The chemical composition of globular clusters in the Local Group

We present detailed abundance measurements for 45 globular clusters (GCs) in galaxies in (and, in one case, beyond) the Local Group. The measurements are based on new high-resolution integrated-light spectra of GCs in NGC 185, NGC 205, M31, M33, and NGC 2403, combined with reanalysis of previous observations of GCs in the Fornax dSph, WLM, NGC 147, NGC 6822, and the Milky Way. The GCs cover the range -2.8 < [Fe/H] < -0.1 and we determined abundances for Fe, Na, Mg, Si, Ca, Sc, Ti, Cr, Mn, Ni, Cu, Zn, Zr, Ba, and Eu. Corrections for non local thermodynamic equilibrium effects are included for Na, Mg, Ca, Ti, Mn, Fe, Ni, and Ba. For several of the galaxies, our measurements provide the first quantitative constraints on the detailed composition of their metal-poor stellar populations. Overall, the GCs in different galaxies exhibit remarkably uniform abundance patterns of the alpha-, iron-peak, and neutron-capture elements, with a dispersion of less than 0.1 dex in [alpha/Fe] for the full sample. There is a hint that GCs in dwarf galaxies are slightly less alpha-enhanced (by about 0.04 dex on average) than those in larger galaxies. One GC in M33 (HM33-B) resembles the most metal-rich GCs in the Fornax dSph (Fornax 4) and NGC 6822 (SC7) by having alpha-element abundances closer to scaled-solar values, possibly hinting at an accretion origin. We find that the alpha-element abundances strongly correlate with those of Na, Sc, Ni, and Zn. Several GCs with [Fe/H]<-1.5 are deficient in Mg compared to other alpha-elements. We find no GCs with strongly enhanced r-process abundances as reported for metal-poor stars in some ultra-faint dwarfs and the Magellanic Clouds. The similarity of the abundance patterns for metal-poor GCs in different environments points to similar early enrichment histories and only allow for minor variations in the initial mass function.Comment: 34 pages + 6 appendices. Accepted for publication in Astronomy & Astrophysic

The Prince and the Pauper: Evidence for the early high-redshift formation of the Galactic α\alpha-poor disc population

Context. The presence of [$\alpha$/Fe]-[Fe/H] bi-modality in the Milky Way disc has animated the Galactic archaeology community since more than two decades. Aims. Our goal is to investigate the chemical, temporal, and kinematical structure of the Galactic discs using abundances, kinematics, and ages derived self-consistently with the new Bayesian framework SAPP. Methods. We employ the public Gaia-ESO spectra, as well as Gaia EDR3 astrometry and photometry. Stellar parameters and chemical abundances are determined for 13 426 stars using NLTE models of synthetic spectra. Ages are derived for a sub-sample of 2 898 stars, including subgiants and main-sequence stars. The sample probes a large range of Galactocentric radii, $\sim$ 3 to 12 kpc, and extends out of the disc plane to $\pm$ 2 kpc. Results. Our new data confirm the known bi-modality in the [Fe/H] - [$\alpha$/Fe] space, which is often viewed as the manifestation of the chemical thin and thick discs. The over-densities significantly overlap in metallicity, age, and kinematics, and none of these is a sufficient criterion for distinguishing between the two disc populations. Different from previous studies, we find that the $\alpha$-poor disc population has a very extended [Fe/H] distribution and contains $\sim$ 20$\%$ old stars with ages of up to $\sim$ 11 Gyr. Conclusions. Our results suggest that the Galactic thin disc was in place early, at look-back times corresponding to redshifts z $\sim$ 2 or more. At ages $\sim$ 9 to 11 Gyr, the two disc structures shared a period of co-evolution. Our data can be understood within the clumpy disc formation scenario that does not require a pre-existing thick disc to initiate a formation of the thin disc. We anticipate that a similar evolution can be realised in cosmological simulations of galaxy formation.Comment: 14 pages, 10 figures, re-submitted to A&

Exploring the mechanisms of renoprotection against progressive glomerulosclerosis

In this review, I introduce the strategy developed by our laboratory to explore the mechanisms of renoprotection against progressive glomerulosclerosis leading to renal death. First, I describe the experimental rat model in which disturbances of vascular regeneration and glomerular hemodynamics lead to irreversible glomerulosclerosis. Second, I discuss the possible mechanisms determining the progression of glomerulosclerosis and introduce a new imaging system based on intravital confocal laser scanning microscopy. Third, I provide an in-depth review of the regulatory glomerular hemodynamics at the cellular and molecular levels while focusing on the pivotal role of Ca2+-dependent gap junctional intercellular communication in coordinating the behavior of mesangial cells. Last, I show that local delivery of renoprotective agents, in combination with diagnostic imaging of the renal microvasculature, allows the evaluation of the therapeutic effects of angiotensin II receptor and cyclooxygenase activity local blockade on the progression of glomerulosclerosis, which would otherwise lead to renal death

