1,499 research outputs found
Soluble microbial product (SMP) characterization in bench-scale aerobic and anaerobic CSTRs under different operational conditions
Increased accuracy of ligand sensing by receptor internalization
Many types of cells can sense external ligand concentrations with
cell-surface receptors at extremely high accuracy. Interestingly, ligand-bound
receptors are often internalized, a process also known as receptor-mediated
endocytosis. While internalization is involved in a vast number of important
functions for the life of a cell, it was recently also suggested to increase
the accuracy of sensing ligand as the overcounting of the same ligand molecules
is reduced. Here we show, by extending simple ligand-receptor models to
out-of-equilibrium thermodynamics, that internalization increases the accuracy
with which cells can measure ligand concentrations in the external environment.
Comparison with experimental rates of real receptors demonstrates that our
model has indeed biological significance.Comment: 9 pages, 4 figures, accepted for publication in Physical Review
MUSE Reveals a Recent Merger in the Post-starburst Host Galaxy of the TDE ASASSN-14li
We present MUSE integral field spectroscopic observations of the host galaxy
(PGC 043234) of one of the closest (, Mpc) and
best-studied tidal disruption events (TDE), ASASSN-14li. The MUSE integral
field data reveal asymmetric and filamentary structures that extend up to
kpc from the post-starburst host galaxy of ASASSN-14li. The
structures are traced only through the strong nebular [O III] 5007, [N
II] 6584, and H emission lines. The total off nuclear [O III]
5007 luminosity is luminosity is erg s and
the ionized H mass is . Based on the BPT
diagram, the nebular emission can be driven by either AGN photoionization or
shock excitation, with AGN photoionization favored given the narrow intrinsic
line widths. The emission line ratios and spatial distribution strongly
resemble ionization nebulae around fading AGNs such as IC 2497 (Hanny's
Voorwerp) and ionization "cones" around Seyfert 2 nuclei. The morphology of the
emission line filaments strongly suggest that PGC 043234 is a recent merger,
which likely triggered a strong starburst and AGN activity leading to the
post-starburst spectral signatures and the extended nebular emission line
features we see today. We briefly discuss the implications of these
observations in the context of the strongly enhanced TDE rates observed in
post-starburst galaxies and their connection to enhanced theoretical TDE rates
produced by supermassive black-hole binaries.Comment: Accepted for publication in ApJ
Light gravitino production in association with gluinos at the LHC
We study the jets plus missing energy signature at the LHC in a scenario
where the gravitino is very light and the gluino is the next-to-lightest
supersymmetric particle and promptly decays into a gluon and a gravitino. We
consider both associated gravitino production with a gluino and gluino pair
production. By merging matrix elements with parton showers, we generate
inclusive signal and background samples and show how information on the gluino
and gravitino masses can be obtained by simple final state observables.Comment: 18 pages, 8 figures, 1 table; v2: typos corrected, version to appear
in JHE
Renewal processes and fluctuation analysis of molecular motor stepping
We model the dynamics of a processive or rotary molecular motor using a
renewal processes, in line with the work initiated by Svoboda, Mitra and Block.
We apply a functional technique to compute different types of multiple-time
correlation functions of the renewal process, which have applications to
bead-assay experiments performed both with processive molecular motors, such as
myosin V and kinesin, and rotary motors, such as F1-ATPase
SSDSS IV MaNGA - Properties of AGN host galaxies
We present here the characterization of the main properties of a sample of 98
AGN host galaxies, both type-II and type-I, in comparison with those of about
2700 non-active galaxies observed by the MaNGA survey. We found that AGN hosts
are morphologically early-type or early-spirals. For a given morphology AGN
hosts are, in average, more massive, more compact, more central peaked and
rather pressurethan rotational-supported systems. We confirm previous results
indicating that AGN hosts are located in the intermediate/transition region
between star-forming and non-star-forming galaxies (i.e., the so-called green
valley), both in the ColorMagnitude and the star formation main sequence
diagrams. Taking into account their relative distribution in terms of the
stellar metallicity and oxygen gas abundance and a rough estimation of their
molecular gas content, we consider that these galaxies are in the process of
halting/quenching the star formation, in an actual transition between both
groups. The analysis of the radial distributions of the starformation rate,
specific star-formation rate, and molecular gas density shows that the
quenching happens from inside-out involving both a decrease of the efficiency
of the star formation and a deficit of molecular gas. All the intermediate
data-products used to derive the results of our analysis are distributed in a
database including the spatial distribution and average properties of the
stellar populations and ionized gas, published as a Sloan Digital Sky Survey
Value Added Catalog being part of the 14th Data Release:
http://www.sdss.org/dr14/manga/manga-data/manga-pipe3d-value-added-catalog/Comment: 48 pages, 14 figures, in press in RMxA
Assessment of different postharvest coffee processes by simultaneous analysis of chemical constituents.
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