Showing papers by "Stony Brook University published in 1979"

Multivariate assessment of conflict in distressed and nondistressed mother‐adolescent dyads

Abstract: A battery of measures was used to assess conflict between mothers and young adolescents (females and males, 11 to 15 years of age). Two groups of families, one composed of a distressed clinical sample (N = 38), the other a nondistressed normative sample (N = 40), participated. The assessment battery included retrospective judgments, frequency estimates, self-monitored home recording, and tape-recorded discussion of a home problem. Content of assessment measures tapped aspects of parental control, decision-making, self-reported interaction behavior, arguments, interaction behavior rated by independent "blind" observers, frequency and anger-intensity of specific problematic issues, and perceptions of positive and negative behaviors of the other family member. Based on univariate analyses, 21 of the 26 defined variables discriminated significantly in the predicted direction. Maternal and adolescent reports of behavior and independent ratings of tape-recorded interaction emerged as strong and consistent discriminators. Stepwise multivariate discriminant analysis provided successful classification of 100% of the families based on the inclusion of nine variables. In a cross-validation sample, 84% of the families were correctly classified. Implications for systematic outcome research as well as clinical application are discussed.

Attachment, positive affect, and competence in the peer group: two studies in construct validation.

Abstract: 2 studies were undertaken to assess the positive affective correlates of secure attachment in infancy and to assess the relation between secure attachment in infancy and competence in the peer group at age 3 1/2 years. In study 1, smiling and smiling combined with vocalizing and/or showing toys distinguished securely from anxiously attached infants during free play at age 18 months. Rated quality of affective sharing distinguished securely from anxiously attached infants during free play at 18 months and 24 months. Thus, secure attachment involves more than the absence of negative or maladaptive behavior directed toward a caregiver. Study 2 assessed cross-age, cross-situational, and cross-behavioral consistency in quality of social adaptation. Quality of infant-mother attachment relationships at age 15 months was related to Q-sort assessments of personal and interpersonal competence in the preschool play-group at age 3 1/2 years. The results contribute to the validation of attachment as an important developmental construct. They also suggest that age appropriate assessment of developmental social competence constructs can be a useful alternative to the study of homotypic behavioral continuity.

On the spectral geometry of spaces with cone-like singularities

Abstract: I describe an extension of a portion of the theory of the Laplace operator on compact riemannian manifolds to certain spaces with singularities. Although this approach can be extended to include quite general spaces, this paper will confine itself to the case of manifolds with cone-like singularities. These singularities are geometrically the simplest possible, but they already serve to illustrate new phenomena that are typical of the more general situation. Moreover, by inductive arguments, the study of simplicial complexes whose simplices have constant curvature and totally geodesic faces (e.g., p.l. manifolds) can in large measure be reduced to the study of cone-like singularities.

Applications of self-control procedures by children: a review.

Abstract: Self-control procedures as used by children to affect their own behavior were reviewed. Particular emphasis was placed on self-instruction, self-determined criteria, self-assessment, and self-reinforcement. Self-punishment, comprehensive programs, and innovative self-control procedures (distraction and restatement of contingencies) were also evaluated. Basic effectiveness, comparisons with similar externally imposed interventions, maintenance, and the augmental value of the procedures were assessed. Important problems for future research were identified.

Rapid host range evolution in a population of the phytophagous mite tetranychus urticae koch.

Abstract: The question of what determines the number and specific identity of the host plants fed on by an herbivore species has been discussed frequently in the last twenty years. At this point, the proximal determinants of host range for many herbivore species are rather well understood (e.g., Waldbauer, 1962; Hsiao and Fraenkel, 1968; Beck, 1974), but there is little detailed information on the evolutionary factors which mold these proximal physiological and behavioral determinants. Ehrlich and Raven's (1964) general survey of butterfly host ranges led them to conclude that present herbivore host ranges were the outcome of a stepwise coevolutionary process in which plants evolved to resist the attack of herbivores and herbivores evolved to overcome this resistance. They felt that this process occurred over a geological time span and resulted in a pattern of herbivore host ranges that reflected the taxonomic affinity of plant species. As interesting and useful as this idea has been, it would be unjustified to conclude that most herbivore host ranges are the outcome of such coevolution. Indeed it is possible that the present diversity of plant defenses was generated in response to relatively few "enemies" (i.e., herbivores, pathogens, and competing plants) and that most herbivores subsequently evolved to survive within an already established matrix of defenses (see Jermy, 1976, for an extreme viewpoint). Moreover, it is possible that herbivore diets expand to include unrelated species of plants, especially if these plants are found in geographical and ecological association (Janzen, 1968). As these plant associations

