediate landslides do not differ significantly from that of archetypal landslides, confirming a link between landslides and subsurface ice. We also find that most intermediate landslides are similar to Type 2 landslides and formed by shallow failure. Clusters of these features suggest ice enhancement near Juling, Kupalo and Urvara craters. Since the majority of Ceres's landslides fall in the intermediate landslide category, placing their attributes in context contributes to a better understanding of Ceres's shallow subsurface and the nature of ground ice.

ABSTRACT Streptococcus suis is a zoonotic pathogen that causes disease in humans after exposure to infected pigs or pig-derived food products. In this study, we examined the serotype distribution, antimicrobial resistance phenotypes and genotypes, integrative and conjugative elements (ICEs), and associated genomic environments of S. suis isolates from humans and pigs in China from 2008 to 2019. We identified isolates of 13 serotypes, predominated by serotype 2 (40/96; 41.7%), serotype 3 (10/96; 10.4%), and serotype 1 (6/96; 6.3%). Whole-genome sequencing analysis revealed that these isolates possessed 36 different sequence types (STs), and ST242 and ST117 were the most prevalent. Phylogenetic analysis revealed possible animal and human clonal transmission, while antimicrobial susceptibility testing indicated high-level resistance to macrolides, tetracyclines, and aminoglycosides. These isolates carried 24 antibiotic resistance genes (ARGs) that conferred resistance to 7 antibiotic classes. The antibiotic resistance genotypes were directly correlated with the observed phenotypes. We also identified ICEs in 10 isolates, which were present in 4 different genetic environments and possessed differing ARG combinations. We also predicted and confirmed by PCR analysis the existence of a translocatable unit (TU) in which the oxazolidinone resistance gene optrA was flanked by IS1216E elements. One-half (5/10) of the ICE-carrying strains could be mobilized by conjugation. A comparison of the parental recipient with an ICE-carrying transconjugant in a mouse in vivo thigh infection model indicated that the ICE strain could not be eliminated with tetracycline treatment. S. suis therefore poses a significant challenge to global public health and requires continuous monitoring, especially for the presence of ICEs and associated ARGs that can be transferred via conjugation. IMPORTANCE S. suis is a serious zoonotic pathogen. In this study, we investigated the epidemiological and molecular characteristics of 96 S. suis isolates from 10 different provinces of China from 2008 to 2019. A subset of these isolates (10) carried ICEs that were able to be horizontally transferred among isolates of different S. suis serotypes. A mouse thigh infection model revealed that ICE-facilitated ARG transfer promoted resistance development. S. suis requires continuous monitoring, especially for the presence of ICEs and associated ARGs that can be transferred via conjugation.

S1094b is the largest (155 m-size) and southernmost known ice-exposing fresh crater discovered so far on Mars, revealing a relatively pure and unstable subsurface ice deposit located at the northern Martian mid-latitudes. In this work, we analyze HiRISE images taken on 27 February 2022 and on 5 December 2022 to perform a multi-temporal analysis of its ice-rich ejecta, combining this analysis with geologic mapping, the boulder size frequency distribution (SFD) and thermal modeling. The objective is to provide a multidisciplinary characterization of both the impact and subsequent exposed ice sublimation processes. The boulder SFD of both February and December cases show a power-law best fit with indices −4.68 ± 0.15 and − 3.47 ± 0.10, respectively. In the same timeframe, the density of boulders per km2 ≥ 1.5 m changes from 3908, to 596. This flattening is mainly due to the sublimation and consequent loss of the smaller-size icy boulders. This is confirmed by the ice volume computation performed on the area, which changed from ∼20,274 ± 3997 m3 to ∼7951 ± 1117 m3, i.e. a decrease of ∼60% in 274 Sols. The thermal models showed that the ice in this region is always unstable, leading to a total of 6504.71 sublimation hours from which we estimated a sublimation rate of ∼0.15 ± 0.04 mm/h (i.e. ∼3.60 ± 0.96 mm/Sol). The presence of this amount of accessible ice at such low latitudes could be a valuable resource for potential future human missions. • Conduction of multitemporal, multidisciplinary analyses on Martian crater S1094b. • Preparation of a geological mapping 5 geologic units and 4 landforms. • Observation of sublimation focusing on the smallest icy boulders loss. • Detection of the 60% water ice sublimation over 281 days. • Average sublimation rate detected at ∼1.96 m3/h or ∼ 0.15 ± 0.04 mm/h. [ABSTRACT FROM AUTHOR]

The Ames Vertical Gun Range (AVGR) is a hypervelocity impact facility hosting a variable angle, two-stage, light-gas gun that can accelerate projectiles up to 7 km s−1. We have used the AVGR to produce impacts into supercooled (73–89 K) synthetic seawater ice targets inside a large impact chamber, whose pressure is 0.3 to 0.7 Torr. We report on the effective novel use of stainless steel meshes (49 μm, 100 μm, 149 μm, and 500 μm) to filter the ejecta plume for the ice grains of a desired size and demonstrate that reproducible temperature, speed, and particle size distribution can be achieved. The resulting ejecta plume of micrometer-sized ice particles (micro grains) from these impacts provides a method to simulate spacecraft encounters with ice particles found in the plumes of the outer Solar System, especially Enceladus. Image analysis of ejecta plume impacts onto aluminum (Al) foil enabled us to determine the ice particle diameter range. We find that the particles in the ejecta plume have speeds from 0.2 to 2 km s−1 and temperatures from 102 to 113 K (−171 to −160 °C). Furthermore, 61–97% by numberof the ice grains have equivalent diameter between 2.5 and 20 μm, that is, in the range 1 μm ≤ radii ≤10 μm, the upper size constrained by Cassini, i.e., ∼2 μm to 50 μm. Overall, the AVGR provides a high-fidelity simulation of ice micro grains impacting spacecraft surfaces and sample-collecting systems. This may be useful in the design, testing, and data analysis of future missions to Enceladus, Europa, and other icy moons. • The Ames Vertical Gun Range is used to create high speed ice particle plumes. • We have calibrated the size and speed of these ice plumes. • A way to test instruments for ice particle collection at Enceladus and Europa. [ABSTRACT FROM AUTHOR]

