An introduction to magnetic resonance imagining, which is based on the principles of nuclear magnetic resonance (NMR), a spectroscopic technique used by scientists to obtain microscopic chemical and physical information about molecules. See, in particular, The Mathematics of NMR: Exponential Functions, Trigonometric Functions, Differentials and Integrals, Vectors, Matrices, Coordinate Transformations, Convolutions, Imaginary Numbers, and The Fourier Transform. Includes a glossary, a list of symbols, and references. The text is available in English, Italian, and Russian.

From the National Audubon Society (previously featured in the 04-19-2019 Scout Report), the Audubon Bird Guide App is an award-winning and free field guide to 800 North American bird species. The app is designed to help novice observers and experienced birders identity, document, and learn about birds. On the app, users just need to enter key information about a bird they have seen (color, size, plumage, etc.) to receive possible matches based on location and time of year. The app also includes thousands of photos, range maps, background information, and audio of bird songs and calls to help in identification. There is also a community element to the app, as users can share photos with others and even find birding hotspots based on others' sightings. On the page linked above, visitors will find information about the app, links to download in the Apple App Store or Google Play, and user guides for getting started and troubleshooting.