Showing papers by "University of California, Santa Barbara published in 1974"

Increasing Spontaneous Play by Suppressing Self-Stimulation in Autistic Children.

Abstract: Appropriate play with toys was studied in two autistic children with high occurrences of self-stimulatory behavior. Each child participated in the experimental sessions in an A-B-A design, where “A” refers to baseline sessions and “B” refers to self-stimulation suppression sessions. It was found that: (a) during the baseline sessions, the children exhibited low levels of play and high levels of self-stimulatory behavior; (b) the per cent of unreinforced, spontaneous, appropriate play increased when self-stimulatory behavior was suppressed; and (c) when the suppression of self-stimulation was discontinued, the per cent of self-stimulation and that of appropriate play approached their presuppression levels. These results seem particularly significant because they identify a set of conditions under which spontaneous appropriate behavior, uncommon in autistic children, occurs at an increased level.

Near thermal energy charge transfer reactions of rare gas ions with diatomic and simple polyatomic molecules: The importance of Franck-Condon factors and energy resonance on the magnitude of the rate constants

Abstract: Charge transfer rate constants for reactions of He+, Ne+, Ar+, Kr+, and Xe+ with N2, O2, CO, NO, CO2, N2O, and CH4 were measured using an ion cyclotron resonance spectrometer. The absolute values of the rate constants were within the upper limit predicted from the Gioumousis‐Stevenson orbiting theory for ion‐molecule reactions. The magnitudes for the charge transfer rate constants are discussed with respect to (1) the availability of an energy level of the molecular ion resonant with the recombination energy of the rare gas ion, and (2) the value of the Franck‐Condon factor connecting this energy level of the molecular ion with the molecular neutral.

Chemical Composition and Buoyancy of Midwater Crustaceans as Function of Depth of Occurrence off Southern California

Abstract: Water, ash, C, H, N, lipid, carbohydrate, chitin and protein contents were determined for 28 species of midwater crustaceans. Variation of these components as a function of depth of occurrence, relative buouancy and respiratory rate of these species was examined. Vertical distribution data for 10 of the species based on discrete depth crawls is provided. The relative bouyancies of 16 of these species were measured. The caloric contents of 21 species were calculated. Lipid content (percent wet weight) and caloric density increased at intermediate depths, but apparently decreased at the greatest depths; it is suggested that this decrease is related to the relatively large size of these organisms and the energy limiting conditions in the deep-sea. Protein content (percent wet weight) decreases with increasing depth of occurrence, and is apparently related to a substantial fraction of the decrease in respiratory rate with increasing depth of occurrence in these species. Within the range of values examined, relative buoyancy appeas to be independent of metabolic rate. It is, therefore, suggested that the energy involved in maintaining an animal in the water column is generally insignificant compared to its overall activity. Furthermory, advantages of neutral buoyancy other than energy conservation may be more important selective factors for this characteristic.

Quantum mechanical streamlines. I. Square potential barrier

Abstract: Exact numerical calculations are made for scattering of quantum mechanical particles hitting a square two-dimensional potential barrier (an exact analog of the Goos-Haenchen optical experiments) Quantum mechanical streamlines are plotted and found to be smooth and continuous, to have continuous first derivatives even through the classical forbidden region, and to form quantized vortices around each of the nodal points A comparison is made between the present numerical calculations and the stationary wave approximation, and good agreement is found between both the Goos-Haenchen shifts and the reflection coefficients The time-independent Schroedinger equation for real wavefunctions is reduced to solving a nonlinear first-order partial differential equation, leading to a generalization of the Prager-Hirschfelder perturbation scheme Implications of the hydrodynamical formulation of quantum mechanics are discussed, and cases are cited where quantum and classical mechanical motions are identical

A spectral-flatness measure for studying the autocorrelation method of linear prediction of speech analysis

Abstract: The purpose of this paper is to introduce a spectral-flatness measure into the study of linear prediction analysis of speech. A spectral-flatness measure is introduced to give a quantitative measure of "whiteness," of a spectrum. It is shown that maximizing the spectral flatness of an inverse filter output or linear predictor error is equivalent to the autocorrelation method of linear prediction. Theoretical properties of the flatness measure are derived, and compared with experimental results. It is shown that possible ill-conditioning of the analysis problem is directly related to the spectral-flatness measure and that prewhitening by a simple first-order linear predictor to increase spectral flatness can greatly reduce the amount of ill-conditioning.

