Chemical bleaching of wood: an investigation into the bleaching of mahogany,walnut, rosewood,padauk, and purpleheart

This paper investigates chemical bleaching of wood to make species-specific practical recommendations for colour adjustment of veneer in furniture conservation. In more detail, chemical bleaching of Honduras mahogany (Swietenia macrophylla), European walnut (Juglans regia), Rio rosewood (Dalbergia nigra), padauk (Pterocarpus spp.), and purpleheart (Peltogyne spp.) is investigated using 11 different bleach solutions. Both oxidative (e.g. hydrogen peroxide and potassium permanganate) and reductive (e.g. oxalic acid and sodium bisulphite) solutions were used. The results show that the wood species react differently with the investigated bleach solutions. It can also be noted that not all investigated solutions were suitable for all wood species. Based on the results, wood species-specific bleach solutions are recommended.     

Course withdrawals: A probit model and policy recommendations

Withdrawals from college courses prior to the assignment of grades, but after the add-drop period, are analyzed. In a probit model student withdrawals appear to occur randomly with notable exceptions. The more experience a student has in college, the more likely it is that he or she will withdraw from any given course. Students who have withdrawn from courses in the past tend to withdraw again. Student motivation measures are related to the withdrawal decision. Physical and mental disabilities affect withdrawals only in certain courses while athletes are no more likely to withdraw from courses than nonathletes. Finally, there appear to be economies of scale in teaching: The more students an instructor teaches in other courses, the less likely it is that students will withdraw from the course under consideration. The number of students enrolled in the course, however, is not significantly related to withdrawals.     

Preschool Children's Judgments about Hypothetical and Actual Transgressions

Preschoolers' ( N = 112) judgments about hypothetical and actual moral and conventional transgressions were examined. Equal numbers of boys and girls at 2 ages (3 and 4 years old) either made judgments about 8 hypothetical moral and conventional transgressions or were interviewed on the same dimensions about 8 naturally occurring moral and conventional transgressions they witnessed in their preschools. Children judged both hypothetical and actual moral transgressions to be more serious, punishable, generalizably wrong, and independent of rules and authority than conventional transgressions. Regardless of domain, hypothetical transgressions were judged to be more wrong independent of rules than actual transgressions, and hypothetical (but not actual) moral transgressions were judged to be more independent of rules than conventional transgressions. 3-year-old girls judged the wrongness of actual moral transgressions to be more independent of authority than did 3-year-old boys. Similar findings were obtained when hypothetical and actual transgressions were matched, and domain differences were still obtained when individual items were examined. Findings are discussed in terms of previous research on preschoolers' conceptions of rules and transgressions.     

Mother-child and father-child mutually responsive orientation in the first 2 years and children's outcomes at preschool age: mechanisms of influence.

Mechanisms accounting for the effects of mutually responsive orientation (MRO) at 7, 15, and 25 months in 102 mother-child and father-child dyads on child internalization and self-regulation at 52 months were examined. Two mediators at 38 months were tested: parental power assertion and child self-representation. For mother-child relationships, the causal pathway involving power assertion was supported for both outcomes. Diminished power assertion fully mediated beneficial effect of mother-child MRO on internalization and partially mediated its effect on self-regulation. For father-child relationships, MRO predicted self-regulation, but the mediational paths were unsupported. Paternal power assertion correlated negatively with both outcomes but was not a mediator. Although MRO with both parents correlated with child self-representation, and it correlated with self-regulation, this mediational path was unsupported.     

Considering ‘best practice’: the social construction of teacher activity and pupil learning as performance

Since the 1997 election of the Labour Party to political power in the UK the foci for educational change have been widespread. One area that has received particularly intense scrutiny is that of teacher activity. In particular, the profession has seen a marked rise in the identification of ‘best practice’. As a term ‘best practice’ has entered the parlance of English educational policy to describe that which seemingly has ‘official’ approval. This paper uses a social constructionist perspective to consider how increases in pupil attainment on national tests are currently used to demonstrate better pupil learning. Specifically, it identifies that the use of such data to describe the plausibility, veracity and legitimacy of teaching before the test as ‘best practice’ is questionable. In so doing, the critique argues that ‘best practice’ confers and retains legitimacy due to its self‐perpetuation within the discourse of performance. The paper concludes by offering three areas for further research and debate.     

