The Persistent Difficulty of Early Fraction Ideas in Early Secondary School Mathematics

This study explored the nature of difficulties of seventh and eighth grade students who struggled building their conceptual understanding of early fraction ideas, in particular ordering fractions. The participants engaged in a sequence of lessons that involved the use of fraction circles. The intervention of four weekly class sessions was adapted from the Rational Number Project (RNP) curriculum that has been created for and refined through teaching experiments in the RNP research since 1979. Pre and post group interviews were conducted with each student group for a sufficient identification of the nature of the students’ difficulties. This study identified the whole number dominance strategies used by the students for ordering fractions before and even after the intervention. The students also revealed minimal use of informal ordering strategies that involve more conceptual than procedural understanding of the concept of initial fraction ideas. Considering the short intervention, there was subtle (but meaningful) evidence for a positive influence of the fraction circle model developed within the RNP on students’ developing understanding of early fraction ideas. This study suggests the need of a remedial intervention for early secondary students showing the persistent difficulty with early fraction ideas. Students need to be given enough time with not only concrete models but also appropriate usage of language to support a complete understanding of how to use the models. Keywords: Rational Number Project (RNP), fraction circle model, initial fraction ideas, ordering fraction

Creating a Virtual World for Mathematics

A virtual world was created using the popular sandbox game Minecraft to support the development of preservice teachers’ knowledge for teaching mathematics. Preservice teachers explored the virtual world for a geometry activity involving area and volume problems. They then discussed how this integration of technology could support students’ effective learning of mathematics in a meaningful way. The findings of the study demonstrated that to a certain extent the Minecraft activity supported the transfer of knowledge from preservice teachers’ mathematics content knowledge to their mathematics pedagogical and instructional practice knowledge. Preservice teachers appreciated the usefulness and effectiveness of the Minecraft activity in enhancing the teaching and learning of mathematics by visualizing mathematical concepts in the virtual world. This integration of technology also gave them an opportunity for professional growth. Although this study focuses on preservice teachers’ perspectives on the Minecraft activity, the technology integration using Minecraft will also be beneficial for students because it engages them in active and discovery learning

Effective Teaching for Place Value Understanding: A Case Study of a Literacy-Integrated Math Curriculum Module

A lesson sequence for place value was developed as an early intervention for kindergarteners. The sequence begins with a children’s picture book involving language familiar to children and continues with hands-on activities for children to make connections between and within multiple representations of place value. Through engaging in the literacy-integrated math curriculum module, kindergartners deepened their understanding of place value and the base-ten number system, as they were consistently engaged in problem solving and mathematical discourse triggered by their own mathematical thinking, as well as purposeful questions prompted by the teacher

The phosphoinositide 3-kinase-dependent activation of Btk is required for optimal eicosanoid production and generation of reactive oxygen species in antigen-stimulated mast cells

Activated mast cells are a major source of the eicosanoids PGD(2) and leukotriene C(4) (LTC(4)), which contribute to allergic responses. These eicosanoids are produced following the ERK1/2-dependent activation of cytosolic phospholipase A(2), thus liberating arachidonic acid, which is subsequently metabolized by the actions of 5-lipoxygenase and cyclooxygenase to form LTC(4) and PGD(2), respectively. These pathways also generate reactive oxygen species (ROS), which have been proposed to contribute to FcepsilonRI-mediated signaling in mast cells. In this study, we demonstrate that, in addition to ERK1/2-dependent pathways, ERK1/2-independent pathways also regulate FcepsilonRI-mediated eicosanoid and ROS production in mast cells. A role for the Tec kinase Btk in the ERK1/2-independent regulatory pathway was revealed by the significantly attenuated FcepsilonRI-dependent PGD(2), LTC(4), and ROS production in bone marrow-derived mast cells of Btk(-/-) mice. The FcepsilonRI-dependent activation of Btk and eicosanoid and ROS generation in bone marrow-derived mast cells and human mast cells were similarly blocked by the PI3K inhibitors, Wortmannin and LY294002, indicating that Btk-regulated eicosanoid and ROS production occurs downstream of PI3K. In contrast to ERK1/2, the PI3K/Btk pathway does not regulate cytosolic phospholipase A(2) phosphorylation but rather appears to regulate the generation of ROS, LTC(4), and PGD(2) by contributing to the necessary Ca(2+) signal for the production of these molecules. These data demonstrate that strategies to decrease mast cell production of ROS and eicosanoids would have to target both ERK1/2- and PI3K/Btk-dependent pathways

