Showing papers by "University of Oregon published in 1998"

Zebrafish hox Clusters and Vertebrate Genome Evolution

Abstract: HOX genes specify cell fate in the anterior-posterior axis of animal embryos. Invertebrate chordates have one HOX cluster, but mammals have four, suggesting that cluster duplication facilitated the evolution of vertebrate body plans. This report shows that zebrafish have seven hox clusters. Phylogenetic analysis and genetic mapping suggest a chromosome doubling event, probably by whole genome duplication, after the divergence of ray-finned and lobe-finned fishes but before the teleost radiation. Thus, teleosts, the most species-rich group of vertebrates, appear to have more copies of these developmental regulatory genes than do mammals, despite less complexity in the anterior-posterior axis.

Flocks, herds, and schools: A quantitative theory of flocking

Abstract: We present a quantitative continuum theory of ``flocking'': the collective coherent motion of large numbers of self-propelled organisms. In agreement with everyday experience, our model predicts the existence of an ``ordered phase'' of flocks, in which all members of even an arbitrarily large flock move together with the same mean velocity $〈\stackrel{\ensuremath{\rightarrow}}{v}〉\ensuremath{ e}0.$ This coherent motion of the flock is an example of spontaneously broken symmetry: no preferred direction for the motion is picked out a priori in the model; rather, each flock is allowed to, and does, spontaneously pick out some completely arbitrary direction to move in. By analyzing our model we can make detailed, quantitative predictions for the long-distance, long-time behavior of this ``broken symmetry state.'' The ``Goldstone modes'' associated with this ``spontaneously broken rotational symmetry'' are fluctuations in the direction of motion of a large part of the flock away from the mean direction of motion of the flock as a whole. These ``Goldstone modes'' mix with modes associated with conservation of bird number to produce propagating sound modes. These sound modes lead to enormous fluctuations of the density of the flock, far larger, at long wavelengths, than those in, e.g., an equilibrium gas. Our model is similar in many ways to the Navier-Stokes equations for a simple compressible fluid; in other ways, it resembles a relaxational time-dependent Ginsburg-Landau theory for an $n=d$ component isotropic ferromagnet. In spatial dimensions $dg4,$ the long-distance behavior is correctly described by a linearized theory, and is equivalent to that of an unusual but nonetheless equilibrium model for spin systems. For $dl4,$ nonlinear fluctuation effects radically alter the long distance behavior, making it different from that of any known equilibrium model. In particular, we find that in $d=2,$ where we can calculate the scaling exponents exactly, flocks exhibit a true, long-range ordered, spontaneously broken symmetry state, in contrast to equilibrium systems, which cannot spontaneously break a continuous symmetry in $d=2$ (the ``Mermin-Wagner'' theorem). We make detailed predictions for various correlation functions that could be measured either in simulations, or by quantitative imaging of real flocks. We also consider an anisotropic model, in which the birds move preferentially in an ``easy'' (e.g., horizontal) plane, and make analogous, but quantitatively different, predictions for that model as well. For this anisotropic model, we obtain exact scaling exponents for all spatial dimensions, including the physically relevant case $d=3.$

Parental monitoring and the prevention of child and adolescent problem behavior: a conceptual and empirical formulation.

Abstract: The present report accomplishes three goals. First, to provide an empirical rationale for placing parental monitoring of children's adaptations as a key construct in development and prevention research. Second, to stimulate more research on parental monitoring and provide an integrative framework for various research traditions as well as developmental periods of interest. Third, to discuss current methodological issues that are developmentally and culturally sensitive and based on sound measurement. Possible intervention and prevention strategies that specifically target parental monitoring are discussed.

Attention, self-regulation and consciousness.

