Representative brain selection using a group-specific tissue probability map

PURPOSE: To determine the anatomy of a standard brain reflecting well-defined group characteristics based on probabilistic information from group-specific anatomical variations. MATERIALS AND METHODS: We constructed a group-specific tissue probabilistic map for 20 subjects and used it to extract voxel-wise probabilistic information for each subject through regional spatial normalization using Automated Image Registration software (AIR 5.2.5). Extracted probabilistic information was then used to determine standard properties of the subjects. For comparison, we employed an empirical scoring function - a measure of entropy - in ordering the data set. A brain with minimum entropy was then selected for a group standard. The evaluation of our proposed method was performed using two different selection schemes: deformation analysis and similarity index measurements. RESULTS: This method showed highly correlated result with previous method by Kochunov et al., with fewer computational tasks. CONCLUSION: This method can thus be used to determine an appropriate standard model to compare with disease-affected brains.     

Palladium nanoparticles entrapped in aluminum hydroxide: dual catalyst for alkene hydrogenation and aerobic alcohol oxidation

[reaction: see text] A new aluminum hydroxide-supported palladium catalyst (1) made by a one-pot synthesis through nanoparticle generation and gelation shows a dual catalytic activity for olefinic hydrogenation and aerobic alcohol oxidation.     

Origin of the giant magnetic moments of Fe impurities on and in Cs films

We have explored the origin of the observed giant magnetic moments ( approximately 7&mgr;(B)) of Fe impurities on the surface and in the bulk of Cs films, using the relativistic local-spin-density-approximation method. We have found that Fe impurities in Cs behave differently from those in noble metals or in Pd. Whereas the induced spin polarization of Cs atoms is negligible, the Fe ion itself is a source of the giant magnetic moment. The 3d electrons of Fe in Cs are localized as the 4f electrons in rare-earth ions so that the orbital magnetic moment becomes as large as the spin magnetic moment. The calculated total magnetic moment M = 6.43&mgr;(B) is close to the experimentally observed value.     

Limit of Solutions of a SDE with a Large Drift Driven by a Poisson Random Measure

We consider a sequence of {X _n} of R ^d-valued processes satisfying a stochastic differential equation driven by a Brownian motion and a compensated Poisson random measure, with _n ~ _n with a large drift. Let be a m-dimensional submanifold (m<d), where F vanishes. Then under some suitable growth conditions for _n ~ _n, and some conditions for F, we show that dist(X _n, )0 before it exits any given compact set, that is, the large drift term forces X _n close to . And if the coefficients converge to some continuous functions, any limit process must actually stay on and satisfy a certain stochastic differential equation driven by Brownian motion and white noise.     

Observation of B --> K(+/-) pi(0) and B --> (K)0 pi(0), and evidence for B --> pi(+)pi(-)

We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: beta(B-->pi(+)pi(-)) = (4.3(+1. 6)(-1.4)+/-0.5)x10(-6), beta(B-->K(0)pi(0)) = (14.6(+5.9+2.4)(-5.1-3. 3))x10(-6), and beta(B-->K(+)/-pi(0)) = (11.6(+3.0+1.4)(-2.7-1.3))x10(-6). We also update our previous measurements for the decays B-->K(+)/-pi(-/+) and B+/--->K(0)pi(+/-).     

Two-body B meson decays to eta and eta('): observation of B --> eta K*

In a sample of 19 x 10(6) produced B mesons, we have observed the decays B-->eta K(*) and improved our previous measurements of B-->eta'K. The branching fractions we measure for these decay modes are B(B+-->eta K(*+)) = (26.4(+9.6)(-8.2)+/-3.3)x10(-6), B(B(0)-->eta K(*0)) = (13.8(+5.5)(-4.6)+/-1.6)x10(-6), B(B(+)-->eta'K(+) = (80(+10)(-9)+/-7)x10(-6), and B(B(0)-->eta'K0) = (89(+18)(-16)+/-9)x10(-6). We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions.     

Unusually high thermal conductivity of carbon nanotubes

Combining equilibrium and nonequilibrium molecular dynamics simulations with accurate carbon potentials, we determine the thermal conductivity lambda of carbon nanotubes and its dependence on temperature. Our results suggest an unusually high value, lambda approximately 6600 W/m K, for an isolated (10,10) nanotube at room temperature, comparable to the thermal conductivity of a hypothetical isolated graphene monolayer or diamond. Our results suggest that these high values of lambda are associated with the large phonon mean free paths in these systems; substantially lower values are predicted and observed for the basal plane of bulk graphite.     

Does hard core interaction change absorbing-type critical phenomena?

It has been generally believed that hard core interaction is irrelevant to absorbing-type critical phenomena because the particle density is so low near an absorbing phase transition. We study the effect of hard core interaction on the N-species branching annihilating random walks with two offspring and report that hard core interaction drastically changes the absorbing-type critical phenomena in a nontrivial way. Through a Langevin equation-type approach, we predict analytically the values of the scaling exponents, nu( perpendicular) = 2, z = 2, alpha = 1/2, and beta = 2 in one dimension for all N>1. Direct numerical simulations confirm our prediction. When the diffusion coefficients for different species are not identical, nu( perpendicular) and beta vary continuously with the ratios between the coefficients.     

Synthesis and characterization of stable blue light‐emitting poly(spirobifluorene) derivatives containing alkoxy group

Polymers containing alkoxy‐substituted spirobifluorene have been prepared from nickel(0)‐mediated coupling or palladium‐catalyzed Suzuki coupling. The polymers were characterized using various spectroscopies, such as ¹H‐NMR, FT‐IR, and elemental analysis. The high glass transition temperature and high decomposition temperature suggested that the resulting polymers possessed a high thermal stability. The obtained polymers possessed weight average molecular weight of 4500–33,000 with polydispersity index of 1.1–1.9 and good solubility. The low onsets of the oxidation potential suggested that the polymers containing alkoxy substituted spirobifluorene possessed a good hole injection property. The photoluminescence and electroluminescence of the polymers containing alkoxy substituted spirobifluorene showed stable blue color by suppressing the excimer formation due to intermolecular interaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2316–2324, 2005     

Stereocontrolled synthesis of steroid side chains via organoboranes. Stereospecific synthesis of 20R- and 20S-25-hydroxycholesterol.

Both 20R- and 20S-25-hydroxycholesterol have been stereospecially prepared from readily 3β-hydroxy-5-androsten-17-one.