Showing papers by "University of Connecticut published in 1985"

A theoretical model of phase transitions in human hand movements

Abstract: Earlier experimental studies by one of us (Kelso, 1981a, 1984) have shown that abrupt phase transitions occur in human hand movements under the influence of scalar changes in cycling frequency. Beyond a critical frequency the originally prepared out-of-phase, antisymmetric mode is replaced by a symmetrical, in-phase mode involving simultaneous activation of homologous muscle groups. Qualitavely, these phase transitions are analogous to gait shifts in animal locomotion as well as phenomena common to other physical and biological systems in which new “modes” or spatiotemporal patterns arise when the system is parametrically scaled beyond its equilibrium state (Haken, 1983). In this paper a theoretical model, using concepts central to the interdisciplinary field of synergetics and nonlinear oscillator theory, is developed, which reproduces (among other features) the dramatic change in coordinative pattern observed between the hands.

Psychopathology in Hospitalized Alcoholics

Abstract: • This study utilized the DSM-III criteria and the National Institute of Mental Health Diagnostic Interview Schedule to assess the prevalence of lifetime psychopathology among hospitalized alcoholics. Antisocial personality (ASP) and substance-use disorder were common psychopathologies among male alcoholics and major depression and phobia were common among female alcoholics. The onset of most psychopathologies preceded the abuse of alcohol among women. In men, however, with the exception of ASP and panic disorder, the onset of psycopathology was subsequent to that of alcohol abuse and/or dependence. Diagnoses of ASP and substance abuse were characterized by early onset of regular intoxication and alcohol abuse. Gender and the presence of specific psychopathology appeared to modify the course and symptom picture of alcoholism. In general, alcoholic women showed a later onset of regular intoxication and a more rapid progression to alcohol abuse and dependence than alcoholic men.

Phonology and the Problems of Learning to Read and Write

Abstract: Learning to read and write depends on abilities that are language related but that go beyond the ordinary abilities required for speaking and listening. Research has shown that the success of learners, whether they are children or adults, is related to the degree to which they are aware of the underlying phonological structure of words. Poor readers are often unable to segment words into their phonological constituents and may have other phonological deficiencies as well. Their difficulties in naming objects and in comprehending sentences, for example, may also stem from a basic problem in the phonological domain.

VIDEOPLACE—an artificial reality

Abstract: The human-machine interface is generalized beyond traditional control devices to permit physical participation with graphic images. The VIDEOPLACE System combines a participant's live video image with a computer graphic world. It also coordinates the behavior of graphic objects and creatures so that they appear to react to the movements of the participant's image in real-time. A prototype system has been implemented and a number of experiments with aesthetic and practical implications have been conducted.

Growth cone morphology and trajectory in the lumbosacral region of the chick embryo

Abstract: We quantitatively analyzed several features of orthogradely labeled peripheral growth cones in the lumbosacral region of the chick embryo. We compared motoneuron growth cones in regions where they appear to express specific directional preferences (the plexus region and regions where muscle nerves diverge from main nerve trunks), which we operationally defined as “decision regions,” to motoneuron growth cones in other pathway regions (the spinal nerve, nerve trunk, and muscle nerve pathways) which we termed, for contrast, “non-decision region.” We found that motoneuron growth cones are larger, more lamellepodial, and have more complex trajectories in decision regions. Sensory growth cone populations, which are thought to be dependent upon motoneurons for outgrowth (Landmesser, L., and M. Honig (1982) Soc. Neurosci. Abstr. 8: 929), do not enlarge or become more lamellepodial in motoneuron decision regions, suggesting that this local environment does not affect all species of growth cones equally and that the alterations in motoneuron growth cones in these regions may be relevant to their specific guidance. In addition, the resemblance between the sensory population and other closely fasciculating growth cones lends support to the suggestion that sensory neurons utilize motoneuron neurites as a substratum. We suggest that the convoluted trajectories, enlarged size, and more lamellepodial morphology of motoneuron growth cones in decision regions is either related directly to the presence of specific cues that guide motoneurons or to some aspect of this environment that allows them to respond to specific cues.