Transient two‐dimensional heat conduction problems solved by the finite element method

Abstract: A finite element weighted residual process has been used to solve transient linear and non-linear two-dimensional heat conduction problems. Rectangular prisms in a space-time domain were used as the finite elements. The weighting function was equal to the shape function defining the dependent variable approximation. The results are compared in tables with analytical, as well as other numerical data. The finite element method compared favourably with these results. It was found to be stable, convergent to the exact solution, easily programmed, and computationally fast. Finally, the method does not require constant parameters over the entire solution domain.

Mechanisms of Avian Egg Recognition: Possible Learned and Innate Factors

Abstract: THE belief that at least some passerine birds reject nonmimetic eggs placed in their nests was confirmed long ago by the experiments of Swynnerton (1916, 1918) and Rensch (1924). The latter worker (Rensch 1925) went on to question whether such birds actually recognize their own eggs (rejection by true egg recognition) or whether they simply reject any egg that differs from the majority (rejection by discordancy). Rensch was interested in egg recognition because he believed it to be vital to the evolutionary interactions between brood parasites and their hosts. Whether birds rejected eggs on the basis of true recognition or discordancy, the behavior would still function as an efficient antiparasite adaptation because brood parasites generally deposit only one egg in each host nest. Although Rensch's (1925) experiments have been widely interpreted as demonstrating rejection by discordancy (e.g. Welty 1963), the bulk of his results actually indicate true egg recognition (Rothstein 1970). Numerous recent experiments and a literature review suggest that most or all passerines that reject foreign eggs practice true egg recognition (Rothstein 1974). Nearly all these recent experiments, though, were conducted on birds that had completed their clutch. The fact that birds that reject foreign eggs practice true egg recognition after completing their clutch prompts two significant questions: (1) Is this recognition as highly developed at earlier stages of the breeding cycle? (2) Which components of rejection by true egg recognition are primarily learned and which are primarily innate? This paper reports on experiments that were designed to deal with these two questions. The new experiments reported here were done on naturally breeding Gray Catbirds (Dumetella carolinensis). Previous experiments showed that catbirds are extremely intolerant of foreign eggs placed in their nests. Single artificial or real cowbird eggs experimentally added to 30 catbird nests in eastern North America (Connecticut, Maryland, and Michigan) were all removed by the catbirds. Catbirds in western North America (Manitoba and Nebraska) may be slightly more tolerant, with 22 of 25 nests yielding ejections of single cowbird eggs. In 17 additional catbird nests (from Connecticut and Maryland), where experiments resulted in clutches consisting of only cowbird eggs or of only one catbird egg and two or more cowbird or other type of foreign eggs, the catbirds ejected the foreign eggs in every instance (see Rothstein 1974 for details).

Synaptic connexions made by horizontal cells within the outer plexiform layer of the retina of the cat and the rabbit

Abstract: Two ultrastructurally distinctive types of horizontal cells are described in the retinae of the cat and the rabbit. Evidence is presented that they have different synaptic connexions in the outer plexiform layer. The majority of the presynaptic structures identified in the outer plexiform layer of the rabbit (as defined on page 320) belong to a neurofilamentous type of horizontal cell. It is suggested that the cat may be the same. No synapses have been identified on to, or from, the second, predominantly neurotubular, type of horizontal cell. No chemical synapses on to, or between, horizontal cells have been found. Thus input of this kind to both types of horizontal cells is as yet only known to be from the photoreceptors. All positively identified postsynaptic processes were the dendrites or perikarya of bipolar cells. Other cell types that are possibly pre- or postsynaptic in the outer plexiform layer are discussed.

Treatment of psychotic children in a classroom environment: I. Learning in a large group.

