Movements In Different Directions Research Articles

Variation in Leaflet Orientation among Soybean Cultivars1

The degree of leaflet orientation was measured for five soybean (Glycine max L., Merr.) cultivars on an hourly basis from 0620 (0700 EST) until 1820 (1900 EST) hours Local Solar Time during the 10 node stage of development (V10) and from 0520 (0700 EDT) until 1820 (2000 EDT) hours during the beginning pod stage (R3). Measurements were taken on 4 separate days during each growth stage. Our primary objective was to determine if differences exist among soybean cultivars in degree of leaflet orientation.There was significant variation among cultivars in the degree of orientation of the center and the side leaflets of trifoliolates at different times of the day.during both growth stages. The orientation of the center leaflets of a trifoliolate differed from that of the side leaflets. The vertical inclination of the center leaflets tended to change over time while the horizontal inclination remained relatively constant. On the other hand, the horizontal inclination of the side leaflets tended to change over time while their vertical orientation remained relatively constant. However, due to their location relative to each other, the different directions of movement of the center vs. side leaflets seem necessary in order for all three leaflets to attain similar exposures to incoming radiation.Maximum variation in leaf movement was noted from 0820 until 1620 hours during both V10 and R3 stages of development. Higher angles of inclination were obtained and maintained during R3 than V10.The K concentration in pulvini was significantly higher (p < 0.01) during the tense state (higher angles of leaflet orientation) than during the relaxed state. It appears that the K concentration in the pulvinus might have some role in regulating the bending and straightening movements of the pulvini, perhaps by inducing changes in turgor pressure.

Spinal motoneuron recruitment in man: rank deordering with direction but not with speed of voluntary movement.

Single motor units in human interosseous muscle are recruited in order from small to large in slow or brisk voluntary abduction of the index finger. When the same muscle acts as a synergist as opposed to a prime mover, about 8 percent of the unit pairs consistently reversed their recruitment order. Motor commands appear to be patterned in terms of movements rather than muscles and to involve different connectivities to the motoneuron pool of a muscle executing movements in different directions.

The thermal effect due to stress-induced martensite formation in Β-CuAlNi single crystals

The thermal effect associated with the formation and reversion of stress-inducedβ′ martensite has been studied in single crystals ofβ1-CuAlNi. The maximum temperature increase for theβ1 →β1′ transformation in a specimen at room temperature ranged from 1.2°C at a strain-rate of 0.025 min−1 to 14°C at a strain-rate of 25 min−1. The large temperature increase is due to lower heat losses at the high strain-rates and a closer approach to adiabatic conditions. The thermal effect for theβ1 →β1 transition was somewhat larger and believed to be due to the different directions of motion of the single transformation interface. A method has been developed which correlates the thermal effect at infinite strain-rate with the entropy change of the transformation resulting in a value of δSβ’1 Β1 = − 1.20 J/mol · K. This result is in good agreement with the entropy changes of −1.18 ± 0.17 J/mol · K calculated from the Clausius-Clapeyron equation. The variation of the thermal effect with specimen temperature (d|δT|/δT) was 0.04 ± 0.01, and could be explained by assuming a constant entropy change for the transformation at different temperatures.

Visual responses to changing size and to sideways motion for different directions of motion in depth: linearization of visual responses.

This psychophysical study explored one possible basis for visually judging the direction of motion in depth. We propose that the changing-size channels precisely compute the algebraic difference between the velocities of opposite edges of a target, thus extracting the velocity component Vz along a line through the eye independent of the trajectory of the target, so that (with added “jitter”) this computation is accurately independent of the component of motion Vx parallel to the frontoparallel plane over a wide range of Vx:Vz ratios. We have no evidence for a complementary channel that computes Vx independently of Vz over any comparable range of Vx: Vz ratios. Our evidence shows that the oscillations of the edges of our stimulus square were equivalent to the oscillation of the square along one of 11 trajectories in depth. All 11 trajectories had the same value of Vz, but the 11 trajectories had different Vx values. In separate experiments, subjects adapted to each trajectory and we measured threshold elevations for two test oscillations, one equivalent to pure z-direction motion and the other equivalent to pure x-direction motion. To a first approximation, threshold elevations for the z-direction test were the same for all 11 trajectories, with the greatest departure from constancy (30%) when two edges of the adapting stimulus were stationary (i.e., equivalent to trajectories that just grazed the eye). Adding an 8-Hz “jitter” oscillation to the 2-Hz adapting oscillation “linearized” the visual response so that threshold elevations were rendered accurately constant (± 5%) for all trajectories tested.

Models of stimulus uncertainty in motion perception.

