Effects of familiar and unfamiliar objects on mother-infant interaction

The purpose of this study was to determine whether the dynamics and structure of mother-child interactions around toys vary with the familiarity of toys. Twelve mother-child dyads with a 5- or 9-month-old infant were filmed two consecutive 5-minute sessions in the presence of familiar or novel objects. By relating the mother’s behaviour to her infant’s, we were able to define episodes consisting of phases of joint engagement of the two partners on the same topic or reference object. In a context involving familiar objects, mothers more often took the initiative to introduce a topic, and they kept the child’s attention focused on the object for longer periods, by means of various manipulations. In contrast, the attractiveness of the novelty gave the infants more initiative, and the mothers followed the child by providing mostly verbal support.     

The structure and optimization of speechreading

Erber (1988) has claimed that one of the reasons for the ascendancy of hearing aids has been the loss of confidence in speechreading. Speechreading can be of value to those suffering from presbyacusis and other hearing disorders, in augmenting hearing aids and cochlear implants, for large numbers of people in developing countries who are unable to afford electronic aids, and for those in advanced countries who are reluctant to wear an aid. I discuss the structure and the optimization of speechreading. New methods to optimize natural speechreading skills are required that must be based on the structure and nature of speechreading. It has been suggested that speechreading is, to some extent, innate, and so 'hard-wired', which would mean that the effect of long-term training is limited. I critique this view and present a macro-analysis of the experimental literature. I suggest that the innate view may be somewhat overstated.     

Maltreatment perpetrators: a 54-month analysis of recidivism

OBJECTIVE: This study compared recidivism rates for alleged maltreatment perpetrators whose initial report was substantiated and those whose initial report was not substantiated, to determine whether they returned to the child welfare system at differing rates. METHOD: Statewide administrative child welfare services data over a period of 4 1/2 years was analyzed. The sample included 31,531 perpetrators of intrafamilial maltreatment. Separate analyses were conducted for each type of maltreatment (sexual abuse, physical abuse, and neglect). RESULTS: Bivariate relationships (substantiation status and recidivism) were analyzed using survival curves, and the study found that recidivism patterns differed by type of maltreatment and by substantiation status at the index event. Multivariate analyses using Cox Proportional Hazards models found that bivariate relationships held true even when controlling for neighborhood mean income, ethnicity, and gender. CONCLUSIONS: The study's finding that perpetrators whose index event was not substantiated return to the child welfare system at a high rate suggests the need to learn how to discriminate those unsubstantiated alleged perpetrators who are most at risk for recidivism. The finding of frequent cross-type recidivism indicates that intervention should focus on common themes across maltreatment types.     

Mechanisms of the relation between perinatal problems, early childhood illness, and psychopathology in late childhood and adolescence

Data on perinatal and early childhood somatic and psychological risk factors of a random sample of children were gathered in early to middle childhood and employed to examine the long-term risk of emotional and behavioral problems of late childhood and adolescence. 3 issues were addressed: First, can syndromic specificity of such effects be identified on scaled and diagnostic measures of syndromes? Second, are these effects attributable to excess risk of low-income children for both perinatal and later childhood problems? Third, are the intervening mechanisms identifiable as intellectual impairment, vulnerability to poor health, poor maternal caretaking, maternal rejection, or maternal stress associated with marital problems? Findings indicated that elevated risk was present for all syndromes, both at the scale level and at the diagnostic level. None of the examined intervening mechanisms fully accounted for the effects of early risks.     

Reformation of VET and demands on teachers’ subject knowledge – Swedish vocational teachers’ recurrent participation in a national CPD initiative

This study investigates continuing professional development (CPD) of vocational teachers, with a focus on recurrent participation. Vocational teachers need to be competent as teachers and in relation to their vocational teaching subject. Reformation of Swedish vocational education in order to strengthen the working-life connection imposes demands on teachers to have up-to-date knowledge about the vocations related to their vocational subjects. To support the reform, vocational teachers have been offered to participate in a new national CPD initiative targeting their vocational competence. The study concerns participation in this initiative. Drawing on a socio-cultural perspective, vocational teachers’ CPD implies boundary-crossing between school and working-life. Theory concerning adults’ participation in education is considered relevant to understand conditions for such boundary-crossing, and learning, among vocational teachers. The article specifically investigates patterns in vocational teachers’ recurrent participation, which is expected to clarify the factors influencing further participation in professional development. The strongest predictor of recurrent participation, when adjusting for the influence of other factors, is the type of municipality that the teacher comes from, with low populated municipalities having the lowest likelihood of participation. Furthermore, recurrent participation is more likely by participating teachers from adult education or from privately owned schools, and by male teachers.     

