Inspired by the synthesis of XB3C3 (X = Sr, La) compounds in the bipartite sodalite clathrate structure, density functional theory (DFT) calculations are performed on members of this family containing up to two different metal atoms. A DFTchemical pressure analysis on systems with X = Mg, Ca, Sr, Ba reveals that the size of the metal cation, which can be tuned to stabilize the B-C framework, is key for their ambient-pressure dynamic stability. High-throughput density functional theory calculations on 105 Pm (3) over bar symmetry XYB6C6 binary-guest compounds (where X, Y are electropositive metal atoms) find 22 that are dynamically stable at 1 atm, expanding the number of potentially synthesizable phases by 19 (18 metals and 1 insulator). The density of states at the Fermi level and superconducting critical temperature, T-c, can be tuned by changing the average oxidation state of the metal atoms, with T-c being highest for an average valence of +1.5. KPbB6C6, with an ambient-pressure Eliashberg T-c of 88 K, is predicted to possess the highest Tc among the studied Pm (3) over barn XB3C3 or Pm (3) over bar XYB6C6 phases, and calculations suggest it may be synthesized using high-pressure high-temperature techniques and then quenched to ambient conditions.

The phase diagram of the Mg-C system has been constructed up to 20 GPa and similar to 4000 K based on complementary Thermo-Calc simulations and experimental data obtained in both ex situ and in situ experiments using X-ray diffraction with synchrotron radiation. Three high-pressure magnesium carbides, namely, beta-Mg2C3, its high-temperature form gamma-Mg2C3, and antifluorite Mg2C, have p-T domains of thermodynamic stability. At the same time, the carbides accessible by ambient-pressure synthesis, alpha-Mg2C3 and MgC2, are either metastable or unstable, depending on the temperature, at least up to 20 GPa. Experimental observations show that at ambient conditions, all carbides are metastable and remain unchanged at least for years.

In mammalian cell nuclei, the nuclear lamina (NL) underlies the nuclear envelope (NE) to maintain nuclear structure. The nuclear lamins, the major structural components of the NL, are involved in the protection against NE rupture induced by mechanical stress. However, the specific role of the lamins in repair of NE ruptures has not been fully determined. Our analyses using immunofluorescence and live-cell imaging revealed that the nucleoplasmic pool of lamin C rapidly accumulated at sites of NE rupture induced by laser microirradiation in mouse embryonic fibroblasts. The accumulation of lamin C at the rupture sites required both the immunoglobulin-like fold domain that binds to barrier-to-autointegration factor (BAF) and a nuclear localization signal. The accumulation of nuclear BAF and cytoplasmic cyclic GMP-AMP synthase (cGAS) at the rupture sites was in part dependent on lamin A/C. These results suggest that nucleoplasmic lamin C, BAF, and cGAS concertedly accumulate at sites of NE rupture for rapid repair.

Chondrites are undifferentiated meteorites that can provide information on the compositions of materials in the early solar System, including the building blocks of the terrestrial planets. While most chondrites belong to well-defined groups based on their mineralogy and chemical composition, a minor fraction have unusual characteristics and are classified as ungrouped chondrites. These ungrouped chondrites reflect the diversity of chondritic materials in the early solar system; however, they are not as well stud-ied as grouped meteorites and their origins are poorly understood. In this study, we present high -precision mass-independent Cr, Ca and Mg isotope data for 17 ungrouped chondrites. The epsilon 54Cr and epsilon 48Ca (epsilon expresses parts per ten thousand mass-independent isotope deviation) data for ungrouped chon-drites also provide important constraints for assessing their relationships to the known chondrite groups, and the radiogenic Mg isotope ratios (mu 26Mg*) can be used to track the early solar system history. We also present the first high-precision data for a Kakangari (KC) chondrite, an enstatite chondrite, and for four enstatite-rich meteorites. The epsilon 54Cr and epsilon 48Ca values for the KC are-0.44 +/- 0.04 and-1.30 +/- 0.25, respec-tively, and epsilon 48Ca value for SAH 97096 (EH3) is-0.19 +/- 0.22 that overlaps with that of those of Earth -Moon system and ordinary chondrites. All the carbonaceous chondrite-like (CC) ungrouped chondrites show positive epsilon 54Cr and epsilon 48Ca values, and all the non-carbonaceous chondrite-like (NC) ungrouped chon-drites and KCs (also belong to the NC trend) show zero or negative epsilon 54Cr and epsilon 48Ca values. This observa-tion confirms the CC-NC dichotomy for primitive solar system materials. LEW 87232 (KC) also shows the highest 55Mn/52Cr ratio and epsilon 53Cr value amongst all the chondrites. There is a positive trend between 55Mn/52Cr ratios and epsilon 53Cr values among all the chondrites that mostly reflects a mixing between mul-tiple chondritic components. Previously it has been reported that there is a bulk 26Al-26Mg correlation line amongst chondrites. This correlation has been interpreted as being due to mixing of CAIs (high 27Al/24Mg ratios and mu 26Mg* values) and other silicate material (e.g., chondrules and matrix). By provid-ing additional 26Al-26Mg chondrite data, we show that there is no 26Al-26Mg correlation line for the chon-drites, ruling out the two-endmember (i.e., CAIs and other silicates) mixing model.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Protoplanets formed in a marginally gravitationally unstable (MGU) disk by either core accretion or disk instability will be subject to dynamical interactions with massive spiral arms, possibly resulting in inward or outward orbital migration, mergers with each other, or even outright ejection from the protoplanetary system. The latter process has been hypothesized as a possible formation scenario for the unexpectedly high frequency of unbound gas giant exoplanets (free floating planets, FFPs). Previous calculations with the EDTONS fixed grid three-dimensional (3D) hydrodynamics code found that protoplanets with masses from 0.01 M (circle plus) to 3 M (Jup) could undergo chaotic orbital evolutions in MGU disks for similar to 1000 yr without undergoing monotonic inward or outward migration. Here the Enzo 2.5 adaptive mesh refinement 3D hydrodynamics code is used to follow the formation and orbital evolution of protoplanets in MGU disks for up to 2000 yr. The Enzo results confirm the basic disk fragmentation results of the EDTONS code, as well as the absence of monotonic inward or outward orbital migration. In addition, Enzo allows protoplanet mergers to occur, unlike EDTONS, resulting in a significant decrease in the number of protoplanets that survive for 1000-2000 yr in the Enzo models. These models also imply that gas giants should be ejected frequently in MGU disks that fragment into large numbers of protoplanets, supporting ejection as a possible source mechanism for the observed FFPs.

