scholarly journals ALLOCATION OF ELECTRICAL RESPONSES FROM THE COMPOUND EYE OF GRASSHOPPERS

1942 ◽  
Vol 26 (1) ◽  
pp. 75-89 ◽  
Author(s):  
Theodore Louis Jahn ◽  
Verner John Wulff
Keyword(s):  
Compound Eye ◽  
Opposite Sign ◽  
Relative Magnitude ◽  
Wave Form ◽  
Component Theory ◽  
Complex Wave ◽  
Optic Ganglion ◽  
D Wave ◽  
Electrical Responses

1. The effect of extirpation of the optic ganglion on the ERG and on electrical oscillations recorded from the compound eye was determined. 2. Extirpation of the optic ganglion prevents the occurrence of oscillations, and it is concluded that they originate in the ganglion. 3. Extirpation of the optic ganglion changes the wave form of the ERG. The sharpness of the b-wave is decreased, the relative magnitude of the c-wave is increased, and the d-wave is obliterated. These changes can be explained by assuming that the ERG is the algebraic sum of two potential changes, one in the compound eye, and another, of opposite sign in the ganglion. This assumption is supported by data from a number of experiments in which the electrode positions were varied. 4. The explanation of the present data (which indicates two sites of origin of the ERG) is similar to the three-component theory which accounts for the complex wave form of the vertebrate ERG.

scholarly journals Recording of Retinal Action Potentials from Single Cells in the Insect Compound Eye

1961 ◽  
Vol 44 (3) ◽  
pp. 571-584 ◽  
Author(s):  
Kén-Ichi Naka
Keyword(s):  
Membrane Potential ◽  
Action Potentials ◽  
Compound Eye ◽  
Single Cells ◽  
Retinula Cell ◽  
Wave Form ◽  
Compound Eyes ◽  
Electrical Responses

Electrical responses were recorded intracellularly from the compound eyes of a fly (Lucilia) and of several dragonflies (Copera, Agriocnemis, and Lestes). An ommatidium of the dragonflies is made up of four retinula cells and a rhabdom composed of three rhabdomeres while the Lucilia has an ommatidium of seven independent retinula cells and rhabdomeres. The intracellular responses presumably recorded from the retinula cell had the same wave form in the two groups of insects: The responses were composed of two components or phases, a transient spike-like potential and a slow one maintained during illumination. The membrane potential, in the range of -25 to -70 mv., was influenced by the level of adaptation, and it was transiently depolarized to zero by high levels of illumination.

Computer Reconstruction of the Cellular Architecture of the Daphnia Magna Optic Ganglion

1975 ◽  
Vol 33 ◽  
pp. 284-285
Author(s):  
E. R. Macagno ◽  
C. Levinthal
Keyword(s):  
Daphnia Magna ◽  
Genetic Background ◽  
Compound Eye ◽  
Synaptic Connectivity ◽  
Serial Sections ◽  
Cross Sectional ◽  
Small Crustacean ◽  
Optic Ganglion ◽  
Structural Invariance ◽  
High Degree

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.

Effect of Forcing Terms and General Characteristics of Torsional Vibrations of Marine Engine Systems with Variable Inertia

1974 ◽  
Vol 18 (02) ◽  
pp. 131-138
Author(s):  
W. D. Carnegie ◽  
M. S. Pasricha
Keyword(s):  
Equations Of Motion ◽  
Mean Value ◽  
Wave Form ◽  
Actual System ◽  
Computer Methods ◽  
Reciprocating Engine ◽  
Complex Wave ◽  
Wave Forms ◽  
Crankshaft Rotation ◽  
Engine Systems

The torsional vibration phenomenon in the running gear of reciprocating engine systems is usually dealt with by considering a series of constant inertias connected by sections of massless shafting. Such a simplified model does not reproduce the exact dynamic characteristics of the actual system. In recent years several cases of marine crankshaft failures have been attributed to the phenomenon of secondary resonance, which is explained by the fact that the effective inertia of each slider crankmechanism varies about a mean value in relation to the position of the crank. When the variableinertia effect is allowed for, the equations of motion taking into account the effect are nonlinear. Assuming small displacements, the equations can be linearized to predict important characteristics of the motion. The motions in the form of complex wave forms are studied at different speeds of engine rotation and some of the wave form solutions are analyzed in the range of present investigations. Computer methods making use of numerical analysis processes, namely, the modifiedEuler's equations and the Runge-Kutta constants, have been applied in the investigations. A study of the effect on the motion of the system due to variation of inertia ratio is carried out at a particular speed of the crankshaft rotation; also investigated are the variations in the motions due to the action of external excitations with respect to changes in phase angle and inertia ratio. General comments on Draminsky's work in the light of the present investigations are included.

scholarly journals Time-domain observation and synthesis of split spheroidal and torsional free oscillations of the 1960 chilean earthquake: Preliminary results

1978 ◽  
Vol 68 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Seth Stein ◽  
Robert J. Geller
Keyword(s):  
Time Domain ◽  
Normal Modes ◽  
Wave Form ◽  
Central Frequency ◽  
Complex Wave ◽  
Location Depth ◽  
The Time Domain ◽  
Theoretical Results ◽  
Good Agreement ◽  
Chilean Earthquake

