Finding co-solvers on Twitter, with a little help from Linked Data

In this paper we propose a method for suggesting potential collaborators for solving innovation challenges online, based on their competence, similarity of interests and social proximity with the user. We rely on Linked Data to derive a measure of semantic relatedness that we use to enrich both user profiles and innovation problems with additional relevant topics, thereby improving the performance of co-solver recommendation. We evaluate this approach against state of the art methods for query enrichment based on the distribution of topics in user profiles, and demonstrate its usefulness in recommending collaborators that are both complementary in competence and compatible with the user. Our experiments are grounded using data from the social networking service Twitter.com

Implementation, impact and costs of policies for safe staffing in acute NHS trusts

The aim of this research has been to describe the implementation of safe staffing policies in NHS general acute Trusts in England looking at costs and consequences, and examining the factors that have influenced implementation. A mix of qualitative and quantitative methods were used (national survey, analysis of national data, four case studies, realist evaluation) to examine the impact of policies nationally, and explore commonality and variation in local responses to safe staffing policies. The report is based on independent research commissioned and funded by the NIHR Policy Research Programme (“Implementation, Impact and Costs of Policies for Safe Staffing in Acute NHS Trusts”, PR-ST-1115-10017). The views expressed are those of the authors and not necessarily those of the NIHR, the Department of Health and Social Care, ‘arm’s length bodies’ or other government departments

Evaluation of semantic web ontologies for modelling art collections

© 2017, Springer International Publishing AG. The need for organising, sharing and digitally processing Cultural Heritage (CH) information has led to the development of formal knowledge representation models (ontologies) for the CH domain. Based on RDF and OWL, the standard data model and ontology language of the Semantic Web, ontologies such as CIDOC-CRM, the Europeana Data Model and VRA, offer enhanced representation capabilities, but also support for inference, querying and interlinking through the Web. This paper presents the results of a small-scale evaluation of the three most commonly used CH ontologies, with respect to their capacity to fulfil the data modelling requirements of art collections

Mesoscale Hydrographic Variability in the Vicinity of Points Conception and Arguello During April May 1983: The OPUS 1983 Experiment

In April and May 1983, interdisciplinary oceanographic observations were made of upwelling events in the Point Conception area off southern California. The principal objective was to observe the structure and time dependence of the upwelling system. To accomplish this, two ships, two aircraft, moorings, drogues, and satellite imagery were all included in the observational effort. During the intensive measurement period three main upwelling events and two intervening relaxation or downwelling intervals were sampled during what was a period of overall longer-term sea surface warming. Surface temperatures during upwelling were as low as 10.5°C in the upwelling center between Point Arguello and Point Conception, while during periods of nonupwelling winds, temperatures reached 14°–15°C in the same area. The upwelling center was also a source of higher-salinity water (33.7‰) relative to the offshore waters that were anomalously fresh (33.3‰). Upwelling was observed off Point Arguello, Point Conception, and the area between with a possible lag of up to a day at Point Conception relative to the other areas. The upwelling plume as observed by surface mapping and remote sensing tended to move in a variety of directions from SE to SW. Part of the movement was usually into the Santa Barbara Channel, but other parts of the plume occasionally moved southwestward. There was no obvious correlation of plume direction with the wind. During relaxation events the entire region was covered by a 10- to 20-m-thick warm (14°–16°C), fresh

Seasonal modulation of mesoscale processes alters nutrient availability and plankton communities in the Red Sea

