Changing classroom culture,curricula, and instruction for proof and proving: how amenable to scaling up,practicable for curricular integration,and capable of producing long-lasting effects are current interventions?

This paper is a commentary on the classroom interventions on the teaching and learning of proof reported in the seven empirical papers in this special issue. The seven papers show potential to enhance student learning in an area of mathematics that is not only notoriously difficult for students to learn and for teachers to teach, but also critically important to knowing and doing mathematics. Although the seven papers, and the intervention studies they report, vary in many ways—student population, content domain, goals and duration of the intervention, and theoretical perspectives, to name a few—they all provide valuable insight into ways in which classroom experiences might be designed to positively influence students’ learning to prove. In our commentary, we highlight the contributions and promise of the interventions in terms of whether and how they present capacity to change the classroom culture, the curriculum, or instruction. In doing so, we distinguish between works that aim to enhance students’ preparedness for, and competence in, proof and proving and works that explicitly foster appreciation for the need and importance of proof and proving. Finally, we also discuss briefly the interventions along three dimensions: how amenable to scaling up, how practicable for curricular integration, and how capable of producing long-lasting effects these interventions are.     

A Theoretical Model for Preparing Incarcerated Youth for Careers in an Increasingly Technological World: Computational Logic as a Vehicle for Improving Human Decision-making Skills

Most youth in juvenile delinquent systems end up incarcerated due in part to poor decision-making skills. This study describes a theoretical framework undergirding the relationships across delinquency, learning climate, decision-making, and computational logic. This framework will inform a team of educators, criminologists, and psychologists, and their peers in computer science and mathematics, instructional software design, and content experts as they build and test an innovative instructional model for youth in secure care settings. The goal of the system is to improve human decision-making skills, while preparing youth for further education potentially leading to careers in STEM fields.     

A praxeological perspective for the design and implementation of a digital role-play game

This paper draws on an empirical work dedicated to discussing a theoretical model for design-based research. The context of our study is a research project for the design, the implementation and the analysis of Insectophagia, a digital role-play game implemented in secondary schools. The model presented in this paper aims at conceptualizing researchers’ and practitioners’ relationships with the notion that knowledge development takes place at a meta-didactical level when the participants develop a shared practice and a shared discourse on practice (a common praxeology). This is done through collaboration and teacher-centered design of innovative learning settings. This model emerges from a double approach: (1) a literature review on collaborative research in education and, (2) an analysis of the verbal interactions of practitioners and researchers involved in the project. The study emphasizes the development of knowledge among participants. It also emphasizes the importance of knowledge brokering for filling the gap between research and practice and thus, for the adoption of digital technology by practitioners.     

东亚植物区系中若干双子叶植物的染色体新计数及其系统学和进化意义

本文报道了东亚植物区系中双子叶植物9个种的体细胞染色体新计数，其中6个是属的新计数，并对这些资料与有关的科或属在系统学和进化上的意义作了讨论。     

A uniformly loaded infinite-length thin plate bent to a cylindrical surface in the presence of couple-stresses

Exact solutions, based on couple-stresses plane strain theory of elasticity, are presented for the normal, shear and couple-stresses, displacements and rotations of an infinite-length (in z-axis) rectangular thin plate simply supported at two opposite edges (i.e.x=±L) and bent by a uniform load. Exact solutions reduce to classical values as l→0. Here l is defined as the new elastic material constant taking account of couple stresses.     

Tracking control of nonlinear automobile idle-speed time-delay system via differential geometry approach

This paper is concerned with the problem of global asymptotical tracking of single-input single-output (SISO) nonlinear time-delay control systems. Based on the input-output feedback linearization technique and Lyapunov method for nonlinear state feedback synthesis, a robust globally asymptotical output tracking controller design methodology for a broad class of nonlinear time-delay control systems is developed. The underlying theoretical approaches are the differential geometry approach and the composite Lyapunov approach. One utilizes the parameterized co-ordinate transformation to transform the original nonlinear system into singularly perturbed model and the composite Lyapunov approach is then applied for output tracking. For the view of practical application, the proposed control methodology has been successfully applied to the famous nonlinear automobile idle-speed control system.     

A Behavioral Approach to Building Cognitive Foundations for Effective Thought and Action

This research documents the process and results of an approach to teaching university undergraduates intentional self-development skills designed to promote self-generated goals, routines, and lifestyle choices. These skills may provide effective behavioral foundations for developing metacognitive awareness, intentionality, and individual well-being. The results of six original behavioral interventions, implemented in two James Madison University courses, provide initial support for the effectiveness of these instructional methodologies.