Search

Rock salt is considered a suitable medium for the permanent disposal of heat-generating radioactive waste due to its isolation properties. However, excavation damage and heating induce complex and heterogeneous thermal-hydrological-mechanical (THM) processes across different zones. Quantifying this heterogeneity is crucial for accurate long-term performance assessment models, but traditional methods lack the necessary resolution. This study employs 4D electrical resistivity tomography (ERT) monitoring during controlled heating experiments in a salt formation to unravel the spatiotemporal dynamics of THM processes. Advanced time-lapse inversion and clustering analysis quantify subsurface properties and map the heterogeneity of THM dynamics. The ERT results can estimate subsurface properties and delineate the damaged and intact zones, enabling appropriate parameterization and representation of processes for long-term modeling. This approach may be used in further improving the predictive models and ensuring the safe long-term disposal of radioactive waste in rock salt.

Research suggests that tasks that use technology as a reorganizer (technology is used to produce dynamic representations) are linked with the development of students' conceptual knowledge, yet many secondary mathematics textbooks in the USA predominantly include tasks that use technology as an amplifier (technology is used to produce static images). Thus, if teachers wish to incorporate tasks that use technology as a reorganizer, they must locate these resources elsewhere or construct them themselves. This study took place in a technology, pedagogy, content course where each prospective teacher (PT) engaged in at least one component of an ideation, rehearsal/refinement, enactment, and reflection intervention, where they were asked to adapt traditional textbook lessons to promote students' rich conceptual understandings of function transformations via technology as reorganizer tasks. A total of 15 PTs agreed to participate, 8 seeking a grade K-8 certification and 7 seeking a grade 6-12 certification. On the initial lesson plan involving linear function transformations, the majority of PTs (13 out of 15) used technology as an amplifier, but on the final lesson plan involving absolute value function transformations, 13 PTs used technology as a reorganizer. There were also increases in the incidence of lesson elements that promoted moderate or rich forms of conceptual knowledge between the initial and final lesson plans. We discuss the implications of these results and introduce readers to dynamic conceptual components as manipulable bridges between different mathematical representations that hold the potential to develop students' richer forms of conceptual knowledge.

We studied how the distal policy mechanisms of curricular aims and objectives articulated in official curriculum documents influenced classroom instruction, and the factors that were associated with the enactment of those curricular aims and objectives. The study was set in the U.S. context, where there is an ambitious effort to transform curriculum and instruction via the Common Core State Standards for Mathematics (CCSSM). The CCSSM represented the curricular aims and objectives in most of the U.S. at the time of the study. We analyzed enactments of this official curriculum in terms of the rigor of mathematical activity in 47 middle school mathematics lessons from multiple state and curriculum contexts. The enactment of the CCSSM was not uniform across contexts, and the lack of uniformity was associated in part with the type of instructional materials used by teachers. The use of instructional materials classified as "delivery mechanism" was associated with activity we characterized as routine procedural rigor. In lessons involving instructional materials classified as "thinking device," we found greater variation and more occurrences of non-routine forms of rigor. These differences between types of instructional materials occurred despite the finding that teachers across the sample held similar views of the CCSSM. We conclude that the teachers responded more to features in the instructional materials than to the curriculum aims and objectives articulated in the CCSSM while planning and enacting lessons, which has implications for policy makers who aim to influence instruction through national standards and for school districts as they select materials.

An important component of the Common Core State Standards for Mathematics (CCSSM), used by the majority of states in the U.S., has the eight standards for mathematical practice (SMPs). While surveys have investigated teachers' perceptions of the CCSSM few have investigated middle school mathematics teachers' (MSMTs') (grades 6-8) perceptions of the SMPs. Similar to other countries, teachers in the United States frequently use mathematics textbooks. Two different types of textbooks have been in use in the United States, conventional and standards-based. The latter were designed on the basis of earlier standards documents including versions of the SMPs. As a result of these changes to the educational system in the U.S., we sought to characterize MSMTs' perceptions of the SMPs and investigate if these perceptions differed by the type of textbook teachers used. We found that MSMTs struggled in naming the SMPs, misinterpreted the modeling SMP, and conflated components of reform-oriented instruction with the SMPs. MSMTs using a standards-based textbook were more likely to view their textbooks as aligned with the SMPs, x[superscript 2](3) = 7.708, p = 0.026 and to view the SMPs as an instructional philosophy for the CCSSM, Fisher's Exact Test = 3.881, p = 0.05. The implications of these results are discussed.

The study explored the verb clauses and thematic development evident in curriculum materials and in transcripts of teachers planning lessons using the materials. A central argument is that though teacher characteristics influence the ways they plan lessons with curriculum materials, the materials themselves influence teachers' planned lessons via the ways mathematics is construed in the materials. We used verb clause and thematic analysis to analyze the features of curriculum materials and teachers' lesson planning using those materials. We found differences between the curriculum materials in terms of how they construed mathematical activity and found that teachers' lesson plans roughly aligned with the features in the materials; this speaks to the impact of features of curriculum materials on teachers' lesson planning. We also found small but perceptible differences between teachers from different curriculum backgrounds, suggesting an enculturating effect from the materials.

