Results 61 to 70 of about 8,281,459 (308)

Constraints on the Equation of State of Dark Energy and the Hubble Constant from Stellar Ages and the Cosmic Microwave Background [PDF]

, 2003
We place constraints on the redshift-averaged, effective value of the equation of state of dark energy, w, using only the absolute ages of Galactic stars and the observed position of the first peak in the angular power spectrum of the cosmic microwave ...
R. Jimenez, L. Verde, T. Treu, D. Stern
semanticscholar   +1 more source

Prolonged Corrected QT Interval as an Early Electrocardiographic Marker of Cyclophosphamide‐Induced Cardiotoxicity in Pediatric Hematology and Oncology Patients

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Background Cyclophosphamide (CY) is associated with potentially fatal cardiotoxicity, yet no electrocardiographic indices have been established for early detection of CY‐induced cardiomyopathy. This study aimed to determine whether corrected QT interval (QTc) prolongation can predict early onset of CY‐related cardiac dysfunction in pediatric ...
Junpei Kawamura, Kentaro Ueno, Takuro Nishikawa, Yoshihiro Takahashi, Koji Nakae, Yasuhiro Okamoto   +5 more
wiley   +1 more source

Spectroscopic Ages for 4 Million Main-sequence Dwarf Stars from LAMOST DR10 Estimated with a Data-driven Approach

The Astrophysical Journal Supplement Series
Stellar age determination for large samples of stars opens new avenues for a broad range of astronomical sciences. While precise stellar ages for evolved stars have been derived from large ground- and space-based stellar surveys, reliable age ...
Jia-Hui Wang, Maosheng Xiang, Meng Zhang, Ji-Wei Xie, Jian Ge, Jinghua Zhang, Lanya Mou, Ji-Feng Liu   +7 more
doaj   +1 more source

Predicting Chronicity in Children and Adolescents With Newly Diagnosed Immune Thrombocytopenia at the Timepoint of Diagnosis Using Machine Learning‐Based Approaches

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Objectives To identify predictors of chronic ITP (cITP) and to develop a model based on several machine learning (ML) methods to estimate the individual risk of chronicity at the timepoint of diagnosis. Methods We analyzed a longitudinal cohort of 944 children enrolled in the Intercontinental Cooperative immune thrombocytopenia (ITP) Study ...
Severin Kasser, Alice Bizeul, Meera Chitlur, Hugo Donato, Jelena Roganovic, Julia E. Vogt, Thomas Kühne   +6 more
wiley   +1 more source

ChronoFlow: A Data-driven Model for Gyrochronology

The Astrophysical Journal
Gyrochronology is a technique for constraining stellar ages using rotation periods, which change over a star’s main-sequence (MS) lifetime due to magnetic braking. This technique shows promise for MS FGKM stars, where other methods are imprecise. However,
Phil R. Van-Lane, Joshua S. Speagle, Gwendolyn M. Eadie, Stephanie T. Douglas, Phillip A. Cargile, Catherine Zucker, Yuxi (Lucy) Lu, Ruth Angus   +7 more
doaj   +1 more source

The Empirical Limits of Gyrochronology

The Astrophysical Journal Letters, 2023
The promise of gyrochronology is that, given a star’s rotation period and mass, its age can be inferred. The reality of gyrochronology is complicated by effects other than ordinary magnetized braking that alter stellar rotation periods.
Luke G. Bouma, Elsa K. Palumbo, Lynne A. Hillenbrand   +2 more
doaj   +1 more source

Stellar ages from asteroseismology [PDF]

Proceedings of the International Astronomical Union, 2008
Asteroseismology has been recognized for a long time as a very powerful mean to probe stellar interiors. The oscillations frequencies are closely related to stellar internal structure properties via the density and the sound speed profiles.
Y. Lebreton, J. Montalbán
semanticscholar   +1 more source

A Systematic Review of Evidence on the Clinical Effectiveness of Surveillance Imaging in Children With Medulloblastoma and Ependymoma

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Surveillance imaging aims to detect tumour relapse before symptoms develop, but it's unclear whether earlier detection of relapse leads to better outcomes in children and young people (CYP) with medulloblastoma and ependymoma. This systematic review aims to identify relevant literature to determine the efficacy of surveillance magnetic ...
Lucy Shepherd, Melissa Taylor, Helen Fulbright, Bob Phillips   +3 more
wiley   +1 more source

An investigation of chromospheric activity spanning the Vaughan-Preston gap: impact on stellar ages [PDF]

, 2009
Context. Chromospheric activity is widely used as an age indicator for solar-type stars based on the early evidence that there is a smooth evolution from young and active to old and inactive stars.
G. Pace, J. Meléndez, L. Pasquini, G. Carraro, J. Danziger, P. François, F. Matteucci, N. C. S. Caup, Eso - Garching, Eso - Chile, I. Trieste, U. Trieste, Gepi   +12 more
semanticscholar   +1 more source

Stellar ages from stellar rotation [PDF]

Proceedings of the International Astronomical Union, 2008
Our ability to determine stellar ages from measurements of stellar rotation, hinges on how well we can measure the dependence of rotation on age for stars of different masses.
S. Meibom
semanticscholar   +1 more source