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1.
Background
Freezing lesions to developing rat cortex induced between postnatal day (P) one and three (P1 – 3) lead to malformations similar to human microgyria, and further correspond to reductions in brain weight and cortical volume. In contrast, comparable lesions on P5 do not produce microgyric malformations, nor the changes in brain weight seen with microgyria. However, injury occurring at all three ages does lead to rapid auditory processing deficits as measured in the juvenile period. Interestingly, these deficits persist into adulthood only in the P1 lesion case [1]. Given prior evidence that early focal cortical lesions induce abnormalities in cortical morphology and connectivity [1–4], we hypothesized that the differential behavioral effects of focal cortical lesions on P1, P3 or P5 may be associated with underlying neuroanatomical changes that are sensitive to timing of injury. Clinical studies indicate that humans with perinatal brain injury often show regional reductions in corpus callosum size and abnormal symmetry, which frequently correspond to learning impairments [5–7]. Therefore, in the current study the brains of P1, 3 or 5 lesion rats, previously evaluated for brain weight, and cortical volume changes and auditory processing impairments (P21-90), were further analyzed for changes in corpus callosum volume. 相似文献2.
3.
A. Faggionato D. Gabrielli M. Ribezzi Crivellari 《Journal of statistical physics》2009,137(2):259-304
We consider a class of stochastic dynamical systems, called piecewise deterministic Markov processes, with states (x,σ)∈Ω×Γ, Ω being a region in ℝ
d
or the d-dimensional torus, Γ being a finite set. The continuous variable x follows a piecewise deterministic dynamics, the discrete variable σ evolves by a stochastic jump dynamics and the two resulting evolutions are fully-coupled. We study stationarity, reversibility
and time-reversal symmetries of the process. Increasing the frequency of the σ-jumps, the system behaves asymptotically as deterministic and we investigate the structure of its fluctuations (i.e. deviations
from the asymptotic behavior), recovering in a non Markovian frame results obtained by Bertini et al. (Phys. Rev. Lett. 87(4):040601,
2001; J. Stat. Phys. 107(3–4):635–675, 2002; J. Stat. Mech. P07014, 2007; Preprint available online at , 2008), in the context of Markovian stochastic interacting particle systems. Finally, we discuss a Gallavotti–Cohen-type symmetry
relation with involution map different from time-reversal. 相似文献
4.
In this paper, we generalize the Kirchhoff-Sobolev parametrix of Klainerman and Rodnianski (Hyperbolic Equ. 4(3):401–433,
2007) to systems of tensor wave equations with additional first-order terms. We also present a different derivation, which better
highlights that such representation formulas are supported entirely on past null cones. This generalization of (Hyperbolic
Equ. 4(3):401–433, 2007) is a key component for extending Klainerman and Rodnianski’s breakdown criterion result for Einstein-vacuum spacetimes in
(J. Amer. Math. Soc. 23(2):345–382, 2009) to Einstein-Maxwell and Einstein-Yang-Mills spacetimes. 相似文献
5.
We study the limit of quasilocal energy defined in Wang and Yau (Phys Rev Lett 102(2):021101, 2009; Commun Math Phys 288(3):919–942, 2009) for a family of spacelike 2-surfaces approaching null infinity of an asymptotically flat spacetime. It is shown that Lorentzian
symmetry is recovered and an energy-momentum 4-vector is obtained. In particular, the result is consistent with the Bondi–Sachs
energy-momentum at a retarded time. The quasilocal mass in Wang and Yau (Phys Rev Lett 102(2):021101, 2009; Commun Math Phys 288(3):919–942, 2009) is defined by minimizing quasilocal energy among admissible isometric embeddings and observers. The solvability of the Euler-Lagrange
equation for this variational problem is also discussed in both the asymptotically flat and asymptotically null cases. Assuming
analyticity, the equation can be solved and the solution is locally minimizing in all orders. In particular, this produces
an optimal reference hypersurface in the Minkowski space for the spatial or null exterior region of an asymptotically flat
spacetime. 相似文献
6.
