Allocentric Versus Egocentric Spatial Memory After Unilateral Temporal Lobectomy in Humans.

Thirty patients who had undergone either a right or left unilateral temporal lobectomy (14 RTL; 16 LTL) and 16 control participants were tested on a computerized human analogue of the Morris Water Maze. The procedure was designed to compare allocentric and egocentric spatial memory. In the allocentric condition, participants searched for a target location on the screen, guided by object cues. Between trials, participants had to walk around the screen, which disrupted egocentric memory representation. In the egocentric condition, participants remained in the same position, but the object cues were shifted between searches to prevent them from using allocentric memory. Only the RTL group was impaired on the allocentric condition, and neither the LTL nor RTL group was impaired on additional tests of spatial working memory or spatial manipulation. The results support the notion that the right anterior temporal lobe stores long-term allocentric spatial memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Locally random reductions: Improvements and applications

A (t, n)-locally random reduction maps a problem instancex into a set of problem instancesy ₁,...,y _n in such a way that it is easy to construct the answer tox from the answers toy ₁,...,y _n, and yet the distribution ont-element subsets ofy ₁,...,y _n depends only on |x|. In this paper we formalize such reductions and give improved methods for achieving them. Then we give a cryptographic application, showing a new way to prove in perfect zero knowledge that committed bitsx ₁,...,x _m satisfy some predicateQ. Unlike previous techniques for such perfect zero-knowledge proofs, ours uses an amount of communication that is bounded by a fixed polynomial inm, regardless of the computational complexity ofQ. These results were presented in preliminary form at the 10th Annual Crypto Conference, Santa Barbara, CA, August 1990. The work of D. Beaver was done at Harvard University, supported in part by NSF Grant CCR-870-4513. The work of J. Kilian was done at MIT and Harvard University, supported by an NSF postdoctoral fellowship.     

On coherence, random-self-reducibility, and self-correction

We study three types of self‐reducibility that are motivated by the theory of program verification. A set A is random‐self‐reducible if one can determine whether an input x is in A by making random queries to an A‐oracle. The distribution of each query may depend only on the length of x. A set B is self‐correctable over a distribution if one can convert a program that is correct on most of the probability mass of to a probabilistic program that is correct everywhere. A set C is coherent if one can determine whether an input x is in C by asking questions to an oracle for C–{x}.?We first show that adaptive coherence is more powerful than nonadaptive coherence, even if the nonadaptive querier is nonuniform. Blum et al.(1993) showed that every random‐self‐reducible function is self‐correctable. It is unknown, however, whether self‐correctability implies random‐self‐reducibility. We show, assuming a reasonable complexity‐theoretic hypothesis, that certain hard, sparse, tally sets exist, and that there is a self‐correctable function which is not random‐self‐reducible. For easily samplable distributions, however, we show that constructing a self‐correctable function that is not random‐self‐reducible is as hard as proving that P is different from PP. Received: 14 June, 1996     

Safety evaluation of an ionized multilayer plastic film used for vacuum cooking and meat preservation.

The main concern in safety evaluation of ionized plastic food packaging materials is the possible formation of unsuspected potential migrants. Solvent extracts and migrates of a polypropylene-based multilayer film, beta-irradiated at 80 kGy and widely used for vacuum cooking of packaged meat were studied, using complementary analytical techniques. 1H-NMR and HPLC showed that 96% of the initial phenolic stabilizer was not found after irradiation. A phosphite stabilizer and its reaction products, identified by GC-MS, accounted for 35% of the initial amount. The sum of all potential migrants derived from the additives accounted for less than 1% of global migration. This global migration was mainly due to oligomers. By comparison our results with literature work done with the same film, but at lower doses, it was suggested that larger electron beam doses reduce the possibility of migration and enhance the consumer's safety.     

Food and packaging interactions: determination of the kinetic parameters of olive oil diffusion in polypropylene using concentration profiles.

The penetration of olive oil into polypropylene was studied in order to allow a complete modellization of food and packaging interactions. Oil concentration profiles through polypropylene food trays were determined by FTIR-microscopy measurements along the thickness at various times. Calculations of the relevant parameters characterizing Fickian diffusion, namely constant diffusivity, coefficient of convective mass transport on the surface and concentration at equilibrium were carried out. This way of working has proven to be considerably shorter and more accurate than the method consisting of recording the global absorbance of the substance absorbed, especially when the amount of diffusing fat is low. Major conclusions are: that absorption of olive oil is strongly influenced by convection; the diffusion coefficient of olive oil in polypropylene is constant. Possible consequences to simplify global migration testing are discussed.     