Ejecta blankets around craters on a km-scale show stark differences in the ejecta mobility (maximal extent of ejecta divided by the crater radius) with latitude and types of plains on Mars, which has been known for a long time (Barlow and Pollak, 2002; Li et al., 2015) but is not well-understood. Our main goal is to explore the idea that the subsurface rheology drives ejecta dynamics and leaves characteristic, observable imprints in the spatial distributions of ejecta. We conduct numerical simulations of impact cratering into a variety of subsurface models and study the impact of varied subsurface material (porous basalt, water ice, water), as well as structure and layering on impact sites and properties of impact ejecta. Our models consider variations in the depth of water or ice covering basalt; the thickness of buried ice; and the depth of burial of ice. We find that ejection angles and velocities depend on these quantities and configurations, e.g. velocities decrease and angles of ejection increase with increasing water layer thickness, buried ice thickness, or thickness of basaltic debris over an ice sheet. As a result, several ejecta characteristics derived from ejecta thickness profiles carry information about the underlying rheology. Specifically, the ejecta mobility, as well as the radial position of the maximum and the slope of the ejecta thickness profiles are diagnostic. The power-law function of the thickness profile of the ejecta blanket right after formation is a good indicator of ejecta from water- or ice-covered targets but not from more complex multi-layered structures, hence we caution against using scaling relations to describe ejecta from such targets. As any surface water/ice volatile mass is unstable on Mars, we also consider the geomorphology of craters and ejecta after the loss of volatiles. Our main findings include the observation that after the loss of surface volatiles, craters which formed in water-covered targets would appear shallower than those formed in basalt. The ejecta mobilities observed today would also be smaller if craters formed in volatile-covered targets than in basalt. Our findings can aid the interpretation of data returned from cameras onboard multiple spacecraft orbiting Mars such as HiRISE, CaSSIS, or CTX, and constitute a proof of concept of the hypothesis that information on the subsurface, including where ice is or was present, is encoded in the ejecta profile and spatial distribution. • Ejecta blankets around km-scale craters are sensitive to subsurface rheology. • Ejection velocities and angles depend on the layering of basalt and water/ice. • Post-sublimation ejecta from volatile-rich subsurfaces are smaller than from basalt. • Craters in volatile-covered targets sublime & become shallower than those in basalt. • These differences can be resolved by spacecraft imaging systems. [ABSTRACT FROM AUTHOR]

Over the last 16 years, the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) has acquired a large body of surface observations at visible and thermal infrared wavelengths. Primary differentiators between the MCS record and other surface datasets include mission duration, regular global coverage, and high emission angles associated with most observations. These data have been analyzed to generate a global median apparent thermal inertia map that smooths out artificial spatial variability (i.e., streaking along orbital ground tracks) common in other maps. At mid and low latitudes, high emission angle observations yield similar nighttime thermal inertia values compared to nadir observations, even if grazing angles should favor vertically rough materials oriented towards MCS (i.e., material poking out of the ground, presumably associated with high thermal inertia rocks and scarps). This result independently confirms that fines control the Martian thermal inertia, not rocks, and also suggests that most rock and bedrock exposures should be characterized by low aspect ratios (i.e., appear platy or flat, regardless of subsurface shape). Selected global temperature maps are also presented. They show the influence of polar processes, the latitudinal distribution of exposed ices, and physical properties of the Martian regolith on surface temperatures. Temperature controls at regional and global scales include the variation of insolation with season and latitude, atmospheric composition, global circulation, the presence of snow precipitations, and various regolith properties (i.e., albedo and thermal inertia). • Leveraging 16 years of Mars Climate Sounder observations, we have generated new thermal inertia and global temperatures maps. • Their analysis confirms that the thermal inertia of the martian surface layer is controlled by the fines, not by rocks. • Generally, Martian rocks must be platy/oblate to match both nadir and high emission angle thermal observations. [ABSTRACT FROM AUTHOR]

In operation for >16 years to date, the Mars Reconnaissance Orbiter (MRO) Shallow Radar (SHARAD) sounder has acquired data at its nominal 300–450 m along-track and 3-km cross-track resolution covering >55% of the Martian surface, with nearly 100% overlap in coverage at that scale in the polar regions and in a number of smaller mid-latitude areas. While SHARAD data have opened a new window into understanding the interior structures and properties of Martian ices, volcanics, and sedimentary deposits up to a few kilometers in depth, they have also led to new revelations about the deeper interior and the behavior of the planet's ionosphere. Here we summarize the data collected by SHARAD over this time period, the methods used in the analysis of that data, and the resulting scientific findings. The polar data are especially rich, revealing complex structures that comprise up to several dozen reflecting interfaces that extend to depths of 3 km, which inform the evolution of Martian climate in the late Amazonian period. SHARAD observations of mid-latitude lobate debris aprons and other glacier-like landforms detect strong basal reflections and low dielectric loss, confirming that they are ice-rich debris-covered glaciers. In other mid-latitude terrains, SHARAD data demonstrate the presence of widespread ground ices, likely at lower concentrations. SHARAD signals also probe non-icy materials, mapping out stacked lava flows, probing low-density materials thought to be ash-fall deposits, and occasionally penetrating sedimentary deposits, all of which reveal the structures and interior properties diagnostic of emplacement processes. SHARAD signals are impacted by their passage through the Martian ionosphere, revealing variations in time and space of the total electron content linked with the remanent magnetic field. Advanced techniques developed over the course of the mission, which include subband and super-resolution processing, coherent and incoherent summing, and three-dimensional (3D) radar imaging, are enabling new discoveries and extending the utility of the data. For 3D imaging, a cross-track spacing at the nominal 3-km resolution is more than sufficient to achieve good results, but finer spacing of 0.5 km or less significantly improves the spatially interpolated radar images. Recent electromagnetic modeling and a flight test show that SHARAD's signal-to-noise ratio can be greatly improved with a large (∼120°) roll of the spacecraft to reduce interference with the spacecraft body. Both MRO and SHARAD are in remarkably fine working order, and the teams look forward to many more years in which to pursue improvements in coverage density, temporal variability in the ionosphere, and data quality that promise exciting new discoveries at Mars. • SHARAD has revealed the internal structure, composition, and history of Mars' polar caps and constrained current heat flow. • SHARAD settled a long-standing debate by showing that mid-latitude glacial landforms are ice-rich debris-covered glaciers. • SHARAD has provided first constraints on the interior composition and stratigraphy of volcanic and sedimentary layers. • SHARAD has provided a new understanding of Martian ionospheric variability and its relationship to crustal magnetic fields. [ABSTRACT FROM AUTHOR]