Shunlong Luo 《Journal of statistical physics》2007,128(5):1177-1188
The classical Fisher information is superadditive in the sense that the Fisher information of a bivariate probability density
is always not less than the sum of those of the marginals. The longstanding conjecture concerning the superadditivity of the
Wigner–Yanase–Dyson information is a quantum analogue of this property. It is remarkable that Hansen constructed a numerical
counterexample to the quantum case (J. Stat. Phys. 126: 643–648, 2007). However, the requirement of superadditivity of an information-theoretic quantity such as the Wigner–Yanase–Dyson information
seems so intuitive, it is desirable to identify conditions as general as possible such that the superadditivity holds. In
this paper, we establish the superadditivity in several physically significant cases. 相似文献
7.
In experiments of games, players frequently make choices which are regarded as irrational in game theory. In papers of Khrennikov
(Information Dynamics in Cognitive, Psychological and Anomalous Phenomena. Fundamental Theories of Physics, Kluwer Academic,
Norwell, 2004; Fuzzy Sets Syst. 155:4–17, 2005; Biosystems 84:225–241, 2006; Found. Phys. 35(10):1655–1693, 2005; in QP-PQ Quantum Probability and White Noise Analysis, vol. XXIV, pp. 105–117, 2009), it was pointed out that statistics collected in such the experiments have “quantum-like” properties, which can not be explained
in classical probability theory. In this paper, we design a simple quantum-like model describing a decision-making process
in a two-players game and try to explain a mechanism of the irrational behavior of players. Finally we discuss a mathematical
frame of non-Kolmogorovian system in terms of liftings (Accardi and Ohya, in Appl. Math. Optim. 39:33–59, 1999). 相似文献
8.
A Fredholm Determinant Representation in ASEP 总被引:3,自引:2,他引:1
In previous work (Tracy and Widom in Commun. Math. Phys. 279:815–844, 2008) the authors found integral formulas for probabilities in the asymmetric simple exclusion process (ASEP) on the integer lattice
ℤ. The dynamics are uniquely determined once the initial state is specified. In this note we restrict our attention to the
case of step initial condition with particles at the positive integers ℤ+ and consider the distribution function for the mth particle from the left. In Tracy and Widom (Commun. Math. Phys. 279:815–844, 2008) an infinite series of multiple integrals was derived for the distribution. In this note we show that the series can be summed
to give a single integral whose integrand involves a Fredholm determinant. We use this determinant representation to derive
(non-rigorously, at this writing) a scaling limit. 相似文献
9.
Applying the well-known Feynman-Kac formula of inhomogeneous case, an interesting and rigorous mathematical proof of generalized
Jarzynski’s equality of inhomogeneous multidimensional diffusion processes is presented, followed by an extension of the second
law of thermodynamics. Then, we explain its physical meaning and applications, extending Hummer and Szabo’s work (Proc. Natl.
Acad. Sci. USA 98(7):3658–3661, [2001]) and Hatano-Sasa equality of steady state thermodynamics (Phys. Rev. Lett. 86:3463–3466, [2001]) to the general multidimensional case. 相似文献
10.
Yaacov Kopeliovich 《Letters in Mathematical Physics》2010,94(3):313-333
Let X be a general cyclic cover of
\mathbbCP1{\mathbb{CP}^{1}} ramified at m points, λ1... λ
m
. we define a class of non-positive divisors on X of degree g −1 supported in the pre images of the branch points on X, such that the Riemann theta function does not vanish on their image in J(X). We generalize the results of Bershadsky and Radul (Commun Math Phys 116:689–700, 1988), Nakayashiki (Publ Res Inst Math Sci 33(6):987–1015, 1997) and Enolskii and Grava (Lett Math Phys 76(2–3):187–214, 2006) and prove that up to a certain determinant of the non-standard periods of X, the value of the Riemann theta function at these divisors raised to a high enough power is a polynomial in the branch point
of the curve X. Our approach is based on a refinement of Accola’s results for 3 cyclic sheeted cover (Accola, in Trans Am Math Soc 283:423–449,
1984) and a generalization of Nakayashiki’s approach explained in Nakayashiki (Publ Res Inst Math Sci 33(6):987–1015, 1997) for general cyclic covers. 相似文献
11.
