Results 41 to 50 of about 1,090,152 (292)

Current Uncertainties in the Use of Cepheids as Distance Indicators

, 2003
The methods of calibrating the luminosities of galactic Cepheids and determining Cepheid reddenings are considered in some detail. Together with work on NGC4258 this suggests that the calibration presented is valid to about 0.1mag (s.e.) at least for ...
Feast, Michael
core   +1 more source

The newfound relationship between extrachromosomal DNAs and excised signal circles

FEBS Letters, EarlyView.
Extrachromosomal DNAs (ecDNAs) contribute to the progression of many human cancers. In addition, circular DNA by‐products of V(D)J recombination, excised signal circles (ESCs), have roles in cancer progression but have largely been overlooked. In this Review, we explore the roles of ecDNAs and ESCs in cancer development, and highlight why these ...
Dylan Casey, Zeqian Gao, Joan Boyes
wiley   +1 more source

The Hubble Tension in Our Own Backyard: DESI and the Nearness of the Coma Cluster

The Astrophysical Journal Letters
The Dark Energy Spectroscopic Instrument (DESI) collaboration measured a tight relation between the Hubble constant ( H _0 ) and the distance to the Coma cluster using the fundamental plane (FP) relation of the deepest, most homogeneous sample of early ...
Daniel Scolnic, Adam G. Riess, Yukei S. Murakami, Erik R. Peterson, Dillon Brout, Maria Acevedo, Bastien Carreres, David O. Jones, Khaled Said, Cullan Howlett, Gagandeep S. Anand   +10 more
doaj   +1 more source

Ultra Luminous X-ray sources - new distance indicators? [PDF]

, 2018
In this paper we fit the NuSTAR and XMM-Newton data of three sources: NGC7793~P13, NGC5907~ULX1, and Circinus~ULX5. Our single model contains emission form non-spherical system: neutron star plus accretion disk directed towards observer.
Adhikari, Tek P., Beldycki, Bartosz, Bresler, Karol, Madej, Jerzy, Rozanska, Agata   +4 more
core   +2 more sources

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

FEBS 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, Yuxi Liu, Stefano Maggi, Debnath Ghosal, Jue Wang, Prashant P. Damke, Stephen D. Carter, Wei Zhao, Sukhithasri Vijayrajratnam, Joseph P. Vogel, Carrie L. Shaffer, Grant J. Jensen   +11 more
wiley   +1 more source

Chicago–Carnegie Hubble Program: A Multiwavelength Search for the Effects of Metallicity on the Cepheid Distance Scale. II. Theoretical Models and Synthetic Spectra

The Astrophysical Journal
This is the second of two papers exploring the effects of metallicity on the multiwavelength properties of Cepheids in terms of their multiwavelength period–luminosity (PL) relations, impacting their use as extragalactic distance indicators and ...
Barry F. Madore, Wendy L. Freedman, Kayla Owens   +2 more
doaj   +1 more source

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

FEBS 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, Puspa Kunwar, Md Ibnul Rifat Rahman, Joanna Koryo Kwao, Nathan Lehman, Zihan Zhang, Trenton Paul, Claire Cheng, Nicholas Truex, Hui‐Ting Lee, Jun Zhang   +10 more
wiley   +1 more source

Ultra-long-period Cepheids as Standard Candles from Gaia to Rubin-LSST

The Astrophysical Journal Supplement Series
An analysis of the properties of ultra-long-period Cepheids (ULPs) could significantly contribute to understanding the Hubble constant tension, e.g., the current discrepancy between determinations based on local distance indicators and those relying on ...
Ilaria Musella, S. Leccia, R. Molinaro, M. Marconi, F. Cusano, M. Di Criscienzo, G. Fiorentino, V. Braga, V. Ripepi, G. De Somma, M. Gatto, E. Luongo, T. Sicignano   +12 more
doaj   +1 more source

INDICATORS FOR THE EVALUATION OF THE TEACHING IN A DISTANCE UNIVERSITY

RIED: Revista Iberoamericana de Educación a Distancia, 1998
Once reached in the Spanish University the objectives related to the democratisation of the access to higher studies and the achievement of the university autonomy, the university environment is now worried about others, like looking forward the quality,
Lorenzo García Aretio
doaj   +1 more source

M33 Cepheids from CFHT/MegaCam Survey

The Astronomical Journal, 2022
In this paper we analyze Sloan g, r, i archival imaging data of M33 taken by Hartman et al. using MegaCam at the Canada–France–Hawaii Telescope. To determine the distance to the M33 galaxy, we performed several analytical steps to identify its Cepheid ...
Samuel Adair, Chien-Hsiu Lee
doaj   +1 more source