730 research outputs found
A new computational method for the functional inequality constrained minimax optimization problem
AbstractIn this paper, we consider a general class of functional inequality constrained minimax optimization problems. This problem is first converted into a semi-infinite programming problem. Then, an auxiliary cost function is constructed based on a positive saturated function. The smallest zero of this auxiliary cost function is equal to the minimal cost of the semi-infinite programming problem. However, this auxiliary cost function is nonsmooth. Thus, a smoothing function is introduced. Then, an efficient computational procedure is developed to estimate the smallest zero of this auxiliary cost function. Furthermore, an error bound is obtained to validate the accuracy of the approximate solution. For illustration, two numerical examples are solved using the proposed approach
Search for Invisible Decays of and in and
Using a data sample of decays collected with the BES
II detector at the BEPC, searches for invisible decays of and
in to and are performed.
The signals, which are reconstructed in final states, are used
to tag the and decays. No signals are found for the
invisible decays of either or , and upper limits at the 90%
confidence level are determined to be for the ratio
and for . These are the first
searches for and decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo
SENP3 promotes an Mff-primed Bcl-xL-Drp1 interaction involved in cell death following ischemia
Dysregulation of the mitochondrial fission machinery has been linked to cell death following ischemia. Fission is largely dependent on recruitment of Dynamin-related protein 1 (Drp1) to the receptor Mitochondrial fission factor (Mff) located on the mitochondrial outer membrane (MOM). Drp1 is a target for SUMOylation and its deSUMOylation, mediated by the SUMO protease SENP3, enhances the Drp1-Mff interaction to promote cell death in an oxygen/glucose deprivation (OGD) model of ischemia. Another interacting partner for Drp1 is the Bcl-2 family member Bcl-xL, an important protein in cell death and survival pathways. Here we demonstrate that preventing Drp1 SUMOylation by mutating its SUMO target lysines enhances the Drp1-Bcl-xL interaction in vivo and in vitro. Moreover, SENP3-mediated deSUMOylation of Drp1 promotes the Drp1-Bcl-xL interaction. Our data suggest that Mff primes Drp1 binding to Bcl-xL at the mitochondria and that Mff and Bcl-xL can interact directly, independent of Drp1, through their transmembrane domains. Importantly, SENP3 loss in cells subjected to OGD correlates with reduced Drp1-Bcl-xL interaction, whilst recovery of SENP3 levels in cells subjected to reoxygenation following OGD correlates with increased Drp1-Bcl-xL interaction. Expressing a Bcl-xL mutant with defective Drp1 binding reduces OGD plus reoxygenation-evoked cell death. Taken together, our results indicate that SENP3-mediated deSUMOlyation promotes an Mff-primed Drp1-Bcl-xL interaction that contributes to cell death following ischemia
Electroweak Supersymmetry around the Electroweak Scale
Inspired by the phenomenological constraints, LHC supersymmetry and Higgs
searches, dark matter search as well as string model building, we propose the
electroweak supersymmetry around the electroweak scale: the squarks and/or
gluinos are around a few TeV while the sleptons, sneutrinos, bino and winos are
within one TeV. The Higgsinos can be either heavy or light. We consider bino as
the dominant component of dark matter candidate, and the observed dark matter
relic density is achieved via the neutralino-stau coannihilations. Considering
the Generalized Minimal Supergravity (GmSUGRA), we show explicitly that the
electroweak supersymmetry can be realized, and the gauge coupling unification
can be preserved. With two Scenarios, we study the viable parameter spaces that
satisfy all the current phenomenological constraints, and we present the
concrete benchmark points. Furthermore, we comment on the fine-tuning problem
and LHC searches.Comment: RevTex4, 28 pages, 8 figures, 8 tables, version to appear in EPJ
Manifestation of triplet superconductivity in superconductor-ferromagnet structures
We study proximity effects in a multilayered superconductor/ferromagnet (S/F)
structure with arbitrary relative directions of the magnetization . If
the magnetizations of different layers are collinear the superconducting
condensate function induced in the F layers has only a singlet component and a
triplet one with a zero projection of the total magnetic moment of the Cooper
pairs on the direction. In this case the condensate penetrates the F
layers over a short length determined by the exchange energy . If
the magnetizations are not collinear the triplet component has, in
addition to the zero projection, the projections . The latter component
is even in the momentum, odd in the Matsubara frequency and penetrates the F
layers over a long distance that increases with decreasing temperature and does
not depend on (spin-orbit interaction limits this length). If the thickness
of the F layers is much larger than , the Josephson coupling between
neighboring S layers is provided only by the triplet component, so that a new
type of superconductivity arises in the transverse direction of the structure.
The Josephson critical current is positive (negative) for the case of a
positive (negative) chirality of the vector . We demonstrate that this
type of the triplet condensate can be detected also by measuring the density of
states in F/S/F structures.Comment: 14 pages; 9 figures. Final version, to be published in Phys. Rev.
Two refreshing views of Fluctuation Theorems through Kinematics Elements and Exponential Martingale
In the context of Markov evolution, we present two original approaches to
obtain Generalized Fluctuation-Dissipation Theorems (GFDT), by using the
language of stochastic derivatives and by using a family of exponential
martingales functionals. We show that GFDT are perturbative versions of
relations verified by these exponential martingales. Along the way, we prove
GFDT and Fluctuation Relations (FR) for general Markov processes, beyond the
usual proof for diffusion and pure jump processes. Finally, we relate the FR to
a family of backward and forward exponential martingales.Comment: 41 pages, 7 figures; version2: 45 pages, 7 figures, minor revisions,
new results in Section
Optimal Control of Nonlinear Switched Systems: Computational Methods and Applications
A switched system is a dynamic system that operates by switching between different subsystems or modes. Such systems exhibit both continuous and discrete characteristics—a dual nature that makes designing effective control policies a challenging task. The purpose of this paper is to review some of the latest computational techniques for generating optimal control laws for switched systems with nonlinear dynamics and continuous inequality constraints. We discuss computational strategiesfor optimizing both the times at which a switched system switches from one mode to another (the so-called switching times) and the sequence in which a switched system operates its various possible modes (the so-called switching sequence). These strategies involve novel combinations of the control parameterization method, the timescaling transformation, and bilevel programming and binary relaxation techniques. We conclude the paper by discussing a number of switched system optimal control models arising in practical applications
Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-
We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi -->
D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7
J/Psi events collected with the BESII detector at the BEPC. No excess of signal
above background is observed, and 90% confidence level upper limits on the
branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi
--> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure
Measurements of psi(2S) decays to octet baryon-antibaryon pairs
With a sample of 14 million psi(2S) events collected by the BESII detector at
the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p
p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their
branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4,
(3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4,
respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter
alpha is determined to be 0.82+-0.17+-0.04.Comment: 8 pages, 8 figure
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