A model is proposed to account for the loss in visibility of moving targets that occurs when an observer is uncertain about the target's direction of motion. The model's key features are an array of directionally selective visual mechanisms and a rule governing the mechanisms from which an observer will derive sensory data. In response to uncertainty about two possible directions of motion, the observer is assumed to use a mechanism whose peak sensitivity is to a direction midway between the two possible directions. Seven experiments, using both reaction time and forced-choice data, demonstrate the predictive advantages of this midway model over competing single-band and multiple-band models. Additionally, the experiments reveal several new properties of human motion perception: (a) Direction and velocity information have orthogonal representations in the visual system; (b) although motion sensitivity does not vary with direction, the precision with which small changes in direction can be recognized does, reflecting differential breadth of tuning for directionally selective mechanisms sensitive to various directions; and (c) motion-analyzing mechanisms are broadly tuned for direction as well as speed. Human psychophysics provides extensive evidence for the existence of visual mechanisms tuned to different directions of motion. Converging on this point are data from a variety of paradigms including selective adaptation (Sekuler & Ganz, 1963), subthreshold summation (Levinson & Sekuler, 1975), and aftereffects (Keck, Palella, & Pantle, 1976). In addition, we recently used a masking procedure to define the direction sensitivity profiles of these mechanisms (Ball & Sekuler, 1979). In general, these studies tell us how much information is potentially available in motion-sensit ive visual elements under ideal conditions. But they tell us little about the use to which that information can be put under nonideal conditions outside the laboratory.

移動距離と空間方向を同時に考慮した全身選択反応時間

Total body reaction time in response to the stimuli demanding different directions of movement has been studied by various authors. However, a study on the effects of more complex stimuli demanding the combinations of both directions and distances of movement has not yet been made. The present investigation was designed to examine total body reaction time of movement elicited by the selective stimuli demanding different distances and directions. "Body Reaction Timer" distributed by Takei Equipment Company was utilized to measure total body reaction time of 32 male and 30 female college athletes. The experimental conditions demanded by the stimuli were the combinations of four directions (front, back, left, and right) and three distances (25, 45, and 60 cm). The subjects performed 24 trials (two trials under each experimental condition). Application of analysis of variance, Tukey method of multiple comparisons and correlation method revealed the following results: 1) In every direction and distance, the reaction time of the male subjects was faster than that of the female subjects. 2) In all directions, the slowest reaction time was recorded when the demanded direction was frontward. The next slowest record was found in backward direction. For the condition of 60 cm distance, the stimuli demanding leftward direction elicited the fastest reaction time. The next fastest time was recorded for the rightward direction. The trend was consistent for both sexes. 3) In the male subjects, the coefficients of correlation between the reaction times for the different distances were higher when the matched distances were closer. The female subjects did not show the same trend. 4) F-ratio among the directions was significant in all the distances for the female subjects. For the male subjects, however, F-ratio for the condition of 45cm distance was not significant.

The Basic Kinematics of the Human Spine

Spinal kinematics concerns the kinds and amounts of motion the human spine undergoes during its normal physiologic movements. This paper is a review of the research in this area and provides information about past and current knowledge. The biomechanic terms essential for the precise and accurate description of spinal kinematics are defined, described, and exemplified. Requirements for a comprehensive description of spinal kinematics are presented to provide a perspective for present knowledge and future research. Finally, the current status of spinal kinematic research is described, and information about the ranges of motion of the human spine for various vertebral levels and for motion in different directions is provided.

Neurones in cat parastriate cortex sensitive to the direction of motion in three-dimensional space.

1. On psychophysical grounds, Beverley & Regan suggested that in man different neural mechanisms mediate the binocular perception of movement in depth and the binocular perception of positional (static) depth. They proposed that the human visual pathway contains several neural mechanisms, each sensitive to a different direction of motion in space. These mechanisms compute the direction of motion from the relative speeds and directions of movement of the left and right retinal images.2. We have recorded from 101 units in area 18 of cat visual cortex, searching for neurones tuned to the direction of motion in three dimensions, with properties that could account for the proposed directionally tuned binocular motion detectors in man. The cat's left eye viewed one bar, while its right eye simultaneously viewed a second bar. Single units were stimulated by independently oscillating the bars from side to side. The apparent direction of movement in three dimensions was altered by varying the relative speeds of the bars and their relative directions of motion. The mean (positional) disparity of the bars could also be varied.3. For one class of neurone (twenty cells), binocular stimulation inhibited firing for trajectories parallel to the frontoparallel plane over a large volume of space. Strong firing was produced by oppositely directed bar movements. Some of these neurones were especially narrowly tuned to the direction of movement in depth, responding only to a range of 2-3 degrees , i.e. to moving bodies that would hit or only narrowly miss the cat. These cells emphasized the direction of movement at the expense of positional information.3. These units occurred in clusters. On the perpendicular penetrations in which they were found, they comprised a substantial majority of all cells encountered.5. For a second class of neurone (nine cells), binocular facilitation produced selective responses to objects moving along trajectories that missed the head.6. The two classes of neurone provide a basis for four proposed directionally tuned binocular motion detectors.7. A third class of neurone (seventeen cells) was selectively sensitive to movements parallel to the frontoparallel plane. There was strong binocular facilitation when the bars moved at the same speeds in the same directions: oppositely directed movements might be more than 100 times less effective. These neurones may signal positional disparity.8. These three classes of neurone cut across established categories. Only when both eyes were stimulated simultaneously with targets moving in different speeds and directions was it possible to demonstrate the binocular interactions described here.