Comparative and functional morphology of hominoid fingers

Abstract: Comparisons of hominoid metacarpals and phalanges reveal differences, many of which are closely linked to locomotor hand postures. The African apes display features of the metacarpals and phalanges which distinguish them from the other Hominoidea. These features are most evident in digits III and IV. The orangutan hand is demonstrably less well adapted to knuckle-walking and is distinctive in its adaptation to power and hook grasping of vertical and horizontal supports, respectively. Orangutan fingers possess a "double-locking" mechanism (Napier, '60), and a slight ulnad shift in the axis of the hand which results in lengthened phalanges of ray IV. Hylobatid apes are more like orangutans in their finger morphology than any of the other Hominoidea, but exhibit unique features of their own. These include elongate phalanges of fingers II-V. Human metacarpals II-V form two sets composed of II-III, and IV-V. The heads of both metacarpals II and III are characterized by axial torsion. This reflects the enhanced manipulatory role of the third finger in humans. Human distal phalanges are unique in the development of pronounced apical tufts. Multivariate analysis of metacarpal III and proximal III yields variables that array the extant apes along an arboreal-terrestrial axis, from hylobatid apes to male gorillas. The positions of taxa on this discriminant concur with observations on the locomotion of free-ranging apes.

Testing implications of data dependencies

Abstract: We present a computation method---the chase---for testing implication of data dependencies by a set of data dependencies. The chase operates on tableaux similar to those of Aho, Sagiv, and Ullman. The chase includes previous tableau computation methods as special cases. By interpreting tableaux alternately as mappings or as templates for instances, we can test implication of functional and join dependencies. This information is useful in determining when a relational database scheme accurately represents the information it is intended to. The chase can also be used to test equivalence of database schemes and as part of the test of whether the relation schemes in a database scheme are independent components.

Genetic variation and host plant relations in a parthenogenetic moth.

Abstract: Ecological genetics is the investigation of the influence of ecological factors on the genetic properties of populations, and the influence of genetic structure on their ecological properties. Ideally, these studies should determine how genetic variation is affected by selection and by the size, dynamics, and degree of subdivision of populations; what ecological factors determine the relative fitness of genotypes; and what effect the genetic composition of a population has on such ecological parameters as its density, stability, and ecological amplitude. Many studies have demonstrated selection in natural populations; indeed, the widespread existence of selection is perhaps the only generalization that can be made about ecological genetics. But most studies are incomplete. A few, such as the analysis of inversion karyotypes in Drosophila pseudoobscura by Dobzhansky

Functional and morphological affinities of the subadult hand (O.H. 7) from Olduvai Gorge.

Abstract: Study of the O.H. 7 hand was based primarily on morphological comparisons with a large series of hand skeletons of extant hominoid primates. Most of the hand elements are fragmentary or have missing epiphyses and only comparisons based on qualitative morphological observations are possible. The distal phalanges are complete, however, and were analyzed metrically utilizing univariate and multivariate statistical techniques. To compensate for size differences among the Hominoidea a number of size adjustments were employed. None of the adjustments were totally satisfactory from theoretical and practical standpoints and none completely eliminated the influence of size. There is no entirely satisfactory procedure to eliminate size and it is advisable to use several techniques that are not closely related, to compare the results and interpret them with caution. In certain features the wrist and fingers resemble those of African apes; in others they are more like modern human hands; in still others they are unique. The scaphoid and the proximal articular surface of the trapezium retain apelike features, as do the proximal and middle phalanges. The pollical carpometacarpal joint and the distal phalanges are closer in morphology to those of modern humans. The scaphoid, proximal phalanges and middle phalanges of rays II-V indicate a hand capable of a strong power grip. A number of features of the thumb and the distal phalanges suggest that the O.H. 7 individual was capable of more precise manipulation than extant apes. FLK NN-A, a first distal phalanx, does not closely resemble the first distal phalanx of any of the living Hominoidea. Multivariate distance analysis indicates, however, that it is closest in overall morphology to the pollical distal phalanx of modern humans. In some features not included in the metric analysis, FLK NN-A also resembles the hallucial distal phalanx of modern humans.

Fact and fantasy: the roles of accuracy and variability in confusing imaginations with perceptual experiences.

Abstract: In Experiment 1, pictures were presented to subjects two, five, or eight times, and subjects were asked to imagine each pciture two, five, or eight times. Subsequently, subjects estimated the number of times each picture had been presented. Their estimates of the frequency of these external events were influenced by imagination trials; this effect was greater for good imagers than for poor imagers. Experiment 2 involved a similar design in which subjects were asked either to imagine the same referent for a word or to imagine a different referent for a word on successive imagination trials. Consistency (same referent) did not increase the influence of imaginations on immediate judgments of external frequency. Thus, the results of Experiment 1 were attributed to the greater accuracy (as opposed to greater consistency) of good imagers' internal generations of the stimuli. Furthermore, variation (imagining different referents), like greater accuracy, increased the effects of imagination trials on immediate but not on delayed judgments of frequency. Possible mechanisms underlying these effects are discussed. In general, the two studies show that qualitative characteristics of completely covert generations influence their impact on estimates of the frequency of external events.

