Discourse topic management and discussion skills in middle childhood: the effects of age and task

Discourse topic management and discussion skills are central for intersubjectivity, learning and education, yet there is little understanding of how such skills develop.The reported research comprises two studies, which examined the skills of discourse topic maintenance, shading and hierarchicalization during middle childhood. Each study compared the performances of same-age and same-sex dyads of 4, 6 and 9 years of age (Study 1: 28 dyads; Study 2: 43 dyads) across two tasks. Overall, topic maintenance varied according to age and task. Study 1 found that task structure constrained the interactions of older children while supporting those of younger children. Older children, but not 4-year-olds maintained topics through collaborative discussion. Study 2 examined these differences further by comparing performance on similar tasks but where one required collaborative discussion for successful completion. Results showed that young children use justifications but not counter-arguments and suggestions, and do not collaborate in discussion. Development in discourse topic management and collaborative discussion skills is linked to an increasing ability to engage in mutually active dialogue, and to adapt to, connect with and comment on alternative perspectives, as well as to functional changes in the use of justifications during dialogue. </jats:p

Enhancing preschoolers reasoning skills : an intervention to optimise the use of justificatory speech acts during peer interaction

It has long been acknowledged that justificatory speech is linked with both social and cognitive development. Yet many studies suggest that pre-school children might lack the ability or experience to produce such discourse in routine interaction. In contrast, researchers such as Eisenberg and Garvey (1981) have found evidence of pre-schoolers' justifications in conflictual play contexts. Although this has positive implications for child development, the conflictual context may sit uneasily with parents' and teachers' expectations. It is encouraging therefore that McWilliam (1999) has demonstrated that pre-schoolers can produce justificatory dialogue in both conflictual and nonconflictual situations, even if occurrence in the latter context is less frequent. Based on this, the aim of the present study was to encourage pre-schoolers' production of justificatory discourse during peer exchanges in a non-conflictual context. Twenty-two dyads from a state-run nursery were subject to verbal modelling of either justificatory speech (experimental condition) or a more commonly used alternative (control condition) in daily ten-minute sessions over five consecutive days. All interactions were videorecorded for subsequent coding and analysis. Results showed that both 'why' questions and 'justifications' were significantly higher in the experimental condition, indicating that pre-schoolers' explanatory speech can be effectively enhanced by a cooperative intervention programme

Understanding the beliefs informing children’s commonsense theories of motion: The role of everyday object variables in dynamic event predictions.

**Background** Children are not blank slates when they begin school; they bring prior conceptions about the everyday world with them. These conceptions usually do not comply with accepted scientific views and have to be changed within the process of education. However, to do this effectively more needs to be known about the relationship between the everyday world and children’s knowledge of scientific principles. **Purpose** This study sought answers to the question of which object variables children use when reasoning, and how these variables are associated with outcomes. The reported study addresses these issues in relation to object motion. **Sample, design and methods** UK primary school children (n = 144) aged 5–11 years were assessed on their predictions of motion along a horizontal, in fall and down an incline using a range of everyday objects by responding to questions where they needed to compare potential motion patterns of the objects. **Results** Round shape and smooth texture of objects were consistently associated with faster motion across age groups as well as across motion dimensions. However, faster horizontal motion was associated with lighter and smaller objects across all ages, whereas faster fall was associated with heavier objects. While younger children predicted faster incline motion for lighter and smaller objects, there was a shift in conceptions with age, with older children predicting faster motion for heavier and bigger objects. **Conclusions** The overall findings are used to support the development of commonsense theories of motion previously identified, and suggestions for educational practice are made. Specifically, it is suggested that these findings may need to be taken into consideration in the development of teacher training programmes

A developmental investigation of the relationship between appraisals and peer self-esteem in children experiencing peer-aggression

Transactional models of stress and coping emphasize the role played by cognitive appraisals in determining psychological adjustment (Lazarus, 1999). This proposition has been supported by research examining young people's adjustment in relation to family conflict and break-up (Grych et al., 1992). Furthermore, this literature suggests that there is a change in the relationship between appraisals and adjustment at around 10 years of age: specificity of appraisal type (e.g. threat, blame) becomes relevant to outcome after 10 years, whereas before 10 there are either no effects of appraisal on adjustment or a diffuse effect of 'negative' appraisals more generally (Jouriles et al., 2000). However, it is currently unclear whether this developmental progression can be generalized from familial- to social-stressors experienced by children and young people. The current study therefore evaluates the model within the context of a commonly experienced social childhood stressor: peer-aggression

Children’s predictions and recognition of fall: The role of object mass

A small but growing body of evidence suggests that alongside misconceptions in predictions about object motion, adults and children hold relevant underlying conceptions, reflected in recognition, which provide greater understanding of such events. However, the relationship between knowledge retrieved in predictions and in recognition is unclear. One significant element contributing to misconceptions about motion is object mass. This aspect was used to provide further insight into the knowledge relationship. Predictions and recognition of fall in 5–11-year-old children (N = 121) were addressed in the present study. The results suggest that children’s recognition of object motion is far better than their expressed anticipation of such events, as they normally recognised correct events as correct and rejected incorrect ones yet predictions were typically in error. Response time data provide additional insight. The findings are discussed in relation to different models of knowledge representations, favouring a hybrid model