Adaptation and habituation characteristics of tectal neurons in the pigeon.

The adaptation and habituation characteristics produced by the repeated presentation of a moving visual stimulus were studied in single cells in the pigeon's optic tectum. Units located near the surface in the stratum opticum showed little adaptation. However, cells located in deeper layers exhibited varying rates and degrees of adaptation and recovery. Approximately two thirds of the units that adapted, individually showed different rates of adaptation to different directions of movement, thus revealing different receptive field profiles in their adapted and recovered states. Some units were described as habituating since a change in the path of the stimulus through the receptive field or a change in the type of stimulus, resulted in the reinstatement of the initial level of responsiveness.

The use of pedometer and actometer in studying daily physical activity in man. Part I: reliability of pedometer and actometer.

The purpose of this study was a critical evaluation of pedometer and actometer for estimating daily physical activity. Both instruments were tested for reliability on a carriage with movements in different directions. To obtain comparable data of different pedometers it was necessary to adjust the spring tension very carefully. The reliability of the individual actometer was satisfactory, but there are large differences between the watches. Therefore, a correction factor (C.F.) was introduced. Some experiments were carried out on a treadmill. 9 Children (aged 5-6 years) and 6 young adult males (aged 21-31 years) walked and ran at different speeds. The energy expenditure was calculated from formulas. The pedometer overestimates the actual step rate with 0.1-0.3 counts per step during fast walking (6-9 km-h-1) and fast running (15 km-h-1). It underestimates the actual step rate with 0.2-0.7 counts per step, while walking slowly. It was shown that the pedometer does not reflect the differences in energy expenditure levels at different speed very well. The actometer units per step increases more or less proportional to the speed of walking and running. In contrast to the pedometer results the actometer results are more related to the energy expediture levels at different speed. The results of this study suggest that the actometer might be a valid indicator of the daily physical activity in terms of energy expenditure.

Tropical Cyclone Motion and Surrounding Parameter Relationships

Abstract Ten years of rawinsonde data for 30 stations in the western North Pacific have been composited relative to tropical cyclone center positions. This information is used to study tropical cyclone motion and surrounding parameter relationships. Tropical cyclone motion and lower troposphere surrounding actual and geostrophic flow fields from 1°–7° radius are very well correlated. This general correlation of surrounding flow features applies equally well for cyclones with different directions of motion, speeds of propagation, intensities and intensity changes. The 700 mb level best specifies cyclone speed. The 500 mb level best specifies cyclone direction. The steering flow concept of cyclone motion appears to be quite valid in the statistical sense. These results may be useful to tropical cyclone forecasters.

Characteristics of human saccadic eye movements in different directions.

Saccadic human eye movements in different directions were recorded by an infrared technique. Disturbances by movements of the eyelids are prevented by means of a plaster pulling down the lower lid. The peak values of the velocity, acceleration, deceleration, and the duration of the saccades were drawn in a direction diagram. Each eye has its specific diagram. The shape of the diagram is independent of the saccadic amplitude. There are directions in which the values are equal for eccentric and centric saccades and those, in which significant differences are to be found. In the latter case centric saccades are faster than the eccentric ones.

Motion characteristics of single units in the pigeon optic tectum

Receptive field characteristics of 153 units in the optic tectum of pigeons were studied using flashed stationary and moving stimuli. With increasing depth receptive fields tended to increase in size and exhibit greater tendencies to adapt or habituate. Approximately 60% of units responded more vigorously to moving than stationary stimuli, 42% of these were narrowly tuned to direction of movement while 58% were broadly tuned. A statistically significant number of broadly tuned directional units preferred forward motion in the visual field and had an even more clearly defined backward null direction. When moving stimuli were repeatedly presented some tectal units adapted at different rates to different directions of motion. At least some units which exhibited waning responses to repeated stimulation were thought to be habituating since a small change in the stimulus path through their receptive field resulted in a renewed higher response rate.

The relation between discrimination and sensitivity in the perception of motion in depth.