Tom M. Evans Elham Doroodchi Behdad Moghtaderi 《Journal of nanoparticle research》2011,13(9):4395-4396
This brief communication provides a response to Murshed et al. (J Nanopart Res 12:2007–2010, 2010). We acknowledge that three of the equations in our original article (Doroodchi et al. J Nanopart Res 11:1501–1507, 2009) contained minor typographical errors. However, we confirm that these misprinted equations have no bearing on the results
presented within that article. In addition, we would like to clarify that we do not challenge the methodology of Leong et
al. (J Nanopart Res 8:245–254, 2006). Instead, we repeated their analysis using a more general form for the temperature field with continuity imposed across
the particle–nanolayer–liquid interfaces and found that the solution reduces to the Renovated-Maxwell model. 相似文献
12.
G. F. Iriarte 《Journal of nanoparticle research》2011,13(4):1737-1745
Artificial nanostructures (Samuelson et al., Physica E 21:560–567, 2004; Xia et al., Adv Mater 15:353–389, 2003) show promise for the organization of functional materials (Huck and Samuelson, Nanotechnology 14:NIL_5–NIL_8, 2003) to create nanoelectronic (Mizuta and Oda, Science 279:208–211, 2008) or nano-optical devices (Mazur et al.; Tanemura et al., Synthesis, Optical Properties and Functional Applications of ZnO
Nano-materials: A Review, 1–3:58–63, 2008). However, in most manufacturing recipes described so far, nanostructures are synthesized in solution and/or uncontrolled
deposition results in random arrangements; this makes it difficult to measure the properties of attached nanodevices or to
integrate them with conventionally fabricated microcircuitry. Here, we describe a fully CMOS compatible process technology
for mass manufacture of polysilicon nanowires by the CVD (chemical vapor deposition) method. The large scale production of
nanowires could successfully be synthesized on silicon (100) substrates. However, the method presented here can successfully
be employed with all technologically useful substrates with good adhesion for silicon such as SiO2, diamond-like carbon or III–V semiconductors. This opens up the possibility for the fabrication of strain-sensitive and defect-sensitive
optoelectronic devices on the optimum III–V substrate (Fonstad et al.). Finally, scanning electron microscopy (SEM) was used
to characterize the as-synthesized nanowires and energy-filtered transmission electron microscopy (EFTEM) and scanning transmission
electron microscopy (STEM) analysis were used to determine the nanowire composition. 相似文献
13.
Anatoliy K. Prykarpatsky Nikolai N. BogoliubovJr. Jolanta Golenia 《International Journal of Theoretical Physics》2008,47(7):1919-1928
Symplectic and symmetry analysis for studying MHD superfluid flows is devised, a new version of the Z. Peradzyński (Int. J.
Theor. Phys. 29(11):1277–1284, [1990]) helicity theorem based on differential-geometric and group-theoretical methods is derived. Having reanalyzed the Peradzyński
helicity theorem within the modern symplectic theory of differential-geometric structures on manifolds, a new unified proof
and a new generalization of this theorem for the case of compressible MHD superfluid flow are proposed. As a by-product, a
sequence of nontrivial helicity type local and global conservation laws for the case of incompressible superfluid flow, playing
a crucial role for studying the stability problem under suitable boundary conditions, is constructed. 相似文献
14.
S. Sonntag J. Roth H.-R. Trebin 《Applied Physics A: Materials Science & Processing》2010,101(1):77-80
Laser induced surface melting of the aluminum–cobalt alloy Al13Co4 is investigated. For the simulations of the lattice ions we use molecular dynamics, while for the time evolution of the electron
temperature a generalized heat-conduction equation is solved. Energy transfer between the sub-systems is allowed by an electron–phonon
coupling term. This combined treatment of the electronic and atomic systems is an extension of the well-known two-temperature
model [Anisimov et al. in JETP Lett. 39(2), 1974]. The alloy shows large structural affinity to decagonal quasicrystals, which have an in-plane five-fold symmetry,while in perpendicular direction the planes are stacked periodically. As a consequence we observe slight
anisotropic melting behavior. 相似文献
15.
