Large-scale multiferroic complex oxide epitaxy with magnetically switched polarization enabled by solution processing

Complex oxides with tunable structures have many fascinating properties, though high-quality complex oxide epitaxy with precisely controlled composition is still out of reach. Here we have successfully developed solution-based single-crystalline epitaxy for multiferroic (1-x)BiTi_(1-y)/2Fe_yMg_(1-y)/2O₃–(x)CaTiO₃ (BTFM–CTO) solid solution in large area, confirming its ferroelectricity at the atomic scale with strong spontaneous polarization. Careful compositional tuning leads to a bulk magnetization of 0.07 ± 0.035 μ_B/Fe at room temperature, enabling magnetically induced polarization switching exhibiting a large magnetoelectric coefficient of 2.7–3.0 × 10⁻⁷ s/m. This work demonstrates the great potential of solution processing in large-scale complex oxide epitaxy and establishes novel room-temperature magnetoelectric coupling in epitaxial BTFM–CTO film, making it possible to explore a much wider space of composition, phase, and structure that can be easily scaled up for industrial applications.     

Evolution and distribution of medullary bone: evidence from a new Early Cretaceous enantiornithine bird

Living birds are unique among vertebrates in the formation of a female-specific bone tissue called medullary bone (MB) that is strictly associated with reproductive activity. MB is a rapidly mobilized source of calcium and phosphorus for the production of eggshell. Among living taxa, its skeletal distribution can be highly extensive such that it even exists in the ribs of some species. Due to its ephemeral nature, MB is rarely fossilized and so little is understood with regard to the origin of MB and its skeletal distribution in early taxa. Here we describe a new Early Cretaceous enantiornithine bird, Mirusavis parvus, gen. et. sp. nov., indicating that skeleton-wide distribution of MB appeared early in avian evolution. We suggest that this represents the plesiomorphic condition for the Aves and that the distribution of MB observed among extant neornithines is a product of increased pneumatization in this lineage and natural selection for more efficient distribution of MB.     

Mastery Learning and Instructional Design Originally published in 1988, PIQ 1.1

Comparisons are drawn between the ideas of mastery learning and those of instructional design. Considerable agreement is noted concerning the main factors contributing to the quality of instruction. Similarities are pointed out in Bloom's alterable variables and a number of the events of instruction described by Gagné. Differences exist in the taxonomic categories of learned performances of the two systems, and in the proposal of instructional design that each category requires a different set of instructional tactics. A noteworthy area of agreement is emphasis on the instructional importance of skill automaticity.     

Gender differences in motivation and strategy use in science: Are girls rote learners?

This study explored Ridley and Novak's (1983) hypothesis that gender differences in science achievement are due to differences in rote and meaningful learning modes. To test this hypothesis, we examined gender differences in fifth- and sixth-grade students' (N = 213) self-reports of confidence, motivation goals (task mastery, ego, and work avoidance), and learning strategies (active and superficial) in whole-class and small-group science lessons. Overall, the results revealed few gender differences. Compared with girls, boys reported greater confidence in their science abilities. Average-achieving girls reported greater use of meaningful learning strategies than did their male counterparts, whereas low-ability boys reported a stronger mastery orientation than did low-ability girls. The results further showed that students report greater confidence and mastery motivation in small-group than whole-class lessons. In contrast, students reported greater work avoidance in whole-class than small-group lessons. In general, the findings provide little support for Ridley and Novak's hypothesis that girls tend to engage in rote-level learning in science classes. Differences in self-reports of motivation and strategy-use patterns were more strongly related to the student's ability level and to the structure of learning activities (small group vs. whole class) than to gender. © 1996 John Wiley & Sons, Inc.     

Social constructivism: Infusion into the multicultural science education research agenda

This article focuses on (a) theoretical underpinnings of social constructivism and multicultural education and (b) aspects of social constructivism that can provide frameworks for research in multicultural science education. According to the author, multicultural science education is “a field of inquiry with constructs, methodologies, and processes aimed at providing equitable opportunities for all students to learn quality science.” Multicultural science education research continues to be influenced by class, culture, disability, ethnicity, gender, and different lifestyles; however, another appropriate epistemology for this area of research is social constructivism. The essence of social constructivism and its implications for multicultural science education research includes an understanding of whatever realities might be constructed by individuals from various cultural groups and how these realities can be reconstituted, if necessary, to include a scientific reality. Hence, multicultural science education should be a field of study in which many science education researchers are generating new knowledge. The author strives to persuade other researchers to expand their research and teaching efforts into multicultural science education, a blending of social constructivism with multicultural science education. This blending is illustrated in the final section of this article. © 1996 John Wiley & Sons, Inc.     

Teachers' attitudes and policies regarding play in elementary schools

Research and theory concerning the value of play for children's development as well as current factors reducing the amount of play time that children experience are discussed. To ascertain play opportunities occurring in the schools, teachers' attitudes toward play, and provision of play for children in grades 1–6 were surveyed. The amount of recess time provided ranged from 0 to 65 min., with a mean of almost 19 min. Findings indicated that teachers from rural areas provided more play time than teachers from suburban areas, who in turn provided more play time than teachers in urban areas. Further, the amount of play time provided was influenced by the teachers' attitudes. That is, teachers who indicated generally positive attitudes toward play tended to allot more time for play in school. However, teachers from upper grade levels, who were more likely to perceive greater pressure to provide highly structured academic instructional programs, tended to de-emphasize the role and value of play and in turn allotted less time for play in school. The results of the present investigation demonstrate that children who are given less recess time are also likely to have teachers who report less positive attitudes toward play. It is recommended that school psychologists be aware of the adverse impact that restricted play opportunities may have on children's development. © 1996 John Wiley & Sons, Inc.     

Concurrent and predictive validity of the LET-II for average children

Memory tests, such as the Learning Efficiency Test-II (LET-II), have frequently been used to describe the memory characteristics of special populations such as persons with learning disabilities, brain damage, or Alzheimer's disease. Yet, few research studies have examined the memory characteristics of normally functioning children and compared these characteristics to their performance on ability tests or real-life achievement criteria. This study investigates the predictive and concurrent validities of the LET-II for performance on the Kuhlmann-Anderson Tests (K-A), class grades, and actual grade level functioning in reading and mathematics for third and fourth grade children of average intelligence. The LET-II memory factor scores correlated significantly with the K-A scores, class grades and actual grade level functioning in reading. The relevance of these findings for norm-referenced psychological tests, and in particular memory tests, in real-life settings is examined. © 1996 John Wiley & Sons, Inc.     

A review of the literature on Attention-Deficit Hyperactivity Disorder children: Peer interactions and collaborative learning

ADHD children may have social skill deficits in at least three main areas: social communication, poor emotional regulation, and social-cognitive biases. They also have cognitive difficulties which have implications for their learning. Based on a review of the literature, it is argued that maladaptive classroom peer interactions for ADHD children may disadvantage their learning on collaborative tasks. Although the literature is sparse in the area of peer interactions and collaborative learning for ADHD children, some suggestions for practice and future research are suggested. © 1996 John Wiley & Sons, Inc.