Energetics of vocalization by an anuran amphibian (Hyla versicolor)

Abstract: The metabolic demands of vocalization byHyla versicolor were determined by measuring oxygen consumption and whole body lactate content of calling animals. A stepwise multiple regression analysis identified both calling rate (calls/h) and call duration (s/call) as significant determinants of oxygen consumption during calling. These two variables accounted for 84% of the total variation in oxygen consumption observed in calling frogs. Aerobic metabolism\(\left( {\dot V_{O_2 } {\text{call}}} \right)\) increased linearly with calling rate and call duration, reaching a peak value of 1.7 ml O2/(g·h) at the highest vocalization effort. For comparison, metabolic rates of the same individuals were also measured during short bouts of vigorous locomotor exercise\(\left( {\dot V_{O_2 } {\text{ex}}} \right)\) induced by mechanical stimulation. The mean value of\(\dot V_{O_2 } {\text{ex}}\) was only 62% of the peak\(\dot V_{O_2 } {\text{call}}\), and 5 of 13 frogs had rates of oxygen consumption during calling that exceeded their\(\dot V_{O_2 } {\text{ex}}\). Whole body lactate levels were measured in two samples of calling frogs, one collected early in the evening (2100–2115 h) and the other 1.5 h later (2230–2245 h). The frogs in the second sample had significantly lower lactate levels (0.10 mg/g) than the frogs collected early in the evening (0.22 mg/g). Hence, vocalization does not entail the use of anaerobic metabolism, although lactate levels may be slightly elevated at the onset of an evening of calling. Calling rates of unrestrained frogs in a large chorus were measured at regular intervals during an evening. During the first half hour of calling, rates increased gradually from an initial mean value of 600 calls/h at 2030 h to nearly 1400 calls/h at 2100 h. These data indicate that acoustic advertisement byHyla versicolor is among the most energetically expensive activities regularly undertaken by any anuran, and indeed, is the most demanding yet measured in an ectothermic vertebrate.

Adhesives Technology Handbook

Abstract: Comprehensive technical treatment of the field of structural adhesive bonding. The data categories include: Definition of Terms; Joint Design and Design Criteria; Surface Preparation of Adherends; Adhesive Types and Their Properties and Applications; Adhesives for Specific Adherends; The Adhesive Bonding Process; Solvent Cementing of Plastics; Effects of Environment on Durability of Adhesive Joints; Quality Control; Test Methods; Standard Specifications and Test Methods (235); Applications of Adhesive Bonding; Appendix -- Sources of Information. -- AATA

Cohesion in the Narratives of Normal and Language-Disordered Children

Abstract: An adaptation of Halliday and Hasan's (1976) description of cohesion in English was applied to the spoken narratives of normal and language-disordered children. Three major questions were addressed...

GABA neurons in the superficial layers of the rat dorsal cochlear nucleus: Light and electron microscopic immunocytochemistry

Abstract: This article is an application of light and electron microscopic immunocytochemistry to the study of the neuronal circuit of the superficial layers in the rat dorsal cochlear nucleus (DCN). An antiserum against the intrinsic marker glutamate decarboxylase (GAD) is used to identify and map axon terminals and neurons that use gamma aminobutyric acid (GABA) as a neurotransmitter. It is demonstrated that layers 1 and 2 of the DCN contain a very high density of GABAergic boutons, matched only by the granule cell domains of the ventral cochlear nucleus, especially the superficial granule cell domain. These two layers also contain much higher concentrations of GABAergic cell bodies than all other magnocellular regions of the cochlear nuclear complex. Cartwheel and stellate neurons, and probably also Golgi cells, previously characterized in Golgi and electron microscopic investigations, appear immunostained and, therefore, are presumably inhibitory. The synaptic relations between parallel fibers, the axons of granule cells, and cartwheel and stellate neurons are confirmed. The present study also supports the conclusion that stellate cells are coupled to one another by gap junctions. Also scattered in layer 1 are large, GABAergic neurons that occur with irregular frequency and presumably represent displaced Purkinje cells, previously identified with a Purkinje-cell-specific marker. Granule neurons and pyramidal neurons remain unstained, even after topical injection of colchicine, which enhances immunostaining of the other glutamate-decarboxylase-positive cells, and therefore must use transmitters different from GABA. The possible analogies between the spiny cartwheel and the aspiny stellate cells of the DCN and the cerebellar Purkinje and stellate/basket cells are discussed in the light of data from Golgi, electon microscopy, and transmitter imunocytochemistry.

The Great Merger Movement in American Business, 1895-1904

Abstract: Between 1895 and 1904 a great wave of mergers swept through the manufacturing sector of the United States' economy. This book explores the causes of the mergers, arguing that there was nothing natural or inevitable about turn-of-the-century combinations. Despite this conclusion, the author does not accept the view that they were necessarily a threat to competition. She shows that most of these consolidations were less efficient that the new rivals that appeared almost immediately, and they quickly lost their positions of market dominance. More over, in most of those few cases where consolidations proved to be more efficient, the nation was better off for their formation. Some exceptions occurred, however, and in these instances anti-trust policy should have had a significant role to play. Unfortunately, the peculiar division of power and authority that characterizes the Federal system of government prevented an effective policy from emerging. Ironically, anti-trust policy proved much more effective against small firms in relatively competitive industries than large firms in oligopolistic ones.

