Massive Formation Research Articles

HSTPROMO Internal Proper-motion Kinematics of Dwarf Spheroidal Galaxies. I. Velocity Anisotropy and Dark Matter Cusp Slope of Draco

We analyze four epochs of Hubble Space Telescope imaging over 18 yr for the Draco dwarf spheroidal galaxy. We measure precise proper motions for hundreds of stars and combine these with existing line-of-sight (LOS) velocities. This provides the first radially resolved 3D velocity dispersion profiles for any dwarf galaxy. These constrain the intrinsic velocity anisotropy and resolve the mass–anisotropy degeneracy. We solve the Jeans equations in oblate axisymmetric geometry to infer the mass profile. We find the velocity dispersion to be radially anisotropic along the symmetry axis and tangentially anisotropic in the equatorial plane, with a globally averaged value βB¯=−0.20−0.53+0.28 , (where 1 – βB≡〈vtan2〉/〈vrad2〉 in 3D). The logarithmic dark matter (DM) density slope over the observed radial range, Γdark, is −0.83−0.37+0.32 , consistent with the inner cusp predicted in ΛCDM cosmology. As expected given Draco’s low mass and ancient star formation history, it does not appear to have been dissolved by baryonic processes. We rule out cores larger than 487, 717, and 942 pc at 1σ, 2σ, and 3σ confidence, respectively, thus imposing important constraints on the self-interacting DM cross section. Spherical models yield biased estimates for both the velocity anisotropy and the inferred slope. The circular velocity at our outermost data point (900 pc) is 24.19−2.97+6.31kms−1 . We infer a dynamical distance of 75.37−4.00+4.73 kpc and show that Draco has a modest LOS rotation, with v/σ=0.22±0.09 . Our results provide a new stringent test of the so-called “cusp–core” problem that can be readily extended to other dwarfs.

Formation Conditions of Ignimbrites of the Khangar Volcano (Kamchatka)

Abstract —The study of minerals, melt inclusions, as well as natural glasses showed that two different melts contributed to the formation of ignimbrites of the Khangar Volcano. The first, providing the information on melt inclusions in plagioclase and quartz phenocrysts, represents the state of magma in a deep source. The other type of melt is responsible for the formation of glasses and microcrystals of feldspars in fiamme. Experimental and analytical studies of melt inclusions showed that crystallization of most plagioclase and quartz phenocrysts from ignimbrites of the Khangar Volcano occurred at temperatures of 840–960 °C and pressures up to 1.1 kbar, from the melt with water contents up to 3.23 wt.%, under the conditions of magma chamber. The presence of syngenetic primary melt and fluid inclusions in plagioclase and quartz phenocrysts from ignimbrites of the Khangar Volcano indicates phase separation (“boiling”) of the melt with mass formation of СО2 microbubbles in magma. The other type of melt is secondary relative to magmatic systems of the Khangar Volcano and is formed by sintering and melting of tuffogenic volcanoclastic material. This melt contributed to the formation of fiamme in the examined ignimbrites. Based on the study of glasses and microcrystals of feldspars in fiamme, it was found that crystallization of oligoclase occurred at temperatures of 770–840 °C in the melt between the spherules (with water content up to 2.91 wt.%). Sanidine crystals grew over spherules at lower temperatures, 680–760 °C.

The Contribution of Host Galaxy Properties in X-Ray Active Galactic Nuclei Clusters

