GLORIA

GEOMAR Library Ocean Research Information Access

You have 0 saved results.
Mark results and click the "Add To Watchlist" link in order to add them to this list.

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Biogeosciences, Copernicus GmbH, Vol. 16, No. 6 ( 2019-03-21), p. 1167-1185
    Abstract: Abstract. The effects of ocean acidification and warming on the concentrations of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) were investigated during a mesocosm experiment in the Lower St. Lawrence Estuary (LSLE) in the fall of 2014. Twelve mesocosms covering a range of pHT (pH on the total hydrogen ion concentration scale) from 8.0 to 7.2, corresponding to a range of CO2 partial pressures (pCO2) from 440 to 2900 µatm, at two temperatures (in situ and +5 ∘C; 10 and 15 ∘C) were monitored during 13 days. All mesocosms were characterized by the rapid development of a diatom bloom dominated by Skeletonema costatum, followed by its decline upon the exhaustion of nitrate and silicic acid. Neither the acidification nor the warming resulted in a significant impact on the abundance of bacteria over the experiment. However, warming the water by 5 ∘C resulted in a significant increase in the average bacterial production (BP) in all 15 ∘C mesocosms as compared to 10 ∘C, with no detectable effect of pCO2 on BP. Variations in total DMSP (DMSPt = particulate + dissolved DMSP) concentrations tracked the development of the bloom, although the rise in DMSPt persisted for a few days after the peaks in chlorophyll a. Average concentrations of DMSPt were not affected by acidification or warming. Initially low concentrations of DMS (〈1 nmol L−1) increased to reach peak values ranging from 30 to 130 nmol L−1 towards the end of the experiment. Increasing the pCO2 reduced the averaged DMS concentrations by 66 % and 69 % at 10 and 15 ∘C, respectively, over the duration of the experiment. On the other hand, a 5 ∘C warming increased DMS concentrations by an average of 240 % as compared to in situ temperature, resulting in a positive offset of the adverse pCO2 impact. Significant positive correlations found between bacterial production and concentrations of DMS throughout our experiment point towards temperature-associated enhancement of bacterial DMSP metabolism as a likely driver of the mitigating effect of warming on the negative impact of acidification on the net production of DMS in the LSLE and potentially the global ocean.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2019
    detail.hit.zdb_id: 2158181-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Biogeosciences, Copernicus GmbH, Vol. 17, No. 6 ( 2020-03-26), p. 1557-1581
    Abstract: Abstract. Arctic sea ice is retreating and thinning and its rate of decline has steepened in the last decades. While phytoplankton blooms are known to seasonally propagate along the ice edge as it recedes from spring to summer, the substitution of thick multiyear ice (MYI) with thinner, ponded first-year ice (FYI) represents an unequal exchange when considering the roles sea ice plays in the ecology and climate of the Arctic. Consequences of this shifting sea ice on the phenology of phytoplankton and the associated cycling of the climate-relevant gas dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) remain ill constrained. In July–August 2014, two contrasting ice edges in the Canadian High Arctic were explored: a FYI-dominated ice edge in Barrow Strait and a MYI-dominated ice edge in Nares Strait. Our results reveal two distinct planktonic systems and associated DMS dynamics in connection to these diverging ice types. The surface waters exiting the ponded FYI in Barrow Strait were characterized by moderate chlorophyll a (Chl a, 〈2.1 µg L−1) as well as high DMSP (115 nmol L−1) and DMS (12 nmol L−1), suggesting that a bloom had already started to develop under the markedly melt-pond-covered (ca. 40 %) FYI. Heightened DMS concentrations at the FYI edge were strongly related to ice-associated seeding of DMS in surface waters and haline-driven stratification linked to ice melt (Spearman's rank correlation between DMS and salinity, rs=-0.91, p〈0.001, n=20). However, surface waters exiting the MYI edge at the head of Nares Strait were characterized by low concentrations of Chl a (〈0.5 µg L−1), DMSP (〈16 nmol L−1), and DMS (〈0.4 nmol L−1), despite the nutrient-replete conditions characterizing the surface waters. The increase in autotrophic biomass and methylated sulfur compounds took place several kilometers (ca. 100 km) away from the MYI edge, suggesting the requisite for ice-free, light-sufficient conditions for a phytoplankton bloom to fully develop and for sulfur compound dynamics to follow and expand. In light of the ongoing and projected climate-driven changes to Arctic sea ice, results from this study suggest that the early onset of autotrophic blooms under thinner, melt-pond-covered ice may have vast implications for the timing and magnitude of DMS pulses in the Arctic.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2158181-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Trials, Springer Science and Business Media LLC, Vol. 21, No. 1 ( 2020-12)
