Seeds of change

It's been eight years since genetically modified seeds first came on the market. Farmers have seen some advantages, but certain consumers, particularly those abroad, are still resisting the technology.Agriculture ; Biotechnology

The Role of Edges and Line-Ends in Illusory Contour Formation

Illusory contours can be induced along directions approximately collinear to edges or approximately perpendicular to the ends of lines. Using a rating scale procedure we explored the relation between the two types of inducers by systematically varying the thickness of inducing elements to result; in varying amounts of "edge-like" or "line-like" induction. Inducers for om illusory figures consisted of concentric rings with arcs missing. Observers judged the clarity and brightness of illusory figures as the number of arcs, their thicknesses, and spacings were parametrically varied. Degree of clarity and amount of induced brightness were both found to be inverted-U functions of the number of arcs. These results mandate that any valid model of illusory contour formation must account for interference effects between parallel lines or between those neural units responsible for completion of boundary signals in directions perpendicular to the ends of thin lines. Line width was found to have an effect on both clarity and brightness, a finding inconsistent with those models which employ only completion perpendicular to inducer orientation.Air Force Office of Scientific Research (F49620-92-J-0334, URI 90-0175, F49620-92-J-0334); National Science Foundation (Graduate Fellowship); Office of Naval Research (N00014-91-J-4100

THE ECONOMIC RECOVERY PROGRAM AND THE 1981 FARM BILL

Agricultural and Food Policy,

XBATTLE: A Dynamic Distributed Model of Generalized Military Conflict

A dynamic distributed model is presented that reproduces the dynamics of a wide range of varied battle scenarios with a general and abstract representation. The model illustrates the rich dynamic behavior that can be achieved from a simple generic model

Elastic properties of silicate melts: Implications for low velocity zones at the lithosphere-asthenosphere boundary.

Low seismic velocity regions in the mantle and crust are commonly attributed to the presence of silicate melts. Determining melt volume and geometric distribution is fundamental to understanding planetary dynamics. We present a new model for seismic velocity reductions that accounts for the anomalous compressibility of silicate melt, rendering compressional wave velocities more sensitive to melt fraction and distribution than previous estimates. Forward modeling predicts comparable velocity reductions for compressional and shear waves for partially molten mantle, and for low velocity regions associated with the lithosphere-asthenosphere boundary (LAB), melt present at <5% distributed in near-textural equilibrium. These findings reconcile seismic observations for the LAB regionally and locally and favor models of strong coupling across the LAB rather than melt channeling due to shear deformation

A What-and-Where Neural Network for Invariant Image Preprocessing

A feedforward neural network for invariant image preprocessing is proposed that represents the position1 orientation and size of an image figure (where it is) in a multiplexed spatial map. This map is used to generate an invariant representation of the figure that is insensitive to position1 orientation, and size for purposes of pattern recognition (what it is). A multiscale array of oriented filters followed by competition between orientations and scales is used to define the Where filter.British Petroleum (89-A-1024); Defense Advanced Research Projects Agency (90-0083); National Science Foundation (IRI 90-00530); Office of Naval Research (N0014-91-J-4100); Air Force Office of Scientific Research (90-0175); NSF Graduate Fellowshi

The What-And-Where Filter: A Spatial Mapping Neural Network for Object Recognition and Image Understanding

The What-and-Where filter forms part of a neural network architecture for spatial mapping, object recognition, and image understanding. The Where fllter responds to an image figure that has been separated from its background. It generates a spatial map whose cell activations simultaneously represent the position, orientation, ancl size of all tbe figures in a scene (where they are). This spatial map may he used to direct spatially localized attention to these image features. A multiscale array of oriented detectors, followed by competitve and interpolative interactions between position, orientation, and size scales, is used to define the Where filter. This analysis discloses several issues that need to be dealt with by a spatial mapping system that is based upon oriented filters, such as the role of cliff filters with and without normalization, the double peak problem of maximum orientation across size scale, and the different self-similar interpolation properties across orientation than across size scale. Several computationally efficient Where filters are proposed. The Where filter rnay be used for parallel transformation of multiple image figures into invariant representations that are insensitive to the figures' original position, orientation, and size. These invariant figural representations form part of a system devoted to attentive object learning and recognition (what it is). Unlike some alternative models where serial search for a target occurs, a What and Where representation can he used to rapidly search in parallel for a desired target in a scene. Such a representation can also be used to learn multidimensional representations of objects and their spatial relationships for purposes of image understanding. The What-and-Where filter is inspired by neurobiological data showing that a Where processing stream in the cerebral cortex is used for attentive spatial localization and orientation, whereas a What processing stream is used for attentive object learning and recognition.Advanced Research Projects Agency (ONR-N00014-92-J-4015, AFOSR 90-0083); British Petroleum (89-A-1204); National Science Foundation (IRI-90-00530, Graduate Fellowship); Office of Naval Research (N00014-91-J-4100, N00014-95-1-0409, N00014-95-1-0657); Air Force Office of Scientific Research (F49620-92-J-0499, F49620-92-J-0334

Parmenides on Knowing What-is and What-is-not

Parmenides presented himself to his audiences as one who had achieved a profound insight into the nature of to eon or “what-is.” In support of this claim he conducted an elenchos or “testing” of the ways of inquiry available for thinking, in the process revealing a set of informative sêmata or “signs.” In this respect Parmenides was speaking the language of discovery heard elsewhere in early Greek poetry. Similarly, his claim that we can neither learn nor know about what-is-not (hence must not say or think “it is not”) was justified by the ordinary meaning of the ancient Greek verbs for learning and knowing. Strikingly, Parmenides’ revisionary metaphysics rested in large measure on a widely shared view of what can be learned, known, and made known to others.Parmênides se apresenta ao seu público como alguém que alcançou um profundo discernimento da natureza de to eon ou “o-que-é”. Para sustentar essa posição ele efetuou um elenchos ou “prova” dos caminhos de inquérito disponíveis para pensar, identificando e depois usando, durante o processo, um conjunto de sēmata ou “signos” informativos. A esse respeito, Parmênides falava a linguagem da descoberta que ouvira na antiga poesia grega. Do mesmo modo, sua afirmação de que nós não podemos nem aprender e nem conhecer o-que-não-é (logo, não devemos dizer ou pensar “não é”) era justificada pelo sentido comum dos antigos verbos gregos para aprender e conhecer. De maneira impressionante, a metafísica revisionista de Parmênides se apoiava em grande medida na visão amplamente compartilhada daquilo que pode ser aprendido, conhecido e tornar conhecido a outros

Jessie Jarrett

This is a story of some of the people who lived on great ranches during the early days of Kansas history. With the exception of Fort Hays, all places described are imaginary; and all persons mentioned are purely fictional and bear no resemblance to anyone living or dead