In this study, the influence of host galaxy properties on X-ray active galactic nuclei (AGN) clusters was investigated using multiwavelength data. X-ray data from the eFEDS main catalog, optical and near-infrared data from the fourth data release of KiDS/VIKING, and mid-infrared data from WISE were utilized. By integrating these datasets and employing the CIGALE code, the star formation rate, luminosity, and stellar mass of the host galaxies were estimated. The analysis reveals significant associations between luminosity, stellar mass, and star formation rate, providing valuable insights into AGN activity. Furthermore, AGN clusters were compared with non-AGN clusters to uncover distinctive characteristics. AGN clusters exhibit differences in their population across various luminosity levels. Interestingly, a significant proportion of AGN clusters is concentrated in the middle range of luminosity (45-46 measured in logL<sub>(0.5-2.0 keV)</sub>) for both low and high redshift classifications. Additionally, galaxies hosting AGNs detected in X-ray emission tend to fall within a specific range of stellar mass (10-11 measured in log(M<sub>⋆</sub>(M<sub>⊚</sub>)). This stellar mass range is populated by a substantial number of AGN galaxies, irrespective of their redshift classification. Moreover, a significant population of X-ray AGN is concentrated within the star formation rate range of 1.5-2.5 (expressed in log(M<sub>⊚</sub> yr<sup>-1</sup>)) in both low and high redshift regions. By analyzing the dependencies on luminosity, stellar mass, and star formation rate, this study provides valuable insights into the correlation and relationship between AGN clusters and their host galaxies. The comparison with non-AGN clusters and the integration of multiwavelength data from eFEDS, KiDS/VIKING, and WISE enhance the depth of analysis, contributing to a comprehensive evaluation of AGN clusters. These findings advance our understanding of the complex relationship between AGN clusters and host galaxy properties in the field of astrophysics.

METHODOLOGY OF INSTITUTIONAL REGULATION OF COMPLEX DEVELOPMENT OF LAND MANAGEMENT AND ASSESSMENT OF ITS EFFECTIVENESS

Modern organizational and economic methods of managing agricultural land use in Ukraine do not ensure its sustainable development, which is reflected in the increasing degradation processes. The current institutional system in Ukraine’s land relations sector is characterized by uncertainty and the lack of clearly established social norms and rules for the ecological management and use of land resources, as well as the roles and statuses of participants in land relations. The absence of a unified national system that meets state and public needs and is supported by an adequate social environment and the ecological awareness of government authorities and citizens hinders the development of effective and competitive agricultural entrepreneurship aimed at creating environmentally clean land resources and producing safe products. A land management system is proposed, where the first level of goal decomposition includes the basic regulatory functions (creation of an ecological network and a system of sustainable land use; forecasting and spatial planning for the use of land and natural resources; development of effective forms of ownership and land use; state support and economic incentives for rational forms of ownership and land use). Regulatory functions, as the main element of the institutional regulation system for the comprehensive development of land management, also serve as the basis for classifying regulatory instruments. The article presents the author’s approach to classifying the instruments of institutional regulation for the comprehensive development of land management according to the basic regulatory functions and their instruments. The institutionalization of land management will contribute to environmentally safe land management in rural areas, the formation of unified land masses, and the reduction of degradation processes. It will also improve the procedures for maintaining land cadastre and monitoring, ensure legislative regulation of access for individuals and legal entities, landowners, and land users to information about land plots and soil quality, which will be used for organizing economic activities, as well as for the economic stimulation of rational land use.

Complicated Appendicitis: An Update on Management: Mini Review

Complicated appendicitis is a complication of acute appendicitis, which is defined as perforation of the appendix, with abscess or mass formation. The management of complicated appendicitis was initially with conservative treatment with intra-venous antibiotics, with percutaneous drainage of abscess reserved for patients with abscess formation. The recent trend has seen a movement towards immediate appendectomy with laparoscopic appendectomy being the preferred surgical option. As there is no definitive consensus on the management of complicated appendicitis, we have conducted this mini review to look at the treatment option for complicated appendicitis in adults and children.

Tumor Dormancy and Reactivation: The Role of Heat Shock Proteins.