Recent data of molecular clouds and protoplanetary disks constrain the composition and structure of the disk and planetesimals. Laboratory experiments suggest that dust accretion in disks stops at pebble sizes. Sublimation and recondensation of water ice at the disk water-snow line suggest that pebbles split into water-rich and water-poor ones. The same conclusion has been recently reached by models of cometary activity consistent with the structure of porous Interplanetary Dust Particles (IDPs) and of porous dust collected by the Stardust and Rosetta missions. The observation of crystalline water ice in protoplanetary disks by the Herschel satellite, the erosion of comets, and the seasonal evolution of the nucleus color require that the two pebble families have a water-ice mass fraction close to 33% and 2%, respectively. Here, we show that the diversity of comets is thus due to random mixtures with different area fractions A p and A r of water-poor and water-rich pebbles, predicting most of the data observed in comets: why the deuterium-to-hydrogen ratio in cometary water correlates to the ratio A p / A r , which pebbles dominate the activity of Dynamically New Comets (DNCs), what is the origin of cometary outbursts, why comets cannot be collisional products, and why the brightness evolution of DNCs during their first approach to the Sun is actually unpredictable. [ABSTRACT FROM AUTHOR]

We present thermophysical, biological, and chemical observations of ice and brine samples from five compositionally diverse hypersaline lakes in British Columbia's interior plateau. Possessing a spectrum of magnesium, sodium, sulfate, carbonate, and chloride salts, these low-temperature high-salinity lakes are analogs for planetary ice-brine environments, including the ice shells of Europa and Enceladus and ice-brine systems on Mars. As such, understanding the thermodynamics and biogeochemistry of these systems can provide insights into the evolution, habitability, and detectability of high-priority astrobiology targets. We show that biomass is typically concentrated in a layer near the base of the ice cover, but that chemical and biological impurities are present throughout the ice. Coupling bioburden, ionic concentration, and seasonal temperature measurements, we demonstrate that impurity entrainment in the ice is directly correlated to ice formation rate and parent fluid composition. We highlight unique phenomena, including brine supercooling, salt hydrate precipitation, and internal brine layers in the ice cover, important processes to be considered for planetary ice-brine environments. These systems can be leveraged to constrain the distribution, longevity, and habitability of low-temperature solar system brines—relevant to interpreting spacecraft data and planning future missions in the lens of both planetary exploration and planetary protection. [ABSTRACT FROM AUTHOR]

Objective: While the overall health system burden of alcohol is large and increasing in Canada, little is known about how this burden differs by sociodemographic factors. The objectives of this study were to assess sociodemographic patterns and temporal trends in emergency department (ED) visits due to alcohol to identify emerging and at-risk subgroups. Methods: We conducted a retrospective population-level cohort study of all individuals aged 10 to 105 living in Ontario, Canada. We identified ED visits due to alcohol between 2003 and 2017 using defined International Classification of Diseases, 10th edition, codes from a pre-existing indicator. We calculated annual age- and sex-standardized, and age- and sex-specific rates of ED visits and compared overall patterns and changes over time between urban and rural settings and income quintiles. Results: There were 829,662 ED visits due to alcohol over 15 years. Rates of ED visits due to alcohol were greater for individual living in the lowest- compared to the highest-income quintile neighbourhoods, and disparities (rate ratio lowest to highest quintile) increased with age from 1.22 (95% CI, 1.19 to 1.25) in 15- to 18-year-olds to 4.17 (95% CI, 4.07 to 4.28) in 55- to 59-year-olds. Rates of ED visits due to alcohol were significantly greater in rural settings (56.0 per 10,000 individuals, 95% CI, 55.7 to 56.4) compared to urban settings (44.8 per 10,000 individuals, 95% CI, 44.7 to 44.9), particularly for young adults. Increases in rates of visits between 2003 and 2017 were greater in rural versus urban settings (82 vs. 68% increase in age- and sex-standardized rates) and varied across sociodemographic subgroups with the largest annual increases in rates of visits in young (15 to 29) low-income women (6.9%, 95%CI, 6.7 to 7.3) and the smallest increase in older (45 to 59) high-income men (2.7, 95%CI, 2.4 to 3.0). Conclusion: Alcohol harms display unique patterns with the highest burden in rural and lower-income populations. Rural–urban and income-based disparities differ by age and sex and have increased over time, which offers an imperative and opportunity for further interventions by clinicians and policy makers. [ABSTRACT FROM AUTHOR]