Abstract: The purpose of this study was to investigate systematically the feasibility of modifying the behavior of autistic children in a classroom environment. In the first experiment, eight autistic children were taught certain basic classroom behaviors (including attending to the teacher upon command, imitation, and an elementary speaking and recognition vocabulary) that were assumed to be necessary for subsequent learning to take place in the classroom. Based on research documenting the effectiveness of one-to-one (teacher-child ratio) procedures for modifying such behaviors, these behaviors were taught in one-to-one sessions. It was, however, found that behaviors taught in a one-to-one setting were not performed consistently in a classroom-sized group, or even in a group as small as two children with one teacher. Further, the children evidenced no acquisition of new behaviors in a classroom environment over a four-week period. Therefore, Experiment II introduced a treatment procedure based upon “fading in” the classroom stimulus situation from the one-to-one stimulus situation. Such treatment was highly effective in producing both a transfer in stimulus control and the acquisition of new behaviors in a kindergarten/first-grade classroom environment.

Prey selection and foraging period of the predaceous rocky intertidal snail, Acanthina punctulata

Abstract: The diet and foraging period of the neogastropod Acanthina punctulata were investigated in order to test various aspects of recent optimal foraging strategy models. This intertidal snail is an actively searching predator which preys on snails and barnacles by boring a hole in the shell and rasping out the flesh. Unlike many gastropod predators, Acanthina drill its gastropod prey at a very specific location on the columella, the thickest portion of the shell.

A behavior modification approach to the treatment of autistic children.

Abstract: When we talk about autistic children we are describing children who manifest several characteristic pathological behaviors (e.g., social withdrawal, self-stimulation, ritualistic behavior, echolalic and psychotic speech, apparent sensory deficit, affective impoverishment). When using such a diagnostic label one is typically conceptualizing autism as a distinct entity; an underlying process that is seen as the cause of these deviant behaviors. Indeed, a great deal of research has focused on this one underlying process as the basis for the psychopathology. From a behavioristic viewpoint, it is quite unnecessary to postulate such an underlying disease or entity, and indeed it is quite possible that the different autistic behaviors are related to several different kinds of antecedent conditions. For example, we do know that many if not all of the behaviors one observes in autistic children exist in other children as well; retarded and blind children self-stimulate as do normal children if they have nothing else to do. Braindamaged children sometimes echo while some retarded children have unusually well-developed rote memories, and so on.

Behavioral assessment of speech anxiety

Abstract: The development and evaluation of an instrument for the behavioral assessment of speech anxiety is described. The BASA consists of eighteen behavioral variables which are separately rated on a ten‐point scale for degree of severity manifested during discrete speech segments. Testing of the BASA on videotape‐recorded classroom speeches of male college students provided evidence supporting its reliability and validity. Four orthogonal BASA factors resulted from varimax rotation: Rigidity, Inhibition, Disfluency, and Agitation.

Giant stromatolites and associated vertical tubes from the upper Proterozoic Noonday Dolomite, Death Valley region, eastern California

Abstract: Stromatolitic domes having apparent growth reliefs up to 100 m or more characterize the lower member of the Noonday Dolomite, late Proterozoic, Death Valley region, eastern California. Long to short, subparallel, initially subvertical tubes penetrate the bedding of these structures at angles that range from 90° where stratification was initially horizontal to downslope angles up to 110° (and acute upslope angles) as initial dips increase. Tubes generally are missing where initial dips exceed 20°. They are common in the larger buildups and most abundant in the upper and central parts of these. They may be open or filled with coarsely sparry secondary dolomite, medium-gray ultra microgranular dolomite, silty brown dolomite, or drusy quartz. They pinch and swell irregularly along their length from a mean diameter of 1.5 cm and are subcircular to irregular in horizontal cross section. Secondary crystalline growths similar to those in many tubes are common along lamination surfaces and as irregular vug fillings. Weathering along intersecting fracture sets locally produces a subvertical lineation in the same orientation as associated tubes. Possible origins considered for the tubes and found improbable are: (1) metazoan burrows, (2) interspaces of columnar stromatolites, (3) columnar stromatolites, (4) solution pipes, and (5) root casts. Instead the spaces now represented by filled vugs, sparry lamination surfaces, and tubes are interpreted as having, in general, a common origin caused by the upward movement of fluids through the stromatolite mounds.