Introduction: Continental hydrothermal systems (CHSs) are geochemically complex, and they support microbial communities that vary across substrates. However, our understanding of these variations across the complete range of substrates in CHS is limited because many previous studies have focused predominantly on aqueous settings.

Responses of the terrestrial biosphere to rapidly changing environmental conditions are a major source of uncertainty in climate projections. In an effort to reduce this uncertainty, a wide range of global change experiments have been conducted that mimic future conditions in terrestrial ecosystems, manipulating CO2, temperature, and nutrient and water availability. Syntheses of results across experiments provide a more general sense of ecosystem responses to global change, and help to discern the influence of background conditions such as climate and vegetation type in determining global change responses. Several independent syntheses of published data have yielded distinct databases for specific objectives. Such parallel, uncoordinated initiatives carry the risk of producing redundant data collection efforts and have led to contrasting outcomes without clarifying the underlying reason for divergence. These problems could be avoided by creating a publicly available, updatable, curated database. Here, we report on a global effort to collect and curate 57,089 treatment responses across 3644 manipulation experiments at 1145 sites, simulating elevated CO2, warming, nutrient addition, and precipitation changes. In the resulting Manipulation Experiments Synthesis Initiative (MESI) database, effects of experimental global change drivers on carbon and nutrient cycles are included, as well as ancillary data such as background climate, vegetation type, treatment magnitude, duration, and, unique to our database, measured soil properties. Our analysis of the database indicates that most experiments are short term (one or few growing seasons), conducted in the USA, Europe, or China, and that the most abundantly reported variable is aboveground biomass. We provide the most comprehensive multifactor global change database to date, enabling the research community to tackle open research questions, vital to global policymaking. The MESI database, freely accessible at , opens new avenues for model evaluation and synthesis-based understanding of how global change affects terrestrial biomes. We welcome contributions to the database on GitHub.

We present chemical abundances and velocities of five stars between 0.3 and 1.1 kpc from the center of the Tucana II ultrafaint dwarf galaxy (UFD) from high-resolution Magellan/MIKE spectroscopy. We find that every star is deficient in metals (-3.6 < [Fe/H] < -1.9) and in neutron-capture elements as is characteristic of UFD stars, unambiguously confirming their association with Tucana II. Other chemical abundances (e.g., C, iron peak) largely follow UFD trends and suggest that faint core-collapse supernovae (SNe) dominated the early evolution of Tucana II. We see a downturn in [alpha/Fe] at [Fe/H] asymptotic to-2.8, indicating the onset of Type Ia SN enrichment and somewhat extended chemical evolution. The most metal-rich star has strikingly low [Sc/Fe] = -1.29 +/- 0.48 and [Mn/Fe] = -1.33 +/- 0.33, implying significant enrichment by a sub-Chandrasekhar mass Type Ia SN. We do not detect a radial velocity gradient in Tucana II ( dv(helio)/d theta(1)=-2.6-2.9+3.0 -1 kpc(-1)), reflecting a lack of evidence for tidal disruption, and derive a dynamical mass of M-1/2(r(h))=1.6(--0.7)(+)(1.1)x10(6 )M(?). We revisit formation scenarios of the extended component of Tucana II in light of its stellar chemical abundances. We find no evidence that Tucana II had abnormally energetic SNe, suggesting that if SNe drove in situ stellar halo formation, then other UFDs should show similar such features. Although not a unique explanation, the decline in [alpha/Fe] is consistent with an early galactic merger triggering later star formation. Future observations may disentangle such formation channels of UFD outskirts.

In previous work, we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds and examined 11 in detail in order to classify them as either Thorne-Zytkow objects (TZOs; red supergiants with a neutron star cores) or super-asymptotic giant branch (sAGB) stars (the most massive stars that will not undergo core collapse). This population includes HV 2112, a peculiar star previously considered in other works to be either a TZO or high-mass asymptotic giant branch (AGB) star. Here we continue this investigation, using the kinematic and radio environments and local star formation history of these stars to place constraints on the age of the progenitor systems and the presence of past supernovae. These stars are not associated with regions of recent star formation, and we find no evidence of past supernovae at their locations. Finally, we also assess the presence of heavy elements and lithium in their spectra compared to red supergiants. We find strong absorption in Li and s-process elements compared to RSGs in most of the sample, consistent with sAGB nucleosynthesis, while HV 2112 shows additional strong lines associated with TZO nucleosynthesis. Coupled with our previous mass estimates, the results are consistent with the stars being massive (similar to 4-6.5 M (circle dot)) or sAGB (similar to 6.5-12 M (circle dot)) stars in the thermally pulsing phase, providing crucial observations of the transition between low- and high-mass stellar populations. HV 2112 is more ambiguous; it could either be a maximally massive sAGB star, or a TZO if the minimum mass for stability extends down to less than or similar to 13 M (circle dot).