More Like this

1. The chemical ecology of tropical forest diversity: Environmental variation, chemical similarity, herbivory, and richness

   https://doi.org/10.1002/ecy.3762  

   Massad, Tara Joy; Richards, Lora A.; Philbin, Casey; Yamaguchi, Lydia Fumiko; Kato, Massuo J.; Jeffrey, Christopher S.; Oliveira, Jr, Celso; Ochsenrider, Kaitlin; de Moraes, Marcílio M.; Tepe, Eric J.; et al (July 2022, Ecology)

   Abstract Species richness in tropical forests is correlated with other dimensions of diversity, including the diversity of plant–herbivore interactions and the phytochemical diversity that influences those interactions. Understanding the complexity of plant chemistry and the importance of phytochemical diversity for plant–insect interactions and overall forest richness has been enhanced significantly by the application of metabolomics to natural systems. The present work used proton nuclear magnetic resonance spectroscopy (¹H‐NMR) profiling of crude leaf extracts to study phytochemical similarity and diversity amongPiperplants growing naturally in the Atlantic Rainforest of Brazil. Spectral profile similarity and chemical diversity were quantified to examine the relationship between metrics of phytochemical diversity, specialist and generalist herbivory, and understory plant richness. Herbivory increased with understory species richness, while generalist herbivory increased and specialist herbivory decreased with the diversity ofPiperleaf material available. Specialist herbivory increased when conspecific host plants were more spectroscopically dissimilar. Spectral similarity was lower among individuals of common species, and they were also more spectrally diverse, indicating phytochemical diversity is beneficial to plants. Canopy openness and soil nutrients also influenced chemistry and herbivory. The complex relationships uncovered in this study add information to our growing understanding of the importance of phytochemical diversity for plant–insect interactions and tropical plant species richness. 

   more » « less
2. The Chemical Composition of the Sun

   https://doi.org/10.5281/zenodo.14988840  

   Bergemann, Maria; Lodders, Katharina; Palme, Herbert (January 2025, Elsevier and Zenodo)

   {"Abstract":["Machine-readable tables accompany the book chapter "Chemical Composition of the Sun", authors Maria Bergemann, Katharina Lodders, Herbert Palme,  Encyclopedia of Astrophysics 1st Edition (edited by I. Mandel, section editor F.R.N. Schneider) to be published by Elsevier as a Reference Module, 2025"]} 

   more » « less
3. The Open Cluster Chemical Abundances and Mapping Survey. V. Chemical Abundances of CTIO/Hydra Clusters Using The Cannon

   https://doi.org/10.3847/1538-3881/ac5835  

   Ray, Amy E.; Frinchaboy, Peter M.; Donor, John; Chojnowski, S. D.; Melendez, Matthew (April 2022, The Astronomical Journal)

   Abstract Open clusters are key chemical and age tracers of Milky Way evolution. While open clusters provide significant constraints on galaxy evolution, their use has been limited due to discrepancies in measuring abundances from different studies. We analyze medium-resolution (R∼ 19,000) Cerro Tololo Inter-American Observatory/Hydra spectra of giant stars in 58 open clusters using The Cannon to determine [Fe/H], [Mg/Fe], [Si/Fe], [Al/Fe], and [O/Fe]. This work adds an additional 55 primarily southern hemisphere open clusters calibrated to the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment DR16 metallicity system. This uniform analysis is compared to previous studies [Fe/H] measurements for 23 clusters and we present spectroscopic metallicities for the first time for 35 open clusters. 

   more » « less
4. Dynamics and chemical mode analysis of plasma thermal-chemical instability

   https://doi.org/10.1088/1361-6595/abde1c  

   Zhong, Hongtao; Shneider, Mikhail N; Mao, Xingqian; Ju, Yiguang (March 2021, Plasma Sources Science and Technology)

   null (Ed.)
5. Modeling the Ages and Chemical Abundances of Elliptical Galaxies

   https://doi.org/10.3847/1538-4357/adc4e6  

   Gountanis, Nicole Marcelina; Weinberg, David H; Beverage, Aliza G; Sandford, Nathan R; Conroy, Charlie; Kriek, Mariska (May 2025, The Astrophysical Journal)

   Abstract Spectroscopic studies of elliptical galaxies show that their stellar population ages, mean metallicity, andαenhancement traced by [Mg/Fe] all increase with galaxy stellar mass or velocity dispersion. We use one-zone galactic chemical evolution (GCE) models with a flexible star formation history (SFH) to model the age, [Mg/H], and [Mg/Fe] inferred from simple stellar population (SSP) fits to observed ellipticals atz∼ 0 andz∼ 0.7. We show that an SSP fit to the spectrum computed from a full GCE model gives ages and abundances close to the light-weighted, logarithmically averaged values of the composite stellar population, 〈age〉, 〈[Mg/H]〉, and 〈[Mg/Fe]〉. With supernova Mg and Fe yields fixed to values motivated by Milky Way stellar populations, we find that predicted 〈[Mg/H]〉–〈age〉 and 〈[Mg/Fe]〉–〈age〉 relations are surprisingly insensitive to SFH parameters: Older galaxies have higher 〈[Mg/Fe]〉, but the detailed form of the SFH has limited impact. The star formation efficiency (SFE) and outflow efficiency affect the early and late evolution of 〈[Mg/H]〉, respectively; explaining observed trends requires higher SFE and lower outflows in more massive galaxies. With core-collapse supernova yields calibrated to the plateau [Mg/Fe]_cc≈ 0.45 observed in many Milky Way studies, our models underpredict the observed 〈[Mg/Fe]〉 ratios of ellipticals by 0.05–0.1 dex. Increasing the core-collapse yield ratio to [Mg/Fe]_cc= 0.55 improves the agreement, though the models remain below the data. We discuss potential resolutions of this discrepancy, including the possibility that many ellipticals terminate their star formation with a self-enriching, terminating burst that reduces the light-weighted age and boosts 〈[Mg/Fe]〉. 

   more » « less