33 research outputs found

    Parameterizing the impact of seawater temperature and irradiance on dimethylsulfide (DMS) in the Great Barrier Reef and the contribution of coral reefs to the global sulfur cycle

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Jackson, R. L., Gabric, A. J., Matrai, P. A., Woodhouse, M. T., Cropp, R., Jones, G. B., Deschaseaux, E. S. M., Omori, Y., McParland, E. L., Swan, H. B., & Tanimoto, H. Parameterizing the impact of seawater temperature and irradiance on dimethylsulfide (DMS) in the Great Barrier Reef and the contribution of coral reefs to the global sulfur cycle. Journal of Geophysical Research:Oceans, 126(3), (2021): e2020JC016783, https://doi.org/10.1029/2020JC016783.Biogenic emissions of dimethylsulfide (DMS) are an important source of sulfur to the atmosphere, with implications for aerosol formation and cloud albedo over the ocean. Natural aerosol sources constitute the largest uncertainty in estimates of aerosol radiative forcing and climate and thus, an improved understanding of DMS sources is needed. Coral reefs are strong point sources of DMS; however, this coral source of biogenic sulfur is not explicitly included in climatologies or in model simulations. Consequently, the role of coral reefs in local and regional climate remains uncertain. We aim to improve the representation of tropical coral reefs in DMS databases by calculating a climatology of seawater DMS concentration (DMSw) and sea-air flux in the Great Barrier Reef (GBR), Australia. DMSw is calculated from remotely sensed observations of sea surface temperature and photosynthetically active radiation using a multiple linear regression model derived from field observations of DMSw in the GBR. We estimate that coral reefs and lagoon waters in the GBR (∼347,000 km2) release 0.03–0.05 Tg yr−1 of DMS (0.02 Tg yr−1 of sulfur). Based on this estimate, global tropical coral reefs (∼600,000 km2) could emit 0.08 Tg yr−1 of DMS (0.04 Tg yr−1 of sulfur), with the potential to influence the local radiative balance.Australian Research Council. Grant Number: DP150101649 National Science Foundation (NSF). Grant Number: 1543450 Ministry of Education, Culture, Sports, Science and Technology Grants-in-Aid for Scientific Research. Grant Number: 23310016,16H02967,24241010,15H01732 Ministry of Education, Culture, Sports, Science and Technology Grant-in-Aid for Young Scientists. Grant Number: 17K1281

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Database of surface level atmospheric dimethylsulfide (DMS) collected for the project The Great Barrier Reef as a significant source of climatically relevant aerosol particles

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    The data provided here consists of surface level atmospheric DMS measurements collected at Heron Island on the southern Great Barrier Reef (23.44°S, 151.91°E) in January-February 2018. This data has resulted from a series of campaigns conducted on the Great Barrier Reef (GBR) to examine the significance of the GBR as a source of new aerosol particles. Accompanying the atmospheric DMS data set are one minute averaged particle number concentrations for the size range fractions 0.5 - 2.5 micron and \u3e2.5 micron collected using a Dylos DC1700 air quality monitor. Surface level solar irradiance (300 -1100 nm) is also provided with the data collected in Jan-Feb 2018 at Heron Island

    Atmospheric dimethylsulfide surface concentrations and supermicron particle number concentrations at Garners Beach (17.82°S, 146.10°E) October 2016.

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    The data provides atmospheric DMS surface concentrations at Garners Beach, on the Far North Queensland coast (17.82°S, 146.10°E) during October 2016. Accompanying the atmospheric DMS dataset are 1 min averaged particle number concentrations in two size ranges (0.5-2.5 micron & \u3e2.5 micron)

    Dimethylsulfide, climate and coral reef ecosystems

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    Dimethylsulfide (DMS) is the major biogenic source of atmospheric sulfur and is mainly derived from dimethylsulfoniopropionate (DMSP) produced by oceanic phytoplankton, marine algae and endosymbiont zooxanthellae in reef-building corals. Although coral reefs occup

    The validation and measurement uncertainty of an automated gas chromatograph for marine studies of atmospheric dimethylsulfide

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    An automated gas chromatograph (GC) is described that can reliably quantify atmospheric dimethylsulfide (DMS) in near real-time at low nmol m−3 concentrations or pmol mol−1 (ppt) mixing ratios. Features of the automated GC include: removal of atmospheric oxidants and moisture; cryogenic pre-concentration of DMS; methylethylsulfide internal standard calibration; and pulsed flame photometric sulfur specific detection. This automated instrument is suitable for field deployment; it was recently used to obtain a continuous DMS dataset at Heron Island in the southern Great Barrier Reef over 14 days during the austral summer. Detailed analysis of the measurement uncertainty of this automated GC was conducted, according to Eurachem/CITAC guidelines, by quantifying and combining the uncertainties of the components that contributed to the analytical result. This gave a relative standard uncertainty of 6.5% which was expanded, using a coverage factor of two, for an interval containing approximately 95% of the expected distribution of values. When applied to the Heron Island summer dataset, the mean atmospheric DMS concentration and expanded uncertainty was 3.9 ± 0.5 nmol m−3 (n = 651). This value and uncertainty interval falls within the range of mean atmospheric DMS values obtained from other studies at the Great Barrier Reef. Wider adoption of chemometrics to quantify atmospheric DMS measurement uncertainty will enable improved comparison of data and assist climate modelling

    Coral reef origins of atmospheric dimethylsulfide at Heron Island, southern Great Barrier Reef, Australia

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    Atmospheric dimethylsulfide (DMSa), continually derived from the world’s oceans, is a feed gas for the tropospheric production of new sulfate particles, leading to cloud condensation nuclei that influence the formation and properties of marine clouds and ultimately the Earth’s radiation budget. Previous studies on the Great Barrier Reef (GBR), Australia, have indicated coral reefs are significant sessile sources of DMSa capable of enhancing the tropospheric DMSa burden mainly derived from phytoplankton in the surface ocean; however, specific environmental evidence of coral reef DMS emissions and their characteristics is lacking. By using on-site automated continuous analysis of DMSa and meteorological parameters at Heron Island in the southern GBR, we show that the coral reef was the source of occasional spikes of DMSa identified above the oceanic DMSa background signal. In most instances, these DMSa spikes were detected at low tide under low wind speeds, indicating they originated from the lagoonal platform reef surrounding the island, although evidence of longer-range transport of DMSa from a 70 km stretch of coral reefs in the southern GBR was also observed. The most intense DMSa spike occurred in the winter dry season at low tide when convective precipitation fell onto the aerially exposed platform reef. This co-occurrence of events appeared to biologically shock the coral resulting in a seasonally aberrant extreme DMSa spike concentration of 45.9 nmol m−3 (1122 ppt). Seasonal DMS emission fluxes for the 2012 wet season and 2013 dry season campaigns at Heron Island were 5.0 and 1.4 µmol m−2 day−1 , respectively, of which the coral reef was estimated to contribute 4 % during the wet season and 14 % during the dry season to the dominant oceanic flux
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