The introduction of dwarfing traits into crops was a major factor in increased grain yields during the "Green Revolution." In most cases those traits were the consequence of altered synthesis or response to the gibberellin (GA) plant hormones. Our current understanding of GA synthesis and physiology has been facilitated by the characterization of…

Context-aware ubiquitous learning (u-learning) is an innovative approach that integrates wireless, mobile, and context-awareness technologies to detect the situation of learners in the real world and provide adaptive support or guidance accordingly. In this paper, a context-aware u-learning environment is developed for guiding inexperienced…

Educated adults solve simple addition problems primarily by direct memory retrieval, as opposed to by counting or other procedural strategies, but they report using retrieval substantially less often with problems in written-word format (four = eight) compared with digit format (4 = 8). It was hypothesized that retrieval efficiency is relatively…

Taking tests enhances learning. But what happens when one cannot answer a test question--does an unsuccessful retrieval attempt impede future learning or enhance it? The authors examined this question using materials that ensured that retrieval attempts would be unsuccessful. In Experiments 1 and 2, participants were asked fictional…

This paper describes a process control experiment. The apparatus includes a three-vessel glass flow system with a variable flow configuration, means for feeding dye solution controlled by a stepper-motor driven valve, and a flow spectrophotometer. Students use impulse response data and nonlinear regression to estimate three parameters of a model…

A new laboratory course has been developed at the University of Virginia for senior- level chemical engineering students. The new course is based on three 4-week long experiments in bioprocess engineering, energy conversion and catalysis, and polymer synthesis and characterization. The emphasis is on the integration of process steps and the…

We present a modified version of Young's interferometer to verify experimentally the four interference laws propounded by Fresnel and Arago. Theoretical analysis is given using the complex algebra and the matrix representation for polarizers, rotators and the electromagnetic field. The advantage of the modified interferometer over other spatial…

Theoretical models and experimental results are presented for the retarded fall of a strong magnet inside a vertical conductive non-magnetic tube. Predictions and experimental results are in good agreement modelling the magnet as a simple magnetic dipole. The effect of varying the pipe wall thickness on the retarding magnetic drag is studied for…

A randomized dietary intervention trial across 4 years examined diet, weight, and obesity incidence (body mass index [BMI] greater than or equal to 30 kg/m[superscript 2]) differences between study groups. Participants were 1,510 breast cancer survivors with BMI greater than or equal to 25 kg/m[superscript 2] at entry. Dietary intake was assessed…

Children's toys provide a rich arena for investigating conceptual flexibility, because they often can be understood as possessing an individual identity at multiple levels of abstraction. For example, many dolls (e.g., Winnie-the-Pooh) and action figures (e.g., Batman) can be construed either as characters from a fictional world or as physical…

Rocket experiments demonstrating conservation of momentum will never fail to generate enthusiasm in undergraduate physics laboratories. In this paper, we describe tests on rockets from two vendors that combine baking soda and vinegar for propulsion. The experiment compared two analytical approximations for the maximum rocket height to the…

The value of video analysis in physics education is well established, and both commercial and free educational video analysis programs are readily available. The video format is familiar to students, contains a wealth of spatial and temporal data, and provides a bridge between direct observations and abstract representations of physical phenomena.…

Mary Anne CLark describes the organization and uses of Genome Island, a virtual laboratory complex constructed in Second Life. Genome Island was created for teaching genetics to university undergraduates but also provides a public space where anyone interested in genetics can spend a few minutes, or a few hours, interacting with genetic…

This article focuses on the communication of compensatory self-presentations (CSP) (i.e., self-presentations that people engage in after publicly receiving unfavorable feedback), with prior work showing that people prudently constrain CSP to areas unrelated (vs. related) to the initial feedback. With the current project we examine the influence…

It is an extraordinary challenge to offer an undergraduate laboratory course in virology that teaches hands-on, relevant molecular biology techniques using nonpathogenic models of human virus detection. To our knowledge, there exists no inexpensive kits or reagent sets that are appropriate for demonstrating real-time PCR (RT-PCR) in an…