Superconducting phase transitions in granular systems

Abstract: We consider a model for granular superconductors consisting of an array of small superconducting particles interacting by Josephson coupling through insulating barriers. We obtain systematically the various critical regions, critical temperature shifts, and crossover regions between zero- and three-dimensional behavior as functions of measurable sample parameters. The qualitative behavior of the system in the various regimes is analyzed and results for the specific heat and fluctuation conductivity in the Gaussian region above ${T}_{c}$ are obtained. The possibility of obtaining large critical regions is emphasized. The conditions for observing the phase-locking transition distinct from quasiordering within the grains are found. Theoretical predictions are compared with existing experimental results.

A linear prediction vocoder simulation based upon the autocorrelation method

Abstract: A detailed discussion of the computer simulation of a linear prediction vocoder system is presented. The basic technique used for analysis is the autocorrelation method of linear prediction. New results include modifications to the simplified inverse filter tracking (SIFT) algorithm for more efficient pitch extraction, coding algorithms for low-bit rate transmission, a simplified synthesizer gain calculation, and a bias correction for the synthesizer driving function. Experimental results are presented which illustrate both the capabilities and limitations of linear prediction vocoders.

The Potassium Content of Gonyaulax polyedra and Phase Changes in the Circadian Rhythm of Stimulated Bioluminescence by Short Exposures to Ethanol and Valinomycin

Abstract: A circadian rhythm in the intracellular level of K+ in Gonyaulax polyedra is reported. When axenic cultures of Gonyaulax in continuous light (60-75 fot candles) are exposed for 4 hours to 0.1 or 0.2% ethanol, the subsequent free-running rhythm in stimulated bioluminescence is phase-shifted, the amount and direction of the shift being dependent on the time in the circadian cycle when cells are treated. The phase-response curve for ethanol closely resembles that for light in similarly maintained cells. When valinomycin (0.1 or 0.2 μg ml−1) is present in addition to ethanol, the phase of the bioluminescence rhythm is returned to that of an untreated cell suspension. Valinomycin thus negates the effect of ethanol on phase. The intracellular K+ level immediately after treatment of a cell suspension for 4 hours with ethanol (0.1%) is about half that of untreated cells. If valinomycin (0.1 μg ml−1) is also present during the 4-hour treatment, the intracellular K+ is only slightly lower than in untreated cells. Increasing the external concentration of K+ or Na+ for 4 hours has no effect on the rhythm of stimulated bioluminescence. These results are interpreted as support for the hypothesis that the mechanism by which circadian oscillations are generated involves changes in membrane properties.

Kalman Filter Applications in Airborne Radar Tracking

Abstract: This paper studies the application of Kalman filtering to single-target track systems in airborne radar. An angle channel Kalman filter is configured which incorporates measures of range, range rate, and on-board dynamics. Theoretical performance results are given and a discussion of methods for reducing the complexity of the Kalman gain computation is presented. A suboptimal antenna controller which operates on the outputs of the angle Kalman filter is also described. In addition, methodological improvements are shown to exist in the design of range and range-rate trackers using the Kalman filter configuration.

Analytic Properties of the Teukolsky Equation

Abstract: The analytic properties of the solutions to the Teukolsky equation in the complex frequency plane are investigated. The scattering coefficientZ in is found to be an analytic function of the frequency except at singularities and at certain branch points in both the upper and lower frequency plane. The implications for the proof of the stability of the Kerr geometry given by Press and Teukolsky are discussed.

