2,203 research outputs found
Observational prospects for gravitational waves from hidden or dark chiral phase transitions
We study the gravitational wave (GW) signature of first-order chiral phase
transitions (PT) in strongly interacting hidden or dark sectors. We do so
using several effective models in order to reliably capture the relevant
non-perturbative dynamics. This approach allows us to explicitly calculate key
quantities characterizing the PT without having to resort to rough
estimates. Most importantly, we find that the transition's inverse duration
normalized to the Hubble parameter is at least two orders of
magnitude larger than typically assumed in comparable scenarios, namely
. The obtained GW spectra then suggest that
signals from hidden PTs occurring at around 100 MeV can be in reach of
LISA, while DECIGO and BBO may detect a stochastic GW background associated
with transitions between roughly 1 GeV and 10 TeV. Signatures of transitions at
higher temperatures are found to be outside the range of any currently proposed
experiment. Even though predictions from different effective models are
qualitatively similar, we find that they may vary considerably from a
quantitative point of view, which highlights the need for true first-principle
calculations such as lattice simulations.Comment: 35 pages, 9 figures. Extended discussion and updated calculation of
gravitational wave spectra, main results unchanged; references added; matches
published versio
Exact solution of a model DNA-inversion genetic switch with orientational control
DNA inversion is an important mechanism by which bacteria and bacteriophage
switch reversibly between phenotypic states. In such switches, the orientation
of a short DNA element is flipped by a site-specific recombinase enzyme. We
propose a simple model for a DNA inversion switch in which recombinase
production is dependent on the switch state (orientational control). Our model
is inspired by the fim switch in Escherichia coli. We present an exact
analytical solution of the chemical master equation for the model switch, as
well as stochastic simulations. Orientational control causes the switch to
deviate from Poissonian behaviour: the distribution of times in the on state
shows a peak and successive flip times are correlated.Comment: Revised version, accepted for publicatio
The distribution of total vitamin b12 holotranscobalamin and the active vitamin b12 fraction in the first 5 weeks postpartum
Introduction Total vitamin B12 levels decrease significantly during pregnancy and recover to normal values within 8-week postpartum. Holotranscobalamin (holoTC) reflects the active part of vitamin B12 and has been shown to remain constant during pregnancy and postpartum. A mechanism of redistribution of vitamin B12 is suggested, with a shift toward holoTC if there is insufficient total vitamin B12 available. Our objective was to examine vitamin B12 deficiency and the active vitamin B12 fraction in postpartum women. Methods Total vitamin B12 and holoTC were measured in 171 women within 48 hours (T0) and at 5 weeks (T5) postpartum. Vitamin B12 deficiency was defined as total vitamin B12 < 180 pmol/L or holoTC <32 pmol/L. The active vitamin B12 fraction was defined as holoTC/total vitamin B12. Results Without intervention, vitamin B12 deficiency based on both serum total vitamin B12 and holoTC changed from 75% and 60%, to respectively 10% and 6% at T5. The fraction of active vitamin B12 was significant higher in vitamin B12 deficient women at both time points and across time (P < .0001 and P = .002). A high fraction of active vitamin B12 was only present in women with total vitamin B12 deficiency at T0. At T5, no high vitamin B12 fraction was found. Conclusion The changes in total vitamin B12 levels seem to be based on a physiological changes rather than vitamin B12 deficiency. The results of this study confirm the hypothesis that a shift toward the metabolic active vitamin B12 (holoTC) occurs in women with insufficient available total vitamin B12
Searching for “Illegal” Junk in the Trunk: Underlying Intentions of (Cr)Immigration Controls in Schengen’s Internal Border Areas
Criminal Justice: Legitimacy, accountability, and effectivit
Eradication of invasive birds from tropical oceanic islands: lessons learned from studies of common mynas Acridotheres tristis
Feare, C., Greenwell, P., Edwards, H., Taylor, J., Van der Woude, J
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