Hydrographic and atmospheric forcing set fundamental constraints on the biogeochemistry of aquatic ecosystems and manifest in the patterns of nutrient availability and recycling, species composition of communities, trophic dynamics, and ecosystem metabolism. In the Red Sea, latitudinal gradients in environmental conditions and primary production have been ascribed to fluctuations in Gulf of Aden Water inflow, upwelling/mixing, and regenerated nutrient utilization i.e. rapidly recycled nitrogen in upper layers. However, our understanding of upper layer dynamics and related changes in plankton communities, metabolism and carbon and nitrogen export is limited. We surmised that stratification and mesoscale eddies modulate the nutrient availability and taxonomic identity of plankton communities in the Red Sea. Based on remote-sensing data of sea level anomalies and high resolution in situ measurements (ScanFish) we selected stations for hydrographic CTD profiles, water sampling (nutrients, seawater oxygen stable isotopes [δ18OSW]), phytoplankton and zooplankton collections. In fall 2014, strong stratification subjected the plankton community to an overall nitrogen and phosphorus shortage. The nutrient deficiency increased numbers of heterotrophic dinoflagellates, microzooplankton, and diazotrophs (Trichodesmium, diatom-diazotroph associations [DDAs]), albeit largely decreased phytoplankton and mesozooplankton abundances. In spring 2015, mesoscale eddies increased the nutrient availability, and the thermohaline characteristics and low δ18OSW point to the interaction of eddies with Gulf of Aden Surface Water (GASW). Cyclonic eddies and, most likely, the availability of nutrients associated with the GASW, increased the abundances of autotrophs (diatoms, Prasinophytes) and supported larger numbers of zooplankton and their larvae. We demonstrate that the interplay of stratification, advection of Gulf of Aden water and mesoscale eddies are key elements to better understand changes in plankton community composition, ecosystem metabolism, and macronutrient export in the Red Sea in space and time

Physical mechanisms routing nutrients in the central Red Sea

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9032–9046, doi:10.1002/2017JC013017.Mesoscale eddies and boundary currents play a key role in the upper layer circulation of the Red Sea. This study assesses the physical and biochemical characteristics of an eastern boundary current (EBC) and recurrent eddies in the central Red Sea (CRS) using a combination of in situ and satellite observations. Hydrographic surveys in November 2013 (autumn) and in April 2014 (spring) in the CRS (22.15°N–24.1°N) included a total of 39 and 27 CTD stations, respectively. In addition, high-resolution hydrographic data were acquired in spring 2014 with a towed undulating vehicle (ScanFish). In situ measurements of salinity, temperature, chlorophyll fluorescence, colored dissolved organic matter (CDOM), and dissolved nitrate: phosphorous ratios reveal distinct water mass characteristics for the two periods. An EBC, observed in the upper 150 m of the water column during autumn, transported low-salinity and warm water from the south toward the CRS. Patches of the low-salinity water of southern origin tended to contain relatively high concentrations of chlorophyll and CDOM. The prominent dynamic feature observed in spring was a cyclonic/anticyclonic eddy pair. The cyclonic eddy was responsible for an upward nutrient flux into the euphotic zone. Higher chlorophyll and CDOM concentrations, and concomitant lower nitrate:phosphorous ratios indicate the influence of the EBC in the CRS at the end of the stratified summer period.King Abdullah University of Science and Technology (KAUST); Core Marine Operation Research Lab (CMOR

Vertical movements of a pelagic thresher shark (Alopias pelagicus): insights into the species' physiological limitations and trophic ecology in the Red Sea

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Arostegui, M. C., Gaube, P., Berumen, M. L., DiGiulian, A., Jones, B. H., Rostad, A., & Braun, C. D. Vertical movements of a pelagic thresher shark (Alopias pelagicus): insights into the species' physiological limitations and trophic ecology in the Red Sea. Endangered Species Research, 43, (2020): 387-394, https://doi.org/10.3354/esr01079.The pelagic thresher shark Alopias pelagicus is an understudied elasmobranch harvested in commercial fisheries of the tropical Indo-Pacific. The species is endangered, overexploited throughout much of its range, and has a decreasing population trend. Relatively little is known about its movement ecology, precluding an informed recovery strategy. Here, we report the first results from an individual pelagic thresher shark outfitted with a pop-up satellite archival transmitting (PSAT) tag to assess its movement with respect to the species’ physiology and trophic ecology. A 19 d deployment in the Red Sea revealed that the shark conducted normal diel vertical migration, spending the majority of the day at 200-300 m in the mesopelagic zone and the majority of the night at 50-150 m in the epipelagic zone, with the extent of these movements seemingly not constrained by temperature. In contrast, the depth distribution of the shark relative to the vertical distribution of oxygen suggested that it was avoiding hypoxic conditions below 300 m even though that is where the daytime peak of acoustic backscattering occurs in the Red Sea. Telemetry data also indicated crepuscular and daytime overlap of the shark’s vertical habitat use with distinct scattering layers of small mesopelagic fishes and nighttime overlap with nearly all mesopelagic organisms in the Red Sea as these similarly undergo nightly ascents into epipelagic waters. We identify potential depths and diel periods in which pelagic thresher sharks may be most susceptible to fishery interactions, but more expansive research efforts are needed to inform effective management.This research was funded by a KAUST Center Part-nership Fund award (4107.3 to the Red Sea Research Cen-ter) and KAUST baseline funding (B.H.J. and M.L.B.).M.C.A. and P.G. acknowledge support from NOAA projectNA15OAR4320063. This study was conducted under a pro-tocol approved by the University of Washington’s Institu-tional Animal Care and Use Committee