Finnish fisheries are regulated first and foremost by the EU Common Fisheries Policy (CFP) and quotas determined by the EU. Certain fisheries have also been certified according to the international Marine Stewardship Council (MSC) standard. The aim of this article is to study the added value that the MSC brings to the governance of the ecological sustainability of Finnish marine fisheries. This is achieved by scrutinizing how the MSC addresses the ecosystem approach and how different experts and stakeholders see the role of the MSC in contributing to sustainable fisheries. We endeavor to unravel the sustainability benefits that non-state regulations can offer for a fishery in the Baltic Sea that is heavily regulated and controlled by the EU. We found that the MSC has led to some minor positive changes in fishing and that the indirect support the MSC provides when following scientific advice is even more important. [ABSTRACT FROM AUTHOR]

We present a chemical kinetics model of the solid-phase chemical evolution of a comet, beginning with a long period of cold-storage in the Oort Cloud, followed by five orbits that bring the comet close to the Sun. Current orbital parameters for Hale–Bopp are used for all orbits. The chemical model is based on an earlier treatment (Garrod 2019) that considered only the cold-storage phase, and which was based on the interstellar ice chemical kinetics model MAGICKAL. The comet is treated as 25 chemically distinct layers, whose thicknesses increase with depth; each layer has a dust component, and the chemical network includes a further 200 atomic/molecular species. The new model includes several key updates to the previous treatment: (i) Time- and depth-dependent temperature profiles based on heat transfer according to heliocentric distance; (ii) a rigorous treatment of back-diffusion (random walk) for species capable of diffusing through the thick bulk-ice layers; (iii) adoption of recent improvements in the kinetic treatment of nondiffusive chemical reaction rates in the ice and on the ice surface. Starting from an initially simple ice composition, interstellar UV photons drive a rapid chemistry in the upper micron of material, but diminished by absorption of the UV by the dust component. Galactic cosmic rays (GCRs) drive a much slower chemistry in the deeper ices over the long cold-storage period, to depths on the order of 10 m. The first solar approach drives off the upper layers of ice material via thermal desorption and/or dissociation (the model does not include a treatment for the more complex cometary outbursts), bringing closer to the surface the deeper material that previously underwent long-term processing by GCRs. Subsequent orbits are more uniform in their chemical behavior after the upper layers are lost. Loss of molecular material leads to concentration of the dust in the upper layers, with a large dust fraction extending to depths on the order of 10 cm after all orbits are complete. Substantial quantities of complex organic molecules (COMs) are formed in the upper 10 m during the cold storage phase, with some of this material released during solar approach; however, their abundances with respect to water appear too low to account for the observed gas-phase values for comet Hale–Bopp, indicating that the majority of complex molecular material observed, at least in comet Hale–Bopp, is an inheritance of primordial material. [Display omitted] • An updated version of the comet chemical kinetics model MAGICKAL is presented. • Cold storage ice processing of Hale–Bopp can produce significant complex organics. • The active phase chemistry of the first two orbits is distinct from later orbits. • The current model underestimates chemical abundances of complex organics. • Ice compositions of a primordial origin are likely required to match observations. [ABSTRACT FROM AUTHOR]

The existence of liquid water at the base of the south polar layered deposits (SPLD) on Mars has been proposed on the basis of radar data, but dry interpretations have been advanced as well. Here, we consider topography of the SPLD surface above the location of hypothesized water using individual altimetry tracks rather than gridded or interpolated data. Liquid water could create negative surface relief through drainage events and subsequent collapse, or positive surface relief through ice expansion. We find meters of positive topographic relief relative to the surrounding region, consistent with thermal expansion of the ice column from the added geothermal heat that would be required to maintain liquid water at the SPLD base. However, topographic analysis of randomly chosen areas throughout the SPLD suggest that positive topographic relief of this amplitude has a 20% chance of occurring through other processes or statistical noise. Therefore, we conclude that both wet and dry interpretations of the radar data remain viable. • MOLA topography shows 2.7–4.7 m of positive topographic relief on the SPLD ice surface above hypothesized basal water. • No evidence for small basins formed from drainage events of basal water is observed. • A few meters of positive topography could plausibly be the result of thermal expansion of relatively warm ice above water. [ABSTRACT FROM AUTHOR]

Comet nuclei in the outer Solar system are constantly irradiated by cosmic rays at low temperatures. Accumulated high concentrations of radicals can undergo fast recombination with significant heating of cometary surface layers. We present the model of comet activity at large heliocentric distances caused by the recombination of radicals. We found that the considered mechanism can cause activity of comets in distant regions of the Solar system, even at the Oort cloud distances. Outbursts in distant comet reservoirs can be a new source of dust and ice particles contributing to the recently discovered anomalous diffuse light in the cosmic extragalactic background optic light and the unexpectedly high flux of dust particles detected by the New Horizons dust counter at the edge of the Kuiper belt. The orbits of small-radii comets in the Oort cloud are highly influenced by cometary outbursts. This effect may account for the observed decrease in the number of small-radius long-period comets. • Recombination of radicals can drive distant cometary outbursts. • Recombination of radicals can lead to significant chemical changes in a comet matter. • Comets in the Oort cloud could be a new possible distant source of dust particles. • The stability of long-period small-radius comets is highly influenced by outbursts. [ABSTRACT FROM AUTHOR]

