4,843 research outputs found
Weyl Invariance and Black Hole Evaporation
We consider the semiclassical dynamics of CGHS black holes with a
Weyl-invariant effective action for conformal matter. The trace anomaly of
Polyakov effective action is converted into the Virasoro anomaly thus leading
to the same flux of Hawking radiation. The covariance of semiclassical
equations can be restored through a non-local redefinition of the
metric-dilaton fields. The resulting theory turns out to be equivalent to the
RST model. This provides a mechanism to solve semiclassical equations of 2D
dilaton gravity coupled to conformal matter for classically soluble models.Comment: LaTeX, needs amssymb, 8 pages. One reference adde
Status of neutrino oscillations 2018: first hint for normal mass ordering and improved CP sensitivity
We present a new global fit of neutrino oscillation parameters within the
simplest three-neutrino picture, including new data which appeared since our
previous analysis~\cite{Forero:2014bxa}. In this update we include new
long-baseline neutrino data involving the antineutrino channel in T2K, as well
as new data in the neutrino channel, data from NOA, as well as new reactor
data, such as the Daya Bay 1230 days electron antineutrino disappearance
spectrum data and the 1500 live days prompt spectrum from RENO, as well as new
Double Chooz data. We also include atmospheric neutrino data from the IceCube
DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we
also update our solar oscillation analysis by including the 2055-day day/night
spectrum from the fourth phase of the Super-Kamiokande experiment. With the new
data we find a preference for the atmospheric angle in the upper octant for
both neutrino mass orderings, with maximal mixing allowed at for normal (inverted) ordering. We also obtain a strong
preference for values of the CP phase in the range ,
excluding values close to at more than 4. More remarkably, our
global analysis shows for the first time hints in favour of the normal mass
ordering over the inverted one at more than 3. We discuss in detail the
origin of the mass ordering, CP violation and octant sensitivities, analyzing
the interplay among the different neutrino data samples.Comment: Updated neutrino oscillation analysis using the most recent results
from T2K, NOA, RENO and Super-Kamiokande. 17 pages, 8 figures, 1 tabl
Participatory varietal selection of potato using the mother & baby trial design: A gender-responsive trainer’s guide.
This guide aims to provide step-by-step guidance on facilitating and documenting the PVS dynamics using the MBT design to select, and eventually release, potato varieties preferred by end-users that suit male and female farmers ’different needs, diverse agro-systems, and management practices, as well as traders ’and consumers’ preferences
Involvement of the Rcs regulon in the persistence of Salmonella Typhimurium in tomatoes
It is becoming clear that human enteric pathogens, like Salmonella, can efficiently colonize vegetative and reproductive organs of plants. Even though the bacterium's ability to proliferate within plant tissues has been linked to outbreaks of salmonellosis, little is known about regulatory and physiological adaptations of Salmonella, or other human pathogens, to their persistence in plants. A screen of Salmonella deletion mutants in tomatoes identified rcsA and rcsB genes as those under positive selection. In tomato fruits, populations of Salmonella rcsB mutants were as much as 100-fold lower than those of the wild type. In the follow-up experiments, competitive fitness of rcsA and rcsB mutants was strongly reduced in tomatoes. Bioinformatics predictions identified a putative Salmonella RcsAB binding box (TTMGGAWWAABCTYA) and revealed an extensive putative RcsAB regulon, of which many members were differentially fit within tomatoes
Functional characterization of highly processive protein-primed DNA polymerases from phages Nf and GA-1, endowed with a potent strand displacement capacity
This paper shows that the protein-primed DNA polymerases encoded by bacteriophages Nf and GA-1, unlike other DNA polymerases, do not require unwinding or processivity factors for efficient synthesis of full-length terminal protein (TP)-DNA. Analysis of their polymerization activity shows that both DNA polymerases base their replication efficiency on a high processivity and on the capacity to couple polymerization to strand displacement. Both enzymes are endowed with a proofreading activity that acts coordinately with the polymerization one to edit polymerization errors. Additionally, Nf double-stranded DNA binding protein (DBP) greatly stimulated the in vitro formation of the TP-dAMP initiation complex by decreasing the K(m) value for dATP of the Nf DNA polymerase by >20-fold. Whereas Nf DNA polymerase, as the φ29 enzyme, is able to use its homologous TP as well as DNA as primer, GA-1 DNA polymerase appears to have evolved to use its corresponding TP as the only primer of DNA synthesis. Such exceptional behaviour is discussed in the light of the recently solved structure of the DNA polymerase/TP complex of the related bacteriophage φ29
High-precision estimate of g4 in the 2D Ising model
We compute the renormalized four-point coupling in the 2d Ising model using
transfer-matrix techniques. We greatly reduce the systematic uncertainties
which usually affect this type of calculations by using the exact knowledge of
several terms in the scaling function of the free energy. Our final result is
g4=14.69735(3).Comment: 17 pages, revised version with minor changes, accepted for
publication in Journal of Physics
Involvement of φ29 DNA polymerase thumb subdomain in the proper coordination of synthesis and degradation during DNA replication
φ29 DNA polymerase achieves a functional coupling between its 3′–5′ exonuclease and polymerization activities by means of important contacts with the DNA at both active sites. The placement and orientation of residues Lys538, Lys555, Lys557, Gln560, Thr571, Thr573 and Lys575 in a modelled φ29 DNA polymerase–DNA complex suggest a DNA-binding role. In addition, crystal structure of φ29 DNA polymerase–oligo (dT)(5) complex showed Leu567, placed at the tip of the thumb subdomain, lying between the two 3′-terminal bases at the exonuclease site. Single replacement of these φ29 DNA polymerase residues by alanine was made, and mutant derivatives were overproduced and purified to homogeneity. The results obtained in the assay of their synthetic and degradative activities, as well as their coordination, allow us to propose: (1) a primer-terminus stabilization role at the polymerase active site for residues Lys538, Thr573 and Lys575, (2) a primer-terminus stabilization role at the exonuclease active site for residues Leu567 and Lys555 and (3) a primer-terminus binding role in both editing and polymerization modes for residue Gln560. The results presented here lead us to propose φ29 DNA polymerase thumb as the main subdomain responsible for the coordination of polymerization and exonuclease activities
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