University of Houston

About: University of Houston is a education organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 23074 authors who have published 53903 publications receiving 1641968 citations.

Recent models and findings in visual backward masking: A comparison, review, and update

Abstract: Visual backward masking not only is an empirically rich and theoretically interesting phenomenon but also has found increasing application as a powerful methodological tool in studies of visual information processing and as a useful instrument for investigating visual function in a variety of specific subject populations. Since the dual-channel, sustained-transient approach to visual masking was introduced about two decades ago, several new models of backward masking and metacontrast have been proposed as alternative approaches to visual masking. In this article, we outline, review, and evaluate three such approaches: an extension of the dual-channel approach as realized in the neural network model of retino-cortical dynamics (Ogmen, 1993), the perceptual retouch theory (Bachmann, 1984, 1994), and the boundary contour system (Francis, 1997; Grossberg & Mingolla, 1985b). Recent psychophysical and electrophysiological findings relevant to backward masking are reviewed and, whenever possible, are related to the aforementioned models. Besides noting the positive aspects of these models, we also list their problems and suggest changes that may improve them and experiments that can empirically test them.

A new elastographic method for estimation and imaging of lateral displacements, lateral strains, corrected axial strains and Poisson's ratios in tissues.

Abstract: A major disadvantage of the current practice of elastography is that only the axial component of the strain is estimated. The lateral and elevational components are basically disregarded, yet they corrupt the axial strain estimation by inducing decorrelation noise. In this paper, we describe a new weighted interpolation method operating between neighboring RF A-lines for high precision tracking of the lateral displacement. Due to this high lateral-tracking precision, quality lateral elastograms are generated that display the lateral component of the strain tensor. These precision lateral-displacement estimates allow a fine correction for the lateral decorrelation that corrupts the axial estimation. Finally, by dividing the lateral elastogram by the axial elastogram, we are able to produce a new image that displays the distribution of Poisson's ratios in the tissue. Results are presented from finite-element simulations and phantoms as well as in vitro and in vivo experiments.

Asymmetric Cation Coordination in Oxide Materials: Influence of Lone-Pair Cations on the Intra-octahedral Distortion in d0 Transition Metals

Abstract: The oxides that contain both a d0 transition metal (Ti4+, Nb5+, W6+, etc.) and a lone-pair cation (Sn2+, Se4+, Te4+, etc.) are examined to investigate the influence of the lone-pair cation on the i...