The source of the residual line broadening in continuous-wave ͑cw͒ decoupled spectra under magic-angle sample spinning conditions is reexamined. It is shown that an important contribution to the line broadening comes from a second-order recoupling of the heteronuclear dipolar-coupling tensor and the chemical-shielding tensor of the irradiated spin. Such an interference between the two tensors leads to a sum of a zeroth-rank, a second-rank, and a fourth-rank tensor component in the Hamiltonian. The zeroth-rank and the fourth-rank tensor components are not averaged out under magic-angle sample spinning ͑MAS͒ conditions, requiring the use of higher-order averaging such as double rotation ͑DOR͒ for obtaining narrow lines. This broadening is distinctly different from off-resonance decoupling effects which transform as a second-rank tensor and can be averaged out by MAS. The properties of this second-order recoupling as a source of structural information are explored, and the conditions for removing the broadening in systems with weak homonuclear dipolar-coupling networks are discussed.

G lobally, efforts to improve science education continue (1, 2). In the United States, primary and secondary (K-12) science education lags on international assessments and struggles to sustain qualified K-12 science teachers and to prepare the next generation of scientists and engineers (2). At U.S. colleges and universities, more than half of entering science majors leave the sciences, most (90%) complaining of ineffective teaching (3). Of those who remain in science, 74% express the same complaint (3). Further work is needed within specific science disciplines on how students most effectively learn that discipline (4). To address K-12 science education, undergraduate science education, and discipline-specific science education research, one approach is seeding university science departments with Science Faculty with Education Specialties (SFES), scientists who take on specialized science education roles within their discipline (5). We present data on SFES in science departments throughout the 23-campus California State University (CSU) system (6), the largest U.S. university system (annual enrollment ~450,000 students). The CSU's primary missions are undergraduate, master's-level graduate, and K-12 teacher education. CSU undergraduates are among the top one-third of their high-school graduating classes. The 23 campuses include institutions that differ substantially in their founding dates, settings, student populations, enrollment sizes, and levels of research orientation. We investigated SFES numbers, characteristics, training, professional activities, and persistence. We identified, with the aid of deans, 156 CSU faculty as SFES and invited all 156 to complete a 111-question survey (7), which we

College and university science departments are increasingly taking an active role in improving science education. Perhaps as a result, a new type of specialized science faculty position within science departments is emerging—referred to here as science faculty with education specialties (SFES)—where individual scientists focus their professional efforts on strengthening undergraduate science education, improving kindergarten-through-12th grade science education, and conducting discipline-based education research. Numerous assertions, assumptions, and questions about SFES exist, yet no national studies have been published. Here, we present findings from a large-scale study of US SFES, who are widespread and increasing in numbers. Contrary to many assumptions, SFES were indeed found across the nation, across science disciplines, and, most notably, across primarily undergraduate, master of science-granting, and PhD-granting institutions. Data also reveal unexpected variations among SFES by institution type. Among respondents, SFES at master of science-granting institutions were almost twice as likely to have formal training in science education compared with other SFES. In addition, SFES at PhD-granting institutions were much more likely to have obtained science education funding. Surprisingly, formal training in science education provided no advantage in obtaining science education funding. Our findings show that the SFES phenomenon is likely more complex and diverse than anticipated, with differences being more evident across institution types than across science disciplines. These findings raise questions about the origins of differences among SFES and are useful to science departments interested in hiring SFES, scientific trainees preparing for SFES careers, and agencies awarding science education funding.

An underlying goal in most chemistry curricula is to enable students to think like chemists, yet there is much evidence to suggest that students can learn to solve problems without thinking conceptually like a chemist. There are few tools, however, that assess whether students are learning to think like Ph.D. faculty, putative experts in the field. Here, we present a card-sorting task that probes how individuals organize information about problems in chemistry. Chemistry faculty tend to organize around "deep" features centered on fundamental ideas in chemistry while novices tend to organize around "surface" features such as problem presentation or specific vocabulary. We used established statistical techniques from card-sorting tasks in other fields and introduce a new quantitative measure that compares individual performance on the sorting task to faculty and novices that is hypothesis-independent. Initial results indicate that the card-sorting task is effective at distinguishing between populations of faculty and novices in chemistry and can be used to track progress toward more expert-like thinking over time through a chemistry education program.