Results 71 to 80 of about 1,934,975 (307)

The Earliest Stage of Galactic Star Formation

open access: yesThe Astrophysical Journal Letters, 2023
Using a recently developed technique to estimate gas temperatures ( T _SF ) in star-forming regions from large photometric surveys, we propose a diagram, analogous to the Hertzsprung–Russell diagram for individual stars, to probe the evolution of ...
Charles L. Steinhardt   +7 more
doaj   +1 more source

Building up the Population III initial mass function from cosmological initial conditions [PDF]

open access: yes, 2016
We simulate the growth of a Population III stellar system, starting from cosmological initial conditions at z=100. We follow the formation of a minihalo and the subsequent collapse of its central gas to high densities, resolving scales as small as ~ 1 AU.
A. Stacy, V. Bromm, Aaron T. Lee
semanticscholar   +1 more source

In situ molecular organization and heterogeneity of the Legionella Dot/Icm T4SS

open access: yesFEBS Letters, EarlyView.
We present a nearly complete in situ model of the Legionella Dot/Icm type IV secretion system, revealing its central secretion channel and identifying new components. Using cryo‐electron tomography with AI‐based modeling, our work highlights the structure, variability, and mechanism of this complex nanomachine, advancing understanding of bacterial ...
Przemysław Dutka   +11 more
wiley   +1 more source

Variations of the stellar initial mass function in semi-analytical models: implications for the mass assembly and the chemical enrichment of galaxies in the GAEA model [PDF]

open access: yes, 2016
In this work, we investigate the implications of the Integrated Galaxy-wide stellar Initial Mass Function (IGIMF) approach in the framework of the semi-analytic model GAEA (GAlaxy Evolution and Assembly), which features a detailed treatment of chemical ...
F. Fontanot   +5 more
semanticscholar   +1 more source

Sequence determinants of RNA G‐quadruplex unfolding by Arg‐rich regions

open access: yesFEBS Letters, EarlyView.
We show that Arg‐rich peptides selectively unfold RNA G‐quadruplexes, but not RNA stem‐loops or DNA/RNA duplexes. This length‐dependent activity is inhibited by acidic residues and is conserved among SR and SR‐related proteins (SRSF1, SRSF3, SRSF9, U1‐70K, and U2AF1).
Naiduwadura Ivon Upekala De Silva   +10 more
wiley   +1 more source

The Initial Mass Function of the Galactic Early-type Field Stars Based on the LAMOST Survey

open access: yesThe Astrophysical Journal
Research on the high-mass end of the initial mass function (IMF) has been limited due to a scarcity of samples. Recently, Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), as the most efficient spectroscopic telescope, has provided new ...
Qida Li   +6 more
doaj   +1 more source

A perturbed parameter model ensemble to investigate Mt. Pinatubo's 1991 initial sulfur mass emission [PDF]

open access: yesAtmospheric Chemistry and Physics, 2015
We have performed more than 300 atmospheric simulations of the 1991 Pinatubo eruption using the AER 2-D sulfate aerosol model to optimize the initial sulfur mass injection as a function of altitude, which in previous modeling studies has often been ...
J.-X. Sheng   +5 more
doaj   +1 more source

The Low-mass Population in the Young Cluster Stock 8: Stellar Properties and Initial Mass Function [PDF]

open access: yesAstrophysical Journal, 2016
The evolution of H ii regions/supershells can trigger a new generation of stars/clusters at their peripheries, with environmental conditions that may affect the initial mass function, disk evolution, and star formation efficiency.
J. Jose   +4 more
semanticscholar   +1 more source

Structural instability impairs function of the UDP‐xylose synthase 1 Ile181Asn variant associated with short‐stature genetic syndrome in humans

open access: yesFEBS Letters, EarlyView.
The Ile181Asn variant of human UDP‐xylose synthase (hUXS1), associated with a short‐stature genetic syndrome, has previously been reported as inactive. Our findings demonstrate that Ile181Asn‐hUXS1 retains catalytic activity similar to the wild‐type but exhibits reduced stability, a looser oligomeric state, and an increased tendency to precipitate ...
Tuo Li   +2 more
wiley   +1 more source

A Modified Initial Mass Function of the First Stars with Explodability Theory under Different Enrichment Scenarios

open access: yesThe Astrophysical Journal
The most metal-poor stars record the earliest metal enrichment triggered by Population III stars. By comparing observed abundance patterns with theoretical yields of metal-free stars, physical properties of their first star progenitors can be inferred ...
Ruizheng Jiang   +3 more
doaj   +1 more source

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