    Abstract: Sepsis is a health problem of global importance; treatments focus on controlling infection and supporting failing organs. Recent clinical research suggests that intravenous vitamin C may decrease mortality in sepsis. We have designed a randomized controlled trial (RCT) to ascertain the effect of vitamin C on the composite endpoint of death or persistent organ dysfunction at 28 days in patients with sepsis. Methods LOVIT (Lessening Organ dysfunction with VITamin C) is a multicenter, parallel-group, blinded (participants, clinicians, study personnel, Steering Committee members, data analysts), superiority RCT (minimum n  = 800). Eligible patients have sepsis as the diagnosis for admission to the intensive care unit (ICU) and are receiving vasopressors. Those admitted to the ICU for more than 24 h are excluded. Eligible patients are randomized to high-dose intravenous vitamin C (50 mg/kg every 6 h for 96 h) or placebo. The primary outcome is a composite of death or persistent organ dysfunction (need for vasopressors, invasive mechanical ventilation, or new and persisting renal replacement therapy) at day 28. Secondary outcomes include persistent organ dysfunction-free days to day 28, mortality and health-related quality of life at 6 months, biomarkers of dysoxia, inflammation, infection, endothelial function, and adverse effects (hemolysis, acute kidney injury, and hypoglycemia). Six subgroup analyses are planned. Discussion This RCT will provide evidence of the effect of high-dose intravenous vitamin C on patient-important outcomes in patients with sepsis. Trial registration clinicaltrials.gov, NCT03680274 , first posted 21 September 2018.
    Type of Medium: Online Resource
    ISSN: 1745-6215
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2040523-6
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Scientific Data, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2022-07-30)
    Abstract: The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use.
    Type of Medium: Online Resource
    ISSN: 2052-4463
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2775191-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Online Resource
    Online Resource
    University of California Press ; 2021
    In:  Elementa: Science of the Anthropocene Vol. 9, No. 1 ( 2021-04-02)
    In: Elementa: Science of the Anthropocene, University of California Press, Vol. 9, No. 1 ( 2021-04-02)
    Abstract: The objective of this study was to assess experimentally the potential impact of anthropogenic pH perturbation (ApHP) on concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP), as well as processes governing the microbial cycling of sulfur compounds. A summer planktonic community from surface waters of the Lower St. Lawrence Estuary was monitored in microcosms over 12 days under three pCO2 targets: 1 × pCO2 (775 µatm), 2 × pCO2 (1,850 µatm), and 3 × pCO2 (2,700 µatm). A mixed phytoplankton bloom comprised of diatoms and unidentified flagellates developed over the course of the experiment. The magnitude and timing of biomass buildup, measured by chlorophyll a concentration, changed in the 3 × pCO2 treatment, reaching about half the peak chlorophyll a concentration measured in the 1 × pCO2 treatment, with a 2-day lag. Doubling and tripling the pCO2 resulted in a 15% and 40% decline in average concentrations of DMS compared to the control. Results from 35S-DMSPd uptake assays indicated that neither concentrations nor microbial scavenging efficiency of dissolved DMSP was affected by increased pCO2. However, our results show a reduction of the mean microbial yield of DMS by 34% and 61% in the 2 × pCO2 and 3 × pCO2 treatments, respectively. DMS concentrations correlated positively with microbial yields of DMS (Spearman’s ρ = 0.65; P & lt; 0.001), suggesting that the impact of ApHP on concentrations of DMS in diatom-dominated systems may be strongly linked with alterations of the microbial breakdown of dissolved DMSP. Findings from this study provide further empirical evidence of the sensitivity of the microbial DMSP switch under ApHP. Because even small modifications in microbial regulatory mechanisms of DMSP can elicit changes in atmospheric chemistry via dampened efflux of DMS, results from this study may contribute to a better comprehension of Earth’s future climate.
