Coral Settlement on Oil/Gas Platforms in the Northern Gulf of Mexico: Preliminary Evidence of Rarity

In recent decades, there have been two areas of shallow hard substrate available for zooxanthellate coral colonization in the North Gulf of Mexico: the Flower Garden Banks (FGB) and oil and gas platforms. We assessed coral recruitment on platforms possessing adult corals around the FGB. In this preliminary experiment, we used terra cotta plates mounted on racks, deployed on six platforms at depths of 15–27 m for a duration of ≤1 yr in two consecutive years. Data on coral spat taxonomic identification, distribution, and densities were collected. Platform spat densities on plates averaged \u3c1/450 cm2, a low value when compared with the East-FGB (E-FGB; data from earlier similar experiment), other Caribbean sites, or the Great Barrier Reef. Spat density was not significantly different between platforms, suggesting that distance between the platforms and the E-FGB, a potential larval source, was large enough (\u3e0.6–1.2 km) to permit extensive larval diffusion. Total spat density also did not vary significantly between settlement racks, indicating that settlement at the spatial scale of meters was relatively homogeneous. Only three species of spat were found—Tubastraea coccinea, Madracis decactis, and Montastraea sp.; the taxonomic composition of coral spat varied from those observed earlier on the E-FGB—Agaricia and Porites. The dominant recruits matched the dominant adults on the platforms— an unusual situation. Tubastraea and Madracis spat densities, respectively, did not vary significantly between platforms or between racks. Because of low recruitment levels, these artificial reef communities may be considered fragile in comparison to many natural ones because of the time required for recovery in the event of a mass coral mortality. These low recruitment levels, however, when integrated over ~30 yr, can result in the successful establishment of adult coral communities on the platforms

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical science. © The Author(s) 2019. Published by Oxford University Press