Results 81 to 90 of about 4,473,250 (366)

Chemical abundances of two extragalactic young massive clusters [PDF]

open access: yes, 2017
We use integrated-light spectroscopic observations to measure metallicities and chemical abundances for two extragalactic young massive star clusters (NGC1313-379 and NGC1705-1).
S. Hernandez   +3 more
semanticscholar   +1 more source

An intracellular transporter mitigates the CO2‐induced decline in iron content in Arabidopsis shoots

open access: yesFEBS Letters, EarlyView.
This study identifies a gene encoding a transmembrane protein, MIC, which contributes to the reduction of shoot Fe content observed in plants under elevated CO2. MIC is a putative Fe transporter localized to the Golgi and endosomal compartments. Its post‐translational regulation in roots may represent a potential target for improving plant nutrition ...
Timothy Mozzanino   +7 more
wiley   +1 more source

Generalized Te([O iii])–Te(He i) Discrepancies in Ionized Nebulae: Possible Evidence of Case B Deviations and Temperature Inhomogeneities

open access: yesThe Astrophysical Journal
The physics of recombination lines in the He i singlet system is expected to be relatively simple, supported by accurate atomic models. We examine the intensities of He i singlets λ 3614,  λ 3965,  λ 5016,  λ 6678, and  λ 7281 and the triplet He i λ 5876
J. E. Méndez-Delgado   +13 more
doaj   +1 more source

The abundance of HCN in circumstellar envelopes of AGB stars of different chemical types

open access: yes, 2013
A multi-transition survey of HCN (sub-) millimeter line emission from a large sample of AGB stars of different chemical type is presented. The data are analysed and circumstellar HCN abundances are estimated.
Bieging, J. H.   +5 more
core   +1 more source

Planetary nebulae in the inner Milky Way [PDF]

open access: yes, 2009
New abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge.
Chiappini   +7 more
core   +1 more source

The RRc Stars: Chemical Abundances and Envelope Kinematics [PDF]

open access: yes, 2017
We analyzed series of spectra obtained for 12 stable RRc stars observed with the echelle spectrograph of the du Pont telescope at Las Campanas Observatory and we analyzed the spectra of RRc Blazhko stars discussed by Govea et al.
C. Sneden   +3 more
semanticscholar   +1 more source

By dawn or dusk—how circadian timing rewrites bacterial infection outcomes

open access: yesFEBS Letters, EarlyView.
The circadian clock shapes immune function, yet its influence on infection outcomes is only beginning to be understood. This review highlights how circadian timing alters host responses to the bacterial pathogens Salmonella enterica, Listeria monocytogenes, and Streptococcus pneumoniae revealing that the effectiveness of immune defense depends not only
Devons Mo   +2 more
wiley   +1 more source

Chemical Abundances in Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 1978
PN can be divided into four types depending on their chemical composition. In order of decreasing heavy element abundances the types are: I) He and N rich, II) intermediate population, III) high velocity, and IV) halo population. The type II PN are overabundant in N and C relative to the Orion Nebula.
openaire   +1 more source

Chemical abundances and metallicity of Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 1997
Confrontations of the dredge-up theory with observed patterns of chemical abundances of planetary nebulae (PNs) have been carried out by many authors (see, e.g., Kaler & Jacoby 1990, 1991; Stasińska & Tylenda 1990). Although these studies suggest that the observational abundance ratios of PNs can qualitatively be explained by the current dredge-
C. Y. Zhang, S. Kwok
openaire   +1 more source

DETAILED CHEMICAL ABUNDANCES IN THE r-PROCESS-RICH ULTRA-FAINT DWARF GALAXY RETICULUM 2 [PDF]

open access: yes, 2016
The ultra-faint dwarf (UFD) galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey. We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber System.
I. Roederer   +12 more
semanticscholar   +1 more source

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