18 research outputs found

    Unexpected large evasion fluxes of carbon dioxide from turbulent streams draining the world’s mountains

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    Inland waters, including streams and rivers, are active components of the global carbon cycle. Despite the large areal extent of the world’s mountains, the role of mountain streams for global carbon fluxes remains elusive. Using recent insights from gas exchange in turbulent streams, we found that areal CO2 evasion fluxes from mountain streams equal or exceed those reported from tropical and boreal streams, typically regarded as hotspots of aquatic carbon fluxes. At the regional scale of the Swiss Alps, we present evidence that emitted CO2 derives from lithogenic and biogenic sources within the catchment and delivered by the groundwater to the streams. At a global scale, we estimate the CO2 evasion from mountain streams to 167 ± 1.5 Tg C yr−1, which is high given their relatively low areal contribution to the global stream and river networks. Our findings shed new light on mountain streams for global carbon fluxes

    Persistent nitrogen limitation of stream biofilm communities along climate gradients in the Arctic

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    Climate change is rapidly reshaping Arctic landscapes through shifts in vegetation cover and productivity, soil resource mobilization, and hydrological regimes. The implications of these changes for stream ecosystems and food webs is unclear and will depend largely on microbial biofilm responses to concurrent shifts in temperature, light, and resource supply from land. To study those responses, we used nutrient diffusing substrates to manipulate resource supply to biofilm communities along regional gradients in stream temperature, riparian shading, and dissolved organic carbon (DOC) loading in Arctic Sweden. We found strong nitrogen (N) limitation across this gradient for gross primary production, community respiration and chlorophyll-a accumulation. For unamended biofilms, activity and biomass accrual were not closely related to any single physical or chemical driver across this region. However, the magnitude of biofilm response to N addition was: in tundra streams, biofilm response was constrained by thermal regimes, whereas variation in light availability regulated this response in birch and coniferous forest streams. Furthermore, heterotrophic responses to experimental N addition increased across the region with greater stream water concentrations of DOC relative to inorganic N. Thus, future shifts in resource supply to these ecosystems are likely to interact with other concurrent environmental changes to regulate stream productivity. Indeed, our results suggest that in the absence of increased nutrient inputs, Arctic streams will be less sensitive to future changes in other habitat variables such as temperature and DOC loading

    SYNOVIAL MAST CELLS CORRELATE WITH LOCAL AND SYSTEMIC INFLAMMATION AND ARE FUNCTIONALLY ASSOCIATED WITH ECTOPIC LYMPHOID STRUCTURES IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS

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    Meeting AbstractThe research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007–2013) under REA grant agreement n° 60876

    SYNOVIAL MAST CELLS CORRELATE WITH LOCAL AND SYSTEMIC INFLAMMATION AND ARE FUNCTIONALLY ASSOCIATED WITH ECTOPIC LYMPHOID STRUCTURES IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS

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    Meeting AbstractThe research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007–2013) under REA grant agreement n° 60876

    Olaparib and durvalumab in patients with relapsed small cell lung cancer (MEDIOLA): An open-label, multicenter, phase 1/2, basket study

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    Introduction: Preclinical studies have demonstrated increased efficacy with combined DNA damage response inhibition and immune checkpoint blockade compared with either alone. We assessed olaparib in combination with durvalumab in patients with relapsed small cell lung cancer (SCLC). Methods: Patients with previously treated limited or extensive-stage SCLC received oral olaparib 300 mg twice daily, as run-in for 4 weeks, then with durvalumab (1500 mg intravenously every 4 weeks) until disease progression. Primary endpoints were safety, tolerability, and 12-week disease control rate (DCR). Secondary endpoints included 28-week DCR, objective response rate (ORR), duration of response, progression-free survival, overall survival, change in tumor size, and programmed death-ligand 1 (PD-L1) expression subgroup analyses. Results: Forty patients were enrolled and analyzed for safety; 38 were analyzed for efficacy. Eleven patients (28.9% [90% confidence interval (CI), 17.2–43.3]) had disease control at 12 weeks. ORR was 10.5% (95% CI, 2.9–24.8). Median progression-free and overall survival were 2.4 (95% CI, 0.9–3.0) months and 7.6 (95% CI, 5.6–8.8) months, respectively. The most common adverse events (≥40.0%) were anemia, nausea, and fatigue. Grade ≥ 3 adverse events occurred in 32 patients (80.0%). PD-L1 levels, tumor mutational burden, and other genetic mutations were evaluated, but no significant correlations with clinical outcomes were observed. Conclusions: Tolerability of olaparib with durvalumab was consistent with the safety profile of each agent alone. Although the 12-week DCR did not meet the prespecified target (60%), four patients responded, and median overall survival was promising for a pretreated SCLC population. Further analyses are required to identify patients most likely to benefit from this treatment approach