Training reading and phoneme awareness skills in children with Down syndrome

The authors report a short-term reading intervention study involving 15 children with Down syndrome (DS) who attended mainstream schools. The intervention programme taught children phoneme segmentation and blending skills in the context of learning letter-sounds and working with words in books. The children were taught by their learning support assistants, who received special training for this purpose. Compared to a waiting group, a group of eight children with DS improved significantly on measures of early literacy skills (letter-sound knowledge, Early Word Recognition) following eight weeks of intervention. The waiting group started to make progress once they received the intervention. Both groups maintained progress on the literacy measures five months after the intervention had finished. The results suggest that children with DS can benefit from structured, phonics-based reading intervention.     

Vulnerability to Bullying: Teacher-reported conduct and emotional problems,hyperactivity, peer relationship difficulties,and prosocial behaviour in primary school children

Twenty five class teachers completed a "Strengths and Difficulties" assessment for 523 children aged from 7 to 11 years of age. Children self-completed a 39-item "My Life in School" questionnaire. One third of the sample were self-reported victims of bullying behaviour. Boys with poor prosocial skills, emotional problems and general difficulties with social interaction, expression of emotion and hyperactivity were at greatest risk of being bullied. There was no significant effect of age. The data support previous research findings that gender influences the prevalence of bullying but not that younger children are more vulnerable. This study provides new evidence that teachers recognise social behaviour and interactions that can significantly affect whether primary school children are bullied.     

Peers'' Perceptions of the Consequences That Victimized Children Provide Aggressors

Fourth- through seventh-grade children (mean age 11.5 years) estimated the likelihood that various consequences would occur following hypothetical acts of aggression toward victimized and nonvictimized classmates. Children also indicated how much they would care if the consequences were to occur. When contemplating aggression toward victimized classmates, children were more likely to expect tangible rewards, more likely to expect signs of victim suffering, and less likely to expect retaliation than when considering aggression against nonvictimized classmates. Also, when considering aggression toward victimized classmates, children cared more about securing tangible rewards but were less disturbed by the thought of hurting their victims or by the thought of their victims retaliating than when imagining aggression toward nonvictimized classmates. The foregoing pattern was stronger for boys than for girls. Implications for theories of aggression and for intervention with aggressive and victimized children are discussed.     

Scientific teams and institutional collaborations: Evidence from U.S. universities, 1981-1999

This paper explores recent trends in the size of scientific teams and in institutional collaborations. The data derive from 2.4 million scientific papers written in 110 top U.S. research universities over the period 1981-1999. The top 110 account for a large share of published basic research conducted in the U.S. during this time.We measure team size by the number of authors on a scientific paper. Using this measure we find that team size increases by 50% over the 19-year period. We supplement team size with measures of domestic and foreign institutional collaborations, which capture the geographic dispersion of team workers. The time series evidence suggests that the trend towards more geographically dispersed scientific teams accelerates beginning with papers published at the start of the 1990s. This acceleration suggests a sharp decline in the cost of collaboration. Our hypothesis is that the decline is due to the deployment of the National Science Foundation's NSFNET and its connection to networks in Europe and Japan after 1987.Using a panel of top university departments we also find that private universities and departments whose scientists have earned prestigious awards participate in larger teams, as do departments that have larger amounts of federal funding. Placement of former graduate students is a key determinant of institutional collaborations, especially collaborations with firms and with foreign scientific institutions. Finally, the evidence suggests that scientific output and influence increase with team size and that influence rises along with institutional collaborations. Since increasing team size implies an increase in the division of labor, these results suggest that scientific productivity increases with the scientific division of labor.