    Type of Medium: Online Resource
    ISSN: 2325-1026
    Language: English
    Publisher: University of California Press
    Publication Date: 2021
    detail.hit.zdb_id: 2745461-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    In: Geoscience Communication, Copernicus GmbH, Vol. 3, No. 1 ( 2020-04-21), p. 89-97
    Abstract: Abstract. Early-career scientists (ECSs) are a large part of the workforce in science. While they produce new scientific knowledge that they share in publications, they are rarely invited to participate in the peer-review process. Barriers to the participation of ECSs as peer reviewers include, among other things, their lack of visibility to editors, inexperience in the review process and lack of confidence in their scientific knowledge. Participation of ECSs in group reviews, e.g. for regional or global assessment reports, provides an opportunity for ECSs to advance their skill set and to contribute to policy-relevant products. Here, we present the outcomes of a group peer review of the First Order Draft of the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC). Overall, PhD students spent more time on the review than those further advanced in their careers and provided a similar proportion of substantive comments. After the review, participants reported feeling more confident in their skills, and 86 % were interested in reviewing individually. By soliciting and including ECSs in the peer-review process, the scientific community would not only reduce the burden carried by more established scientists but also permit their successors to develop important professional skills relevant to advancing climate science and influencing policy.
    Type of Medium: Online Resource
    ISSN: 2569-7110
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2924602-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Intensive Care Medicine, Springer Science and Business Media LLC, Vol. 48, No. 12 ( 2022-12), p. 1736-1750
    Type of Medium: Online Resource
    ISSN: 0342-4642 , 1432-1238
    RVK:
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 1459201-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    In: Intensive Care Medicine, Springer Science and Business Media LLC, Vol. 49, No. 3 ( 2023-03), p. 381-383
    Type of Medium: Online Resource
    ISSN: 0342-4642 , 1432-1238
    RVK:
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2023
    detail.hit.zdb_id: 1459201-0
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    In: International Journal of Epidemiology, Oxford University Press (OUP), Vol. 52, No. 2 ( 2023-04-19), p. 355-376
    Abstract: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death.
    Type of Medium: Online Resource
    ISSN: 0300-5771 , 1464-3685
    RVK:
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2023
    detail.hit.zdb_id: 1494592-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    In: Biogeosciences, Copernicus GmbH, Vol. 15, No. 8 ( 2018-04-23), p. 2449-2465
    Abstract: Abstract. We present seawater concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) measured across a transect from the Labrador Sea to the Canadian Arctic Archipelago during summer 2015. Using an automated ship-board gas chromatography system and a membrane-inlet mass spectrometer, we measured a wide range of DMS (∼ 1 to 18 nM) and DMSP (∼ 1 to 150 nM) concentrations. The highest DMS and DMSP concentrations occurred in a localized region of Baffin Bay, where surface waters were characterized by high chlorophyll a (chl a) fluorescence, indicative of elevated phytoplankton biomass. Across the full sampling transect, there were only weak relationships between DMS(P), chl a fluorescence and other measured variables, including positive relationships between DMSP : chl a ratios and several taxonomic marker pigments, and elevated DMS(P) concentrations in partially ice-covered areas. Our high spatial resolution measurements allowed us to examine DMS variability over small scales (〈 1 km), documenting strong DMS concentration gradients across surface hydrographic frontal features. Our new observations fill in an important observational gap in the Arctic Ocean and provide additional information on sea–air DMS fluxes from this ocean region. In addition, this study constitutes a significant contribution to the existing Arctic DMS(P) dataset and provides a baseline for future measurements in the region.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2018
    detail.hit.zdb_id: 2158181-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...