Use of the Ober2 Model B-1200 system for analysis of eye movements made during reading.

BACKGROUND: The Ober2 Model B-1200 system uses infrared reflections to record and analyze eye movements made during reading. The system's ability to analyze data from normal subjects and the reliability of the data produced by subjects who read standard paragraphs were investigated. METHODS: Forty-two optometry students and 20 junior high school students, all self-assessed normal readers, read five different Taylor test paragraphs during each of two sessions. Ober2 Model B-1200 analysis was attempted for each paragraph; when analysis was successful, grade-equivalent scores based on fixations, span of recognition, regressions, fixation duration, and reading rate were determined. RESULTS: The Ober2 Model B-1200 system was unsuccessful in analyzing data from 30% of the paragraph presentations; manual calibration procedures allowed no additional data analysis. Using mean grade-equivalent data from 16 optometry student subjects for whom all 10 paragraphs could be analyzed, significant differences were found between results for two of the test paragraphs. Split-half inter-session reliability coefficients for grade-equivalent data ranged from 0.84 to 0.95. No intra-session learning or fatigue effects on reading data were found. CONCLUSIONS: Although the Ober2 Model B-1200 potentially can provide valuable information on eye movements made during reading, problems exist with respect to its ability to analyze data. The analysis failures significantly limited the value of this system.

A new approach to optimal selection of services in health care organizations.

A new reimbursement policy adopted by Medicare in 1983 caused financial difficulties for many hospitals and health care organizations. Several organizations responded to these difficulties by developing systems to carefully measure their costs of providing services. The purpose of such systems was to provide relevant information about the profitability of hospital services. This paper presents a new method of making hospital service selection decisions: it is based on an optimization model that avoids arbitrary cost allocations as a basis for computing the costs of offering a given service. The new method provides more reliable information about which services are profitable or unprofitable, and it provides an accurate measure of the degree to which a service is profitable or unprofitable. The new method also provides useful information about the sensitivity of the optimal decision to changes in costs and revenues. Specialized algorithms for the optimization model lead to very efficient implementation of the method, even for the largest health care organizations.

Four new haplotypes observed in Algerian beta-thalassemia patients.

beta-Thalassemia, a heterogeneous group of human anemias affecting the expression of beta-globin, is caused by a number of molecular defects. Restriction endonuclease mapping of ethnic populations has revealed many polymorphisms within and around the beta-like globin genes, combinations of which are assigned as haplotypes. Several haplotypes appear to be strongly linked with the molecular defects causing thalassemia in Greek and Italian patients (Orkin et al. 1982). We describe here haplotypes from 40 Algerian beta-thalassemic patients and eight normals determined by restriction endonuclease mapping at seven polymorphic sites. Four haplotypes previously unreported were observed in these thalassemic patients; this argues the existence in this population of undescribed beta-thalassemia alleles. The knowledge of the haplotypes in thalassemic families could be used for prenatal diagnosis of homozygote forms.

GAGESIGHT: A Computer Vision System for Automatic Inspection of Instrument Gauges.

GAGESIGHT is a computer vision system recently integrated into production which demonstrates new flexibility in production automation technology. The vision algorithm accommodates significant misregistration in the position and orientation of objects, and adjusts process control parameters accordingly. The GAGESIGHT system is easily reconfigured for inspecting new types of objects by executing a teach program, and responding to a few instructions at an interactive display console. GAGESIGHT, intially intended for the automatic inspection and assembly of pointers and other components to instrument gauges, is finding new applications as well since the approach employed makes few assumptions regarding the objects being viewed.

The genetics and biochemistry of urease in Ustilago violacea.

Two complementing loci in different linkage groups of the basidiomycete Ustilago violacea are involved in urease activity: a structural one (ure-1) and a second inferred to involve a permease (ure-2) locus. Two types of complementing mutations occur in the structural locus: null activity (ure-la) and obviously reduced activity (ure-1b). The ure-2 mutants lacked urease activity in vivo on the phenol red-urea est medium, but gave extracts with wild-type activity. Extracts from wild-type strains gave one site of urease activity after polyacrylamide gel electrophoresis. A number of ure-1b mutants and activity revertants from ure-1a mutants yielded electrophoretically variant urease sites. The results are discussed in terms of enzyme polymorphism in haploid eukaryotes by one (missense) or two (null, then missense) mutations.