Symmetrical Aspects of Urban Regeneration in Seoul

Korea has developed very rapidly since 1980s highlighted with Seoul olympic, and urbanization necessarily incurred. Population grew with increasing housing demands, but old towns could not provide enough land. The old town was already congested, and living conditions fell off. Therefore, new towns outside the old town were planned and built through three sequential phases. This suburbanization brought about heavy load on commuter transportation and air pollution. At the same time, improper infrastructure and amenities turned new towns into bedtowns. To escape from bedtowns, people returned to the old town, and urban remodeling was needed to accommodate adequate living conditions. In doing so, local characteristics were lost. Urban regeneration aroused as a countermeasure to this mishap. In this study, urban regeneration reinforced with smart technologies is suggested to revive lost placeness, communal connectivity, and urban orientation. Gentrification is another important issue to be resolved for the sustainable urbanization. This study focused on symmetrical aspects of the successful urban regeneration

Alignment of Classroom History Assessments and the 7th National Curriculum in Korea: Assessing Historical Knowledge and Reasoning Skills

This study examined the extent to which middle and high school classroom history assessments align with the educational objectives outlined in the 7th National Curriculum in Korea. In particular, the alignment between the classroom assessments and the educational objectives focused on the level of cognitive reasoning skills and the breadth of historical knowledge. The technical quality of the classroom assessment items, and the extent to which teachers had professional development activities related to the design, use, and interpretation of assessments were also examined. Korean history assessments for the 2004 school year from 22 middle schools and 10 high schools were collected and analyzed. The classroom assessments and the educational objectives were analyzed to examine their alignment with respect to the depth of understanding, breadth of knowledge, and balance of representation. An item writing guideline developed by Haladyna, et al. (1989, 2002) was used to examine the technical quality of the items. A brief survey of history teachers was conducted to obtain information about their assessment related professional development activities. The results of the study indicated that a relatively large percent of the assessment items from both middle and high schools tended to measure lower levels of historical reasoning than those required by the objectives, resulting in a small percent of items being consistent with the cognitive level of objectives. The distribution of the test items was not balanced across the objectives, rather they tended to emphasize factual knowledge, and the assessments did not thoroughly cover the span of knowledge represented in the curriculum. There were little differences across different levels and types of schools. However, multiple-choice test items from high schools were more likely to assess higher levels of historical understanding than middle school test items. In contrast, the performance assessment tasks for middle school students provided more opportunities to use higher level thinking skills. Most of the items were well developed in terms of formatting and writing test item stems and alternatives. The teacher survey suggested that teachers had little professional development related to the design, use, and interpretation of assessments in both their training courses and activities before and during their professional careers

Genotypic Characterization of Vibrio vulnificus Clinical Isolates in Korea

AbstractObjectivesVibrio vunificus is known to cause septicemia and severe wound infections in patients with chronic liver diseases or an immuno-compromised condition. We carried out the molecular characterization of V. vulnificus isolates from human Vibrio septicemia cases based on pulsed-field gel electrophoresis (PFGE) using NotI and SfiI.Methods and ResultsPFGE was used to characterize a total of 78 strains from clinical cases after NotI or SfiI digestion. The geographical distribution of PFGE patterns for the strains from the southern part of Korea, a high-risk region for Vibrio septicemia, indicated that the isolates from southeastern Korea showed a comparatively higher degree of homology than those from southwestern Korea.ConclusionsWe report the genetic distribution of V. vulnficus isolated from Vibrio septicemia cases during 2000–2004 in Korea. This method has potential use as a subspecies-typing tool for V. vulnificus strains isolated from distant geographic regions