The Abuse of Power: A Theological Problem

Reviewed Book: Poling, James N. (James Newton). The Abuse of Power: A Theological Problem. Nashville: Abingdon Press, 1991

Representation and Characterization of Non-Stationary Processes by Dilation Operators and Induced Shape Space Manifolds

We have introduce a new vision of stochastic processes through the geometry induced by the dilation. The dilation matrices of a given processes are obtained by a composition of rotations matrices, contain the measure information in a condensed way. Particularly interesting is the fact that the obtention of dilation matrices is regardless of the stationarity of the underlying process. When the process is stationary, it coincides with the Naimark Dilation and only one rotation matrix is computed, when the process is non-stationary, a set of rotation matrices are computed. In particular, the periodicity of the correlation function that may appear in some classes of signal is transmitted to the set of dilation matrices. These rotation matrices, which can be arbitrarily close to each other depending on the sampling or the rescaling of the signal are seen as a distinctive feature of the signal. In order to study this sequence of matrices, and guided by the possibility to rescale the signal, the correct geometrical framework to use with the dilation's theoretic results is the space of curves on manifolds, that is the set of all curve that lies on a base manifold. To give a complete sight about the space of curve, a metric and the derived geodesic equation are provided. The general results are adapted to the more specific case where the base manifold is the Lie group of rotation matrices. The notion of the shape of a curve can be formalized as the set of equivalence classes of curves given by the quotient space of the space of curves and the increasing diffeomorphisms. The metric in the space of curve naturally extent to the space of shapes and enable comparison between shapes.Comment: 19 pages, draft pape

Atomistic simulation of structure and dynamics of columnar phases of hexabenzocoronene derivatives

Using atomistic molecular dynamics simulations we study solid and liquid crystalline columnar discotic phases formed by alkyl-substituted hexabenzocoronene mesogens. Correlations between the molecular structure, packing, and dynamical properties of these materials are established

The oldest amputation on a Neolithic human skeleton in France

While 'surgical' practices such as trepanations are well attested since the first stages of the European Neolithic, the amputation of limbs in Prehistoric periods has not been well-documented until the case presented here. The particularly well-preserved remains of an aged male were recently uncovered in the Neolithic site (4900-4700 BC) of Buthiers-Boulancourt in the vicinity of Paris, France. It was already noticed in situ that the distal part of the left humerus was abnormal and this led us to the hypothesis of a partially healed 'surgical' amputation.The further investigations reported here confirm a traumatic origin and a partial cicatrisation after surgery, indicating that the patient survived. It also proves the remarkable medical skills developed during Prehistorical times. In addition, the associated grave goods are original, including the skeleton of an animal, a polished schist axe and a massive 30 cm long flint pick. Despite the serious handicap from which he suffered in this pastoral-agricultural community, the buried man obviously enjoyed some particular social status, as suggested by the remarkable and 'prestigious' accompanying grave-goods. If indeed this man benefited from some form of community care, this would indicate the level of social solidarity in Western Europe almost 7000 years ago

The Effects of radial inflow of gas and galactic fountains on the chemical evolution of M31

Galactic fountains and radial gas flows are very important ingredients in modeling the chemical evolution of galactic disks. Our aim here is to study the effects of galactic fountains and radial gas flows in the chemical evolution of the disk of M31. We adopt a ballistic method to study the effects of galactic fountains on the chemical enrichment of the M31 disk. We find that the landing coordinate for the fountains in M31 is no more than 1 kpc from the starting point, thus producing negligible effect on the chemical evolution of the disk. We find that the delay time in the enrichment process due to fountains is no longer than 100 Myr and this timescale also produces negligible effects on the results. Then, we compute the chemical evolution of the M31 disk with radial gas flows produced by the infall of extragalactic material and fountains. We find that a moderate inside-out formation of the disk coupled with radial flows of variable speed can very well reproduce the observed gradient. We discuss also the effects of other parameters such a threshold in the gas density for star formation and an efficiency of star formation varying with the galactic radius. We conclude that the most important physical processes in creating disk gradients are the inside-out formation and the radial gas flows. More data on abundance gradients both locally and at high redshift are necessary to confirm this conclusion.Comment: Accepted by A&