Tumors are a heterogeneous group of cell masses originating in various organs or tissues. The cellular composition of the tumor cell mass interacts in an intricate manner, influenced by humoral, genetic, molecular, and tumor microenvironment cues that dictate tumor growth or suppression. As a result, tumors undergo a period of a dormant state before their clinically discernible stage, which surpasses the clinical dormancy threshold. Moreover, as a genetically imprinted strategy, early-seeder cells, a distinct population of tumor cells, break off to dock nearby or extravasate into blood vessels to secondary tissues, where they form disseminated solitary dormant tumor cells with reversible capacity. Among the various mechanisms underlying the dormant tumor mass and dormant tumor cell formation, heat shock proteins (HSPs) might play one of the most important roles in how the dormancy program plays out. It is known that numerous aberrant cellular processes, such as malignant transformation, cancer cell stemness, tumor invasion, metastasis, angiogenesis, and signaling pathway maintenance, are influenced by the HSPs. An accumulating body of knowledge suggests that HSPs may be involved in the angiogenic switch, immune editing, and extracellular matrix (ECM) remodeling cascades, crucial genetically imprinted strategies important to the tumor dormancy initiation and dormancy maintenance program. In this review, we highlight the biological events that orchestrate the dormancy state and the body of work that has been conducted on the dynamics of HSPs in a tumor mass, as well as tumor cell dormancy and reactivation. Additionally, we propose a conceptual framework that could possibly underlie dormant tumor reactivation in metastatic relapse.

Simultaneous derivation of galaxy physical properties with multimodal deep learning

ABSTRACT Upcoming telescopes and surveys will revolutionize our understanding of the Universe by providing unprecedented amounts of observations on extragalactic objects, which will require new tools complementing traditional astronomy methods, in particular machine learning techniques, and above all, deep architectures. In this study, we apply deep learning methods to estimate three essential parameters of galaxy evolution, i.e. redshift, stellar mass, and star formation rate (SFR), from a data set recently analysed and tailored to the Euclid context, containing simulated H-band images and tabulated photometric values. Our approach involved the development of a novel architecture called the FusionNetwork, combining two components suited to the heterogeneous data, ResNet50 for images, and a Multilayer Perceptron (MLP) for tabular data, through an additional MLP providing the overall output. The key achievement of our deep learning approach is the simultaneous estimation of the three quantities, previously estimated separately. Our model outperforms state-of-the-art methods: overall, our best FusionNetwork improves the fraction of correct SFR estimates from ∼70 to ∼80 per cent, while providing comparable results on redshift and stellar mass.

Gastroretentive fibrous dosage forms for prolonged delivery of sparingly-soluble tyrosine kinase inhibitors. Part 1: Dosage form design, and models of expansion, post-expansion mechanical strength, and drug release

At present, the efficacy and safety of many sparingly-soluble tyrosine kinase inhibitors (TKIs) delivered by the prevalent oral dosage forms are compromised by excessive fluctuations in the drug concentration in blood. To mitigate this limitation, in this four-part study gastroretentive fibrous dosage forms that deliver drug into the gastric fluid (and into the blood) at a controlled rate for prolonged time are presented. The dosage form comprises a cross-ply structure of expandable, water-absorbing, high-molecular-weight hydroxypropyl methylcellulose (HPMC)-based fibers coated with a strengthening, enteric excipient. The intervening spaces between the coated fibers are solid annuli of drug particles, and low-molecular-weight HPMC and enteric excipients. The central regions of the annuli are open channels. In this part, models are developed for dosage form expansion, post-expansion mechanical strength, and drug release. The models suggest that upon immersing in a dissolution fluid, the fluid percolates the open channels, diffuses into the annuli and the coated fibers, and the dosage form expands. The expansion rate is inversely proportional, and the post-expansion mechanical strength proportional to the thickness of the strengthening coating. Drug particles are released from the annuli as the surrounding excipient dissolves. The drug release rate is proportional to the concentration of low-molecular-weight HPMC at the annulus/dissolution fluid interface. The dosage forms can be readily designed for expansion in a few hours, formation of a high-strength viscoelastic mass, and drug release at a constant rate over a day.