We analyze the large-time behavior of various kinetic models for the redistribution of wealth in simple market economies introduced
in the pertinent literature in recent years. As specific examples, we study models with fixed saving propensity introduced
by Chakraborti and Chakrabarti (Eur. Phys. J. B 17:167–170, 2000), as well as models involving both exchange between agents and speculative trading as considered by Cordier et al. (J. Stat.
Phys. 120:253–277, 2005) We derive a sufficient criterion under which a unique non-trivial stationary state exists, and provide criteria under which
these steady states do or do not possess a Pareto tail. In particular, we prove the absence of Pareto tails in pointwise conservative
models, like the one in (Eur. Phys. J. B 17:167–170, 2000), while models with speculative trades introduced in (J. Stat. Phys. 120:253–277, 2005) develop fat tails if the market is “risky enough”. The results are derived by a Fourier-based technique first developed
for the Maxwell-Boltzmann equation (Gabetta et al. in J. Stat. Phys. 81:901–934, 1995; Bisi et al. in J. Stat. Phys. 118(1–2):301–331, 2005; Pareschi and Toscani in J. Stat. Phys. 124(2–4):747–779, 2006) and from a recursive relation which allows to calculate arbitrary moments of the stationary state. 相似文献
16.
We prove that the quotient of the group algebra of the braid group introduced by Funar (Commun Math Phys 173:513–558, 1995) collapses in characteristic distinct from 2. In characteristic 2 we define several quotients of it, which are connected to the classical Hecke and Birman-Wenzl-Murakami quotients, but which admit in addition a symmetry of order 3. We also establish conditions on the possible Markov traces factorizing through it. 相似文献
17.
18.
Azad A. Siddiqui 《General Relativity and Gravitation》2011,43(4):1189-1196
There exist Kruskal like coordinates for the Reissner–Nordstrom (RN) black hole spacetime which are regular at coordinate
singularities. Non-existence of such coordinates for the extreme RN black hole spacetime has already been shown. Also the
Carter coordinates available for the extreme case are not manifestly regular at the coordinate singularity, therefore, a numerical
procedure was developed to obtain free fall geodesics and flat foliation for the extreme RN black hole spacetime. The Kottler–Schwarzschild–de
Sitter (KSSdS) spacetime geometry is similar to the RN geometry in the sense that, like the RN case, there exist non-singular
coordinates when there are two distinct coordinate singularities. There are no manifestly regular coordinates for the extreme
KSSdS case. In this paper foliation of all the cases of the KSSdS spacetime by flat spacelike hypersurfaces is obtained by
introducing a non-singular time coordinate. 相似文献
19.
The work by Ott et al. (Math. Res. Lett. 16:463–475, 2009) established memory loss in the time-dependent (non-random) case of uniformly expanding maps of the interval. Here we find
conditions under which we have convergence to the normal distribution of the appropriately scaled Birkhoff-like partial sums
of appropriate test functions. A substantial part of the problem is to ensure that the variances of the partial sums tend
to infinity (cf. the zero-cohomology condition in the autonomous case). In fact, the present paper is the first one where
non-random examples are also found, which are not small perturbations of a given map. Our approach uses martingale approximation
technique in the form of Sethuraman and Varadhan (Electron. J. Probab. 10:121–1235, 2005). 相似文献
20.
E. Ryckman 《Journal of statistical physics》2008,132(3):473-486
For arbitrary β>0, we use the orthogonal polynomials techniques developed in (Killip and Nenciu in , 2005; Killip and Nenciu in Int. Math. Res. Not. 50: 2665–2701, 2004) to study certain linear statistics associated with the circular and Jacobi β ensembles. We identify the distribution of these statistics then prove a joint central limit theorem. In the circular case,
similar statements have been proved using different methods by a number of authors. In the Jacobi case these results are new. 相似文献