Task-specific monitoring of nuclear medicine technologists' radiation exposure

Many studies have demonstrated that the exposure of nuclear medicine technologists arises primarily from radioactive patients rather than from preparation of radiopharmaceuticals. However, in order to devise strategies to reduce staff exposure, it is necessary to identify the specific tasks within each procedure that result in the highest radiation doses. An ESM Eberline FH41B-10 radiation dosemeter, which records the ambient dose equivalent rate, was used to monitor the radiation exposure of a technologist and to record the dose rate in microSv per hour every 32 s throughout a working day. The technologist recorded the procedures that were being performed so that the procedures that resulted in higher doses could be identified clearly. The measured doses clearly showed that the major contributions to the technologist's dose were the following: (1) transferring incapacitated patients from the imaging table to a hospital trolley; (2) difficult injections without syringe shields; and (3) setting up patients for gated myocardial scans. The average dose to the technologist from transferring patients after a bone scan was 0.54 microSv, 40% of the total dose of 1.3 microSv for the complete bone scan procedure. The average dose received injecting 900 MBq of 99Tcm-HDP using a tungsten syringe shield was 0.57microSv, but the highest dose was 1.6 microSv, in a patient in whom the injection was difficult. A 0.5 mm lead apron was found to reduce the dose when setting up a patient for a gated stress 99Tcm-sestamibi myocardial scan by approximately a factor of 2. The average dose per patient for this task was reduced from 1.1 to 0.6 microSv. It is recommended that staff waiting for assistance with patient transfers stand away from the patient, that tungsten syringe shields be used for all radiopharmaceutical injections and that a 0.5 mm lead apron be worn when attending patients containing high activities of 99Tcm radiopharmaceuticals, such as those having myocardial imaging.     

Schwa-Deletion in Hindi Text-to-Speech Synthesis

We describe the phenomenon of schwa-deletion in Hindi and how it is handled in the pronunciation component of a multilingual concatenative text-to-speech system. Each of the consonants in written Hindi is associated with an inherent schwa vowel which is not represented in the orthography. For instance, the Hindi word pronounced as [namak] (salt) is represented in the orthography using the consonantal characters for [n], [m], and [k]. Two main factors complicate the issue of schwa pronunciation in Hindi. First, not every schwa following a consonant is pronounced within the word. Second, in multimorphemic words, the presence of a morpheme boundary can block schwa deletion where it might otherwise occur. We propose a model for schwa-deletion which combines a general purpose schwa-deletion rule proposed in the linguistics literature (Ohala, 1983), with additional morphological analysis necessitated by the high frequency of compounds in our database. The system is implemented in the framework of finite-state transducer technology.     

FACTORS DESCRIPTIVE OF PSYCHOPATHOLOGY AND BEHAVIOR OF HOSPITALIZED PSYCHOTICS.

"A sample of 423 psychotic patients from five veterans hospitals was observed and rated on behavior in the interview and on the ward. The intercorrelations between 55 of the rating scales were subjected to a multiple group factor analysis. The 11 oblique first order factors were interpreted." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of a physical symptom as a defense against psychosis.

It was hypothesized that, since anxiety is one of the main stress factors in producing psychotic symptoms, a psychotic's symptoms might decrease if his anxiety could be decreased. Using a single schizophrenic patient the authors attempted to relieve him of his psychotic symptoms by replacing them with a physical one. The symptom chosen was backache because the patient's history suggested that it would be more acceptable to him. A "conditioning" method, extending over a period of 3 months, was followed by all staff members having contact with the patient. Following this procedure, although no basic personality change occurred, the patient was able to make a satisfactory adjustment outside the hospital using his "back pain" as a defense. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Work redesign and motivation.

