Results 121 to 130 of about 536,015 (293)

A stepwise emergence of evolution in the RNA world

FEBS Letters, EarlyView.
How did biological evolution emerge from chemical reactions? This perspective proposes a gradual scenario of self‐organization among RNA molecules, where catalytic feedback on random mixtures plays the central role. Short oligomers cross‐ligate, and self‐assembly enables heritable variations. An event of template‐externalization marks the transition to
Philippe Nghe
wiley   +1 more source

Statistics and Habitability of F-type Star–Planet Systems

The Astrophysical Journal Supplement Series
F-type star–planet systems represent an intriguing case for habitability studies. Although F-type stars spend considerably less time on the main sequence (MS) than G-, K-, and M-type stars, they still offer a unique set of features, allowing for the ...
Shaan D. Patel, Manfred Cuntz, Nevin N. Weinberg   +2 more
doaj   +1 more source

Search for Cold Debris Disks around M-dwarfs [PDF]

, 2006
Debris disks are believed to be related to planetesimals left over around stars after planet formation has ceased. The frequency of debris disks around M-dwarfs which account for 70% of the stars in the Galaxy is unknown while constrains have already been found for A- to K-type stars.
arxiv   +1 more source

Triggered star formation and Young Stellar Population in Bright-Rimmed Cloud SFO 38

, 2010
We have investigated the young stellar population in and around SFO 38, one of the massive globules located in the northern part of the Galactic HII region IC 1396, using the Spitzer IRAC and MIPS observations (3.6 to 24 micron) and followed up with ...
Allen, Balog, Beltrán, Bhaswati Mookerjea, Contreras, Cutri, de Zeeuw, Getman, Gray, Gutermuth, H. C. Bhatt, Hartmann, Hernández, Hernández, Hillenbrand, Hosokawa, Ikeda, Indebetouw, Jaschek, Jørgensen, Matthews, Megeath, Mercer, Muzerolle, Muzerolle, Muzerolle, Muzerolle, Ogura, Patel, Reipurth, Robitaille, Robitaille, Rumpa Choudhury, Saraceno, Siess, Stern, Sternberg, Stickland, Sugitani, Sugitani, Sugitani, Tapia, Valdes, White   +43 more
core   +1 more source

Stellar Diameters and Temperatures II. Main Sequence K & M Stars [PDF]

, 2012
We present interferometric diameter measurements of 21 K- and M- dwarfs made with the CHARA Array. This sample is enhanced by literature radii measurements to form a data set of 33 K-M dwarfs with diameters measured to better than 5%.
Anderson, Argue, Arribas, Baraffe, Berger, Bessel, Blackwell, Boyajian, Boyajian, Boyajian, Boyajian, Bárbara Rojas-Ayala, Chabrier, Chris Farrington, Christou, Claret, Cutri, Cutri, David Ciardi, David H. Berger, Delfosse, Demarque, Dotter, Douglas Gies, Ducati, Edvardsson, Erro, Gail Schaefer, Gerard van Belle, Glass, Gray, Hanbury Brown, Harold A. McAlister, Irwin, J. Robert Parks, Jeremy Jones, Johnson, Johnson, Judit Sturmann, Kaspar von Braun, Kraus, Lane, Laszlo Sturmann, Luck, López-Morales, López-Morales, Markwardt, Mercedes López-Morales, Mermilliod, Mermilliod, Morales, Mullan, Neves, Niconov, Nils H. Turner, Olsen, P. J. Goldfinger, Philip S. Muirhead, Ramírez, Ribas, Ribas, Rojas-Ayala, Russel White, Siess, Stephen R. Kane, Stephen Ridgway, Tabetha S. Boyajian, ten Brummelaar, Theo A. ten Brummelaar, Todd Henry, Torres, Valenti, van Belle, van Belle, van Leeuwen, VandenBerg, VandenBerg, Voges, von Braun, von Braun, von Braun, Wei-Chun Jao, Weiss, Wright   +83 more
core   +3 more sources

The carboxylate “gripper” of the substrate is critical for C‐4 stereo‐inversion by UDP‐glucuronic acid 4‐epimerase

FEBS Letters, EarlyView.
UDP‐glucuronic acid 4‐epimerase (UGAepi) catalyzes NAD+‐dependent interconversion of UDP‐glucuronic acid (UDP‐GlcA) and UDP‐galacturonic acid (UDP‐GalA) via C4‐oxidation, 4‐keto‐intermediate rotation, and C4‐reduction. Here, Borg et al. examined the role of the substrate's carboxylate group in the enzymic mechanism by analyzing NADH‐dependent reduction
Annika J. E. Borg, Laura De Cnop, Bernd Nidetzky   +2 more
wiley   +1 more source

Demography of Stellar Radio Population within 500 pc: A VLASS-Gaia DR3 Study

The Astronomical Journal
In this work, we have carried out a systematic analysis of the Very Large Array Sky Survey (VLASS) quick look catalogs together with Gaia DR3 to identify the optical counterparts of 3 GHz radio emitters within 500 pc to obtain a homogeneous statistical ...
D. Ayanabha, Mayank Narang, Manoj Puravankara, B. Shridharan, H. Tyagi, Bihan Banerjee, Prasanta K. Nayak, Arun Surya   +7 more
doaj   +1 more source

The Ionizing Stars of the Galactic Ultra-Compact HII Region G45.45+0.06

, 2008
Using the NIFS near-infrared integral-field spectrograph behind the facility adaptive optics module, ALTAIR, on Gemini North, we have identified several massive O-type stars that are responsible for the ionization of the Galactic Ultra-Compact HII region
Aspin, Aspin, Blum, Blum, Blum, Castelli, Feldt, Figuerêdo, Figuerêdo, Geballe, Kraus, Lumsden, Okumura, Peter J. McGregor, Ralchenko, Robert D. Blum, Sterling, Yamashita   +17 more
core   +1 more source

B cell mechanobiology in health and disease: emerging techniques and insights into therapeutic responses

FEBS Letters, EarlyView.
B cells sense external mechanical forces and convert them into biochemical signals through mechanotransduction. Understanding how malignant B cells respond to physical stimuli represents a groundbreaking area of research. This review examines the key mechano‐related molecules and pathways in B lymphocytes, highlights the most relevant techniques to ...
Marta Sampietro, Marco Cellani, Cristina Scielzo   +2 more
wiley   +1 more source

Orbital period analysis of eclipsing Z Cam-type Dwarf Nova EM Cygni: Evidence of magnetic braking and a third body [PDF]

arXiv, 2010
Combining with our newest CCD times of light minimum of EM Cygni, all 45 available times of light minimum including 7 data with large scatters are compiled and the updated O-C analysis is made. The bestfit for the O-C diagram of EM Cygni is a quadratic-plus-sinusoidal fit.
arxiv