8,891 research outputs found
Holographic entanglement of purification for thermofield double states and thermal quench
We explore the properties of holographic entanglement of purification (EoP)
for two disjoint strips in the Schwarzschild-AdS black brane and the Vaidya-AdS
black brane spacetimes. For two given strips on the same boundary of
Schwarzschild-AdS spacetime, there is an upper bound of the separation beyond
which the holographic EoP will always vanish no matter how wide the strips are.
In the case that two strips are in the two boundaries of the spacetime
respectively, we find that the holographic EoP exists only when the strips are
wide enough. If the width is finite, the EoP can be nonzero in a finite time
region. For thermal quench case, we find that the equilibrium time of
holographic EoP is only sensitive to the width of strips, while that of the
holographic mutual information is sensitive not only to the width of strips but
also to their separation.Comment: 23 pages, 12 figures, major correction of section
Di-μ-thioÂcyanato-bisÂ({2,4-dichloro-6-[2-(diethylÂamino)ethylÂiminoÂmethÂyl]phenolato}copper(II))
The title compound, [Cu2(NCS)2(C13H17Cl2N2O)2], was obtained by the reaction of 3,5-dichloroÂsalicylaldehyde, N,N-diethylÂethane-1,2-diamine, sodium thioÂcyanate, and copper(II) acetate in an ethanol solution. It crystallizes as a centrosymmetric dimer with a very long Cu⋯S axial bond [2.972 (3) Å]. The Cu atom is five-coordinated by the three donor atoms of the Schiff base ligand, 2,4-dichloro-6-[(2-diethylÂaminoÂethylÂimino)methÂyl]phenol, one N atom of a thioÂcyanate group, and one S atom of a symmetry-related thioÂcyanate group, forming a slightly distorted square-pyramidal geometry
Reengineering an object-oriented framework for extensible query optimization
In this thesis, we describe a third-generation extensible query optimization framework that has evolved from the OPT++ framework of Navin Kabra for relational databases. Our framework does not change the infrastructure of the OPT++ architecture, which consists of three components: a Search Strategy component, a Search Space component and an Algebra component. However, we address the problems encountered while building two query optimizers in the framework: a simple bottom-up optimizer and an instance of the PostgreSQL query optimizer and enhance the modularity and the collaboration of the three components of the framework at detailed level, which in turn leads to a more flexible, easier to extend and cleaner implementation. The framework has been validated by implementing the two query optimizers. While both these cases were for the relational data model, we believe the design does cover the optimization process for other data models
Self-organization and phase transition in financial markets with multiple choices
Market confidence is essential for successful investing. By incorporating
multi-market into the evolutionary minority game, we investigate the effects of
investor beliefs on the evolution of collective behaviors and asset prices.
When there exists another investment opportunity, market confidence, including
overconfidence and under-confidence, is not always good or bad for investment.
The roles of market confidence is closely related to market impact. For low
market impact, overconfidence in a particular asset makes an investor become
insensitive to losses and a delayed strategy adjustment leads to a decline in
wealth, and thereafter, one's runaway from the market. For high market impact,
under-confidence in a particular asset makes an investor over-sensitive to
losses and one's too frequent strategy adjustment leads to a large fluctuation
in asset prices, and thereafter, a decrease in the number of agents. At an
intermediate market impact, the phase transition occurs. No matter what the
market impact is, an equilibrium between different markets exists, which is
reflected in the occurrence of similar price fluctuations in different markets.
A theoretical analysis indicates that such an equilibrium results from the
coupled effects of strategy updating and shift in investment. The runaway of
the agents trading a specific asset will lead to a decline in the asset price
volatility and such a decline will be inhibited by the clustering of the
strategies. A uniform strategy distribution will lead to a large fluctuation in
asset prices and such a fluctuation will be suppressed by the decrease in the
number of agents in the market. A functional relationship between the price
fluctuations and the numbers of agents is found
Coupled effects of local movement and global interaction on contagion
By incorporating segregated spatial domain and individual-based linkage into
the SIS (susceptible-infected-susceptible) model, we investigate the coupled
effects of random walk and intragroup interaction on contagion. Compared with
the situation where only local movement or individual-based linkage exists, the
coexistence of them leads to a wider spread of infectious disease. The roles of
narrowing segregated spatial domain and reducing mobility in epidemic control
are checked, these two measures are found to be conducive to curbing the spread
of infectious disease. Considering heterogeneous time scales between local
movement and global interaction, a log-log relation between the change in the
number of infected individuals and the timescale is found. A theoretical
analysis indicates that the evolutionary dynamics in the present model is
related to the encounter probability and the encounter time. A functional
relation between the epidemic threshold and the ratio of shortcuts, and a
functional relation between the encounter time and the timescale are
found
Sox10+ adult stem cells contribute to biomaterial encapsulation and microvascularization.
Implanted biomaterials and biomedical devices generally induce foreign body reaction and end up with encapsulation by a dense avascular fibrous layer enriched in extracellular matrix. Fibroblasts/myofibroblasts are thought to be the major cell type involved in encapsulation, but it is unclear whether and how stem cells contribute to this process. Here we show, for the first time, that Sox10+ adult stem cells contribute to both encapsulation and microvessel formation. Sox10+ adult stem cells were found sparsely in the stroma of subcutaneous loose connective tissues. Upon subcutaneous biomaterial implantation, Sox10+ stem cells were activated and recruited to the biomaterial scaffold, and differentiated into fibroblasts and then myofibroblasts. This differentiation process from Sox10+ stem cells to myofibroblasts could be recapitulated in vitro. On the other hand, Sox10+ stem cells could differentiate into perivascular cells to stabilize newly formed microvessels. Sox10+ stem cells and endothelial cells in three-dimensional co-culture self-assembled into microvessels, and platelet-derived growth factor had chemotactic effect on Sox10+ stem cells. Transplanted Sox10+ stem cells differentiated into smooth muscle cells to stabilize functional microvessels. These findings demonstrate the critical role of adult stem cells in tissue remodeling and unravel the complexity of stem cell fate determination
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