Abstract: Consciousness has many aspects. These include awareness of the world, feelings of control over one9s behaviour and mental state (volition), and the notion of a continuing self. Focal (executive) attention is used to control details of our awareness and is thus closely related to volition. Experiments suggest an integrated network of neural areas involved in executive attention. This network is associated with our voluntary ability to select among competing items, to correct error and to regulate our emotions. Recent neuroimaging studies suggest that these various functions involve separate areas of the anterior cingulate. We have adopted a strategy of using marker tasks, shown to activate the brain area by imaging studies, as a means of tracing the development of attentional networks. Executive attention appears to develop first to regulate distress during the first year of life. During later childhood the ability to regulate conflict among competing stimuli builds upon the earlier cingulate anatomy to provide a means of cognitive control. During childhood the activation of cingulate structures relates both to the child9s success on laboratory tasks involving conflict and to parental reports of self–regulation and emotional control. These studies indicate a start in understanding the anatomy, circuitry and development of executive attention networks that serve to regulate both cognition and emotion.

Parenting Stress and Child Adjustment: Some Old Hypotheses and New Questions

Abstract: Individual differences in parenting stress, experienced by most parents as those aversive feelings that are associated with the demands of the parenting role, have been shown to be an important aspect of parent, child, and family functioning. A definition of parenting stress is provided, along with its application to more general stress models. Three implicit hypotheses in much of the past research on parenting stress and behavior are evaluated: (a) parenting stress is causally related to poor parenting, (b) poor parenting is causally related to problems in child adjustment, and (c) parenting behavior mediates the associations between parenting stress and child adjustment. In addition, three questions for future research regarding within-family and within-Individual variation in parenting stress are raised: (a) Is parenting stress genetically influenced? (b) Do mothers and fathers show similar or different levels of parenting stress? (c) Is parenting stress “child specific” within families?

Vertebrate genome evolution and the zebrafish gene map.

Abstract: In chordate phylogeny, changes in the nervous system, jaws, and appendages transformed meek filter feeders into fearsome predators. Gene duplication is thought to promote such innovation. Vertebrate ancestors probably had single copies of genes now found in multiple copies in vertebrates and gene maps suggest that this occurred by polyploidization. It has been suggested that one genome duplication event occurred before, and one after the divergence of ray-finned and lobe-finned fishes. Holland et al., however, have argued that because various vertebrates have several HOX clusters, two rounds of duplication occurred before the origin of jawed fishes. Such gene-number data, however, do not distinguish between tandem duplications and polyploidization events, nor whether independent duplications occurred in different lineages. To investigate these matters, we mapped 144 zebrafish genes and compared the resulting map with mammalian maps. Comparison revealed large conserved chromosome segments. Because duplicated chromosome segments in zebrafish often correspond with specific chromosome segments in mammals, it is likely that two polyploidization events occurred prior to the divergence of fish and mammal lineages. This zebrafish gene map will facilitate molecular identification of mutated zebrafish genes, which can suggest functions for human genes known only by sequence.

Behavioral, Social, and Emotional Assessment of Children and Adolescents

Abstract: Part: I: Foundations and Methods of Assessment. Foundations of Assessment. Assessment and Classification. Direct Behavioral Observation. Behavior Rating Scales. Interviewing Techniques. Sociometric Techniques. Self-report Assessment. Projective-expressive Techniques. Part II: Assessment of Specific Problems, Competencies, and Populations. Assessing Externalizing Problems. Assessing Internalizing Problems. Assessing Other Behavioral, Social, and Emotional Problems. Assessing Social Skills and Peer Relations. Assessing Social and Emotional Behavior of Young Children. Assessment and Cultural Diversity

What Is Beyond the Big Five

Abstract: Previous investigators have proposed that various kinds of person- descriptive content—such as differences in attitudes or values, in sheer evalu- ation, in attractiveness, or in height and girth—are not adequately captured by the Big Five Model. We report on a rather exhaustive search for reliable sources of Big Five-independent variation in data from person-descriptive adjectives. Fifty-three candidate clusters were developed in a college sample using diverse approaches and sources. In a nonstudent adult sample, clusters were evaluated with respect to a minimax criterion: minimum multiple correlation with factors from Big Five markers and maximum reliability. The most clearly Big Five- independent clusters referred to Height, Girth, Religiousness, Employment Status, Youthfulness, and Negative Valence (or low-base-rate attributes). Clus- ters referring to Fashionableness, Sensuality/Seductiveness, Beauty, Masculin- ity, Frugality, Humor, Wealth, Prejudice, Folksiness, Cunning, and Luck appeared to be potentially beyond the Big Five, although each of these clusters demonstrated Big Five multiple correlations of .30 to .45, and at least one correlation of .20 and over with a Big Five factor. Of all these content areas, Religiousness, Negative Valence, and the various aspects of Attractiveness were found to be represented by a substantial number of distinct, common adjectives. Results suggest directions for supplementing the Big Five when one wishes to

