Results 61 to 70 of about 883,477 (298)

Protein pyrophosphorylation by inositol pyrophosphates — detection, function, and regulation

FEBS Letters, EarlyView.
Protein pyrophosphorylation is an unusual signaling mechanism that was discovered two decades ago. It can be driven by inositol pyrophosphate messengers and influences various cellular processes. Herein, we summarize the research progress and challenges of this field, covering pathways found to be regulated by this posttranslational modification as ...
Sarah Lampe, Tanmay Kumar Mohanty, Rashna Bhandari, Dorothea Fiedler   +3 more
wiley   +1 more source

Stark broadening of N II spectral lines [PDF]

Serbian Astronomical Journal
The Stark broadening parameters, widths, and shifts, for spectral lines within the 45 N II multiplets, were calculated for collisions with electrons, protons and helium ions, by using the semiclassical perturbation method. The obtained data were
Dimitrijević Milan S., Christova Magdalena D., Sahal-Bréchot Sylvie   +2 more
doaj   +1 more source

Positive-P phase space method simulation in superradiant emission from a cascade atomic ensemble

, 2012
The superradiant emission properties from an atomic ensemble with cascade level configuration is numerically simulated. The correlated spontaneous emissions (signal then idler fields) are purely stochastic processes which are initiated by quantum ...
C. W. Gardiner, C. W. Gardiner, D. Bouwmeester, D. F. Walls, H. H. Jen, H. Haken, L. Mandel, M. A. Nielsen, M. O. Scully, M. Sargent, P. E. Kloeden, R. Loudon, W. H. Press   +12 more
core   +1 more source

Integration of circadian and hypoxia signaling via non‐canonical heterodimerization

FEBS Letters, EarlyView.
CLOCK, BMAL1, and HIFs are basic helix‐loop‐helix and Per‐Arnt‐Sim domain (bHLH‐PAS) proteins, which function as transcription factors. bHLH‐PAS proteins are designated in two classes. Many class I proteins are regulated by environmental signals via their PAS domains, but such signals have not been identified for all.
Sicong Wang, Katja A. Lamia
wiley   +1 more source

Extended Photoionization Cross Section Calculations for C III

Applied Sciences
Spectral features of photoionization of various levels of C III are reported. These include characteristics of Rydberg and Seaton resonances, low and high excited levels, lifetimes, and total and partial cross sections.
V. Stancalie
doaj   +1 more source

Broad UV Emission Lines in Type-1 Active Galactic Nuclei: A Note on Spectral Diagnostics and the Excitation Mechanism

Atoms, 2020
This paper reviews several basic emission properties of the UV emission lines observed in the spectra of quasars and type-1 active galactic nuclei, mainly as a function of the ionization parameter, metallicity, and density of the emitting gas.
Paola Marziani, Ascension del Olmo, Jaime Perea, Mauro D’Onofrio, Swayamtrupta Panda   +4 more
doaj   +1 more source

Elastic scattering losses in the four-wave mixing of Bose Einstein Condensates

, 2004
We introduce a classical stochastic field method that accounts for the quantum fluctuations responsible for spontaneous initiation of various atom optics processes. We assume a delta-correlated Gaussian noise in all initially empty modes of atomic field.
Bach R, Bonifacio R, Bonifacio R, Chwede?czuk J, Drummond P D, Gardiner C W, Goldstein E V, Goldstein E V, Goldstein E V, Haake F, Harris S E, J Chwedeńczuk, Javanainen J, K Rzazewski, M Trippenbach, Magde D, Mandel L, Mostowski J, Mostowski J, Perina J, Poulsen U V, Raymer M G, Trippenbach M, Trippenbach M, Vardi A, Yariv A, Yurovsky V A, Zin P Chwede?czuk J Perez A Trippenbach M Rza??ewski K   +27 more
core   +1 more source

Time after time – circadian clocks through the lens of oscillator theory

FEBS Letters, EarlyView.
Oscillator theory bridges physics and circadian biology. Damped oscillators require external drivers, while limit cycles emerge from delayed feedback and nonlinearities. Coupling enables tissue‐level coherence, and entrainment aligns internal clocks with environmental cues.
Marta del Olmo, Carolin Ector, Hanspeter Herzel   +2 more
wiley   +1 more source

Vacuum-Induced Processes in Multilevel Atoms

, 2010
Publisher Summary Atoms commonly do not act as isolated objects, but rather are open quantum systems, as they interact with the environment. Typically, this environment is formed by the electromagnetic vacuum field. The interaction of atoms with the environment modifies the atomic dynamics, with spontaneous emission as the most obvious example ...
Kiffner, M., Macovei, M., Evers, J., Keitel, C.   +3 more
openaire   +3 more sources

Random Lasing in an Inhomogeneous and Disordered System of Cold Atoms

, 2015
We consider light trapping in an amplifying medium consisting of cold alkali-metal atoms; the atomic gas plays a dual role as a scattering and as a gain medium. We perform Monte-Carlo simulations for the combined processes.
Gerasimov, L. V., Havey, M. D., Kupriyanov, D. V.   +2 more
core   +1 more source