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The paper reports a study on the involvement of the visual system during work at video terminal. The results of the investigations on a group of operators in a computation centre were used for describing an optimum anatomicofunctional visual type for work at video terminal and the hygiene rules to be observed during work at the computer screen.
An on-line computer system for administration of the radioisotope use has been developed. This system consists of a multi-job type host computer and two sets of personal computers with identification card-readers. The personal computers are employed as terminal devices for radioisotope users. By the use of an identification card, entrance and leaving times are recorded automatically. Furthermore, an easy operation of the personal computer permits users to access to the information of their registered radioisotopes, such as nuclides, chemical forms, updated activities, storage locations, and history of usage. A recording sheet on which those data are printed is provided from the personal computer. After the use of radioisotopes, users can record their data on the recording sheets. These records are used as the input data to this system to update the data of the used radioisotopes. Owing to the concise format of the recording sheet and various sorting programs developed in present work, this system enables us to grasp the exact flow of the radioisotopes from purchase to disposal. Out-put data from high-speed kanji printer can provide many important books which are legally requested to be kept for administration of the radioisotope use.
The coming years promise great advances in the storing, recording, and communication of medical data. Handheld computers may make bedside terminals obsolete. CD-ROM's storage capacity will eliminate data retention problems as well as provide for storage images. Doctors should be able to access computers merely by talking. Home monitoring equipment that the physician can access by telephone should reduce hospital stays. Computerized decision support, neurocomputing, cost-cutting through automation: all these concepts are at the cutting edge of medical information technology.
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The afferent innervation pattern of inner hair cells in the apex of the guinea pig cochlea was studied using serial reconstruction of semithick (0.25-micron) sections and high-voltage electron microscopy (HVEM). This thickness produced a good compromise between the ability to resolve details of the synaptic contacts between the hair cells and sensory neurons and the number of sections required to reconstruct the nerve terminals within the receptor organ. The use of a goniometer allowed the sections to be tilted to angles optimum for viewing either the synaptic membrane specializations or the presynaptic bodies. Reasonably good images of 0.25-micron sections could be obtained using a conventional 120-keV microscope, but the images produced by the HVEM were clearly superior. The sensory nerve terminals and hair cells were reconstructed using a microcomputer-based computer-aided-design system. Nerve terminals with complex shapes could be successfully rendered as surface models viewed as stereo pairs. The advantages and limitations of the techniques used are discussed.
The authors have developed this system (AIS), realized via CM 1420 mini-computer for many-terminal regime. The program provides operation in both the instruction and control modes; the control is realized via a display, that permits individual dialogues of students with the computer. The dialogue involves 12-16 questions in the curriculum. The answers are estimated and remembered by the computer. When the operation in the control mode is over, a register with students' marks is printed out. Therefore, the suggested AIS promotes autotraining of the students in this course and rules out the subjective aspects in assessment of students' knowledge.
Transmission electron micrographs from serial sections were obtained from the neural pole of outer hair cells (OHCs) in the Japanese macaque (Macaca fuscata) and reconstructions of nerve terminals were made using computer software. Data are based on observations of six cells in the basal turn, eight in the middle turn and four in the apex. In general, the number of afferent (type II) terminals on each OHC increased from base to apex, and for a given turn, the numbers appeared unrelated to OHC row. On the other hand, the number of efferent terminals was greater in the middle turn than in other areas, and the number decreased from row 1 to row 3. Reciprocal synapses increased in frequency from the upper basal turn apicalward. The total number of terminals synapsing on an individual OHC increased from base to apex by nearly 100%. Three-dimensional reconstructions showed that nerve fibers terminating on basal and middle turn OHCs ascended directly from sub-OHC regions to synapse on the subnuclear regions of the OHC. In contrast, apical turn fibers ran horizontally at the level of the subnuclear region and the terminals appeared as en passant swellings along a single fiber. Although physiological data are wanting for the macaque, the anatomical findings suggest that functional differences may exist along the length of the cochlea.
Pigeons were trained on a two-link concurrent chain schedule in which responses on two keys were reinforced according to independent variable-interval schedules by the production of a change in key color. Further responses on the key on which the stimulus change had been produced gave a single food reinforcement and a return to concurrent variable-interval conditions. On one key the terminal link was a two-valued mixed-interval schedule, while on the other, the terminal link was a fixed-interval schedule. When the mixed-interval values were kept constant and the fixed-interval values varied, relative response rates in the initial concurrent links matched relative reinforcement rates in the terminal links when these were computed from cubic transformations of the reciprocals of the intervals comprising the terminal link schedules.
Extensive use of video display terminals (VDTs) and reports of suspected adverse health effects attributed to their operation have increased operator concern and interest. Information to assist supervisors and health personnel in responding to health-related questions and in evaluating the workplace for dangers concerning VDTs is provided.