The GALAH Survey : Non-LTE departure coefficients for large spectroscopic surveys

19 pages, 25 figures, 2 tables, arXiv abstract abridged; accepted for publication in A&AMassive sets of stellar spectroscopic observations are rapidly becoming available and these can be used to determine the chemical composition and evolution of the Galaxy with unprecedented precision. One of the major challenges in this endeavour involves constructing realistic models of stellar spectra with which to reliably determine stellar abundances. At present, large stellar surveys commonly use simplified models that assume that the stellar atmospheres are approximately in local thermodynamic equilibrium (LTE). To test and ultimately relax this assumption, we have performed non-LTE calculations for $13$ different elements (H, Li, C, N, O, Na, Mg, Al, Si, K, Ca, Mn, and Ba), using recent model atoms that have physically-motivated descriptions for the inelastic collisions with neutral hydrogen, across a grid of $3756$ 1D MARCS model atmospheres that spans $3000\leq T_{\mathrm{eff}}/\mathrm{K}\leq8000$, $-0.5\leq\log{g/\mathrm{cm\,s^{-2}}}\leq5.5$, and $-5\leq\mathrm{[Fe/H]}\leq1$. We present the grids of departure coefficients that have been implemented into the GALAH DR3 analysis pipeline in order to complement the extant non-LTE grid for iron. We also present a detailed line-by-line re-analysis of $50126$ stars from GALAH DR3. We found that relaxing LTE can change the abundances by between $-0.7\,\mathrm{dex}$ and $+0.2\,\mathrm{dex}$ for different lines and stars. Taking departures from LTE into account can reduce the dispersion in the $\mathrm{[A/Fe]}$ versus $\mathrm{[Fe/H]}$ plane by up to $0.1\,\mathrm{dex}$, and it can remove spurious differences between the dwarfs and giants by up to $0.2\,\mathrm{dex}$. The resulting abundance slopes can thus be qualitatively different in non-LTE, possibly with important implications for the chemical evolution of our Galaxy.Peer reviewe

Clinical characteristics and outcomes in leptomeningeal disease with or without brain metastasis: insights from an explorative data analysis of the Charité LMD registry

INTRODUCTION AND OBJECTIVES: Leptomeningeal disease (LMD) involves disseminating cancer cells to the leptomeninges and cerebrospinal fluid. The impact of intracranial parenchymal brain metastases and extracranial disease burden at LMD diagnosis remains unclear. This study evaluates these factors alongside local and systemic therapies before and after LMD diagnosis. METHODS: A retrospective analysis was conducted on 188 patients diagnosed with LMD between 2011 and 2024. Data on demographics, imaging findings, and treatments were collected. Kaplan-Meier estimates were used for survival analysis, and independent prognostic factors were identified using a backward-stepwise Cox regression model. RESULTS: Primary cancers included breast cancer (34.0%), non-small cell lung cancer (22.3%), and melanoma (14.4%). LMD was diagnosed via MRI in 56.4% of cases, cerebrospinal fluid (CSF) cytology in 2.7%, and both in 41.0%. Median overall survival was 2.8 months [95% CI: 2.4 - 3.7]. Independent prognostic factors for improved survival included male sex (HR: 0.61 [95% CI: 0.40 - 0.93], p = 0.020), absence of hydrocephalus at LMD diagnosis (HR: 0.42 [95% CI: 0.22 - 0.79], p = 0.007), and targeted therapy post-diagnosis (HR: 0.33 [95% CI: 0.20 - 0.55], p < 0.001). Two or more lines of systemic therapy before LMD diagnosis increased mortality risk (HR: 1.73 [95% CI: 1.16 - 2.59], p = 0.007). Lack of CNS parenchymal disease at LMD diagnosis also increased risk (HR: 0.51 [95% CI: 0.30 - 0.89], p = 0.017). Pre-diagnosis radiation therapy showed no survival benefit, while post-diagnosis radiation improved outcomes (HR: 0.47 [95% CI: 0.32 - 0.70], p < 0.001). CONCLUSION: Absence of hydrocephalus and use of targeted therapy post-diagnosis are favorable prognostic factors, while extensive prior systemic therapy and CNS parenchymal disease worsen outcomes. Tailored therapies addressing intracranial disease are crucial for improving survival in LMD patients