The redesign of jobs and work systems is frequently carried out to increase organizational productivity and/or to improve the quality of the work experiences of organization members. Four theoretical approaches to work redesign (activation theory, motivation–hygiene theory, job characteristics theory, and the sociotechnical theory) are reviewed and compared, and the kinds of personal and work outcomes that can reasonably be expected from restructuring jobs are discussed. A number of unanswered questions (e.g., the role of individual differences, diagnostic and evaluation methodologies, and the job of the supervisor) about the strategy and tactics of redesigning jobs are presented, and some problems in installing work redesign programs in existing organizations are outlined. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid Annealing Response of the Hardened 1802 Bulk CMOS Microprocessor

Rapid annealing test results show that the hardened RCA/Sandia 1802 Bulk CMOS Microprocessor will function immediately after application of intense ionizing radiation pulses. This result was established in LINAC tests using a comprehensive test procedure which exercised the ?P in logarithmic time intervals from 10 ?s to 1000 s. It was found that no loss of functionality occurs for doses up to about 280 KRads. At 790 KRads, the device initially loses functionality but anneals in 600 ms. At 1.6 MRads, the device loses functionality for 4 s, and at 2.4 MRads, the device loses functionality for at least 1000 s. A sample size of five devices was used. The 1802 ?P was tested using hardware and software especially designed for this purpose. The microprocessor was exercised using software routines of exponentially increasing length starting at 10 ?s after the pulse. A measure of ?P functionality was therefore provided at logarithmically increasing sample times, After 2 seconds was reached, the routines repeated every two seconds up to 1000 seconds when the test ended. The hardware and software are described in detail.     

Children's choice of playground equipment: Development of methodology for integrating user preferences into environmental engineering.

Determined whether preference scaling techniques could be used to aid engineering system design. Children's play equipment was selected as the design area. Paired comparison and rank-order methods were used to determine whether 48 3rd-4th graders had preferences for different types of play equipment; whether these preferences were reliable over time; and whether actual use of play equipment was predictable from the preference scales developed. Photographic stimuli were used for the scaling and were presented to Ss. The frequency of use of play equipment was also determined using time-lapse photography. Results indicate that (a) Ss did have stable and reliable preferences for play equipment and (b) these preferences were correlated with actual usage of the equipment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-Temperature/Field Alternating-Current Behavior of ZnO-Based Varistors

The ac electrical response of the grain boundary in the ZnO–Bi₂O₃-based varistor system (in the frequency range 10⁻²≤f≤10⁷ Hz) has been analyzed using complex plane analysis techniques as a function of temperature (90°≤T≤150°C) and electric field (E_60%lmA/cm2≤E≤E_lmA/cm2). The high-temperature/field data were best represented in the impedance plane. The lumped parameter equivalent circuit representation, containing a voltage variable resistive element associated with the grain boundary, was in agreement with a model previously reported in the literature. The resulting equivalent circuit representation of the grain-boundary response consisting of a resistance and a capacitance are interpreted in terms of various phenomena occurring at the electrical thickness of the grain boundary.     

Interactive Graphical Minimax Location of Multiple Facilities with General Constraints

An optimal algorithm for solving constrained minimax location problems has been previously reported, with the major limitation that only a single new service facility is allowed. Algorithmic extensions have now been developed and implemented on an advanced color-graphics system for the location of any number of new facilities to collectively serve the set of existing facilities. The minimax criterion is again considered for the optimization, and nonconvex constraint sets are permitted.     

Improved Wavenumber Resolution for Small Arrays

The objective of the method described is to compute the Fourier transform of a function of space and time with a significant improvement in the resolution of spatial frequencies, particularly in the case of small arrays for which the size of the array is on the order of one wavelength (or less). This improvement is initially developed by considering the conversion of spatial frequency into temporal frequency through the oscillatory motion of a single receiver. A more practical scheme is next presented in which the oscillatory motion is created synthetically by the appropriate sequential sampling of individual elements in a receiving array. Both forms of this method (realand synthetic motion) besides providing some degree of ?super-resolution? are linear and indicative of amplitude as well as phase.