The significance of circumstances for college students' ratings of their teachers and courses

Abstract: Although firm generalizations and conclusions cannot yet be drawn from the extant research on the effects on teacher and course ratings of the circumstances surrounding these evaluations, at least some studies have shown that college students' ratings of their teachers and courses are somewhat higher when students remain anonymous rather than identifying themselves, when the purported use of the ratings is an official or administrative one for use in salary, promotion, or tenure considerations rather than otherwise, and when the instructor is present rather than absent during the rating session. (The differences between each of these contrasted circumstances are usually rather small and do not inevitably appear across studies.) Certain variations in rating format have been found to make a difference in the ratings obtained, whereas other have not. From limited evidence, the exact timing (or occasion) of evaluation appears not to be important to ratings. Variability in sampling procedures, as it affects the composition of students available to complete rating forms, may or may not turn out to be a generally important element in ratings (as directly relevant data are collected). The analysis concludes with a discussion of (1) the presumed “bias” in ratings produced in certain of the rating conditions and (2) the more general issue of the comparability of ratings made in different circumstances of evaluation.

Teaching autistic children to use sign language: some research issues.

Abstract: Three questions are raised with respect to the use of sign language as an alternative system of communication for nonverbal autistic children. First, does teaching a child to sign facilitate speech development? The data suggest that following simultaneous communication training, mute children are not likely to learn to talk; however, a combination of simultaneous communication training and separate vocal training may have a synergetic effect on speech development. In contrast, children who initially have good verbal imitation skills apparently show gains in speech following simultaneous communication training alone. Second, what is the upper limit of sign acquisition? Data suggest that abstract concepts, syntax, and generative skills can be taught. Procedures used in the operant conditioning of speech may prove useful in training complex signing skills. Third, does sign acquisition result in a general improvement in adaptive functioning? It appears that following sign training, some children do show increases in spontaneous communication, decreases in self-stimulatory behavior, and improvement in social skills. However, these outcomes are often difficult to interpret. Some data are described that help clarify the relationship between sign training and general behavioral improvement.

Computed tomography and biomechanical analysis of fossil long bones

Abstract: Computerized transverse axial scanning (computed tomography) is a relatively new radiographic technique designed to recover precise cross-sectional images (tomograms) of 3-dimensional objects. This highly sensitive process permits tissues of similar density to be separated and displayed unambiguously. These special features are, therefore, ideal for analyzing the cross-sectional geometry of intact fossil long bones, even when they are highly mineralized and their medullary cavities are occluded by matrix. In order to demonstrate the utility of this method in assessing the complex relationship between fossil structure and probable function, geometrical and biomechanical properties of midshaft tomograms of femora and tibiae have been analyzed for a comparative primate sample consisting of Megaladapis edwardsi (an extinct giant prosimian from Madagascar), Indri indri (the largest extant prosimian), and Homo sapiens.

An Attenuated Form of Congenital Virilizing Adrenal Hyperplasia

Abstract: The families of two patients with hirsutism and oligomenorrhea were studied with iv ACTH (Cortrosyn) stimulation. The parents responded with a combined incremental rise of progesterone and 17-hydroxyprogesterone greater than 6.5 ng/dl-min, a response seen in the heterozygote parents of patients with congenital virilizing adrenal hyperplasia (CVAH). One sibling in one family responded as do heterozygous subjects,while two other siblings responded normally. The abnormal response of the two pairs of parents and the sibling along with the pattern of steroid secretion observed in the propositi suggest that the so-called adult-onset CVAH is a mild form of the homozygous state of CVAH.

Telemetered electromyography of flexor digitorum profundus and flexor digitorum superficialis in Pan troglodytes and implications for interpretation of the O. H. 7 hand.

Abstract: The importance of knuckle-walking in the locomotor repertoire of African apes raises the possibility that the long digital flexors may be specially adapted more to meet the demands of ground quadrupedalism than those of suspension. To investigate this possibility, the activities of the flexor digitorum superficialis and flexor digitorum profundus were studied by means of telemetered electromyography in three chimpanzees. Results clearly indicate that the fasciculi of these muscles to digits bearing weight in knuckle-walking are not called upon to contract in quadrupedal postures or in slow and moderately fast quadrupedal locomotion except to help clear the fingers from the ground as the forelimb begins its recovery stroke. At the most rapid speeds, a slight to moderate level of activity sometimes occurs in the latter half of stance phase. The long digital flexors display maximum and sustained activity during suspension. It is concluded that any role for these muscles in maintenance of stability at the metacarpophalangeal joints during knuckle-walking must be predominantly passive. Prominent markings for insertions of these muscles in a fossil hand (such as O.H. 7) suggest use of the forelimb in suspensory climbing behaviors.

One particle reduced density matrix of impenetrable bosons in one dimension at zero temperature

Abstract: We compute exactly the one particle reduced density matrix ρ (r) of a system of impenetrable bosons in one dimension at zero temperature. We do this by relating ρ (r) to a certain double scaling limit of the transverse correlation function of the one‐dimensional spin 1/2 X–Y model. We study the asymptotic behavior of ρ (r) for large r. This expansion contains oscillatory terms which arise due to the intrinsic quantum mechanical nature of the problem. We use these results to discuss the analytic structure of the momentum density function n (k).