Using the CERN Program-Library Graphics and Interactive Data Display

Small scale Monte Carlo programming is growing rapidly due to the ease with which complex problems may be formulated by any programmer. These programmers may choose to exploit graphics and interactive displays available in the program library developed and maintained by CERN (the Center for European Nuclear Research). This paper outlines the use of graphics and interactive data display features of the CERN program library, developed for visualizing simulated data events in particle detectors. One example uses GEANT, CERN\u27s Monte Carlo modeling program, to simulate 300 MeV/c protons incident on a silicon slab. Display packages for GEANT are available both on-line and off-line for 3-D tracking of particles through any detector system. On-line displays provide the user a qualitative sense of the inner workings of various detector components. On-line displays may be updated for each particle track in the detector system, so any design change in detector geometry or component material may have its consequences visualized immediately. This visualization is useful for repeatedly making gross changes in the detector system. CERN has been very generous in making its program library available to any institution tied to groups working on experiments at CERN, however peripherally

Negative feedback control of jasmonate signaling by an alternative splice variant of JAZ10

The plant hormone jasmonate (JA) activates gene expression by promoting ubiquitin-dependent degradation of JAZ transcriptional repressor proteins. A key feature of all JAZ proteins is the highly conserved Jas motif, which mediates both JAZ degradation and JAZ binding to the transcription factor MYC2. Rapid expression of JAZ genes in response to JA is thought to attenuate JA responses, but little is known about the mechanisms by which newly synthesized JAZ proteins exert repression in the presence of the hormone. Here, we show that desensitization to JA is mediated by an alternative splice variant (JAZ10.4) of JAZ10 that lacks the Jas motif. Unbiased protein-protein interaction screens identified three related bHLH transcription factors (MYC2, MYC3, and MYC4) and the co-repressor NINJA as JAZ10.4-binding partners. We show that the N-terminal region of JAZ10.4 contains a cryptic MYC2-binding site that resembles the Jas motif, and that the ZIM motif of JAZ10.4 functions as a transferable repressor domain whose activity is associated with recruitment of NINJA. Functional studies showed that expression of JAZ10.4 from the native JAZ10 promoter complemented the JA-hypersensitive phenotype of a jaz10 mutant. Moreover, treatment of these complemented lines with JA resulted in rapid accumulation of JAZ10.4 protein. Our results provide an explanation for how the unique domain architecture of JAZ10.4 links transcription factors to a co-repressor complex, and suggest how JA-induced transcription and alternative splicing of JAZ10 pre-mRNA creates a regulatory circuit to attenuate JA responses.Fil: Moreno, Javier Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina. Michigan State University; Estados UnidosFil: Shyu, Christine. Michigan State University; Estados UnidosFil: Campos, Marcelo L.. Michigan State University; Estados UnidosFil: Patel, Lalita C.. Michigan State University; Estados UnidosFil: Chung, Hoo Sun. Michigan State University; Estados UnidosFil: Yao, Jian. Michigan State University; Estados UnidosFil: He, Sheng Hang. Michigan State University; Estados UnidosFil: Howe, Gregg A.. Michigan State University; Estados Unido

Optimizing Tracking Software for a Time Projection Chamber

International research collaborations will be using accelerators in the U.S. and Europe to produce and detect t5 phase transition in high-density nuclear matter called the Quark-Gluon Plasma, formed in collisions between pairs of A=200 nuclei, for projectiles with kinetic energies large compared to their rest mass energies. Each collaboration will use time projection chambers (TPC) to track thousands ofsecondary charged particles formed in the aftermath ofeach central primary collision. Creating and optimizing TPC tracking software is difficultinsuch a high multiplicity environment, particularly for particles with a low momentum (below 300 MeV/C). A thigh momenta, energy loss is low enough for particle-tracking to use unchanging helix parameters. However, at low momenta, tracking requires changing helix parameters as energy is lost along the path. Tracking software, written for particles of high momenta, may identify the track of a single low momentum particle as two or three separate tracks. This tracking problem was corrected by changing the main tracking algorithm to merge together these two-or-three fragmented, low-momentum particle tracks. Event displays were found exceedingly helpful in diagnosing the problems and optimizing the algorithms

Creation and Implementation of a Tracking Module for a Small-Geometry, Vertex Time Projection Chamber

A charged-particle tracking module was written and tested using pixel data generated from CERN\u27s Monte Carlo detector-modeling program GEANT. This tracking module was customized for testing the design of a micro-strip gas time project chamber, designed by Drs. Margetis and Wieman of the Relativistic Nuclear Collisions Group at Lawrence Berkeley Laboratory. This low-mass, high-resolution, small-geometry vertex time projection chamber was designed for possible use with a larger instrument in an experiment using the relativistic heavy ion collider, RHIC, under construction at Brookhaven National Laboratory in New York. Implementing this tracking module involved generating tables and source code in a manner which is accessible to any user who is familiar with general purpose programming, using event-based data-processing. This charged-particle tracking module project was initiated in Summer-1994 as part of a 10-week, undergraduate research project at Lawrence Berkeley Laboratory, sponsored by LBL\u27s Office of Science and Engineering Education. Further research on this project is underway at UALR