Neighborhood predictors of plant performance.

Abstract: We developed models of inter-individual interference to predict the fecundity of individuals in populations of the annual plant species, Arabidopsis thaliana. An individual plant is modeled as having a neighborhood which is a circular area of fixed radius with the plant at its center. Other plants which share the circle with the focal plant are termed neighbors of the focal plant. We developed an index of neighborhood interference which is the independent variable in a non-linear regression model that predicts individual plant fecundity. We present methods of exploratory data analysis that are useful in determining a best neighborhood radius, defined as that radius which minimizes residual sum of squares, and in deciding on the functional form of the interference index. In developing the interference index for Arabidopsis, we focus on aspects of the spatial distribution of neighbors: their number, distance and angular dispersion. We found that a best (or optimal) neighborhood radius can be resolved, which provides the best predictor of plant performance. Fecundity predictors based on adult neighbors were noticeably better than those based on neighbors at the seedling stage. Rosettes of Arabidopsis may change location during development (they fall over) and the new “fallen” positions do provide some improvement in the predictor. Taking into account distance to neighbors within the neighborhood provided only negligible improvement in the model. Finally, the incorporation of angular dispersion in the crowding index produced a considerably better fit. The fecundity predictor that included number of neighbors and angular dispersion in the crowding index explained about 70% of the variation in individual seed set.

Mobilization and Meaning: Toward an Integration of Social Psychological and Resource Perspectives on Social Movements

Abstract: This paper presents a model of the mobilization of people into movements that is compatible with a resource mobilization perspective on social movement organizations as the unit of analysis, but substitutes a cognitive social psychology based on attribution theory and the sociology of knowledge for the incentive model typically used in this perspective. We focus on the problem, neglected by resource mobilization theorists, of explaining the translation of objective social relationships into subjectively experienced, collectively defined grievances. On a macro level, our model gives independent causal weight to ideology without discounting the role that resources also play in defining group goals. On a social psychological level, we identify three distinct organizational strategies–conversion, coalition, and direct action–for mobilizing persons as participants and examine some cognitive and organizational consequences of each strategy. We conclude that incorporation of a more adequate social psychology of individual participation is not only compatible with the organizational focus and emphasis on rationality of the resource mobilization perspective, but can provide important insights into problems both social movement theorists and social movement organizers see as significant.

Reactivity to alcohol-related cues: physiological and subjective responses in alcoholics and nonproblem drinkers.

Abstract: Physiological reactivity and self-reported desire to drink in nonproblem drinkers (N = 11 women and 15 men) and hospitalized alcoholics (N = 25 women and 34 men) were examined while subjects held and sniffed their preferred alcoholic beverage. Skin conductance level (SCL) and heart rate during alcohol exposure were significantly higher in the alcoholics than in the non-alcoholics. Self-reported desire to drink and SCL during alcohol exposure were correlated for alcoholics but not for nonalcoholics. Among alcoholics, SCL change was positively correlated with the number of heavy-drinking days in the month preceding admission to treatment. Consistent with conditioning models of relapse, alcoholics showed a distinctive response to alcohol cues, characterized by autonomic reactivity and concordance between this reactivity and self-reported desire for alcohol.

Mercury sampling of open ocean waters at the picomolar level

Abstract: Severe mercury contamination (30 times ambient levels) was observed in open ocean seawater samples collected at depth using a tested polyvinyl chloride (PVC) sampler in a classical hydrographic manner. Consistently smaller Hg concentrations (0.4 to 2.0 ng l−1) were obtained with an improvised technique using synthetic line suspended below the metal hydrographic cable; results agreed favorably with collections of the mixed layer obtained by hand and with samples collected at depth using the Schaule-Patterson sampler. These observations and additional tests with a synthetic hydrowire indicate that reactive Hg concentrations in the open ocean are, for the most part, considerably less than previously reported. While Hg distributions in the open ocean display no distinctive water column features, higher concentrations were observed in the northwest Atlantic Ocean (∼1.0 ng l−1) compared to the North Pacific (∼0.35 ng l−1). First-order geochemical modelling predicts a short (∼500 y) oceanic residence time for Hg, indicating that it may follow pathways in the oceans analogous to other very reactive elements, such as lead and manganese.

Specificity of early motoneuron growth cone outgrowth in the chick embryo.