Groundwater identification using geophysical tools and its implications for the stability of slopes in an open pit mine

The open pit mining development begins with the opening of pits with the rock mass excavation and formation of slopes and berms for ore exploration. Knowledge about the geological conditions represents an important step in this process, since rock masses generally have heterogeneous characteristics and the presence of discon- tinuities can become an aggravating factor in the safety of operations. The characterization and classification of these discontinuities, as well as the identification of the groundwater in the rock mass, has a great importance to ensure the safety of operations during the mine's production process, in addition to ensure the effectiveness of its decommissioning process. The use of DC resistivity geophysical method has been increasing to characterization and identification lithological types and presence of water, since it is a non-invasive research tool with fast ability to obtain data. DC resistivity together with visual investigation methods, such as obtaining the discontinuities orientation and their alteration characteristics, provides important information for the characterization of the rock mass. Given this importance, the present work aimed to use DC resistivity to identify the presence of water and its correlation with lithology and rock mass structure in order to identify how these variables influence the occurrence of ruptures. To this end, two-dimensional resistivity sections were designed and related to visual inspection data and kinematic analyzes obtained from structural data of the rock mass. The integration of these results indicated that the ruptures present in the investigated mine slopes are related to zones whose predominant lithology is volcanic breccia with the presence of water in the subsurface. These ruptures compromise the stability of the slopes and consequently make the decommissioning mine process difficult.

Toward more realistic mass functions for ultradense dark matter halos

Ultradense dark matter halos (UDMHs) are high concentrations of dark matter, assumed to have formed deep in the radiation-dominated era from amplified primordial perturbations. In this work we improve the previous works for the calculation of UDMH abundance by elaborating on the formation process of these halos by including various physical and geometrical modifications in the analysis. In particular, we investigate the impact of angular momentum, dynamical friction and triaxial collapse on the predicted mass functions for UDMHs. We perform the calculations for four primordial power spectra with different amplified features that allow for primordial black hole and UDHM formation in wide and narrow mass ranges. We also apply this analysis in the context of two possible scenarios for dark matter: the single-component and the multi-component. We find that the abundance of UDMHs is prominently enhanced in the presence of these more realistic mass functions.

Improving Breast Cancer Detection with Convolutional Neural Networks and Modified ResNet Architecture.

The pathogenesis of breast cancer is characterized by dysregulated cell proliferation, leading to the formation of a neoplastic mass. Conventional methodologies for analyzing carcinomatous distal areas within whole-slide images (WSIs) tissue regions may lack comprehensive insights. This study aims to introduce an innovative methodology based on convolutional neural networks (CNN), specifically employing a CNN Modified ResNet architecture for breast cancer detection. The research seeks to address the limitations of existing approaches and provide a robust solution for the comprehensive analysis of tissue regions. The dataset utilized in this study comprises approximately 275,000 RGB image patches, each standardized at 50x50 pixels. The CNN Modified ResNet architecture is implemented, and a comparative evaluation against diverse architectures is conducted. Rigorous validation tests employing established performance metrics are carried out to assess the proposed methodology. The proposed architecture achieves a notable 89% accuracy in breast cancer detection, surpassing alternative methods by 2%. The results signify the efficacy and superiority of the CNN Modified ResNet model in analyzing carcinomatous distal areas within WSIs tissue regions. In conclusion, this study demonstrates the potential of the CNN Modified ResNet architecture as an effective tool for breast cancer detection. The enhanced accuracy and comprehensive analysis capabilities make it a promising approach for advancing the understanding of neoplastic masses in WSIs tissue regions. Further research and validation could solidify its role in clinical applications and diagnostic procedures.

