Citation data have remained hidden behind proprietary, restrictive licensing agreements, which raises barriers to entry for analysts wishing to use the data, increases the expense of performing large-scale analyses, and reduces the robustness and reproducibility of the conclusions. For the past several years, the National Institutes of Health (NIH) Office of Portfolio Analysis (OPA) has been aggregating and enhancing citation data that can be shared publicly. Here, we describe the NIH Open Citation Collection (NIH-OCC), a public access database for biomedical research that is made freely available to the community. This dataset, which has been carefully generated from unrestricted data sources such as MedLine, PubMed Central (PMC), and CrossRef, now underlies the citation statistics delivered in the NIH iCite analytic platform. We have also included data from a machine learning pipeline that identifies, extracts, resolves, and disambiguates references from full-text articles available on the internet. Open citation links are available to the public in a major update of iCite (https://icite.od.nih.gov).

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The perception of Korean's three-way voiceless stop contrast depends on the combination of a number of acoustic properties including closure duration,f0, VOT and spectral slope. Production studies indicate that these same properties systematically vary according to a stop's position in the hierarchical prosodic structure of an utterance. This study investigated interactions between prosodic structure and the recognition of tense, lax and aspirated stops by using stimuli that contained stops produced at one position in the prosodic hierarchy cross-spliced into utterances at a different prosodic level. The results of the experiment showed that recognition of tense and aspirated stops remained high regardless of the degree of mismatch between the underlying prosodic position of a segment and the domain into which it was inserted. Misrecognition rates were higher for cross-spliced lax stops, and underlying Utterance and Intonation Phrase initial lax stops spliced into the syllable level were perceived as aspirated by a majority of listeners. These findings are interpreted in terms of Cho & Keating's (2001) study of domain-initial strengthening and the acoustic overlap that is observed between stop manner and prosodic position. These results are taken as preliminary evidence that could support Cho & Keating's (2001) suggestion that prosodically conditioned acoustic differences aid listeners in discerning intended phrasings.