Cerebral organization for language in deaf and hearing subjects: Biological constraints and effects of experience

Abstract: Cerebral organization during sentence processing in English and in American Sign Language (ASL) was characterized by employing functional magnetic resonance imaging (fMRI) at 4 T. Effects of deafness, age of language acquisition, and bilingualism were assessed by comparing results from (i) normally hearing, monolingual, native speakers of English, (ii) congenitally, genetically deaf, native signers of ASL who learned English late and through the visual modality, and (iii) normally hearing bilinguals who were native signers of ASL and speakers of English. All groups, hearing and deaf, processing their native language, English or ASL, displayed strong and repeated activation within classical language areas of the left hemisphere. Deaf subjects reading English did not display activation in these regions. These results suggest that the early acquisition of a natural language is important in the expression of the strong bias for these areas to mediate language, independently of the form of the language. In addition, native signers, hearing and deaf, displayed extensive activation of homologous areas within the right hemisphere, indicating that the specific processing requirements of the language also in part determine the organization of the language systems of the brain.

Molecular basis of double‐stranded RNA‐protein interactions: structure of a dsRNA‐binding domain complexed with dsRNA

Abstract: Protein interactions with double-stranded RNA (dsRNA) are critical for many cell processes; however, in contrast to protein-dsDNA interactions, surprisingly little is known about the molecular basis of protein-dsRNA interactions. A large and diverse class of proteins that bind dsRNA do so by utilizing an approximately 70 amino acid motif referred to as the dsRNA-binding domain (dsRBD). We have determined a 1.9 A resolution crystal structure of the second dsRBD of Xenopus laevis RNA-binding protein A complexed with dsRNA. The structure shows that the protein spans 16 bp of dsRNA, interacting with two successive minor grooves and across the intervening major groove on one face of a primarily A-form RNA helix. The nature of these interactions explains dsRBD specificity for dsRNA (over ssRNA or dsDNA) and the apparent lack of sequence specificity. Interestingly, the dsRBD fold resembles a portion of the conserved core structure of a family of polynucleotidyl transferases that includes RuvC, MuA transposase, retroviral integrase and RNase H. Structural comparisons of the dsRBD-dsRNA complex and models proposed for polynucleotidyl transferase-nucleic acid complexes suggest that similarities in nucleic acid binding also exist between these families of proteins.

International Marketing and Export Management

Abstract: Chapter 1 - International Marketing and Exporting Chapter 2 - Bases of International Marketing Chapter 3 - The International Environment: Culture, Economic and Competition Chapter 4- The International Environment: Government, Political and Legal forces Chapter 5 - Export Market Selection: Definition and Strategies Chapter 6 - Information for International Market(ing) Decisions Chapter 7 - Market Entry Strategies Chapter 8 - Export Entry Modes Chapter 9 -- Non-export Entry Modes Chapter 10 - Product Decisions Chapter 11 - Pricing Decisions Chapter 12 - Financing and Methods of Payment Chapter 13 - Promotion and Marketing Communication Chapter 14 - Handling Export Orders and Supply Chain Management Chapter 15 - Organization of International Marketing Activities