Two-component regulatory system TCS08 of a serotype 4 strain in pneumococcal pneumonia pathogenesis

ObjectivesStreptococcus pneumoniae, a human respiratory pathogen, causes diseases with severe morbidity and mortality rates worldwide. The two-component regulatory system (TCS) is an important signaling pathway that enables regulation of gene expression in response to environmental cues, thereby allowing an organism to adapt to a variety of host niches. Here we examined the contribution of pneumococcal TCS08 to bacterial colonization, the development of pneumonia, and pulmonary dysfunction. MethodsWe employed an hk08 knockout mutant (Δhk08) with a background of the TIGR4 wild-type (WT) strain to verify whether TCS08 is associated with bacterial colonization and the development of pneumonia in a murine infection model. To clarify the association of hk08 inactivation-induced phenotypic changes with their virulence, we examined pneumococcal capsule production, colony morphology, and surface-displayed protein profiles. ResultsPneumococcal TCS08 was involved in bacterial colonization in the respiratory tract. Interruption of the signaling pathway of TCS08 by hk08 inactivation impaired mouse survival and increased the bacterial burden within the respiratory tract. Furthermore, a histopathological examination revealed massive inflammatory cell infiltration, edema formation, and diffuse alveolar damage in the lung tissues of mice infected with Δhk08 versus the WT or complemented strain. Interestingly, virulence-associated phenotype changes, including capsule production, increased chain length, and surface-displayed protein profile, were observed in the Δhk08 strain. ConclusionsThe present findings indicate that TCS08 contributes to pneumococcal colonization and pulmonary dysfunction by assisting adaptation to the respiratory tract milieu, leading to the development of pneumonia.

BANG-MaNGA: A census of kinematic discs and bulges across mass and star formation in the local Universe

In this work, we aim to quantify the relevance of kinematically identified bulges and discs and their role in the process of galaxy quenching. To achieve this, we utilised an analysis of the SDSS-MaNGA survey conducted with the GPU-based code BANG which simultaneously models galaxy photometry and kinematics to decompose galaxies into their structural components. We found that below M⋆ ≃ 1011 M⊙, galaxies span a wide range in their dynamical properties. The overall dynamical state of a galaxy is determined by the relative prominence of a dispersion-supported inner region and a rotationally supported disc. Our decomposition reveals a natural separation between these classes, with only a minor fraction of stellar mass retained by structures exhibiting intermediate dynamical support. When examining galaxies in terms of their star formation activity, an apparent substantial decrease in rotational support is observed as they move below the star-forming main sequence. This behaviour is particularly evident when using luminosity-weighted tracers of kinematics, while it almost vanishes with mass-weighted tracers. Luminosity-weighted quantities not only capture differences in kinematics but also in the stellar population, potentially leading to biased interpretations of galaxy dynamical properties and quenching. Our findings indicate that quenching implies almost no any structural transformation in galaxies below M⋆ ≃ 1011 M⊙. Processes such as disc fading are more likely explanations for the observed differences in mass-weighted and luminosity-weighted galaxy properties. When the galactic disc ceases star formation, its mass-to-light ratio does indeed increase without any significant morphological transformation. The picture is remarkably different above M⋆ ≃ 1011 M⊙. In this case, regardless of the tracer used, a substantial increase in galaxy dispersion support is observed along with a significant structural change. A different quenching mechanism, most likely associated with mergers, dominates. Notably, this mechanism is confined to a very limited range of high masses.

Efficiency of embryo complementation and pluripotency maintenance following multiple passaging of in vitro-derived bovine embryos.

Context Current methods to obtain bovine embryos of high genetic merit include approaches that require skilled techniques for low-efficiency cloning strategies. Aims The overall goal herein was to identify the efficacy of alternative methods for producing multiple embryos through blastomere complementation while determining maintenance of cell pluripotency. Methods Bovine oocytes were fertilised in vitro to produce 4-cell embryos from which blastomeres were isolated and cultured as 2-cell aggregates using a well-of-the-well system. Aggregates were returned to incubation up to 7days (Passage 1). A second passage of complement embryos was achieved by splitting 4-cell Passage 1 embryos. Passaged embryos reaching the blastocyst stage were characterised for cell number and cell lineage specification in replicate with non-reconstructed zona-intact embryos. Key results Passage 1 and 2 embryo complements yielded 29% and 25% blastocyst development, respectively. Passage 1 embryos formed blastocysts, but with a reduction in expression of SOX2 and decreased size compared to non-reconstructed zona-intact embryos. Passage 2 embryos had a complete lack of SOX2 expression and a reduction in transcript abundance of SOX2 and SOX17, suggesting loss of pluripotency markers that primarily affected inner cell mass (ICM) and hypoblast formation. Conclusions In vitro fertilised bovine embryos can be reconstructed with multiple passaging to generate genetically identical embryos. Increased passaging drives trophectoderm cell lineage specification while compromising ICM formation. Implications These results may provide an alternative strategy for producing genetically identical bovine embryos through blastomere complementation with applications towards the development of trophoblast and placental models of early development.