In this article, the author presents a set of design principles that were used to construct and refine a lesson involving the TI-Nspire handheld graphing calculator through multiple enactments in high school algebra classrooms to assist students in constructing a deeper understanding of systems of linear inequalities, a high school algebra content standard in the Common Core State Standards for Mathematics (CCSSM) (NGA Center and CCSSO 2010). These principles are rooted in years of crafting and implementing technology-based lessons in secondary school mathematics classrooms. Furthermore, they are research-based and aligned with the Common Core. These principles could be used to develop a technology-rich lesson as is done in this article or could be used as a framework to assist in revising a found resource. In this article, the author argues that using these principles to construct or adapt existing technological resources offers students opportunities to develop deeper mathematical understandings and nurture their capacity to investigate mathematics. This article also highlights the power of planning a lesson with others and reflecting on lesson implementation either alone or with others.

RNA alternative polyadenylation contributes to the complexity of information transfer from genome to phenome, thus amplifying gene function. Here, we report the first X. tropicalis resource with 127,914 alternative polyadenylation (APA) sites derived from embryos and adults. Overall, APA networks play central roles in coordinating the maternal-zygotic transition (MZT) in embryos, sexual dimorphism in adults and longitudinal growth from embryos to adults. APA sites coordinate reprogramming in embryos before the MZT, but developmental events after the MZT due to zygotic genome activation. The APA transcriptomes of young adults are more variable than growing adults and male frog APA transcriptomes are more divergent than females. The APA profiles of young females were similar to embryos before the MZT. Enriched pathways in developing embryos were distinct across the MZT and noticeably segregated from adults. Briefly, our results suggest that the minimal functional units in genomes are alternative transcripts as opposed to genes.

Team sport athletes face a variety of nutritional challenges related to recovery during the competitive season. The purpose of this article is to review nutrition strategies related to muscle regeneration, glycogen restoration, fatigue, physical and immune health, and preparation for subsequent training bouts and competitions. Given the limited opportunities to recover between training bouts and games throughout the competitive season, athletes must be deliberate in their recovery strategy. Foundational components of recovery related to protein, carbohydrates, and fluid have been extensively reviewed and accepted. Micronutrients and supplements that may be efficacious for promoting recovery include vitamin D, omega-3 polyunsaturated fatty acids, creatine, collagen/vitamin C, and antioxidants. Curcumin and bromelain may also provide a recovery benefit during the competitive season but future research is warranted prior to incorporating supplemental dosages into the athlete's diet. Air travel poses nutritional challenges related to nutrient timing and quality. Incorporating strategies to consume efficacious micronutrients and ingredients is necessary to support athlete recovery in season.

Eight middle school mathematics teachers' perceptions and uses of curriculum materials and the Common Core State Standards for Mathematics (CCSSM) were investigated. Adapting a noticing framework and models of dialogic instruction and direct instruction, teachers' noticing practices with curriculum materials and the CCSSM when planning, enacting, and reflecting on lessons were examined. Teachers who were committed to implementing the CCSSM and who were using one of two substantively different curriculum programs were purposefully selected. Data sources included multiple forms of interviews and classroom observations. The teaching evidenced three distinct noticing patterns. These patterns indicated that teachers' curriculum materials were associated with how teachers perceived and enacted the CCSSM. Teaching with a curriculum program that was designed as a thinking device prioritized the Standards for Mathematical Practice of CCSSM evidenced noticing that was consistent with dialogic instruction. Teaching with a curriculum program that was designed as a delivery mechanism prioritized the Content Standards of CCSSM and evidenced noticing consistent with direct instruction. Findings indicated that the designated curriculum and contributed to differing interpretations of CCSSM and served as a lens for noticing. However, a dialogic curriculum program was not sufficient to support dialogic approaches in practice. One pattern showed teachers planning dialogic lessons, but the lesson enactments were not consistent with teachers' plans, with evidence that the teachers were not aware that their practices differed from dialogic approaches. Implications for research and practice are discussed.

This research addresses the issue of how to support students' representational fluency--the ability to create, move within, translate across, and derive meaning from external representations of mathematical ideas. The context of solving linear equations in a combined computer algebra system (CAS) and paper-and-pencil classroom environment is targeted as a rich and pressing context to study this issue. We report results of a collaborative teaching experiment in which we designed for and tested a functions approach to solving equations with ninth-grade algebra students, and link to results of semi-structured interviews with students before and after the experiment. Results of analyzing the five-week experiment include instructional supports for students' representational fluency in solving linear equations: (a) sequencing the use of graphs, tables, and CAS feedback prior to formal symbolic transpositions, (b) connecting solutions to equations across representations, and (c) encouraging understanding of equations as equivalence relations that are sometimes, always, or never true. While some students' change in sophistication of representational fluency helps substantiate the productive nature of these supports, other students' persistent struggles raise questions of how to address the diverse needs of learners in complex learning environments involving multiple tool-based representations.