Main conclusion: ICEs are key transcription factors in response to cold in plant, they also balance plant growth and stress tolerance. Thus, we systematize the information about ICEs published to date. Low temperature is an important factor affecting plant growth and development. Exposing to cold condition results in a suit of effects on plants including reduction of plant growth and reproduction, and decrease in crop yield and quality. Plants have evolved a series of strategies to deal with cold stress such as reprogramming of the expression of genes and transcription factors. ICEs (Inducer of CBF Expression), as transcription factors regulating CBFs (C-repeat binding factor), play key roles in balancing plant growth and stress tolerance. Studies on ICEs focused on the function of ICEs on cold tolerance, growth and development; post-translational modifications of ICEs and crosstalk between the ICEs and phytohormones. In this review, we focus on systematizing the information published to date. We summarized the main advances of the functions of ICEs on the cold tolerance, growth and development. And we also elaborated the regulation of ICEs protein stability including phosphorylation, ubiquitination and SUMOylation of ICE. Finally, we described the function of ICEs in the crosstalk among different phytohormone signaling pathway and cold stress. This review provides perspectives for ongoing research about cold tolerance, growth and development in plant. [ABSTRACT FROM AUTHOR]

Formaldehyde has been widely observed in the icy mantle of interstellar grains. H2CO may be formed from successive hydrogenations of CO and may further contribute to the chemical complexity of the Interstellar medium (ISM) participating to heterogeneous reactions with colliding gas phase atoms. Within this context, Eley-Rideal and Langmuir-Hinshelwood rate constants of H2 formation on a formaldehyde doped amorphous water ice grain model of the ISM, were computed over a wide temperature range [15–2000 K]. We used classical molecular dynamics (MD) simulations to build the model of the H2CO doped ice surface. Then we studied theoretically by means of hybrid QM/MM ab initio and molecular mechanics methodology (ONIOM) H atoms abstraction from formaldehyde molecules and the H2 formation. Specifically, we investigate the reactivity of the gas phase H atom toward one formaldehyde molecule lying at one of the slab surfaces. The reaction path and the energetics are predicted, the mechanism is found to be exothermic by 14.89 kcal/mol and the barrier is 6.75 kcal/mol at the QM level CBS/DLPNO-CCSD(T)//ONIOM/aug-cc-pVTZ. We employ two approaches that take into account tunnelling and non-classical reflection effects by means of the Zero Curvature Tunnelling (ZCT), and the Small Curvature Tunnelling (SCT) which all provided comparable results to predict the kinetics of the reaction path. The rate constants show important quantum tunnelling effects at low temperatures when compared to rates obtained from the purely classical transition-state theory (TST) and from the canonical variational transition state theory (CVT). Corner cutting effects are highlighted in the SCT calculations by 4 to 5 orders of magnitude with respect to ZCT rate constants at low temperatures.

Data in this article are related to the research article “Rapid rounding of icy clasts during simulated fluvial transport in the Titan Tumbler”. Whereas that research focused on low-temperature ice abrasion in the context of Saturn's moon Titan, the full dataset on experiments testing the breakdown of water ice under a variety of tested conditions is reported in this article. Following the work of previous terrestrial studies, these experiments utilize tumblers that produce collisions to simulate some aspects of mechanical weathering during fluvial transport. Data files publicly available on Mendeley Data include measures of mass and roundness of clasts of specific grain sizes as well as raw images, videos, and the MATLAB script used for analysis. In this article, the varying conditions of temperature, initial clast size, shape, ice type, number of clasts for each of the 42 experiments are reported, along with best-fit models of abrasion typically applied in terrestrial tumbler studies. This text describes the methodology, including the development of icy clasts, operation of the tumblers, measurement of clast properties, calculation of derived parameters, and application of abrasion models. Exploration of various approaches to tumbler development and data acquisition are reported to benefit future researchers in this area. Experiments on the abrasion of different materials benefit from cross-comparison, which is also a fundamental aspect of planetary science.

ICES upholds a strong reputation for generating high-quality evidence to inform policy and practice through its collaborations with a broad range of health system stakeholders including government policymakers and healthcare providers including clinicians. Supported by the Ontario Ministry of Health and Ministry of Long-Term Care, the ICES Applied Health Research Question (AHRQ) Program leverages the data holdings and, scientific and clinical expertise to generate evidence tailored to the information needs of requestors. This paper outlines the approach, process, strengths, challenges and the resulting influence and impact to the healthcare landscape in Ontario.

In order to determine the effect of impact angle on the impact strength of icy planetesimals, we conducted a range of oblique impact experiments for spherical ice and snow targets simulating icy planetesimals at different thermal evolution stages. The ice targets had no porosity and the snow targets had a porosity of 0.5. A polycarbonate or glass sphere impacted the ice targets at 744–1747 m s−1 and the snow targets at 938–5085 m s−1 over a range of impact angles from grazing to head-on collisions. All experiments were conducted using a two-stage light gas gun and a target chamber set in a cold room of −15 °C at Kobe University, Japan. The impact strength, which is a specific energy, Q , when the largest fragment mass is a half of the original target mass, for the ice and snow targets in a head-on collision was determined to be 12 and 520 J kg−1, respectively, whereas it was found that the impact strength depended on the impact velocity. Thus, the normalized largest fragment mass, m l / M t , could well scale with the velocity dependent Q , that is, Q v i γ (where m l and M t are the masses of largest fragment and target, respectively, and v i is the impact velocity). At high Q , m l / M t increased drastically with the decrease of impact angle when the impact angle was smaller than a critical angle, θ c , and θ c ~ 30° for the ice targets and θ c ~ 45° for the snow targets. At small Q , m l / M t continued to increase as the impact angle became smaller for both types of targets. The m l / M t for oblique impacts had a good correlation with the effective specific energy, Q eff = Q sin 2 θ , where θ is the impact angle, and the effective impact strength was determined to be 16 J kg−1 and 499 J kg−1 for the ice and snow targets, irrespective of the impact angle. Furthermore, the scaling parameter, Π s _ eff , which was proposed by Housen and Holsapple (1990) but includes Q eff instead of Q , multiplied by 1 − ϕ λ , where ϕ is the porosity, showed even better correlation with m l / M t , and all m l / M t data of ice and snow targets could be merged, irrespective of impact velocity and ϕ. Based on our experimental results and a theory on the oblique impact of solar system bodies proposed by Shoemaker (1962) , we could estimate the degree of disruption (m l / M t) at any impact energy and any impact angle for icy planetesimals. Our findings demonstrate that the degree of disruption for icy planetesimals that have experienced sufficient thermal evolution was larger than that for those that did not experience significant thermal evolution. • We conducted impact experiments for ice and snow spheres at various impact angles. • We found that impact strength for head-on collisions depended on impact velocity. • Effective specific energy was useful in describing the effect of the impact angle. • We estimated the degree of disruption at various impact energies and impact angles. [ABSTRACT FROM AUTHOR]