AstroSat observations of interacting galaxies NGC 7469 and IC 5283

Aims. We carry out deep near-ultrviolet (NUV) and far-ultrviolet (FUV) imaging of an interacting galaxy system, comprised of a Seyfert type 1 galaxy NGC 7469 and its companion IC 5283. Our aim is to resolve and map the star-forming regions in the outer arms and look for signs of interaction between the two galaxies. Methods. We used AstroSat Ultra Violet Imaging Telescope (UVIT) to obtain NUV and FUV images of NGC 7469 in a range of filters. We have carried out photometry of star-forming regions in the two galaxies and found their spatial distributions. We also obtained the distributions of star formation rates (SFR) in NGC 7469 and IC 5283 using the estimates obtained from the FUV and NUV bands. We also carried out Kolmogorov-Smirnov tests to look for differences in the SFRs in the two galaxies. We derived the spectral energy distribution (SED), leading to the determination of physical parameters, including the overall SFR, stellar mass (M*), dust mass (MDust), and specific star formation rates (sSFRs) in both the galaxies. Results. Our NUV and FUV images show the presence of an outer spiral arm that is better resolved. We have identified 33 new star-forming regions out of 51 total identified in the UVIT composite image. Enhanced star formation activity is observed to coincide with the interaction, and KS tests show that there are no significant differences in the SFR distributions of NGC 7469 and IC 5283, indicating that the interaction between the galaxies has not influenced their star formation processes differently. The SED plots and the photometric results demonstrate that most of the star formation activity is confined inside the central starburst (SB) ring.

Effect of combination of genomic variation–based machine learning and clinical pathology on accurate diagnosis of tumors: Lung adenocarcinoma and lung squamous cell carcinoma.

11174 Background: Non-small cell lung cancer (NSCLC) is the most prevalent form of lung cancer, with lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) being the predominant subtypes. Given the significant differences in treatment approaches and clinical outcomes between LUAD and LUSC, accurate identification of these pathological subtypes prior to treatment initiation is crucial. Methods: This study aimed to enhance the diagnostic accuracy for LUAD and LUSC by integrating a machine learning artificial intelligence (AI) model with the expertise of pathologists. The AI model was trained and validated on a cohort of 10,693 and 5,571 cases from the OrigiMed database, each confirmed by at least three pathologists. Targeted sequencing of 450 cancer-related genes was performed. Results: Analysis of the validation set demonstrated an overall accuracy of 89.2% across 28 tumor types, with individual accuracies ranging from 22.2% to 100%. For the top one prediction, the AI model achieved an accuracy of 82.7% for LUAD and 67.9% for LUSC. However, when considering the top three predictions, the accuracy significantly increased to 92.1% for LUAD and 93.0% for LUSC. To further validate the diagnostic capability of the AI model, a large sample of 4,531 LUAD cases and 207 LUSC cases from 4,502 patients was collected for comparative analysis with pathologists' diagnoses. The results indicated that 87.9% of LUAD cases and 83.6% of LUSC cases were consistent with the AI model's diagnosis, while 4.9% of LUAD and 9.7% of LUSC cases showed discrepancies. To investigate these inconsistencies, a subset of 30 LUAD cases and 16 LUSC cases was selected for re-evaluation by independent pathologists. Four poorly differentiated cases from the discrepancy group were ultimately diagnosed as 2 LUADs and 2 LUSCs, supporting the initial AI diagnosis. For instance, Patient 40 was initially diagnosed with LUSC; however, the AI system identified the pathology as LUAD, which may be attributed to the detection of the KIF5B-RET fusion. This diagnosis was subsequently corroborated by an additional pathologist who observed gland-like structures and ambiguous solid mass formations within the tumor tissue, consistent with LUAD histopathology. Conclusions: In summary, we have presented a machine learning AI model that leverages next-generation sequencing (NGS) technology for the auxiliary diagnosis of cancer. By applying this AI model to diagnose LUAD and LUSC and comparing it with the diagnoses made by human pathologists, we have demonstrated that the integration of pathological diagnosis and AI machine learning can significantly enhance and even surpass the diagnostic capabilities of human physicians. This advancement holds great potential in improving the accuracy of tumor diagnosis and the precision of treatment.