Multiple sources of test bias on the WISC-R and Bender-Gestalt Test.

Test bias on the WISC-R and Bender-Gestalt Test was assessed through multiple statistical procedures: internal consistency, item difficulty, correlations of item–total correlations, concurrent validity, and construct validity. These procedures were applied to WISC-R and Bender data of 436 7–14 yr olds from 3 racial–ethnic groups (Anglo-American, Black, and Mexican American) and 2 social classes (low and middle). The statistical procedures investigated bias as a function of children's sex, race, socioeconomic status, age, birth order, health, family size, family structure, and urban acculturation. On the Bender, evidence of bias was infrequent and irregular. On the WISC-R, group differences were most discernible for age (as expected), sex, family structure, and race. Although these differences are noteworthy, consistent patterns of bias were not apparent among the 9 comparison groups. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reliability Programs for Commercial Communication Satellites

This paper describes reliability programs that are in use for commercial communication satellites. Environmental conditions are presented along with system concerns and design, constraints. Significant procurement policy factors are pointed out, including the development of a request for proposal, contractual provisions, on-site representation of the procuring organization at prime contractor and other facilities, and incentive provisions in contracts. The implementation of procurement policies is discussed from an historic perspective with reference to a present-day list of salient plan elements and experiences that inspired the invoking of these elements. Some of the payoffs of reliability program efforts are mentioned. While the complexity of commercial communications satellites has been increasing, high system reliability has been maintained. As an example, the continuity of service for the INTELSAT space segment has been greater than 0.99995 since 1970. This has been achieved largely through effective reliability programs that have been based on conservative design techniques and stringent product assurance requirements.     

The polyunsaturated fatty acid and cholesterol concentrations of plasma and aorta and their relationship to avian atherosclerosis

Growing cockerels were fed diets varying in level of protein and cholesterol and in the type of fat. Their plasma and aortas were examined for cholesterol, polynsaturated fatty acids, and atherosclerotic involvement.

1. 1.
   The cholesterol levels of plasma and aorta were increased by low-protein diets and by added dietary cholesterol, singly or in combination.     

Molecular basis of lipoamide dehydrogenase deficiency in Ashkenazi Jews

PURPOSE: To measure binocular function and patient satisfaction with monovision induced by photorefractive keratectomy (PRK) in myopic presbyopic patients. SETTING: Refractive Department, Cleveland Clinic, Cleveland, Ohio, USA. METHODS: This study comprised 21 myopic presbyopic patients with monovision induced by PRK. Sixteen emmetropic patients who had PRK served as a control group. Monovision was induced by undercorrecting the nondominant eye by 1.25 diopters for near vision and correcting the dominant eye with emmetropia for distance vision. Monocular and binocular uncorrected Snellen visual acuities at 20 feet and 13 inches, manifest refraction, ocular dominance, stereopsis at 20 feet and 13 inches, monocular and binocular contrast sensitivities, Worth-4-Dot test at 20 feet and 1/3 of a meter, and fusional convergence amplitudes were examined in each patient. RESULTS: In the monovision group at near and distance, 20 patients (95.3%) had binocular visual acuity of 20/25 or better. No patient in the monovision group used reading glasses postoperatively; 4 of 16 patients (25.0%) in the control group used such glasses. All patients maintained binocular fusion and stereo acuity ranging from 40 to 800 seconds of arc. Mean patient satisfaction was 86% (range 40% to 100%). In the control group, 12 patients (75.0%) had binocular distance visual acuity of 20/25 or better and 11 (68.8%) had binocular near visual acuity of 20/25 or better. CONCLUSION: Monovision PRK patients had better near vision than control PRK patients, with minimal compromise in stereo acuity and overall high patient satisfaction.     

Migration of additives from polymers into food simulants: numerical solution of a mathematical model taking into account food and polymer interactions

The principle of a computing program describing precisely the migration of additives from a polymer into a food simulant is presented. As six parameters are used to fit the simulant sorption and additive extraction kinetics, the parameters have been determined by independent experiments. Owing to the complicated coupling between the liquid and additive diffusion processes, migration kinetics cannot be obtained by a mathematical resolution of kinetic equations, but they must be calculated by numerical analysis. The method is applied to a UV absorber in polypropylene migrating into glyceryl tripelargonate, a pure triglyceride, of which behaviour and average molecular weight are similar to official fatty food simulants. Properly designed experiments validate the model used to fit the migration kinetics. The possibility of erasing any parameters is also discussed.