The Lunar Flashlight cubesat mission was designed and flown to collect new data on the abundance and distribution of water ice frost in lunar permanently shadowed regions (PSRs) using active laser spectroscopy. Key advantages of active spectroscopy are that it can collect surface reflectance data in locations and conditions where passive spectroscopy cannot operate, specifically nightside locations where no indirect lighting is available, and in the deepest parts of PSRs where indirect lighting may be too faint for passive spectroscopy. Lunar Flashlight launched in 2022 but because of a propulsion system failure, did not make it to the Moon to conduct its science investigation. However, Lunar Flashlight proved to be an extremely successful technology demonstration mission, meeting or exceeding all its technology-focused mission goals, including demonstrating its instrument functionality. This paper describes the extensive ground and test campaigns to characterize the Lunar Flashlight laser reflectometer instrument and its planned utility for science observations, along with recommendations for future instrument design, development, verification, and use. • The Lunar Flashlight mission lasted from December 2022 to June 2023. • As a Technology Demonstration mission, Lunar Flashlight met all its technology goals. • Despite not reaching the Moon, the Lunar Flashlight laser spectroscopy payload was successfully tested. • The payload ground and flight performance data can be used for future instrument development. [ABSTRACT FROM AUTHOR]

The ammonium ion (NH 4 +) has been suggested to be present in interstellar ices and has been observed on the surfaces of planetary bodies using infrared (IR) spectroscopy as the primary means of identification. Evidence for several ammonium salts has also been found in the dust and surface ices of comet 67P/Churyumov-Gerasimenko. Here we present a laboratory study of ammonium cyanide (NH 4 CN) and report on several properties of this compound, measured with higher accuracy than in previous reports, including its IR band strengths and optical constants for use in quantifying its abundance in interstellar and planetary ices. We also report the first measurements since 1882 of NH 4 CN vapor pressures, sublimation fluxes, and sublimation enthalpy measured at temperatures relevant to subliming cometary ices (134–155 K). The density and refractive index of NH 4 CN at 125 K and the sublimation enthalpy and vapor pressures of NH 3 at ~100 K are also reported. • Laboratory study of ammonium cyanide and ammonia. • Ammonium cyanide infrared spectra and band strengths at low temperatures. • Ammonium cyanide infrared optical constants, mass density and refractive index. • Sublimation pressure and enthalpy of sublimation for ammonium cyanide. • Vapor pressure and enthalpy of sublimation for ammonia. [ABSTRACT FROM AUTHOR]

Liquid free ion-conductive elastomers (ICEs) have demonstrated promising potential in various advanced application scenarios including sensor, artificial skin, and human-machine interface. However, ICEs that synchronously possess toughness, adhesiveness, stability, and anti-bacterial capability are still difficult to achieve yet highly demanded. Here, a one-pot green and sustainable strategy was proposed to fabricate multifunctional ICEs by extracting non-cellulose components (mainly lignin and hemicellulose) from lignocellulose with polymerizable deep eutectic solvents (PDES) and the subsequent in-situ photo-polymerization process. Ascribing to the uniform dispersion of non-cellulose components in PDES, the resultant ICEs demonstrated promising mechanical strength (a tensile strength of ~1200 kPa), high toughness (~9.1 MJ m−3), favorable adhesion (a lap-shear strength up to ~61.5 kPa toward metal), conducive stabilities, and anti-bacterial capabilities. With the help of such advantages, the ICEs exhibited sensitive (a gauge factor of ~23.5) and stable (~4000 cycles) performances in human motion and physiological signal detection even under sub-zero temperatures (e.g., −20 °C). Besides, the residue cellulose can be mechanically isolated into nanoscale fibers, which matched the idea of green chemistry. [Display omitted] • Lignocellulose was treated by PDES to fabricate reinforced ICEs and nanocellulose. • The PDESL ICEs exhibited excellent mechanical properties and durability. • The PDESL ICEs displayed favorable adhesiveness to various substrates. • The PDESL ICEs sensors can precisely detect human movements signals under −20 °C. [ABSTRACT FROM AUTHOR]

The thermo-mechanical evolution of icy moons cannot be understood without taking into account the complex interaction between the solid ice crust and the liquid water ocean. This interaction is controlled by the heat flux from the ocean and the material properties of ice. In recent years, the mass and energy exchange between the crust and the ocean has been studied using two complementary approaches. While in the first approach, the heat flux from the ocean is governed by the internal dynamics of the ocean and is independent of the processes at the phase boundary, the other approach assumes that the heat flux from the ocean is controlled by variations in the melting temperature along the boundary and the role of the ocean in heat transfer is passive. Here we present a new method for modeling the heat transfer in the interior of icy moons. Our approach is based on solving the heat transfer equations simultaneously in the ice shell and the ocean, and is more general than the previous ones in that it consistently links the global ocean circulation with the melting temperature variations arising from the deformation of the ice-water phase boundary. The method is used to study the role of ocean circulation in the formation of surface and ice-water interface topographies. We show that the additional heat flux generated by variations in the melting temperature along the phase boundary counteracts the heat flux from the deep ocean but is not able to completely suppress it. The deep ocean heat flux is more reduced at high latitudes than near the equator, where the ocean circulation is dominated by strong zonal flows hampering the heat transfer in the meridional direction. Our simulations predict the shape and topography that are comparable in magnitude to those observed on Titan (∼ 500 m) and explain the absence of a degree-2 sectoral component in the spherical harmonic expansion of Titan's topography. • We present a new method for modeling ice shell-ocean interaction on icy moons. • Ocean circulation can play important role in forming the large-scale topography. • Heat flux driven by phase transition effects is less important that expected. • The model predicts the correct shape and topography of Titan on degree 2. [ABSTRACT FROM AUTHOR]