In Situ Sulfur Isotope Geochemistry Using Secondary Ion Mass Spectrometry of Sulfides in the ABM Replacement-Style Volcanogenic Massive Sulfide Deposit, Finlayson Lake District, Yukon, Canada

Abstract The ABM deposit is a bimodal-felsic, replacement-style volcanogenic massive sulfide deposit located in the Finlayson Lake district, Yukon, Canada, that is hosted by back-arc-affinity felsic volcanic rocks of the Yukon-Tanana terrane. Massive sulfide mineralization occurs as a series of stacked and stratabound lenses subparallel to the volcanic stratigraphy, surrounded by an envelope of pervasive white mica and chlorite alteration. Three major mineral assemblages occur: (1) a pyrite-sphalerite assemblage enriched in Zn-Pb-As-Sb-Ag-Au that formed at temperatures ∼200–270 °C, (2) a pyrite-chalcopyrite-magnetite-pyrrhotite assemblage enriched in Cu-Bi-Se-Co that formed at temperatures ∼300–350 °C, and (3) a chalcopyrite-pyrrhotite-pyrite stringer assemblage formed at temperatures >300 °C. In situ analysis of the sulfur isotopic ratios (δ34S) using secondary ion mass spectrometry has been performed on sulfides (pyrite, pyrrhotite, chalcopyrite, galena, and arsenopyrite) from samples representative of the major mineral assemblages. The δ34S results range between +4.0 and +12.5‰. The pyrite-sphalerite assemblage has an average δ34S value of +6.6 ± 1.8‰ (n = 31), whereas the higher temperature assemblages have an average δ34S value of +9.9 ± 1.4‰ (n = 59). Examination of the δ34S values of adjacent mineral pairs shows that the sulfides were formed under disequilibrium conditions and were not significantly altered or re-equilibrated by greenschist facies metamorphism that affected the ABM deposit post-volcanogenic massive sulfide formation. The observed range of δ34S values suggests that H2S derived from thermochemical sulfate reduction of seawater sulfate and/or an igneous sulfur source as the likeliest sources of S for the sulfides in the ABM deposit. Modeling of thermochemical sulfate reduction of contemporaneous Late Devonian seawater sulfate (δ34S ∼ +25‰) at temperatures estimated for the fluids forming the ABM deposit mineral assemblages (200–350 °C) shows that the reduction of 5–30% of the seawater sulfate would result in isotopic signatures similar to those observed at the ABM deposit. This model also explains the distribution of δ34S values across the mineral assemblages, as thermochemical sulfate reduction at higher temperatures (350 °C) results in more isotopically positive δ34S values. Modeling of mixing lines between thermochemical sulfate reduction at different temperatures and an igneous sulfur source suggests that leaching of magmatic/volcanic rocks also acted as a source of sulfur and was a likely a major contributor (70–95%) to the hydrothermal fluid system at the ABM deposit.

