12,909 research outputs found
Can Neuroscience Help Predict Future Antisocial Behavior?
Part I of this Article reviews the tools currently available to predict antisocial behavior. Part II discusses legal precedent regarding the use of, and challenges to, various prediction methods. Part III introduces recent neuroscience work in this area and reviews two studies that have successfully used neuroimaging techniques to predict recidivism. Part IV discusses some criticisms that are commonly levied against the various prediction methods and highlights the disparity between the attitudes of the scientific and legal communities toward risk assessment generally and neuroscience specifically. Lastly, Part V explains why neuroscience methods will likely continue to help inform and, ideally, improve the tools we use to help assess, understand, and predict human behavior
Spectro-Morphology of Galaxies
We present a quantitative method to classify galaxies, based on
multi-wavelength data and elaborated from the properties of nearby galaxies.
Our objective is to define an evolutionary method that can be used for low and
high redshift objects. We estimate the concentration of light (C) at the galaxy
center and the 180 degree-rotational asymmetry (A), computed at several
wavelengths, from ultraviolet (UV) to I-band. The variation of the indices of
concentration and asymmetry with the wavelength reflects the proportion and the
distribution of young and old stellar populations in galaxies. In general C is
found to decrease from optical to UV, and A is found to increase from optical
to UV: the patchy appearance of galaxies in UV with no bulge is often very
different from their counterpart at optical wavelengths, with prominent bulges
and more regular disks. The variation of C and A with the wavelength is
quantified. By this way, we are able to distinguish five types of galaxies that
we call spectro-morphological types: compact, ringed, spiral, irregular and
central-starburst galaxies, which can be differentiated by the repartition of
their stellar populations. We discuss in detail the morphology of galaxies of
the sample, and describe the morphological characteristics of each
spectro-morphological type. We apply spectro-morphology to three objects at a
redshift z=1 in the Hubble Deep Field North, that gives encouraging results for
applications to large samples of high-redshift galaxies. This method of
morphological classification could be used to study the evolution of the
morphology with the redshift and is expected to bring observational constraints
on scenarios of galaxy evolution.Comment: Accepted for publication in Astronomy & Astrophysic
SAGE measurements of the stratospheric aerosol dispersion and loading from the Soufriere Volcano
Explosions of the Soufriere volcano on the Caribbean Island of St. Vincent reduced two major stratospheric plumes which the stratospheric aerosol and gas experiment (SAGE) satellite tracked to West Africa and the North Atlantic Ocean. The total mass of the stratospheric ejecta measured is less than 0.5% of the global stratospheric aerosol burden. No significant temperature or climate perturbation is expected. It is found that the movement and dispersion of the plumes agree with those deduced from high altitude meteorological data and dispersion theory. The stratospheric aerosol dispersion and loading from the Soufrier volcano was measured
Efficient calculation of the antiferromagnetic phase diagram of the 3D Hubbard model
The Dynamical Cluster Approximation with Betts clusters is used to calculate
the antiferromagnetic phase diagram of the 3D Hubbard model at half filling.
Betts clusters are a set of periodic clusters which best reflect the properties
of the lattice in the thermodynamic limit and provide an optimal finite-size
scaling as a function of cluster size. Using a systematic finite-size scaling
as a function of cluster space-time dimensions, we calculate the
antiferromagnetic phase diagram. Our results are qualitatively consistent with
the results of Staudt et al. [Eur. Phys. J. B 17 411 (2000)], but require the
use of much smaller clusters: 48 compared to 1000
Critical Currents of Josephson-Coupled Wire Arrays
We calculate the current-voltage characteristics and critical current
I_c^{array} of an array of Josephson-coupled superconducting wires. The array
has two layers, each consisting of a set of parallel wires, arranged at right
angles, such that an overdamped resistively-shunted junction forms wherever two
wires cross. A uniform magnetic field equal to f flux quanta per plaquette is
applied perpendicular to the layers. If f = p/q, where p and q are mutually
prime integers, I_c^{array}(f) is found to have sharp peaks when q is a small
integer. To an excellent approximation, it is found in a square array of n^2
plaquettes, that I_c^{array}(f) \propto (n/q)^{1/2} for sufficiently large n.
This result is interpreted in terms of the commensurability between the array
and the assumed q \times q unit cell of the ground state vortex lattice.Comment: 4 pages, 4 figure
Systematic study of d-wave superconductivity in the 2D repulsive Hubbard model
The cluster size dependence of superconductivity in the conventional
two-dimensional Hubbard model, commonly believed to describe high-temperature
superconductors, is systematically studied using the Dynamical Cluster
Approximation and Quantum Monte Carlo simulations as cluster solver. Due to the
non-locality of the d-wave superconducting order parameter, the results on
small clusters show large size and geometry effects. In large enough clusters,
the results are independent of the cluster size and display a finite
temperature instability to d-wave superconductivity.Comment: 4 pages, 3 figures; updated with version published in PRL; added
values of Tc obtained from fit
Pseudogap and antiferromagnetic correlations in the Hubbard model
Using the dynamical cluster approximation and quantum monte carlo we
calculate the single-particle spectra of the Hubbard model with next-nearest
neighbor hopping . In the underdoped region, we find that the pseudogap
along the zone diagonal in the electron doped systems is due to long range
antiferromagnetic correlations. The physics in the proximity of is
dramatically influenced by and determined by the short range correlations.
The effect of on the low energy ARPES spectra is weak except close to the
zone edge. The short range correlations are sufficient to yield a pseudogap
signal in the magnetic susceptibility, produce a concomitant gap in the
single-particle spectra near but not necessarily at a location in
the proximity of Fermi surface.Comment: 5 pages, 4 figure
Magnetoresistance due to Domain Walls in Micron Scale Fe Wires with Stripe Domains
The magnetoresistance (MR) associated with domain boundaries has been
investigated in microfabricated bcc Fe (0.65 to 20 m linewidth) wires with
controlled stripe domains. Domain configurations have been characterized using
magnetic force microscopy. MR measurements as a function of field angle,
temperature and domain configuration are used to estimate MR contributions due
to resistivity anisotropy and domain walls. Evidence is presented that domain
boundaries enhance the conductivity in such microstructures over a broad range
of temperatures (1.5 K to 80 K).Comment: 8 pages, 3 postscript figures, and 2 jpg images (Fig 1 and 2) to
appear in IEEE Transactions on Magnetics (Fall 1998
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