The habitability of large icy moons has long been disputed due to the presence of an high-pressure (HP) ice layer located between the core and the internal liquid ocean, preventing a direct contact and facilitated exchanges between both. In our previous study (Lebec et al. 2023), we have shown that under certain conditions and considering the phase change at the upper boundary of the HP ice shell, heat and mass transfer can occur and be efficient. Now, the aim of this work is to study the effects of impurities inside the HP ices on the flow dynamics and the mass transfer efficiency from the core to the ocean. These salts can enter the ice layer either by diffusion, which is a very inefficient process, or by partial melting at the bottom of the ice layer, if the temperature is high enough. In that case, the liquid water can interact with the core and get enriched in salts. This salty water, which can be lighter than high-pressure ices, could rise through the ice shell and refreeze. The resulting salts/ice mixture can be transported into the ocean by convection in the solid state but could also impede it due to its density higher than that of pure ice. The efficiency of convection depends on the buoyancy number B s a l t s , which is the ratio of density increase associated to salts compared to the decrease associated to temperature. To explore the impact of salts, we model a flux of salts from the core and the advection of these salts using Lagrangian tracers in order to study the effects of the Rayleigh number, the buoyancy number and K , which is the partition coefficient of the salts between the ocean and the HP ices at the top interface, on the heat and salts transfer efficiency through the HP ice layer, as well as the implications for the evolution of salt concentration in the ocean of large icy moons and ocean worlds. We present a scaling of the bottom temperature and the top radial velocity w t o p as function of the Rayleigh number R a q for various values of the buoyancy number and a scaling of the effective flux of salts across the top interface with the ocean as function of the buoyancy number for various values of the partition coefficient. We perform a numerical application for Ganymede and show that depending on the values of the system parameters, a significant percentage of the salts entering the HP ice layer from the core can efficiently flow into the ocean. • Advection of salts through high-pressure ice layers of large ocean worlds is modeled. • Salts affect the density and overall dynamics of high-pressure ice layers. • Salts can be easily transported through the HP ice shell depending on the buoyancy number. [ABSTRACT FROM AUTHOR]

James Webb Space Telescope's NIRSpec infrared imaging spectrometer observed the outer solar system dwarf planets Eris and Makemake in reflected sunlight at wavelengths spanning 1 through 5 μm. Both objects have high albedo surfaces that are rich in methane ice, with a texture that permits long optical path lengths through the ice for solar photons. There is evidence for N 2 ice absorption around 4.2 μm on Eris, though not on Makemake. No CO ice absorption is seen at 4.67 μm on either body. For the first time, absorption bands of two heavy isotopologues of methane are observed at 2.615 μm (13CH 4), 4.33 μm (12CH 3 D), and 4.57 μm (12CH 3 D). These bands enable us to measure D/H ratios of (2.5 ± 0.5) × 10−4 and (2.9 ± 0.6) × 10−4, along with 13C/12C ratios of 0.012 ± 0.002 and 0.010 ± 0.003 in the surface methane ices of Eris and Makemake, respectively. The measured D/H ratios are much lower than that of presumably primordial methane in comet 67P/Churyumov-Gerasimenko, but they are similar to D/H ratios in water in many comets and larger outer solar system objects. This similarity suggests that the hydrogen atoms in methane on Eris and Makemake originated from water, indicative of geochemical processes in past or even ongoing hot environments in their deep interiors. The 13C/12C ratios are consistent with commonly observed solar system values, suggesting no substantial enrichment in 13C as could happen if the methane currently on their surfaces was the residue of a much larger inventory that had mostly been lost to space. Possible explanations include geologically recent outgassing from the interiors as well as processes that cycle the surface methane inventory to keep the uppermost surfaces refreshed. • New JWST NIRSpec infrared spectral observations of Eris and Makemake. • Absorption bands of 13CH4 and CH3D used to measure isotopic ratios in CH4. • Similarity to D/H in water suggests source in interior geochemistry. [ABSTRACT FROM AUTHOR]

Nitrogen, carbon monoxide, and methane are key materials in the far outer Solar System where their high volatility enables them to sublimate, potentially driving activity at very low temperatures. Knowledge of their vapor pressures and latent heats of sublimation at relevant temperatures is needed to model the processes involved. We describe a method for using a quartz crystal microbalance to measure the sublimation flux of these volatile ices in the free molecular flow regime, accounting for the simultaneous sublimation from and condensation onto the quartz crystal to derive vapor pressures and latent heats of sublimation. We find vapor pressures to be somewhat lower than previous estimates in literature, with carbon monoxide being the most discrepant of the three species, almost an order of magnitude lower than had been thought. These results have important implications across a variety of astrophysical and planetary environments. • New vapor pressure measurements for N2, CO, and CH4 ices. • Uses quartz crystal microbalance to measure sublimation. • Accounts for simultaneous deposition from surrounding gas. • CO ice has lower vapor pressure than previously thought. [ABSTRACT FROM AUTHOR]