Abstract: During development, chick lumbosacral motoneurons have been reported to form precise topographic projections within the limb from the time of initial outgrowth. This observation implies, first, that motoneurons select the appropriate muscle nerve pathway and, second, that they restrict their ramification within the primary uncleaved muscle masses to appropriate regions. Several reports based on electrophysiology and orthograde horseradish peroxidase (HRP) labeling have shown muscle nerve pathway selection to be fairly precise. However, studies based on retrograde labeling with HRP have produced conflicting reports on the extent to which vertebrate motoneurons make projection errors. Since it is difficult to distinguish between true projection errors and HRP leakage when using retrograde labeling, we decided to assess the distribution of labeled growth cones in 25-micron serial plastic sections, following orthograde labeling of identifiable subpopulations of motoneurons during the period of initial axon outgrowth. Examination of a large number of muscle nerves revealed no segmentally inappropriate axons, confirming earlier reports that muscle nerve pathway selection is very accurate. In addition, we observed that growth cones take widely divergent trajectories into the same muscle nerve, suggesting that growth cones are responding independently to some specific environmental cue rather than being passively channeled at this point. The distribution of labeled growth cones within the muscle masses provided direct evidence that motoneurons did not at any time project to obviously inappropriate muscle regions.(ABSTRACT TRUNCATED AT 250 WORDS)

d-Glucose Transport System of Zymomonas mobilis

Abstract: The properties of the d-glucose transport system of Zymomonas mobilis were determined by measuring the uptake of nonmetabolizable analogs (2-deoxy-d-glucose and d-xylose) by wild-type cells and the uptake of d-glucose itself by a mutant lacking glucokinase. d-Glucose was transported by a constitutive, stereospecific, carrier-mediated facilitated diffusion system, whereby its intracellular concentration quickly reached a plateau close to but not above the external concentration. d-Xylose was transported by the d-glucose system, as evidenced by inhibition of its uptake by d-glucose. d-Fructose was not an efficient competitive inhibitor of d-glucose uptake, indicating that it has a low affinity for the d-glucose transport system. The apparent Km of d-glucose transport was in the range of 5 to 15 mM, with a Vmax of 200 to 300 nmol min−1 mg of protein−1. The Km of Z. mobilis glucokinase (0.25 to 0.4 mM) was 1 order of magnitude lower than the Km for d-glucose transport, although the Vmax values for transport and phosphorylation were similar. Thus, glucose transport cannot be expected to be rate limiting at concentrations of extracellular glucose normally used in fermentation processes, which greatly exceed the Km for the transport system. The low-affinity, high-velocity, nonconcentrative system for d-glucose transport described here is consistent with the natural occurrence of Z. mobilis in high-sugar environments and with the capacity of Z. mobilis for rapid conversion of glucose to metabolic products with low energetic yield.

Government expenditure and economic growth in the developed countries: 1952-76

Abstract: In the past decade or more the pace of economic growth has slowed considerably and the share of government expenditure in national product has increased considerably.' The average annual growth rate of per capita GDP for the 16 most important developed market economies was 6.3% from 1955-73 and 2.0% from 1973-79. The average share of government in GDP went from 27% in 1955 to 34% in 1970 to 43% in 1979.2 The simple correlation proves nothing, but it suggests the growth of government might be one of the causes of the slowdown. Many economists have theorized that government production is staticly less efficient than private sector production with competitive markets. (see

The Effects of Task Size and Similarity on the Decision Behavior of Bank Loan Officers

Abstract: Research on decision-making behavior has shown that decision strategies used by individuals are contingent upon the characteristics of the task. For example, as the task size i.e., the number of alternatives and/or the number of dimensions describing each alternative increases, individuals tend to quickly eliminate alternatives that do not meet a criterion level for any dimension i.e., they adopt a noncompensatory decision strategy, in which a high value on one dimension cannot offset or compensate for a low value on another dimension. Most of this research has involved consumers making buying decisions. The purpose of the research reported here was to determine if contingent decision behavior extends to experts experienced bank loan officers making business decisions loan decisions. In this study two task characteristics task size, and similarity of loan profiles describing alternatives were varied in a bank loan decision context. Two process tracing methods information boards and think-aloud verbal protocol analysis were used to obtain evidence of how eleven bank loan officers made choices among alternative loan candidates. Of particular interest was the effect that changes in task characteristics had on loan officers' decision strategies. The results indicated that when faced with tasks of increasing size, loan officers adapted their behavior in a manner consistent with an increased use of noncompensatory decision strategies. In contrast, when the loan profiles of candidate companies were similar loan officers exhibited an increased use of compensatory strategies. It was also found that when both the task size and similarity of alternatives were varied loan officers adapted their behavior as if they processed these characteristics serially. These results indicate that contingent behavior associated with the two types of task characteristics may be quite different. A priori, there was reason to believe that expert loan officers would not exhibit contingent decision behavior. The fact that their decision strategies were contingent upon task characteristics has important implications for managerial practice and research. First, the results have design implications for information and decision support systems for lending institutions. Second, future research should investigate the consequences of serial processing of task characteristics.