Silver Single Atoms Combined with Clusters on Carbon Nanotubes Mediates Exclusive Electrochemical CO2‐to‐CO Conversion

AbstractThe electrochemical reduction of CO2 (eCO2RR) that exclusively produces one product at industrial current density is crucial for the substantial storage of renewable energy. Modulating the electronic structure of atomically dispersed catalysts can effectively regulate the adsorption of rate‐determining‐step intermediates to achieve the desired products. Here, the study constructs a hybrid catalyst consisting of single Ag atoms and Ag atomic clusters supported on nitrogen‐doped multi‐walled carbon nanotubes that can effectively regulate the important intermediate structure of *COOH. The X‐ray photoelectron and X‐ray absorption near‐edge spectroscopies demonstrate that turning Ag single atoms into Ag clusters can weaken the electron transfer between Ag–N and present a relatively rich electron state. Thus, the rate‐determining step of *COOH massive formation is significantly accelerated, as proven by in situ synchrotron infrared spectroscopy and density functional theory calculations. Using this strategy, a CO Faradaic efficiency outperforming 99% from −0.3 to −0.8 V (vs reversible hydrogen electrode) with current densities above 200 mA cm−2 and a half‐cell energetic efficiency of 86% is achieved. This work highlights a promising approach to advancing synergistic catalysts for achieving more controllable and efficient eCO2RR.

Sex specific emergence of trisomic Dyrk1a-related skeletal phenotypes in the development of a Down syndrome mouse model.

Skeletal insufficiency affects all individuals with Down syndrome (DS) or Trisomy 21 (Ts21) and may alter bone strength throughout development due to a reduced period of bone formation and early attainment of peak bone mass compared to typically developing individuals. Appendicular skeletal deficits also appear in males before females with DS. In femurs of male Ts65Dn DS model mice, cortical deficits were pronounced throughout development, but trabecular deficits and Dyrk1a overexpression were transitory until postnatal day (P) 30 when there were persistent trabecular and cortical deficits and Dyrk1a was trending overexpression. Correction of DS-related skeletal deficits by a purported DYRK1A inhibitor or through genetic means beginning at P21 was not effective at P30, but germline normalization of Dyrk1a improved male bone structure by P36. Trabecular and cortical deficits in female Ts65Dn mice were evident at P30 but subsided by P36, typifying periodic developmental skeletal normalizations that progressed to more prominent bone deficiencies. Sex-dependent differences in skeletal deficits with a delayed impact of trisomic Dyrk1a are important to find temporally specific treatment periods for bone and other phenotypes associated with Ts21.

Toward Cosmological Simulations of the Magnetized Intracluster Medium with Resolved Coulomb Collision Scale

We present the first results of one extremely high-resolution, nonradiative magnetohydrodynamical cosmological zoom-in simulation of a massive cluster with a virial mass of M vir = 2.0 × 1015 solar masses. We adopt a mass resolution of 4 × 105 M ⊙ with a maximum spatial resolution of around 250 pc in the central regions of the cluster. We follow the detailed amplification process in a resolved small-scale turbulent dynamo in the intracluster medium (ICM) with strong exponential growth until redshift 4, after which the field grows weakly in the adiabatic compression limit until redshift 2. The energy in the field is slightly reduced as the system approaches redshift zero in agreement with adiabatic decompression. The field structure is highly turbulent in the center and shows field reversals on a length scale of a few tens of kiloparsecs and an anticorrelation between the radial and angular field components in the central region that is ordered by small-scale turbulent dynamo action. The large-scale field on megaparsec scales is almost isotropic, indicating that the structure formation process in massive galaxy cluster formation suppresses any memory of both the initial field configuration and the amplified morphology via the turbulent dynamo. We demonstrate that extremely high-resolution simulations of the magnetized ICM are within reach that can simultaneously resolve the small-scale magnetic field structure, which is of major importance for the injection of and transport of cosmic rays in the ICM. This work is a major cornerstone for follow-up studies with an on-the-fly treatment of cosmic rays to model in detail electron-synchrotron and gamma-ray emissions.