1. Binocular discrimination of the direction of a target's motion in depth was measured in terms of the smallest angular difference in direction that could be detected with a probability 50% better than chance. Directional discrimination was measured for targets moving along 16 different trajectories directed to the left and right of the nose. 2. The relative velocities of the retinal images in the left and right eyes gave a sensitive cue to the direction of the target's motion in depth. 3. The direction of motion was bets discriminated when the target moved along a line directed close to the nose. A change in direction of only 0.2 degrees from this direction of motion could be detected. Discrimination showed two other maxima, one on each side of the central maximum. Discrimination fell to about 0.6-0.8 degrees when the target's direction was changed by only 6 degrees to either side of the nose. 4. The curve of sensitivity to movement in depth had a generally inverse shape to the directional discrimination curve: sensitivity was minimal for trajectories directed near the nose and increased for trajectories directed so as to miss the head. 5. The directional discrimination curve can be related to the sensitivity curves of the four postulated neural mechanisms tuned to different directions of motion in depth; there are three discrimination maxima and, correspondingly, three trajectories for which the slopes of adjacent sensitivity curves differ maximally. This suggests that binocular psychophysical judgements of the direction along which a target moves in depth are to some extent mediated by neural mechanisms that compare (e.g. subtract) the outputs of directionally tuned movement detectors. One function of such neural comparators might be to enhance psychophysical sensitivity to the direction along which a target moves in depth, and thus to provide a physiological basis for precisely judging whether or not an object will hit the head. 6. We suggest that the neural basis for judging the direction of moving objects has an analogy in colour vision where opponent-colour mechanisms enhance sensitivity to wave-length differences in such a way that wave-lengths are more easily discriminated in those parts of the spectrum where the slopes of the pigment action spectra differ maximally.

Electrophysiological evidence for existence of neurones sensitive to direction of depth movement.

RECENT psychophysical evidence suggests that there are movement detectors in the human visual pathway selectively sensitive to different directions of motion in three-dimensional space1–5. In animals (such as the cat) there are single nerve cells with properties which suggest that they signal when an object is moving in depth away from the plane of binocular fixation6.

A radar study of premonsoon squall lines over Gangetic West Bengal

Occurrence and life cycle of premonsoon squall lines in Gangetic West Bengal, their dependence on the surfac6 and upper air meteorological parameters were analysed from other echoes observed at Calcutta for the period 1963-67. Presence of high terrain in Chota Nagpur plateau of Bihar and solar insolation found to be responsible for the initial formation of squall lines. The phenomenon leading to simultaneous appearance of multiple squall lines in different regions and their movement in different directions were discussed. It has been noticed that squall line move generally in a direction within 040° clockwise of the prevailing wind at 4.5-km level and the corresponding direction of surface squall observed to be within 020° of the direction of movement of squall line.

Selectivities of human visual mechanisms for direction of movement and contour orientation.

The luminance threshold for horizontal contours which move upward is raised by prior exposure of any of wide range of different directions of movement. The threshold for a stationary grating of horizontal bars is raised only by prior exposure of similarly oriented bars. It is also found that sensitivity to changes in orientation of a stationary grating is greater than sensitivity to changes in the direction in which a grating moves. It is proposed that the interactions between pre-exposed adapting stimuli and the stimuli for which thresholds are determined reflect the orientation and direction selectivities of the underlying mechanisms.

Perception of simultaneous stroboscopic movements in different directions and the gestalttheory hypothesis of physiological short circuiting

The author takes into account the Higginson's point of view about the Gestalttheory hypothesis of ‘cerebral short-circuit’ in order to explain the phenomena of stroboscopic movement. He describes the experience he has made about the perception of several simultaneous apparent movements in different directions and a phenomenon of a double simultaneous apparent movement in opposite directions of two shapes along the same path. To explain this phenomenon the author formulates the hypothesis of the ‘simultaneous polyfunctionalism of similar organic elements in the apparent movement's perception’.

On the Irregularities of Motion of the Foucault Pendulum

Synopsis. In a brief historical statement, emphasis is put upon the current opinion that a Foucault pendulum must be very long and very heavy in order to be successful. It is then shown that the elliptical motion so common in Foucault pendulum experiments is not due to insufficient length or weight, or even to atmospheric disturbances, but simply and solely to unequal freedom of motion in different directions. The disturbing influences are within the pendulum itself. Different forms of support and suspension are discussed, and methods of eliminating the disturbing influences are suggested. What the author describes as a double roller support is shown to be superior to any other form of support thus far proposed. With this support and a perfectly annealed double bifilar suspension, a 2\textonehalf{}-meter pendulum weighing a single kilogram succeeds perfectly.

Electric Crane Construction

A LARGE measure of flexibility in the supply of power is an essential feature in all hoisting machinery. Not only must the point from which the load is suspended be capable of movement in different directions, but the whole machine must be able to travel, and these requirements render electricity a particularly well-adapted agent for the working of such machinery. A modern book on cranes becomes thus quite naturally a book on electric cranes. Electric Crane Construction. By Claude W. Hill. Pp. xx + 313. (London: C. Griffin and Co., Ltd., 1911.) Price 25s. net.