Residual stress analysis and bow simulation of crystalline silicon solar cells

The pressure to reduce solar energy costs encourages efforts to reduce the thickness of silicon wafers. Thus, the cell bowing problem associated with the use of thin wafers has become increasingly important, as it can lead to the cracking of cells and thus to high yield losses. In this paper, a systematic approach for simulating the cell bowing induced by the firing process is presented. This approach consists of three processes: (1) the material properties are determined using a nanoidentation test; (2) the thicknesses of aluminum (Al) paste and silver (Ag) busbars and fingers are measured using scanning electron microscopy; (3) non-linear finite element analysis (FEA) is used for simulating the cell bowing induced by the firing process. As a result, the bowing obtained using FEA simulation agrees better with the experimental data than that using the bowing calculations suggested in literature. In addition, the total in-plane residual stress state in the wafer/cell due to the firing process can be determined using the FEA simulation. A detailed analysis of the firing-induced stress state in single crystalline silicon (sc-Si), cast, and edge-defined film-fed growth (EFG) multi-crystalline silicon wafers of different thicknesses is presented. Based on this analysis, a simple residual stress calculation is developed to estimate the maximum in-plane principal stress in the wafers. It is also proposed that the metallization pattern, Ag busbars and fingers screen printed on the front of a solar cell, can be designed using this approach. A practical case of a 3-busbar Si solar cell is presented.     

A sociocultural perspective on mediated activity in third grade science

This ethnographic study of a third grade classroom examined elementary school science learning as a sociocultural accomplishment. The research focused on how a teacher helped his students acquire psychological tools for learning to think and engage in scientific practices as locally defined. Analyses of classroom discourse examined both how the teacher used mediational strategies to frame disciplinary knowledge in science as well as how students internalized and appropriated ways of knowing in science. The study documented and analyzed how students came to appropriate scientific knowledge as their own in an ongoing manner tied to their identities as student scientists. Implications for sociocultural theory in science education research are discussed. John Reveles is an assistant professor in the Elementary Education Department at California State University, Northridge. He received his Ph.D. from the University of California, Santa Barbara in 2005. Before pursuing his Ph.D., he worked as a bilingual elementary school teacher for 3 years. His research focuses on the development of scientific literacy in elementary school settings; sociocultural influences on students' academic identity; equity of access issues in science education; qualitative and quantitative research methods. Within the Michael D. Eisner College of Education, he teaches elementary science curriculum methods courses, graduate science education seminars, and graduate research courses. Gregory Kelly is a professor of science education at Penn State University. He is a former Peace Corps Volunteer and physics teacher. He received his Ph.D. from Cornell in 1994. His research focuses on classroom discourse, epistemology, and science learning. This work has been supported by grants from Spencer Foundation, National Science Foundation, and the National Academy of Education. He teaches courses concerning the uses of history, philosophy, sociology of science in science teaching and teaching and learning science in secondary schools. He is editor of the journal Science Education. Richard Durán is a Professor in the Gevirtz Graduate School of Education, University of California, Santa Barbara. His research and publications have been in the areas of literacy and assessment of English Language Learners and Latino students. He has also conducted research on after school computer clubs, technology and learning as part of the international UC Links Network. With support from the Kellogg Foundation, he is implementing and investigating community and family-centered intervention programs serving the educational progress of Latino students in the middle and high school grades.     

Historical Evolution of the Field View and Textbook Accounts

We analyzed how two basic electromagnetism textooks approach the concept of electric field. We limited our study to the reasons given in these textbooks for the introduction of the field representation and to how accurate, coherent, and complete these reasons are. Because many times historical reasons are intertwined with textbooks' explanations of physical phenomena, we used the historical evolution of the field representation to guide our analysis. The analysis shows that one textbook mixes up the historical and pedagogical reasons for the introduction of the concept of field. The other one presents a sketch that might lead students to understand the field and the action-at-a-distance views as supplementing each other.