    A global database of greenhouse gas fluxes from tropical inland waters

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    peer reviewedStrong consensus exists that inland waters emit globally significant quantities of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Tropical inland waters are often considered major contributors to these greenhouse gas fluxes, yet consistent and reliable estimates of aquatic greenhouse gas fluxes are lacking for the tropics. One of the limitations to obtaining a more accurate quantification of these fluxes is the lack of a curated and openly accessible data repository of greenhouse gas observations from across the tropics. To address this issue, we are developing the first comprehensive database of greenhouse gas concentrations and fluxes for tropical and subtropical inland waters (streams, rivers, lakes, reservoirs, wetlands). Our database includes over 15,000 records of gas concentration and flux measurements that were extracted from a total of 290 publications between 1975 and 2023. In this presentation we provide an overview of the database, summarise basic patterns of gas concentrations and fluxes across the region, and derive priority research areas for tropical inland water greenhouse gas research. We show that improved greenhouse gas emission estimates will require (1) addressing the observational gap in the mountainous and seasonal tropics, (2) developing approaches that cross boundaries between ecosystem types and scales, and (3) sharing and publishing data more systematically

    Olaparib and durvalumab in patients with germline BRCA-mutated metastatic breast cancer (MEDIOLA):an open-label, multicentre, phase 1/2, basket study

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    Background Poly (ADP-ribose) polymerase inhibitors combined with immunotherapy have shown antitumour activity in preclinical studies. We aimed to assess the safety and activity of olaparib in combination with the PD-L1-inhibitor, durvalumab, in patients with germline BRCA1-mutated or BRCA2-mutated metastatic breast cancer. Methods The MEDIOLA trial is a multicentre, open-label, phase 1/2, basket trial of durvalumab and olaparib in solid tumours. Patients were enrolled into four initial cohorts: germline BRCA-mutated, metastatic breast cancer; germline BRCA-mutated, metastatic ovarian cancer; metastatic gastric cancer; and relapsed small-cell lung cancer. Here, we report on the cohort of patients with breast cancer. Patients who were aged 18 years or older (or aged 19 years or older in South Korea) with germline BRCA1-mutated or BRCA2-mutated or both and histologically confirmed, progressive, HER2-negative, metastatic breast cancer were enrolled from 14 health centres in the UK, the USA, Israel, France, Switzerland, and South Korea. Patients should not have received more than two previous lines of chemotherapy for metastatic breast cancer. Patients received 300 mg olaparib in tablet form orally twice daily for 4 weeks and thereafter a combination of olaparib 300 mg twice daily and durvalumab 1.5 g via intravenous infusion every 4 weeks until disease progression. Primary endpoints were safety and tolerability, and 12-week disease control rate. Safety was analysed in patients who received at least one dose of study treatment, and activity analyses were done in the full-analysis set (patients who received at least one dose of study treatment and were not excluded from the study). Recruitment has completed and the study is ongoing. This trial is registered with ClinicalTrials.gov, NCT02734004. Findings Between June 14, 2016, and May 2, 2017, 34 patients were enrolled and received both study drugs and were included in the safety analysis. 11 (32%) patients experienced grade 3 or worse adverse events, of which the most common were anaemia (four [12%]), neutropenia (three [9%]), and pancreatitis (two [6%]). Three (9%) patients discontinued due to adverse events and four (12%) patients experienced a total of six serious adverse events. There were no treatment-related deaths. 24 (80%; 90% CI 64.3-90.9) of 30 patients eligible for activity analysis had disease control at 12 weeks. Interpretation Combination of olaparib and durvalumab showed promising antitumour activity and safety similar to that previously observed in olaparib and durvalumab monotherapy studies. Further research in a randomised setting is needed to determine predictors of therapeutic benefit and whether addition of durvalumab improves long-term clinical outcomes compared with olaparib monotherapy. Copyright (C) 2020 Elsevier Ltd. All rights reserved
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