Onset and Evolution of Upwelling along the West Coast of India

To describe the onset and evolution of upwelling along the south west coast of India, authors collected a series of conductivity temperature depth measurements on board INS Sagardhwani extending from 7 °N – 15 °N during the period extending from February 2017 - October 2017. In this paper we utilised the undulations of the 23 °C isotherm as a proxy to study the upwelling phenomenon. The upward movement of the waters at the southern tip off India (77.5 °E) in the subsurface levels was observed to commence from late February 2017 in depths around 80 m and by the end of May 2017, it is observed to rise rapidly to the surface. The upwelled waters reach the surface during the 2nd week of July all along the Indian coast, and then intensified during August 2017. Beyond 12 °N maximum upwelling is seen in July and thereafter in early August 2017 upwelling was intense till October 2017

Effect of Azimuthal Asymmetry Caused by Upwelling on 3D Ocean Acoustic Propagation

3-D underwater parabolic equation model based on implicit finite difference method has been implemented for South Eastern Arabian Sea (SEAS). The bathymetric and geo-acoustic features have been integrated in the model for a 50 km circular region in SEAS. The model can simulate the effects of azimuthal variation in oceanographic features and compute azimuthally coupled pressure due to an omni-directional source. The azimuthal variation in oceanographic conditions can be observed during an upwelling event. In the first case study, the effect of upwelling event on three-dimensional acoustic propagation has been studied by using sound speed profile data derived from INS Sagardhwani observations. The difference in Transmission loss mosaic for upslope and downslope propagation is due to bathymetry as well as upwelling. In the second case study, the effect of upwelling only, is studied by running a model corresponding to range independent sound speed profile field and range dependent bathymetry. It was observed that during this upwelling event, the transmission loss is higher at longer ranges during upslope propagation than downslope propagation. This is due to the increase in the thickness of sonic layer duct as acoustic wave propagates from shallow to deep water. The effect of azimuthal variation

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 research.Peer reviewe

Winter Thermohaline Features along 10 degree N in the Bay of Bengal

To commemorate the contributions made by Indian Naval Ship (INS) Kistna during the first International Indian ocean expedition programme a scientific cruise was planned in the Bay of Bengal during November 2017 onboard INS Sagardhwani. The objective was to study the thermohaline properties along 10 °N in the Bay of Bengal and understand the sound channel characteristics in the region. A fresh water cap of ~20 m thickness is noticed in the top layers of the Bay of Bengal occupying the region extending from 83 °E – 93 °E. A prominent anti-cyclonic eddy was noticed around 10 °N centered between 90 °E and 93 °E, a negative sea level (west of 90 °E) co-exists with a positive sea level anomaly to its east along the observational tracks along 10 °N. The climatological temperature and salinity sections also shows the same features as observed along the transect. The study also sheds light on the deep sound channel characteristics along the 10 °N channel

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