Coupled Temporal Memories in Parkinson's Disease: A Dopamine-Related Dysfunction

Abstract: Dysfunction of the basal ganglia and the brain nuclei interconnected with them leads to disturbances of movement and cognition, including disordered timing of movement and perceptual timing deficits. Patients with Parkinson's disease (PD) were studied in temporal reproduction tasks. We examined PD patients when brain dopamine (DA) transmission was impaired (OFF state) and when DA transmission was reestablished, at the time of maximal clinical benefit following administration of levodopa + apomorphine (ON state). Patients reproduced target times of 8 and 21 sec trained in blocked trials with the peak interval procedure, which were veridical in the ON state, comparable to normative performance by healthy young and aged controls (Experiment 1). In the OFF state, temporal reproduction was impaired in both accuracy and precision (variance). The 8-sec signal was reproduced as longer and the 21-sec signal was reproduced as shorter than they actually were (Experiment 1). This ''migration'' effect was dependent upon training of two different durations. When PD patients were trained on 21 sec only (Experiment 2), they showed a reproduction error in the long direction, opposite to the error produced under the dual training condition of Experiment 1. The results are discussed as a mutual attraction between temporal processing systems, in memory and clock stages, when dopaminergic regulation in the striatum is dysfunctional.

Comparison of two community alternatives to incarceration for chronic juvenile offenders.

Abstract: The relative effectiveness of group care (GC) and multidimensional treatment foster care (MTFC) was compared in terms of their impact on criminal offending, incarceration rates, and program completion outcomes for 79 male adolescents who had histories of chronic and serious juvenile delinquency. Results show that boys who participated in MTFC had significantly fewer criminal referrals and returned to live with relatives more often. Multiple regression analyses showed that assignment to a treatment condition (i.e., GC or MTFC) predicted official and self-reported criminality in follow-up beyond other well-known predictors of chronic juvenile offending (i.e., age at 1st offense, number of previous offenses, age at referral).

The role of inhibitory processes in young children's difficulties with deception and false belief

Abstract: This research examines whether children's difficulties with deception and false belief arise from a lack of inhibitory control rather than from a conceptual deficit. In 3 studies, 3-year-olds deceived frequently under conditions requiring relatively low inhibitory control (e.g., misleading pictorial cues or arrows) but failed to do so under conditions of high inhibitory control (deceptive pointing). Study 2 ruled out that the findings were due to social intimidation: Children were equally successful using an arrow to deceive under anonymous and public conditions. Study 3 indicated that, under well-controlled conditions, children did not reveal greater understanding of false belief in deceptive than nondeceptive conditions. The results of these studies suggest that children may have greater deceptive abilities than some earlier studies indicated, and that the source of their difficulty on deceptive pointing tasks lies in a failure of inhibitory control. More generally, it is argued that children's performance on false belief tasks is also likely to be affected by inhibition deficits.

High‐versus low‐Context culture: A comparison of Chinese, Korean, and American cultures

Abstract: The potential usefulness of Hall's concept of high- versus low-context cultures to international marketing has been discussed widely. However, implications of this concept in marketing have largely been discussed descriptively and little attempt has been made to empirically compare various cultures in a real setting. In this article the authors report the findings from a cross-cultural study that attempts to show whether Hall's description of the characteristics of high- and low-context cultures can indeed be empirically confirmed. With the use of a survey consisting of 16 items, subjects from three different countries—China, Korea, and the U.S.—representing both high- and low-context cultures, are studied. Overall, the results show that the three cultures differ in a way that is consistent with Hall's conceptualization. Specifically, the Chinese and Korean subjects are shown to exhibit tendencies that are consistent with Hall's description of high-context cultures, and the American subjects are shown to exhibit tendencies that are consistent with low-context cultures. For example, the subjects from China and Korea are found to be more socially oriented, to be more confrontation-avoiding, and to have more trouble dealing with new situations. The article concludes by pointing to a further need for efforts in developing measurement scales for the concept. © 1998 John Wiley & Sons, Inc.

Scalar expectancy theory and peak-interval timing in humans.

Abstract: The properties of the internal clock, temporal memory, and decision processes used to time short durations were investigated. The peak-interval procedure was used to evaluate the timing of 8-, 12-, and 21-s intervals, and analyses were conducted on the mean response functions and on individual trials. A distractor task prevented counting, and visual feedback on accuracy and precision was provided after each trial. Mean response distributions were (a) centered at the appropriate real-time criteria, (b) highly symmetrical, and (c) scalar in their variability. Analysis of individual trials indicated more memory variability relative to response threshold variability. Taken together, these results demonstrate that humans show the same qualitative timing properties that other animals do, but with some quantitative differences.