Urea is a prebiotic molecule that has been detected in few sources of the interstellar medium (ISM) and in Murchison meteorite. Being stable against ultraviolet radiation and high-energy electron bombardment, urea is expected to be present in interstellar ices. Theoretical and experimental studies suggest that isocyanic acid (HNCO) and formamide (NH 2 CHO) are possible precursors of urea. However, uncertainties still exist regarding its formation routes. Previous computational works characterised urea formation in the gas phase or in presence of few water molecules by reaction of formamide with nitrogen-bearing species. In this work, we investigated the reaction of HNCO + NH 3 on an 18 water molecules ice cluster model mimicking interstellar ice mantles by means of quantum chemical computations. We characterised different mechanisms involving both closed-shell and open-shell species at B3LYP-D3(BJ)/ma-def2-TZVP level of theory, in which the radical–radical H 2 NCO + NH 2 coupling has been found to be the most favourable one due to being almost barrierless. In this path, the presence of the icy surfaces is crucial for acting as reactant concentrators/suppliers, as well as third bodies able to dissipate the energy liberated during the urea formation. • Urea formation from HNCO + NH 3 on water ice mantles is not viable in the ISM. • The reaction between NH 2 and HNCO presents a high energy barrier to occur in the ISM. • The H 2 NCO + NH 2 coupling on ice mantles is the most favourable urea synthetic path. • The main role of ices in these reactions is of reactant concentrator/supplier. • Urea can probably be detected in molecular clouds rich in N-containing molecules. [ABSTRACT FROM AUTHOR]

Due to the lack of in-situ geotechnical data from lunar Permanently Shadowed Regions (PSRs), it is important that a versatile icy regolith simulant be used in terrestrial development of rovers, excavators, and water extractors intended for operating in lunar PSRs. Fine tuning of existing icy regolith simulant properties is not possible; for a given water percentage they either exhibit strength similar to high strength concrete or to sand, but nothing in between. In this work we present a novel method for creating icy lunar regolith simulant, called Pressure Sintered icy lunar regolith Simulant. PSS is notable for being created from solid phase water, and for being tailorable to a wide range of mechanical properties through the sintering of ice and regolith grains, induced by applied uniaxial pressure. Samples were produced at 0%, 2%, 5%, and 10% ice content as measured by weight, and were pressed at four different pressure levels. Penetration resistance was measured for each of these samples, and it was observed that a continuous distribution of penetration resistance levels could be achieved by varying the applied pressure and ice content. Significant relaxation of samples during the pressing process was also observed. The production method for PSS is included, and is followed by the penetration resistance and density results along with some qualitative observations. Finally, we make recommendations for the use of PSS in terrestrial testing activities. • The mechanical properties of Pressure Sintered icy lunar regolith simulant can be tuned without changing ice content. • Icy regolith simulant mechanical properties are primarily driven by the interaction of ice and regolith grains, rather than the interaction of regolith grains with each other. • Bulk density and penetration resistance cannot predict water content in Pressure Sintered icy lunar regolith Simulant. [ABSTRACT FROM AUTHOR]

Various Solar System objects are covered in layers of ice that are dominated by H 2 O, CH 4 , and N 2 and in which complex chemical processes take place. In this work, the influence of composition and irradiation duration on the volatile irradiation products of mixed CH 4 :N 2 , CH 4 :H 2 O, and CH 4 :H 2 O:N 2 ices after electron irradiation are studied. The ices were irradiated for 2 or 4 h with 5 keV electrons, followed by a temperature programmed desorption, where the desorption of the volatile irradiation products was observed. The formation of C 2 H x and C 3 H x is observed in all ices and for both irradiation times. For the ices containing H 2 O, molecules as large as tentatively identified C 4 H x and C 5 H x are observed to co-desorb with water, whereas for CH 4 :N 2 a continuous desorption signal is observed instead of a sharp desorption peak. A decrease in signal intensity from the 2 to the 4 h irradiation is observed for most m/z signals in CH 4 :H 2 O and CH 4 :H 2 O:N 2 ices, whereas the opposite is recorded for CH 4 :N 2 , where in general larger signal for longer irradiation duration is seen. The addition of nitrogen to the CH 4 :H 2 O ice did not lead to clear identification of different molecules, but instead to a decrease of the observed signal for complex molecules, suggesting that the addition of nitrogen to the CH 4 :H 2 O mixture primarily leads to a more effective incorporation of material in an organic residue. The analysis of the residue will be subject of future work to complement the findings in this study. • Water in an irradiated ice changes the desorption behavior of complex molecules. • Addition of nitrogen to ices includes more complex molecules into organic residues. • Both of these points combined could have implications for comets and KBOs. [ABSTRACT FROM AUTHOR]

Europa's icy surface likely overlies an ocean, but the ice thickness is not known. Here we model the temporal growth of a Europan shell of pure ice subject to varying ice–ocean heat fluxes, ice rheologies, and internal heating rates. Both constant and viscosity-dependent internal heating rates are included, yielding similar results for particular viscosities. A growing shell starting from an ice-free initial state transitions from conduction to convection at O(10 5) to O(10 7) years, with thicknesses of O(1–10) km. For low ice–ocean heat fluxes and larger viscosities, and in the absence of internal heating of the shell, the time to reach a steady-state thickness exceeds the estimated age of Europa's surface, whence the shell may still be growing. We conclude by presenting a method for inferring estimates of ice–ocean heat fluxes (modulo uncertainties introduced by internal heating) and vertical ocean velocities from the ice-thickness measurements expected from the upcoming Clipper mission, assuming the shell is in a conductive steady state. • Ice–ocean heat flux and ice rheology control the evolution of Europa's ice shell. • The transition from conduction to convection occurs between 105 and 107 years depending on the rheology and ice–ocean heat flux. • Europa's ice shell may still be growing. • Steady-state conductive ice thicknesses are controlled by ice–ocean heat fluxes and can give insight to ocean dynamics. [ABSTRACT FROM AUTHOR]