Measuring data rot: An analysis of the continued availability of shared data from a Single University.

To determine where data is shared and what data is no longer available, this study analyzed data shared by researchers at a single university. 2166 supplemental data links were harvested from the university's institutional repository and web scraped using R. All links that failed to scrape or could not be tested algorithmically were tested for availability by hand. Trends in data availability by link type, age of publication, and data source were examined for patterns. Results show that researchers shared data in hundreds of places. About two-thirds of links to shared data were in the form of URLs and one-third were DOIs, with several FTP links and links directly to files. A surprising 13.4% of shared URL links pointed to a website homepage rather than a specific record on a website. After testing, 5.4% the 2166 supplemental data links were found to be no longer available. DOIs were the type of shared link that was least likely to disappear with a 1.7% loss, with URL loss at 5.9% averaged over time. Links from older publications were more likely to be unavailable, with a data disappearance rate estimated at 2.6% per year, as well as links to data hosted on journal websites. The results support best practice guidance to share data in a data repository using a permanent identifier.

Teaching Cheminformatics through a Collaborative Intercollegiate Online Chemistry Course (OLCC).

While cheminformatics skills necessary for dealing with an ever-increasing amount of chemical information are considered important for students pursuing STEM careers in the age of big data, many schools do not offer a cheminformatics course or alternative training opportunities. This paper presents the Cheminformatics Online Chemistry Course (OLCC), which is organized and run by the Committee on Computers in Chemical Education (CCCE) of the American Chemical Society (ACS)'s Division of Chemical Education (CHED). The Cheminformatics OLCC is a highly collaborative teaching project involving instructors at multiple schools who teamed up with external chemical information experts recruited across sectors, including government and industry. From 2015 to 2019, three Cheminformatics OLCCs were offered. In each program, the instructors at participating schools would meet face-to-face with the students of a class, while external content experts engaged through online discussions across campuses with both the instructors and students. All the material created in the course has been made available at the open education repositories of LibreTexts and CCCE Web sites for other institutions to adapt to their future needs.

The influence of vibrational excitation on the photoisomerization of trans-stilbene in solution.

Preparing electronically excited trans-stilbene molecules in deuterated chloroform using both one-photon excitation and excitation through an intermediate vibrational state explores the influence of vibrational energy on excited-state isomerization in solution. After infrared excitation of either two quanta of C-H stretch vibration |2ν(CH)> at 5990 cm(-1) or the C-H stretch-bend combination |ν(CH) + ν(bend)> at 4650 cm(-1) in the ground electronic state, an ultraviolet photon intercepts the vibrationally excited molecules during the course of vibrational energy flow and promotes them to the electronically excited state. The energy of the infrared and ultraviolet photons together is the same as that added in the one-photon excitation. Transient broadband-continuum absorption monitors the lifetime of electronically excited molecules. The lifetime of excited-state trans-stilbene after one-photon electronic excitation with 33,300 cm(-1) of energy is (51 +/- 6) ps. The excited-state lifetimes of (55 +/- 9) ps and (56 +/- 7) ps for the cases of excitation through |2ν(CH)> and |ν(CH) + ν(bend)>, respectively, are indistinguishable from that for the one-photon excitation. Vibrational relaxation in the electronically excited state prepared by the two-photon excitation scheme is most likely faster than the barrier crossing, making the isomerization insensitive to the method of initial state preparation.