50 research outputs found

    Thermophilic Bacterial Activity in a Deep-Sea Sediment from the Pacific Ocean

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    Thermophilic bacterial activity was detected in a deep-sea sediment sample from the South Pacific Ocean at 12 degrees S, 135 degrees W, an area of the seafloor distant from known hydrothermal venting. Incubation of sediments amended with C-14-glutamate indicated maximal respiration (evolution of (CO2)-C-14) and assimilation (incorporation of C-14 into acid-precipitated macromolecules) of substrate at 52 degrees C, relative to 4 and 22 degrees C. A parallel experiment at another site (2 degrees S, 140 degrees W) yielded no evidence of thermophily. Thermophilic bacteria may be deposited in deep-sea sediments following their long-distance dispersal from hydrothermal vents (e.g. the East Pacific Rise and other sites), via either continuous venting or formation of megaplumes

    Preferential Depletion of Zinc Within Costa Rica Upwelling Dome Creates Conditions for Zinc Co-Limitation of Primary Production

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    The Costa Rica Dome (CRD) is a wind-driven feature characterized by high primary production and an unusual cyanobacterial bloom in surface waters. It is not clear whether this bloom arises from top-down or bottom-up processes. Several studies have argued that trace metal geochemistry within the CRD contributes to the composition of the phytoplankton assemblages, since cyanobacteria and eukaryotic phytoplankton have different transition metal requirements. Here, we report that total dissolved zinc (Zn) is significantly depleted relative to phosphate (P) and silicate (Si) within the upper water column of the CRD compared with other oceanic systems, and this may create conditions favorable for cyanobacteria, which have lower Zn requirements than their eukaryotic competitors. Shipboard grow-out experiments revealed that while Si was a limiting factor under our experimental conditions, additions of Si and either iron (Fe) or Zn led to higher biomass than Si additions alone. The addition ofFe and Zn alone did not lead to significant enhancements. Our results suggest that the depletion of Zn relative to P in upwelled waters may create conditions in the near-surface waters that favor phytoplankton with low Zn requirements, including cyanobacteria

    Bluefin Tuna Larvae in Oligotrophic Ocean Foodwebs, Investigations of Nutrients to Zooplankton: Overview of the BLOOFINZ-Gulf of Mexico program

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    Western Atlantic bluefin tuna (ABT) undertake long-distance migrations from rich feeding grounds in the North Atlantic to spawn in oligotrophic waters of the Gulf of Mexico (GoM). Stock recruitment is strongly affected by interannual variability in the physical features associated with ABT larvae, but the nutrient sources and food-web structure of preferred habitat, the edges of anticyclonic loop eddies, are unknown. Here, we describe the goals, physical context, design and major findings of an end-to-end process study conducted during peak ABT spawning in May 2017 and 2018. Mesoscale features in the oceanic GoM were surveyed for larvae, and five multi-day Lagrangian experiments measured hydrography and nutrients; plankton biomass and composition from bacteria to zooplankton and fish larvae; phytoplankton nutrient uptake, productivity and taxon-specific growth rates; micro- and mesozooplankton grazing; particle export; and ABT larval feeding and growth rates. We provide a general introduction to the BLOOFINZ-GoM project (Bluefin tuna Larvae in Oligotrophic Ocean Foodwebs, Investigation of Nitrogen to Zooplankton) and highlight the finding, based on backtracking of experimental waters to their positions weeks earlier, that lateral transport from the continental slope region may be more of a key determinant of available habitat utilized by larvae than eddy edges per se.Postprint1,74

    The IDENTIFY study: the investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer - a multicentre observational study

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    Objective To evaluate the contemporary prevalence of urinary tract cancer (bladder cancer, upper tract urothelial cancer [UTUC] and renal cancer) in patients referred to secondary care with haematuria, adjusted for established patient risk markers and geographical variation. Patients and Methods This was an international multicentre prospective observational study. We included patients aged ≄16 years, referred to secondary care with suspected urinary tract cancer. Patients with a known or previous urological malignancy were excluded. We estimated the prevalence of bladder cancer, UTUC, renal cancer and prostate cancer; stratified by age, type of haematuria, sex, and smoking. We used a multivariable mixed-effects logistic regression to adjust cancer prevalence for age, type of haematuria, sex, smoking, hospitals, and countries. Results Of the 11 059 patients assessed for eligibility, 10 896 were included from 110 hospitals across 26 countries. The overall adjusted cancer prevalence (n = 2257) was 28.2% (95% confidence interval [CI] 22.3–34.1), bladder cancer (n = 1951) 24.7% (95% CI 19.1–30.2), UTUC (n = 128) 1.14% (95% CI 0.77–1.52), renal cancer (n = 107) 1.05% (95% CI 0.80–1.29), and prostate cancer (n = 124) 1.75% (95% CI 1.32–2.18). The odds ratios for patient risk markers in the model for all cancers were: age 1.04 (95% CI 1.03–1.05; P < 0.001), visible haematuria 3.47 (95% CI 2.90–4.15; P < 0.001), male sex 1.30 (95% CI 1.14–1.50; P < 0.001), and smoking 2.70 (95% CI 2.30–3.18; P < 0.001). Conclusions A better understanding of cancer prevalence across an international population is required to inform clinical guidelines. We are the first to report urinary tract cancer prevalence across an international population in patients referred to secondary care, adjusted for patient risk markers and geographical variation. Bladder cancer was the most prevalent disease. Visible haematuria was the strongest predictor for urinary tract cancer

    Microbial abundance of phytoplankton and bacteria from RV/Tangaroa cruise TAN1810SALP to Chatham Rise vicinity, east of New Zealand, Oct - Nov. 2018

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    Dataset: Microbial abundanceMicrobial abundance of phytoplankton and bacteria from RV/Tangaroa cruise TAN1810SALP to Chatham Rise vicinity, east of New Zealand, Oct - Nov. 2018. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/809670NSF Division of Ocean Sciences (NSF OCE) OCE-1756465, NSF Division of Ocean Sciences (NSF OCE) OCE-175661

    Pigment data by phytoplankton taxa from CTD casts from NOAA Ship R/V Nancy Foster cruises NF1704 and NF1802 in the Gulf of Mexico, May 2017 and 2018

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    Dataset: GoMex pigmentsPigment data by phytoplankton taxa from CTD casts from NOAA Ship R/V Nancy Foster cruises NF1704 and NF1802 in the Gulf of Mexico, May 2017 and 2018. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/835619NSF Division of Ocean Sciences (NSF OCE) OCE-1851558, National Oceanic and Atmospheric Administration (NOAA) NA16NMF432005
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