For several years and under various aspects we have studied diet termination in twenty-two early and late treated patients with phenylketonuria. Time of diet termination was the completed eighth year. For evaluation of possible functional CNS deficits, we applied psychometric tests, methods for testing psychomotor behavior and, in addition, neurophysiological parameters and registrations of sleep EEG. EEG morphology was studied visually and the rhythms of the different phases of sleep were quantified by computerized spectral analysis. EEG was studied during diet therapy when phenylalanine levels in blood were low and after a relatively short period of four months with elevated phenylalanine blood levels. At least two years after diet termination with correspondingly elevated phenylalanine blood levels the EEG was studied once more. Compared to the respective findings before diet termination in these patients there were no significant changes of the sleep EEG seen, neither on visual nor on spectral analysis. We have seen in this study minor EEG changes in early treated children and overtly pathological EEG changes in late treated PKU patients with cerebral damage, both before and after diet termination. Ultrastructural CNS defects may be the cause of these anomalies which do not respond to the actual biochemical situation at the age of eight to ten years. The morphology of such defects may include altered synaptic maturation and may occur already in an early phase before the diet therapy is implemented.
Molecular dynamics computer simulations were performed for the 25-residue N-terminal tail of the H3 histone protein in the proximity of a DNA segment of 10 base pairs (bp), representing a model for the linker DNA in chromatin. Several least biased configurations were used as initial configurations. The secondary structure content of the protein was increased by the presence of DNA close to it, but the locations of the secondary motifs were different for different initial orientations of the DNA grooves with respect to the protein. As a common feature to all simulations, the electrostatic attraction between negatively charged DNA and positively charged protein was screened by the water solvent and counterbalanced by the intrinsic compaction of the protein due to hydrophobic effects. The protein secondary structure limited the covering of DNA by the protein to 4-5 bp. The degree of compaction and charge density of the bound protein suggests a possible role of H3 tail in a nonspecific bending and plasticity of the linker DNA when the protein is located in the crowded dense chromatin.
Conformational studies of the peptides constructed from achiral amino acid residues Aib and Delta(Z)Phe (I) Ac-Aib-Delta(Z)Phe-NHMe (II), and Ac-(Aib-Delta(Z)Phe)(3)-NHMe; peptides III-VI having L-Leu or D-Leu at either the N- or the C-terminal position and of peptides VII-X having Leu residues in different enantiomeric combinations at both the N- and the C-terminal positions in peptide II have been studied to design the peptide with the required helical sense. Peptide II, as expected, adopts degenerate left- and right-handed helical structures. It has been shown that the peptides IV and VI having D-Leu at either the N or the C terminus can be realized in the right-handed helical structure with the phi,psi values of -20 degrees and -60 degrees for the Aib/Delta(Z)Phe residues. L-Leu and D- Leu at both the terminals in peptides VII and VIII, respectively, have hardly any effect as both the left- and the right-handed structures are found to be degenerate. Peptides III and IX can be realized in right- and left-handed helical structures, respectively, in solvents of low polarity whereas peptides V and X are predicted to be in the right-handed helical structures stabilized by carbonyl-carbonyl interactions without the formation of hydrogen bonds. The conformational states with the phi,psi values of 0 degrees and -85 degrees in peptide V are characterized by rise per residue of 2.03 A, rotation per residue of 117.5 degrees , and 3.06 residues per turn. In all peptides having Leu residue at the N terminus, the methyl moiety of the acetyl group is involved in the CH/pi interactions with the Cepsilon--Cdelta edge of the aromatic ring of Delta(Z)Phe (3) and the amino group NH of Delta(Z)Phe is involved in the NH/pi interactions with its own aromatic ring. The CH(3) groups of the Aib residues are also involved in CH/pi interactions with the i + 1th and i + 3th Delta(Z)Phe's aromatic side chains.
A direct numerical integration method, as modified by Du Fort and Frankel (1953), has been used to solve the partial differential equation system which describes the spread of action potential in a mammalian nerve terminal. Branching of the terminal as well as inhomogeneous distributions of Na+ and K+ voltage-dependent channels (Brigant and Mallart 1982) have been incorporated in the model. Using the channel densities and the kinetic parameters measured in the node of Ranvier, the depolarization in the terminal branches has an amplitude of only 60% of the action potential in the node. Furthermore, the time courses of the calculated membrane currents differ considerably from the ones measured by Brigant and Mallart (1982) and by Konishi and Sears (1984). Increasing the Na+ and K+ channel densities may considerably increase the terminal depolarization and also reproduce qualitatively the current wave-forms observed experimentally. The model can also reproduce some of the effects of pharmacological channel blocks. The simulation allows a new interpretation of the different components of membrane current along the terminal.
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Explore the source record for details and available documents.