The detection of intentional contingencies in simple animations in patients with delusions of persecution

Background. It has been proposed that delusions of persecution are caused by the tendency to over-attribute malevolent intentions to other people's actions. One aspect of intention attribution is detecting contingencies between an agent's actions and intentions. Here, we used simplified stimuli to test the hypothesis that patients with persecutory delusions over-attribute contingency to agents' movements. Method. Short animations were presented to three groups of subjects: (1) schizophrenic patients; (2) patients with affective disorders; and (3) normal control subjects. Patients were divided on the basis of the presence or absence of delusions of persecution. Participants watched four types of film featuring two shapes. In half the films one shape's movement was contingent on the other shape. Contingency was either ‘intentional’: one shape moved when it ‘saw’ another shape; or ‘mechanical’: one shape was launched by the other shape. Subjects were asked to rate the strength of the relationship between the movement of the shapes. Results. Normal control subjects and patients without delusions of persecution rated the relationship between the movement of the shapes as stronger in both mechanical and intentional contingent conditions than in non-contingent conditions. In contrast, there was no significant difference between the ratings of patients with delusions of persecution for the conditions in which movement was animate. Patients with delusions of persecution perceived contingency when there was none in the animate non-contingent condition. Conclusions. The results suggest that delusions of persecution may be associated with the over-attribution of contingency to the actions of agents

The influence of polydispersity and inhomogeneity on EXAFS of bimetallic catalysts

The effect of polydispersity and inhomogeneity of supported bimetallic catalysts on the EXAFS analysis is investigated with some simple model calculations. These show that EXAFS is very insensitive to polydispersity. Polydispersity and inhomogeneous distribution of the metals over the particles however have only limited influence on the ability to distinguish between core-shell particles and particles with random distribution of both metals

Quantitative Plating of Gamma-Irradiated Cultures of a Blue-Green Alga

A method for quantitative recovery of the blue-green alga, Anacystis nidulans, after treatment with gamma rays is described, and data for the survival of the alga after exposure to a gamma source is presented. No conclusions could be drown by applying a multi-target model relating dosage to survival. Application of the data lo a revised target-theoretical expression which included the effects of a dose-dependent repair mechanism indicates that such a mechanism is present in A. nidulans. The validity of these dose-response models is discussed

Photoproduction of π+ mesons from hydrogen

The differential cross section for π+ photoproduction has been determined at 19 points, at center-of-mass angles from 30 to 150 deg, and at photon energies from 162 to 225 MeV. The data are concentrated near 180 MeV, where a full angular distribution has been determined. The relative values of the cross sections are accurate to 5% or better, and the absolute normalization is accurate to 4%. The experiment provides data of improved accuracy which are in general consistent with previous results. The extrapolation to threshold gives a value for (k*/p*)(dσ/dΩ)* at threshold of 16.1±0.7 μb/sr, where k*, p*, and (dσ/dΩ)* are the photon energy, pion momentum, and differential cross section, all in the center-of-mass system

Effect of skin dielectric properties on the read range of epidermal ultra-high frequency radio-frequency identification tags

This Letter presents an investigation of the effect of human tissue conductivity and permittivity on the performance of epidermal transfer tattoo ultra-high frequency radio-frequency identification (RFID) tags. The measurements were carried out on 20 individuals and the variations in the measured dielectric properties correlate well with variations in the measured tag read range on the individuals and to a lesser extent with their body mass index values. Simulation results also showed the effects of permittivity and conductivity on the designed resonance frequency of the RFID tag

III-V photonic crystal wire cavity laser on silicon wafer

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A Fisher-Rao metric for paracatadioptric images of lines

In a central paracatadioptric imaging system a perspective camera takes an image of a scene reflected in a paraboloidal mirror. A 360° field of view is obtained, but the image is severely distorted. In particular, straight lines in the scene project to circles in the image. These distortions make it diffcult to detect projected lines using standard image processing algorithms. The distortions are removed using a Fisher-Rao metric which is defined on the space of projected lines in the paracatadioptric image. The space of projected lines is divided into subsets such that on each subset the Fisher-Rao metric is closely approximated by the Euclidean metric. Each subset is sampled at the vertices of a square grid and values are assigned to the sampled points using an adaptation of the trace transform. The result is a set of digital images to which standard image processing algorithms can be applied. The effectiveness of this approach to line detection is illustrated using two algorithms, both of which are based on the Sobel edge operator. The task of line detection is reduced to the task of finding isolated peaks in a Sobel image. An experimental comparison is made between these two algorithms and third algorithm taken from the literature and based on the Hough transform

Creating traveling waves from standing waves from the gyrotropic paramagnetic properties of Fe3+^{3+} ions in a high-Q whispering gallery mode sapphire resonator

We report observations of the gyrotropic change in magnetic susceptibility of the Fe$^{3+}$ electron paramagnetic resonance at 12.037GHz (between spin states $|1/2>$ and $|3/2>$) in sapphire with respect to applied magnetic field. Measurements were made by observing the response of the high-Q Whispering Gallery doublet (WGH$_{\pm17,0,0}$) in a Hemex sapphire resonator cooled to 5 K. The doublets initially existed as standing waves at zero field and were transformed to traveling waves due to the gyrotropic response.Comment: Accepted for publication in Phys. Rev.