Prospective Family Predictors of Aggression toward Female Partners for At-Risk Young Men.

Abstract: Social learning models of the intergenerational transmission of aggression were tested for an at-risk sample of young adult men who entered a longitudinal study (Oregon Youth Study) in Grade 4 and were assessed with a female partner in young adulthood (17-20 years old). The associations of 2 family process variables--parental dyadic aggression and unskilled parenting, assessed both in late childhood and early adolescence with the son's later aggression toward a partner--were examined. Parental antisocial behavior was hypothesized to be associated with both family process variables. Unskilled parenting was hypothesized to play a key role in the son's later aggression toward an intimate partner, mediated by his development of antisocial behavior by adolescence. Fully prospective structural equation models were tested with multimethod, multiagent data, including both observed and reported aggression toward the partner. Findings indicate that the major hypothesized pathways through unskilled parenting practices and the boys' antisocial behavior were implicated in the intergenerational transmission of aggression.

First Step to Success An Early Intervention Approach for Preventing School Antisocial Behavior

Abstract: This article reports results of a 4-year study designed to develop and initially evaluate a combined home and school intervention approach to preventing school antisocial behavior. The First Step to Success program targets at-risk kindergartners who show the early signs of an antisocial pattern of behavior (e.g., aggression, oppositional-defiant behavior, severe tantrumming, victimization of others). First Step to Success consists of three interconnected modules: (a) proactive, universal screening of all kindergartners; (b) school intervention involving the teacher, peers, and the target child; and (c) parent/caregiver training and involvement to support the child's school adjustment. The major goal of the program is to divert at-risk kindergartners from an antisocial path in their subsequent school careers. Two cohorts of at-risk kindergartners, consisting of 24 and 22 students, were identified and exposed to the First Step to Success program during the 1993–1994 and 1994–1995 school years, respectively....

Brain mechanisms of quantity are similar in 5-year-old children and adults

Abstract: Both 5-year-old children and adults determine the quantity of a number by the use of a similar parietal lobe mechanism. Event related potentials indicate that input from Arabic digits and from dot patterns reach areas involved in determining quantity about 200 ms after input. However, voluntary key presses indicating the relation of the input to the quantity five take almost three times as long in children. The ability to trace the networks of brain areas involved in the learning of school subjects should aid in the design and testing of educational methods.

The Future of ‘Gender and Organizations’: Connections and Boundaries

Abstract: ‘Gender and organizations’, a fruitful connection between two previously separate areas of study, has had a relatively short but bountiful history. Much of the research and theorizing within the general rubric of ‘gender and organizations’ has required the breaking of conceptual boundaries and the forging of new connections that go beyond the coalescence of two fields of inquiry. We have not exhausted the possibilities suggested by broken boundaries and new connections. This may be a particularly auspicious time to be breaking boundaries, for the apparent worldwide changes in work and organizing are not well enough understood with many of our old intellectual tools. In this paper I discuss briefly what our studies of gender and organization have, in my view, accomplished so far, and then review some issues and questions stimulated by thinking about broken boundaries and new connections, possibilities that, for me, represent part of the future for ‘gender and organizations.’

Vacuole Biogenesis in Saccharomyces cerevisiae: Protein Transport Pathways to the Yeast Vacuole

Abstract: Delivery of proteins to the vacuole of the yeast Saccharomyces cerevisiae provides an excellent model system in which to study vacuole and lysosome biogenesis and membrane traffic. This organelle receives proteins from a number of different routes, including proteins sorted away from the secretory pathway at the Golgi apparatus and endocytic traffic arising from the plasma membrane. Genetic analysis has revealed at least 60 genes involved in vacuolar protein sorting, numerous components of a novel cytoplasm-to-vacuole transport pathway, and a large number of proteins required for autophagy. Cell biological and biochemical studies have provided important molecular insights into the various protein delivery pathways to the yeast vacuole. This review describes the various pathways to the vacuole and illustrates how they are related to one another in the vacuolar network of S. cerevisiae.