Abstract The rotationally and elliptically split normal modes of the earth are observed for the 1960 Chilean earthquake by analysis in the time domain. One hundred and fifty hours of the Isabella, California, strain record are narrow band filtered about the central frequency of each split multiplet to isolate the complex wave form resulting from the interference of the different singlets. We compute synthetic seismograms using our previous theoretical results, which show the dependence of the amplitude and phase of the singlets on source location, depth, mechanism, and the position of the receiver. By comparing these synthetics to the filtered record, we conclusively demonstrate the splitting of modes whose splitting had not been definitely resolved: torsional modes (0T3, 0T4) and spheroidal modes (0S4, 0S5). The splitting of 0S2 and 0S3 is reconfirmed. We obtain good agreement between the synthetics and the filtered data for a source mechanism (previously determined from long-period surface waves) of thrust motion on a shallow dipping fault.

scholarly journals The foreshock activity of the 1971 San Fernando earthquake, California

1978 ◽  
Vol 68 (5) ◽  
pp. 1265-1279
Author(s):  
Mizuho Ishida ◽  
Hiroo Kanamori
Keyword(s):  
Small Area ◽  
Main Shock ◽  
Source Region ◽  
Structural Heterogeneity ◽  
Propagation Path ◽  
Wave Form ◽  
Epicentral Area ◽  
Complex Wave ◽  
Wave Forms ◽  
San Fernando

abstract All of the earthquakes which occurred in the epicentral area of the 1971 San Fernando earthquake during the period from 1960 to 1970 were relocated by using the master-event method. Five events from 1969 to 1970 are located within a small area around the main shock epicenter. This cluster of activity is clearly separated spatially from the activity in the surrounding area, so these five events are considered foreshocks. The wave forms of these foreshocks recorded at Pasadena are, without exception, very complex, yet they are remarkably similar from event to event. The events which occurred in the same area prior to 1969 have less complex wave forms with a greater variation among them. The complexity is most likely the effect of the propagation path. A well located aftershock which occurred in the immediate vicinity of the main shock of the San Fernando earthquake has a wave form similar to that of the foreshocks, which suggests that the foreshocks are also located very close to the main shock. This complexity is probably caused by a structural heterogeneity in the fault zone near the hypocenter. The seismic rays from the foreshocks in the inferred heterogeneous zone are interpreted as multiple-reflected near the source region which yielded the complex wave form. The mechanisms of the five foreshocks are similar to each other but different from either the main shock or the aftershocks, suggesting that the foreshocks originated from a small area of stress concentration where the stress field is locally distorted from the regional field. The number of small events with S-P times between 3.8 to 6 sec recorded at Mt. Wilson each month suggests only a slight increase in activity of small earthquakes near the epicentral area during the 2-month period immediately before the main shock. However, because of our inability to locate these events, the evidence is not definitive. Since the change in the wave forms is definite the present result suggests that detailed analyses of wave forms, spectra, and mechanism can provide a powerful diagnostic method for identifying a foreshock sequence.

The Analysis of Wave Form for 3-D Wave Tank

2012 ◽  
Vol 463-464 ◽  
pp. 1392-1396
Author(s):  
Yun Wang ◽  
Bing Nan Li ◽  
Zhen Ying Xu ◽  
Yong Kang Zhang
Keyword(s):  
Numerical Model ◽  
Differential Equations ◽  
Viscous Fluid ◽  
Fluid Motion ◽  
Volume Of Fluid ◽  
Wave Form ◽  
Wave Tank ◽  
Form Analysis ◽  
Viscous Fluid Motion ◽  
D Wave

The 3-D numerical model of wave tank is developed considering the effects of wave generating and absorbing based on viscous fluid motion differential equations (N-S equation) and the volume of fluid (VOF) method by the use of FLUENT solver. The simulation is also made by the analysis of the existing methods of wave simulation. The wave form of the 3-D wave tank is analyzed with the result of diverse diversification at different wave location and their relationship. The flow path of each particle of the wave during the propagation is also been analyzed, which provides guidance for the wave form analysis.

Measurement of heat input in complex wave form welding

2010 ◽  
Vol 27 (3) ◽  
pp. 201-204
Author(s):  
Teresa Melfi ◽  
Daniel Joe
Keyword(s):  
Heat Input ◽  
Wave Form ◽  
Complex Wave

Electrical Responses of the Retinal Nerve and Optic Ganglion of the Squid

Science ◽  
1960 ◽  
Vol 132 (3429) ◽  
pp. 737-738 ◽  
Author(s):  
E. F. MacNichol ◽  
W. E. Love
Keyword(s):  
Optic Ganglion ◽  
Electrical Responses

scholarly journals The Development of the Rhabdom and the Appearance of the Electrical Response in the Insect Eye

1962 ◽  
Vol 46 (1) ◽  
pp. 143-157 ◽  
Author(s):  
Eisuke Eguchi ◽  
Kén-Ichi Naka ◽  
Masutaro Kuwabara
Keyword(s):  
Bombyx Mori ◽  
Action Potentials ◽  
Photochemical Reaction ◽  
Compound Eye ◽  
Electrical Response ◽  
Photic Stimulation ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Insect Eye ◽  
Electrical Responses

Electron microscopic studies on the development of the rhabdom in the compound eye of the silkworm moth and pupa (Bombyx mori) were carried out in parallel with the recording of the electrical response to photic stimulation. No electrical response to photic stimulation was recorded from the pupal compound eye which had no trace of differentiation of the rhabdom. With the differentiation of development of the rhabdom in the pupal compound eye, electrical responses could be recorded, and the amplitude of such electrical responses increased with the progress of development of the rhabdom. These observations suggest that the rhabdom is probably the site of the photochemical reaction which leads to the generation of the slow retinal action potentials.

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