Instructional practices in secondary science: How teachers achieve local and standards-based success

This article reports on analyses of the instructional practices of six middle- and high-school science teachers in the United States who participated in a research-practice partnership that aims to support reform science education goals at scale. All six teachers were well qualified, experienced, and locally successful—respected by students, parents, colleagues, and administrators—but they differed in their success in supporting students' three-dimensional learning. Our goal is to understand how the teachers' instructional practices contributed to their similarities in achieving local success and to differences in enabling students' learning, and to consider the implications of these findings for research-practice partnerships. Data sources included classroom videos supplemented by interviews with teachers and focus students and examples of student work. We also compared students' learning gains by teacher using pre–post assessments that elicited three-dimensional performances. Analyses of classroom videos showed how all six teachers achieved local success—they led effectively managed classrooms, covered the curriculum by teaching almost all unit activities, and assessed students' work in fair and efficient ways. There were important differences, however, in how teachers engaged students in science practices. Teachers in classrooms where students achieved lower learning gains followed a pattern of practice we describe as activity-based teaching, in which students completed investigations and hands-on activities with few opportunities for sensemaking discussions or three-dimensional science performances. Teachers whose students achieved higher learning gains combined the social stability characteristic of local classroom success with more demanding instructional practices associated with scientific sensemaking and cognitive apprenticeship. We conclude with a discussion of implications for research-practice partnerships, highlighting how partnerships need to support all teachers in achieving both local and standards-based success.     

The distribution of partnership returns: Evidence from co-authorships in economics journals

Partnerships can be found in many areas of social and economic life. These arrangements have become particularly prevalent in research and development activities where organizations increasingly seek partners to complement their own technological capabilities. R&D partnerships, however, are fraught with challenges because the conditions for optimum effectiveness and efficiency of cooperation are still not fully understood. Academic partnerships are also very common and offer a fertile ground for investigation.     

Team learning in IT implementation projects: Antecedents and consequences

This study investigates the antecedents and consequences of team learning, which is composed of information acquisition, dissemination, and implementation, in information technology (IT) implementation projects. By investigating 129 IT implementation project teams, we found that (1) information acquisition and information dissemination have a positive impact on project outcomes, such as speed-to-users, lower implementation cost, and operational effectiveness, and (2) team behavior and enabler variables, such as teamwork, team communication, interpersonal trust between team members, team commitment, and senior manager support, positively influence team learning. We also found that team anxiety moderates the relationship between team learning and project outcomes.     

Synchronization of discrete-time complex dynamical networks with interval time-varying delays via non-fragile controller with randomly occurring perturbation

This paper addresses synchronization problem for discrete-time complex dynamical networks with interval time-varying delays. In order to achieve the synchronization, a feedback controller subjected to randomly occurring perturbations will be considered. The randomly occurring perturbations are assumed to belong to the Binomial sequence. By constructing a suitable Lyapunov–Krasovskii functional, and utilizing reciprocally convex approach and Finsler?s lemma, the synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. The networks are represented by the use of Kronecker product technique. The effectiveness of the proposed methods will be verified via numerical examples.     

A dynamic auction for multi-object procurement under a hard budget constraint

This contribution revisits the problem of allocating R&D subsidies by government agencies. Typically, the applicants’ financial constraints are private information. The literature has recommended the use of auctions in order to reduce information rents and thus improve the efficiency of how scarce public funds are allocated. We propose a new open clock auction for this procurement problem. This auction is strategically simple, as it exhibits truthtelling in dominant strategies and satisfies ex-post rationality, while observing the budget constraint. We test the auction in Monte-Carlo simulation and discuss its applicability and limitations. Moreover, we highlight connections to recent advances in computer science.     

Fabrication of two dimensional polyethylene terephthalate nanofluidic chip using hot embossing and thermal bonding technique

We present in this paper a method for obtaining a low cost and high replication precision 2D (two dimensional) nanofluidic chip with a PET (polyethylene terephthalate) sheet, which uses hot embossing and a thermal bonding technique. The hot embossing process parameters were optimized by both experiments and the finite element method to improve the replication precision of the 2D nanochannels. With the optimized process parameters, 174.67 ± 4.51 nm wide and 179.00 ± 4.00 nm deep nanochannels were successfully replicated into the PET sheet with high replication precision of 98.4%. O₂ plasma treatment was carried out before the bonding process to decrease the dimension loss and improve the bonding strength of the 2D nanofluidic chip. The bonding parameters were optimized by bonding rate of the nanofluidic chip. The experiment results show that the bonding strength of the 2D PET nanofluidic chip is 0.664 MPa, and the total dimension loss of 2D nanochannels is 4.34 ± 7.03 nm and 18.33 ± 9.52 nm, in width and depth, respectively. The fluorescence images demonstrate that there is no blocking or leakage over the entire micro- and nanochannels. With this fabrication technology, low cost polymer nanochannels can be fabricated, which allows for commercial manufacturing of nano-components.     

Tilted post arrays for separating long DNA

Recent simulations by Chen and Dorfman [Electrophoresis 35, 405–411 (2014)] suggested that “tilting” the electric field with respect to the lattice vectors of a hexagonal post array would lead to a substantial improvement in electrophoretic DNA separations therein. We constructed such an array where the electric field is applied at an angle equidistant between the two lattice vectors. This tilted array leads to (i) baseline resolution of 20 kbp DNA and λ DNA (48.5 kbp) in a 4 mm channel and (ii) measurable separation resolutions for electric fields up to 50 V/cm, both of which are improvements over untilted post arrays of the same post density. The predicted time required to reach a resolution of unity is approximately 5 min, independent of electric field. The separations are more reproducible at higher fields.     

Persistent Focal Behavior and Physical Activity Performance

This article examines the proclivity and performance attributes of focal students across time and activities using data from 9,345 students. Three systematic focal behavior partitions are examined: Across activities, across time, and across activities and time. A student’s performance is focal if it ends in 0 or 5 for push-ups and 0 for curl-ups. Chi-square tests confirm that individual focal outcomes and systematic focal outcomes occur more frequently than random processes would suggest. In each instance, the only cell that is less populated than random processes would suggest is the one that exhibits no systematic focal behavior and the cell that exhibits the greatest deviation from expected is the full focal cell. Focal students outperform their peers on three activities at two assessments. Students with two-systematically focal outcomes have superior performance to students with no systematic focal outcomes but inferior performance to those with three or four focal outcomes.     

Introduction to Sample Size Choice for Confidence Intervals Based on t Statistics

Sample size can be chosen to achieve a specified width in a confidence interval. The probability of obtaining a narrow width given that the confidence interval includes the population parameter is defined as the power of the confidence interval, a concept unfamiliar to many practitioners. This article shows how to utilize the Statistical Analysis System (SAS) proc power procedure to determine an appropriate sample size and achieve sufficient power for a specified confidence interval. Two examples in sport and exercise science are used to illustrate sample size determination for confidence intervals in the dependent and independent t tests. The relevant SAS code and output are provided with detailed annotations. As the use of confidence intervals becomes a more integral part of studies in sport and exercise science, the reporting and analysis of their power should be considered much like that of hypothesis tests.