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In this tutorial paper, we describe some basic principles and practical considerations for designing probe circuits for NMR or MRI. The goal is building a bridge from material that is familiar from undergraduate physics courses to more specialized information needed to put together and tune a resonant circuit for magnetic resonance. After a brief overview of DC and AC circuits, we discuss the properties of circuit elements used in an NMR probe and how they can be assembled into building blocks for multi-channel circuits. We also discuss the use of transmission lines as circuit elements as well as practical considerations for improving circuit stability and power handling. 

ABSTRACT Specifications grading is a student-centered assessment method that enables flexibility and opportunities for revision. Here, we describe the first known full implementation of specifications grading in an upper-division chemical biology course. Due to the rapid development of relevant knowledge in this discipline, the overarching goal of this class is to prepare students to interpret and communicate about current research. In the past, a conventional points-based assessment method made it challenging to ensure that satisfactory standards for student work were consistently met, particularly for comprehensive written assignments. Specifications grading was chosen because the core tenet requires students to demonstrate minimum learning objectives to achieve a passing grade and complete more content of increased cognitive complexity to achieve higher grades. This strict adherence to determining grades based on demonstrated skills is balanced by opportunities for revision or flexibility in assignment deadlines. These options are made manageable for the instructors through the use of a token economy with a limited number of tokens that students can choose to use when needed. Over the duration of the course, a validated survey on self-efficacy showed slight positive trends, student comprehension and demonstrated skills qualitatively improved, and final grade distributions were not negatively affected. Instructors noticed that discussions with students were more focused on course concepts and feedback, rather than grades, while overall grading time was reduced. Responses to university-administered student feedback surveys revealed some self-reported reduction in anxiety, as well as increased confidence in managing time and course material. Recommendations are provided on how to continue to improve the overall teaching and learning experience for both instructors and students. 

ABSTRACT A major challenge for science educators is teaching foundational concepts while introducing their students to current research. Here we describe an active learning module developed to teach protein structure fundamentals while supporting ongoing research in enzyme discovery. It can be readily implemented in both entry-level and upper-division college biochemistry or biophysics courses. Preactivity lectures introduced fundamentals of protein secondary structure and provided context for the research projects, and a homework assignment familiarized students with 3-dimensional visualization of biomolecules with UCSF Chimera, a free protein structure viewer. The activity is an online survey in which students compare structure elements in papain, a well-characterized cysteine protease from Carica papaya, to novel homologous proteases identified from the genomes of an extremophilic microbe (Halanaerobium praevalens) and 2 carnivorous plants (Drosera capensis and Cephalotus follicularis). Students were then able to identify, with varying levels of accuracy, a number of structural features in cysteine proteases that could expedite the identification of novel or biochemically interesting cysteine proteases for experimental validation in a university laboratory. Student responses to a postactivity survey were largely positive and constructive, describing points in the activity that could be improved and indicating that the activity was an engaging way to learn about protein structure.