Person Perception, Self-Identity, and Ethnic Group Preference in Anglo, Black, and Chicano Preschool and Third-Grade Children

Abstract: Seventy-two preschool and 68 third-grade Anglo, Black, and Chicano children were shown color photographs of young male adults from the same three ethnic groups as Ss. All children were able to discriminate between the photographs of the white and Black males, but the preschool Ss were unable to make the finer discrimination between the Anglo and Chicano photographs. All pools of Ss indicated the appropriate photograph when asked which looked most like them. Among the preschool Ss neither the Blacks nor the Chicanos expressed a significant preference for their own ethnic group, while a significant number of the Anglo Ss selected the Anglo photograph as the one they liked the most. At the third-grade level, only the Chicano Ss displayed a strong preference for their own ethnic group.

Effects of phonological speech foreignness upon three dimensions of attitude of selected American listeners

Abstract: The development and evaluation of the multi‐dimensional Speech Dialect Attitudinal Scale is described. Use of this semantic differential by townspeople and university students to rate audiotape recordings of European and American speakers’ spontaneous English monologues provided data of high reliability and consistent factor structure. Results indicated that native‐born speakers were rated significantly higher than their foreign‐born counterparts on three attitudinal dimensions.

The optical properties of alanine and proline diketopiperazines

Abstract: The optical properties of the diketopiperazine chromophore of the cyclic dipeptides have been investigated as a function of molecular conformation. The rotatory strengths of L-alanyl–L-alanine diketopiperazine and L-prolyl–L-proline diketopiperazine have been calculated as a function of the angle of fold of the diketopiperazine ring. The results of these theoretical calculations have been compared with experimental circular dichroism and optical rotatory dispersion data. It is shown that the observed optical properties of these molecules can be explained only if their diketopiperazine rings are folded in opposite directions. The direction of fold is established for each molecule. In solution, the diketopiperazine ring of L-alanyl-L-alanine diketopiperazine is folded in the direction opposite to that found by X-ray diffraction analysis of crystals. It has been observed that the degree of conservatism of the π π* couplet of L-propyl–L-proline diketopiperazine depends markedly upon the nature of the solvent that is used. In addition, a shoulder has been discovered in the CD spectrum of L-alanyl–L-alanine diketopiperazine, which may not be directly attributable to the n π* and π π* transitions of the peptide chromophores.

Relative Motion and the Adjacency Principle

Abstract: The perception of motion of physically moving points of light was investigated in terms of the distinction between absolute and relative motion cues and the change in the effectiveness of the latter as a function of the frontoparallel separation between the points. In situations in which two competing relative motion cues were available to determine the perceived path of motion of a point of light, it was found that the relative motion cue between more adjacent points was more effective than the relative motion cue between more separated points. In situations in which only one relative motion cue was available to determine the perceived motion of a point it was found that the effectiveness of this cue as compared with the absolute motion cue decreased with increased separation. These results are predictable from the adjacency principle which states that the effectiveness of cues between objects is an inverse function of object separation. Some consequences of the study for the theory of motion perception ...

Effect of thermal noise on current-voltage characteristics of Josephson junctions

Abstract: Measurements are reported of the current-voltage ($I\ensuremath{-}V$) characteristics of externally shunted oxide-barrier tunnel junctions at temperatures $T$ and critical currents ${I}_{c}$ such that the Josephson coupling energy $(\frac{\ensuremath{\hbar}}{2e}){I}_{c}$ is comparable to the thermal energy $kT$. The measurements are in complete quantitative agreement with the theory of Ambegaokar and Halperin in the limit that the dimensionless parameter ${\ensuremath{\beta}}_{c}=(\frac{2e}{\ensuremath{\hbar}})(\frac{{I}_{c}C}{{\ensuremath{\sigma}}^{2}})\ensuremath{\ll}1$, where $C$ is the capacitance and $\ensuremath{\sigma}$ the total conductance of the shunted junction. Measurements for larger values of ${\ensuremath{\beta}}_{c}$ are in qualitative agreement with the theory of Kurkij\"arvi and Ambegaokar. In addition, the Ambegaokar-Halperin theory is generalized to include the $cos\ensuremath{\phi}$ pair-quasiparticle interference term. It is concluded that a measurement of the $cos\ensuremath{\phi}$ term using only the $I\ensuremath{-}V$ characteristic will be difficult.