Results 61 to 70 of about 36,167 (318)

Did Globular Clusters Reionize the Universe? [PDF]

, 2002
A problem still unsolved in cosmology is the identification of the sources of radiation able to reionize HI in the intergalactic medium (IGM) by z~6. Theoretical works and observations seem to indicate that the fraction, f_esc, of HI ionizing radiation ...
Becker, Benson, Bianchi, Cayrel, Chaboyer, Chernoff, Ciardi, Deharveng, Djorgovski, Dove, Fall, Ferguson, Giallongo, Gnedin, Gnedin, Gnedin, Gnedin, Harris, Harris, Harris, Hu, Hurwitz, Kundu, Kundu, Lanzetta, Larson, Leitherer, Madau, Massimo Ricotti, McLaughlin, McLaughlin, Meiksin, Miralda-Escudé, Peebles, Persic, Ricotti, Ricotti, Ricotti, Songaila, Steidel, Stetson, Taniguchi, Van Den Bergh, Wood, Zepf   +44 more
core   +3 more sources

The cytoskeletal control of B cell receptor and integrin signaling in normal B cells and chronic lymphocytic leukemia

FEBS Letters, EarlyView.
In lymphoid organs, antigen recognition and B cell receptor signaling rely on integrins and the cytoskeleton. Integrins act as mechanoreceptors, couple B cell receptor activation to cytoskeletal remodeling, and support immune synapse formation as well as antigen extraction.
Abhishek Pethe, Tanja Nicole Hartmann
wiley   +1 more source

VARIABLE STARS IN THE GLOBULAR CLUSTER NGC 2808 [PDF]

The Astronomical Journal, 2013
The first calibrated broadband BVI time-series photometry is presented for the variable stars in NGC 2808, with observations spanning a range of twenty-eight years. We have also redetermined the variability types and periods for the variable stars identified previously by Corwin et al, revising the number of probable fundamental-mode RR Lyrae variables
Kunder, Andrea, Stetson, Peter B., Catelan, Marcio, Walker, Alistair R., Amigo, Pia   +4 more
openaire   +8 more sources

Social context prevents heat hormetic effects against mutagens during fish development

FEBS Letters, EarlyView.
This study shows that sublethal heat stress protects fish embryos against ultraviolet radiation, a concept known as ‘hormesis’. However, chemical stress transmission between fish embryos negates this protective effect. By providing evidence for the mechanistic molecular basis of heat stress hormesis and interindividual stress communication, this study ...
Lauric Feugere, Claudio Silva De Freitas, Adam Bates, Kenneth B. Storey, Pedro Beltran‐Alvarez, Katharina C. Wollenberg Valero   +5 more
wiley   +1 more source

Star-crossed Clusters: Asteroseismic Ages for Individual Stars Are in Tension with the Ages of Their Host Clusters

The Astrophysical Journal Letters
A meta-analysis of seismic ages determined for individual stars in the well-studied open and globular clusters NGC 6819, NGC 6791, M67, M4, M19, M80, and M9 reveals both high variance across measurements and a possible discrepancy with independent ...
Jamie Tayar, Meridith Joyce
doaj   +1 more source

Predictions for Self-Pollution in Globular Cluster Stars [PDF]

The Astrophysical Journal, 2001
Full evolutionary models have been built to follow the phases of asymptotic giant branch evolution with mass loss for metal mass fractions from Z=0.0002 to Z=0.004. For the first time, we find that temperatures close to or even larger than 10^8 K are achieved at low Z; the full CNO cycle operates at the base of the envelope, the Oxygen abundance for ...
Italo Mazzitelli, Raffaele Gratton, Francesca D'Antona, Paolo Ventura   +3 more
openaire   +4 more sources

Globular cluster formation triggered by the initial starburst in galaxy formation [PDF]

, 1999
We propose and investigate a new formation mechanism for globular clusters in which they form within molecular clouds that are formed in the shocked regions created by galactic winds driven by successive supernova explosions shortly after the initial ...
IKEUCHI Satoru, TANIGUCHI Yoshiaki, TRENTHAM Neil, 了 池内   +3 more
core   +4 more sources

Modifications in FLAP's second cytosolic loop influence 5‐LOX interaction, inhibitor binding, and leukotriene formation

FEBS Letters, EarlyView.
The enzyme 5‐lipoxygenase (5‐LOX) catalyzes the first step in the biosynthesis of leukotrienes (LTs) involved in inflammatory pathophysiology. After cellular stimulation, 5‐LOX translocates to the nucleus, interacting with the 5‐LOX‐activating protein (FLAP) to form LTA4 from arachidonic acid (AA).
Erik Romp, Katharina Rataj, Stefanie König, Marcia E. Newcomer, Oliver Werz, Ulrike Garscha   +5 more
wiley   +1 more source

Rotation and Hα Emission in a Young SMC Cluster: A Spectroscopic View of NGC 330

The Astrophysical Journal
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff of the young (∼40 Myr) Small Magellanic Cloud globular cluster NGC 330.
Paul I. Cristofari, Andrea K. Dupree, Antonino P. Milone, Matthew G. Walker, Mario Mateo, Aaron Dotter, John I. Bailey III   +6 more
doaj   +1 more source

Rotation of Horizontal‐Branch Stars in Globular Clusters [PDF]

The Astrophysical Journal, 2000
The rotation of horizontal branch stars places important constraints on angular momentum evolution in evolved stars and therefore rotational mixing on the giant branch. Prompted by new observations of rotation rates of horizontal branch stars, we calculate simple models for the angular momentum evolution of a globular cluster giant star from the base ...
Sills, Alison, Pinsonneault, M. H.
openaire   +5 more sources