Simultaneous Measurements of Dinitrogen Fixation and Denitrification Associated With Coral Reef Substrates : Advantages and Limitations of a Combined Acetylene Assay

Nitrogen (N) cycling in coral reefs is of key importance for these oligotrophic ecosystems, but knowledge about its pathways is limited. While dinitrogen (N-2) fixation is comparably well studied, the counteracting denitrification pathway is under-investigated, mainly because of expensive and relatively complex experimental techniques currently available. Here, we combined two established acetylene-based assays to one single setup to determine N-2-fixation and denitrification performed by microbes associated with coral reef substrates/organisms simultaneously. Accumulating target gases (ethylene for N-2-fixation, nitrous oxide for denitrification) were measured in gaseous headspace samples via gas chromatography. We measured N-2-fixation and denitrification rates of two Red Sea coral reef substrates (filamentous turf algae, coral rubble), and demonstrated, for the first time, the co-occurrence of both N-cycling processes in both substrates. N-2-fixation rates were up to eight times higher during the light compared to the dark, whereas denitrification rates during dark incubations were stimulated for turf algae and suppressed for coral rubble compared to light incubations. Our results highlight the importance of both substrates in fixing N, but their role in relieving N is potentially divergent. Absolute N-2-fixation rates of the present study correspond with rates reported previously, even though likely underestimated due to an initial lag phase. Denitrification is also presumably underestimated due to incomplete nitrous oxide inhibition and/or substrate limitation. Besides these inherent limitations, we show that a relative comparison of N-2-fixation and denitrification activity between functional groups is possible. Thus, our approach facilitates cost-efficient sample processing in studies interested in comparing relative rates of N-2-fixation and denitrification.Peer reviewe

Spectral imaging of the central molecular zone in multiple 7-mm molecular lines

We have imaged 24 spectral lines in the central molecular zone (CMZ) around the Galactic Centre, in the range 42–50 GHz. The lines include emission from the CS, CH3OH, HC3N, SiO, HNCO, HOCO+, NH2CHO, OCS, HCS+, CCS, C34S, 13CS, 29SiO, H13CCCN, HCC13CN and HC5N molecules, and three hydrogen recombination lines. The area covered is Galactic longitude −0.7 to 1.8and latitude −0.3 to 0.2, including the bright cores around Sgr A, Sgr B2, Sgr C and G1.6-0.025. This work used the 22-m Mopra radio telescope in Australia, obtaining ~1.8 km s−1 spectral and ~ 65 arcsec spatial resolutions. We present peak images from this study and conduct a principal component analysis on the integrated emission from the brightest 10 lines, to study similarities and differences in the line distribution. We examine the integrated line intensities and line ratios in selected apertures around the bright cores, as well as for the complete mapped region of the CMZ. We compare these 7-mm lines to the corresponding lines in the 3-mm band, for five molecules, to study the excitation. There is a variation in 3 to 7-mm line ratio across the CMZ, with relatively higher ratio in the centre around Sgr B2 and Sgr A. We find that the lines are sub-thermally excited, and from modelling with RADEX find that non-Local Thermodynamic Equilibrium conditions apply, with densities of the order of 104 cm−3