Background: We present an analysis of students' responses to application-based questions on the topic of growth and control of microorganisms, from a questionnaire administered to 348 second and third year students of an Indian university who were enrolled in its undergraduate programs in Biotechnology or Microbiology. We examined aspects of the…

In this article, we discuss what it means to learn troublesome "threshold concepts" about writing that cannot be adequately grappled with in a single course or assignment. Here, two faculty members and a graduate of a writing major reflect on elements of the writing curriculum, the writing center practicum, and the learning dispositions…

A different method to study the charging and discharging processes of a capacitor is presented. The method only requires a high impedance voltmeter. The charging and discharging processes of a capacitor are usually studied experimentally using an oscilloscope and, therefore, both processes are studied as a function of time. The approach presented…

Pre-recorded video demonstrations of laboratory experiments are used to introduce students to various experiments in a lab course instead of an in-class tutorial. In addition to saving time for both the students and the instructor, this allows students to watch the videos in an "on-demand" setting at their convenience, which is helpful…

In this NSF-supported project, two Anasazi FT-NMRs are being integrated simultaneously across the chemistry curriculum at Western Kentucky University (WKU) and Elizabethtown Community and Technical College (ECTC). The collaborative project adds to a new curriculum initiative by integrating NMR throughout the chemistry curriculum to enhance both…

A watt balance is an electromechanical device that allows a mass to be determined in terms of measurable electrical and mechanical quantities, themselves traceable to the fundamental constants of physics. International plans are well advanced to redefine the unit of mass, the kilogram, in terms of a fixed numerical value for the Planck constant. A…

An undergraduate laboratory exercise is described to demonstrate the biochemical applications of electron paramagnetic resonance (EPR) spectroscopy. The beta93 cysteine residue of hemoglobin is labeled by the covalent binding of 3-maleimido-proxyl (5-MSL) and 2,2,5,5-tetramethyl-1-oxyl-3-methyl methanethiosulfonate (MTSL), respectively. The excess…

The essential oil of "Nepeta cataria" L. (catnip), an herbaceous plant known popularly as a stimulant for the domestic cat, is enriched in two diastereomeric iridoid lactones (nepetalactones) that vary in ratio. Although the diastereomers are chromatographically separable and exhibit different 1D NMR spectra, it is not possible to…

Drawing a schematic energy diagram for the decomposition of H[subscript 2]O[subscript 2] catalyzed by MnO[subscript 2] through a simple thermometric measurement outlined in this study is intended to integrate students' understanding of thermochemistry and kinetics of chemical reactions. The reaction enthalpy, delta[subscript r]H, is…

An undergraduate exercise in computational chemistry that investigates the energy barrier for pyramidal inversion of amines and phosphines is presented. Semiempirical calculations (PM3) of the ground-state and transition-state energies for NR[superscript 1]R[superscript 2]R[superscript 3] and PR[superscript 1]R[superscript 2]R[superscript 3] allow…

Modern undergraduate organic chemistry textbooks provide detailed discussion of stoichiometric Cr- and Mn-based reagents for the oxidation of alcohols, yet the use of such oxidants in instructional and research laboratories, as well as industrial chemistry, is increasingly avoided. This work describes a laboratory exercise that uses ambient air as…

One of my principal goals at the University of Minnesota is to transform the university's entry-level geoscience program into an effective ''concluding'' geoscience course that provides students with a clear understanding of the many interactions between Earth processes and human society. Although place-based learning appeared to be a promising…

We present a simple and accurate experiment to obtain the speed of sound in air using a conventional speaker and a microphone connected to a computer. A free open source digital audio editor and recording computer software application allows determination of the time-of-flight of the wave for different distances, from which the speed of sound is…

An increasingly interconnected world requires people to become versatile communicators in a variety of different settings. Language centers have a critical role to play in this process by offering language and culture training in multiple languages to students, professionals and the wider community alike. They may do so from the perspective of…

Youth with autism spectrum disorder often have complex medical needs. Disruptions of healthcare during the transition from pediatric to adult healthcare may put youth with autism spectrum disorder at higher risk of medical emergencies and high medical costs. We conducted a study among transition-age youth (14-25 years old) receiving healthcare at…