Light chain phosphorylation regulates the movement of smooth muscle myosin on actin filaments.

Abstract: In smooth muscles there is no organized sarcomere structure wherein the relative movement of myosin filaments and actin filaments has been documented during contraction Using the recently developed in vitro assay for myosin-coated bead movement (Sheetz, MP, and JA Spudich, 1983, Nature (Lond), 303:31-35), we were able to quantitate the rate of movement of both phosphorylated and unphosphorylated smooth muscle myosin on ordered actin filaments derived from the giant alga, Nitella We found that movement of turkey gizzard smooth muscle myosin on actin filaments depended upon the phosphorylation of the 20-kD myosin light chains About 95% of the beads coated with phosphorylated myosin moved at velocities between 015 and 04 micron/s, depending upon the preparation With unphosphorylated myosin, only 3% of the beads moved and then at a velocity of only approximately 001-004 micron/s The effects of phosphorylation were fully reversible after dephosphorylation with a phosphatase prepared from smooth muscle Analysis of the velocity of movement as a function of phosphorylation level indicated that phosphorylation of both heads of a myosin molecule was required for movement and that unphosphorylated myosin appears to decrease the rate of movement of phosphorylated myosin Mixing of phosphorylated smooth muscle myosin with skeletal muscle myosin which moves at 2 microns/s resulted in a decreased rate of bead movement, suggesting that the more slowly cycling smooth muscle myosin is primarily determining the velocity of movement in such mixtures

Reliability of Goniometric Measurements in Patients with Duchenne Muscular Dystrophy

Abstract: Previous studies of reliability of goniometric measurements have produced varied findings suggesting the need to document further the reliability of measuring range of motion in different patient groups. The purpose of this study was to determine the intratester and intertester reliability of goniometric measurements of seven common upper and lower extremity joint limitations in children with Duchenne muscular dystrophy. Five physical therapists participated in the study. The procedure and order of measurements were standardized. Results showed that intratester reliability for all measurements was high (ICC = .81 to .94), but intertester reliability showed a wide variation (ICC = .25 to .91). The results of this study indicate the need to use the same examiner for long-term follow-up and for assessing results of specific treatment interventions.

Employee Ingratiation: The Role of Management

Abstract: Ingratiation, a political process to seek one's own self-interest, may be detrimental to an organization if it becomes excessive. Traditionally, ingratiation has been viewed as a set of individually-initiated behaviors. This paper attempts to show that ingratiation is organizationally induced as well as individually initiated and that it is the interaction of these two forces that determines the amount of ingratiatory behavior in an organization. A set of potentially testable propositions regarding causes of ingratiation is developed and discussed.

Distinctively Elderly Mobility: Types and Determinants

Abstract: Distinctive types of mobility are identified for the elderly, many of whom also move for traditional reasons. Using a longitudinal data set from adult residents in Rhode Island, univariate, chi square, and logit analyses indicate associations between sociodemographic characteristics of the elderly and their mobility behavior. Mobility for assistance reasons is associated with older age, unmarried status, higher previous mobility, and renter status. Mobility in preparation for aging (e.g., to an elderly complex) is more likely for unmarried, previously mobile residents. Out-of-state mobility to amenity destinations is not limited to the elderly, but younger, married, more affluent elderly were more likely to make such moves.

Differential induction of glucose-regulated and heat shock proteins: effects of pH and sulfhydryl-reducing agents on chicken embryo cells.

Abstract: Glucose-regulated and heat shock proteins are two subsets of eukaryotic stress proteins that can be induced differentially, simultaneously, and reciprocally. Two new inducers, low extracellular pH and 2-mercaptoethanol, that stimulate chicken embryo cells to synthesize glucose-regulated proteins rapidly were found. Two classes of cellular targets for mercaptoethanol were defined operationally, one dependent on and the other independent of protein synthesis. A new inducer of heat shock proteins, high extracellular pH, was found as well. Inductions by low and high extracellular pH were inhibited by actinomycin D but were insensitive to cycloheximide. Inductions of glucose-regulated and heat shock proteins are discussed in terms of changes in intracellular pH and sulfhydryl oxidation states.