31,065 research outputs found
Relative Entropy: Free Energy Associated with Equilibrium Fluctuations and Nonequilibrium Deviations
Using a one-dimensional macromolecule in aqueous solution as an illustration,
we demonstrate that the relative entropy from information theory, , has a natural role in the energetics of equilibrium and
nonequilibrium conformational fluctuations of the single molecule. It is
identified as the free energy difference associated with a fluctuating density
in equilibrium, and is associated with the distribution deviate from the
equilibrium in nonequilibrium relaxation. This result can be generalized to any
other isothermal macromolecular systems using the mathematical theories of
large deviations and Markov processes, and at the same time provides the
well-known mathematical results with an interesting physical interpretations.Comment: 5 page
SS Ari: a shallow-contact close binary system
Two CCD epochs of light minimum and a complete R light curve of SS Ari are
presented. The light curve obtained in 2007 was analyzed with the 2003 version
of the W-D code. It is shown that SS Ari is a shallow contact binary system
with a mass ratio and a degree of contact factor f=9.4(\pm0.8%). A
period investigation based on all available data shows that there may exist two
distinct solutions about the assumed third body. One, assuming eccentric orbit
of the third body and constant orbital period of the eclipsing pair results in
a massive third body with and P_3=87.00.278M_{\odot}$. Both of the cases
suggest the presence of an unseen third component in the system.Comment: 28 pages, 9 figures and 5 table
Nonsaturating magnetoresistance and nontrivial band topology of type-II Weyl semimetal NbIrTe4
Weyl semimetals, characterized by nodal points in the bulk and Fermi arc
states on the surface, have recently attracted extensive attention due to the
potential application on low energy consumption electronic materials. In this
report, the thermodynamic and transport properties of a theoretically predicted
Weyl semimetal NbIrTe4 is measured in high magnetic fields up to 35 T and low
temperatures down to 0.4 K. Remarkably, NbIrTe4 exhibits a nonsaturating
transverse magnetoresistance which follows a power-law dependence in B.
Low-field Hall measurements reveal that hole-like carriers dominate the
transport for T 80 K, while the significant enhancement of electron
mobilities with lowering T results in a non-negligible contribution from
electron-like carriers which is responsible for the observed non-linear Hall
resistivity at low T. The Shubnikov-de Haas oscillations of the Hall
resistivity under high B give the light effective masses of charge carriers and
the nontrivial Berry phase associated with Weyl fermions. Further
first-principles calculations confirm the existence of 16 Weyl points located
at kz = 0, 0.02 and 0.2 planes in the Brillouin zone.Comment: 5 figures, 1 tabl
Dihadron Azimuthal Correlations in 200 GeV Au-Au and 2.76 TeV Pb-Pb Collisions
In a multisource thermal model, we detailedly show dihadron azimuthal correlations for 20–40% and 50–80% in Au-Au collisions at sNN=200 GeV and over a centrality range from 10–15% to 70–80% in Pb-Pb collisions at sNN=2.76 TeV. The model can approximately describe the azimuthal correlations of particles produced in the collisions. The px amplitude of the corresponding source is magnified, and the source translates along the direction. The factor αx, in most cases, increases with the increase of the centrality in Pb-Pb collisions at sNN=2.76 TeV
Stochastic Physics, Complex Systems and Biology
In complex systems, the interplay between nonlinear and stochastic dynamics,
e.g., J. Monod's necessity and chance, gives rise to an evolutionary process in
Darwinian sense, in terms of discrete jumps among attractors, with punctuated
equilibrium, spontaneous random "mutations" and "adaptations". On an
evlutionary time scale it produces sustainable diversity among individuals in a
homogeneous population rather than convergence as usually predicted by a
deterministic dynamics. The emergent discrete states in such a system, i.e.,
attractors, have natural robustness against both internal and external
perturbations. Phenotypic states of a biological cell, a mesoscopic nonlinear
stochastic open biochemical system, could be understood through such a
perspective.Comment: 10 page
Identification and expression analysis of vitellogenin from silk-producing insect, Actias selene Hubner
This study mainly shows the DNA sequence and expression analysis of vitellogenin in Actias selene (Ash-Vg). Specific primers were designed to amplify Ash-Vg gene by polymerase chain reaction (PCR) and the obtained DNA sequence was 7329 bp long, including 6 exons and 5 introns with an open reading frame encoding a 1774 amino acids peptide. A Bm DSX binding site and some conserved signatures such as CdxA and GATA-X were found in the 5Œ-flanking region of Ash-Vg gene. Meanwhile, the cDNAencoding the small subunit of Ash-Vg protein was obtained by PCR and ligated to pET-28a vector for protein expression. A 45 KD recombinant protein was successfully expressed in Escherichia coli cells which were confirmed by sodium dodesyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis. The semi-quantitative PCR was also carried out to explore the specific expression of Ash-Vg and the results showed that the Ash-Vg gene expressed differently in various developmental stages and tissues.Key words: Actias selene Hubner, vitellogenin, DNA sequence, expression
An Army of Me: Sockpuppets in Online Discussion Communities
In online discussion communities, users can interact and share information
and opinions on a wide variety of topics. However, some users may create
multiple identities, or sockpuppets, and engage in undesired behavior by
deceiving others or manipulating discussions. In this work, we study
sockpuppetry across nine discussion communities, and show that sockpuppets
differ from ordinary users in terms of their posting behavior, linguistic
traits, as well as social network structure. Sockpuppets tend to start fewer
discussions, write shorter posts, use more personal pronouns such as "I", and
have more clustered ego-networks. Further, pairs of sockpuppets controlled by
the same individual are more likely to interact on the same discussion at the
same time than pairs of ordinary users. Our analysis suggests a taxonomy of
deceptive behavior in discussion communities. Pairs of sockpuppets can vary in
their deceptiveness, i.e., whether they pretend to be different users, or their
supportiveness, i.e., if they support arguments of other sockpuppets controlled
by the same user. We apply these findings to a series of prediction tasks,
notably, to identify whether a pair of accounts belongs to the same underlying
user or not. Altogether, this work presents a data-driven view of deception in
online discussion communities and paves the way towards the automatic detection
of sockpuppets.Comment: 26th International World Wide Web conference 2017 (WWW 2017
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