7 research outputs found

    Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2.

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    Future climate change and increasing atmospheric CO2 are expected to cause major changes in vegetation structure and function over large fractions of the global land surface. Seven global vegetation models are used to analyze possible responses to future climate simulated by a range of general circulation models run under all four representative concentration pathway scenarios of changing concentrations of greenhouse gases. All 110 simulations predict an increase in global vegetation carbon to 2100, but with substantial variation between vegetation models. For example, at 4 °C of global land surface warming (510-758 ppm of CO2), vegetation carbon increases by 52-477 Pg C (224 Pg C mean), mainly due to CO2 fertilization of photosynthesis. Simulations agree on large regional increases across much of the boreal forest, western Amazonia, central Africa, western China, and southeast Asia, with reductions across southwestern North America, central South America, southern Mediterranean areas, southwestern Africa, and southwestern Australia. Four vegetation models display discontinuities across 4 °C of warming, indicating global thresholds in the balance of positive and negative influences on productivity and biomass. In contrast to previous global vegetation model studies, we emphasize the importance of uncertainties in projected changes in carbon residence times. We find, when all seven models are considered for one representative concentration pathway × general circulation model combination, such uncertainties explain 30% more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151% for non-HYBRID4 models. A change in research priorities away from production and toward structural dynamics and demographic processes is recommended.The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7 2007-2013) under Grant 238366. R.B., R.K., R.D., A.W., and P.D.F. were supported by the Joint Department of Energy and Climate Change/Department for Environment, Food and Rural Affairs Met Office Hadley Centre Climate Programme (GA01101). A.I. and K.N. were supported by the Environment Research and Technology Development Fund (S-10) of the Ministry of the Environment, Japan. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for the Coupled Model Intercomparison Project (CMIP), and we thank the climate modeling groups responsible for the GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM, and NorESM1-M models for producing and making available their model output. For CMIP, the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. This work has been conducted under the framework of the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The ISI-MIP Fast Track project was funded by the German Federal Ministry of Education and Research (BMBF) with project funding Reference 01LS1201A.This is the author accepted manuscript. The final version is available from PNAS via http://dx.doi.org/10.1073/pnas.122247711

    Mysid crustaceans as standard models for the screening and testing of endocrine-disrupting chemicals

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    Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Ecotoxicology 16 (2007): 205-219, doi:10.1007/s10646-006-0122-0.Investigative efforts into the potential endocrine-disrupting effects of chemicals have mainly concentrated on vertebrates, with significantly less attention paid to understanding potential endocrine disruption in the invertebrates. Given that invertebrates account for at least 95% of all known animal species and are critical to ecosystem structure and function, it remains essential to close this gap in knowledge and research. The lack of progress regarding endocrine disruption in invertebrates is still largely due to: (1) our ignorance of mode-of-action, physiological control, and hormone structure and function in invertebrates; (2) lack of a standardized invertebrate assay; (3) the irrelevance to most invertebrates of the proposed activity-based biological indicators for endocrine disruptor exposure (androgen, estrogen and thyroid); (4) limited field studies. Past and ongoing research efforts using the standard invertebrate toxicity test model, the mysid shrimp, have aimed at addressing some of these issues. The present review serves as an update to a previous publication on the use of mysid shrimp for the evaluation of endocrine disruptors (Verslycke et al., 2004a). It summarizes recent investigative efforts that have significantly advanced our understanding of invertebrate-specific endocrine toxicity, population modeling, field studies, and transgeneration standard test development using the mysid model.Supported by a Fellowship of the Belgian American Educational Foundation

    Management of Concomitant Inflammatory Bowel Disease or Uveitis in Patients with Psoriatic Arthritis: An Updated Review Informing the 2021 GRAPPA Treatment Recommendations.

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    OBJECTIVE: Several advanced therapies have been licensed across the related conditions of psoriatic arthritis (PsA), Crohn disease (CD), ulcerative colitis (UC), and noninfectious uveitis. We sought to summarize results from randomized controlled trials (RCTs) investigating the efficacy and safety of advanced therapies for these related conditions in patients with PsA. METHODS: We updated the previous systematic search conducted in 2013 with literature reviews of MEDLINE, Embase, and the Cochrane Library (from February 2013 to August 2020) on this subject; only those new studies are presented here. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. RESULTS: The number of RCTs meeting eligibility criteria were 12 for CD, 15 for UC, and 5 for uveitis. The tumor necrosis factor inhibitor (TNFi) class appears to be efficacious and safe across CD, UC, and uveitis, with the exception of etanercept. Interleukin 12/23 inhibitors (IL-12/23i) are efficacious for CD and UC. Phase II and III RCTs of Janus kinase inhibitors (JAKi) and IL-23i in CD and UC are promising in terms of efficacy and safety. IL-17i must be used with great caution in patients with PsA at high risk of inflammatory bowel disease (IBD). RCTs in uveitis have mainly studied adalimumab. CONCLUSION: We have identified 32 recent RCTs in IBD and uveitis and updated recommendations for managing patients with PsA and these related conditions. A multispecialty approach is essential to effectively, safely, and holistically manage such patients. Advanced therapies are not equally efficacious across these related conditions, with dosing regimens and safety varying

    Management of Concomitant Inflammatory Bowel Disease or Uveitis in Patients with Psoriatic Arthritis: An Updated Review Informing the 2021 GRAPPA Treatment Recommendations

    Get PDF
    Objective: Several advanced therapies have been licensed across the related conditions of psoriatic arthritis (PsA), Crohn disease (CD), ulcerative colitis (UC), and noninfectious uveitis. We sought to summarize results from randomized controlled trials (RCTs) investigating the efficacy and safety of advanced therapies for these related conditions in patients with PsA. Methods: We updated the previous systematic search conducted in 2013 with literature reviews of MEDLINE, Embase, and the Cochrane Library (from February 2013 to August 2020) on this subject; only those new studies are presented here. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Results: The number of RCTs meeting eligibility criteria were 12 for CD, 15 for UC, and 5 for uveitis. The tumor necrosis factor inhibitor (TNFi) class appears to be efficacious and safe across CD, UC, and uveitis, with the exception of etanercept. Interleukin 12/23 inhibitors (IL-12/23i) are efficacious for CD and UC. Phase II and III RCTs of Janus kinase inhibitors (JAKi) and IL-23i in CD and UC are promising in terms of efficacy and safety. IL-17i must be used with great caution in patients with PsA at high risk of inflammatory bowel disease (IBD). RCTs in uveitis have mainly studied adalimumab. Conclusion: We have identified 32 recent RCTs in IBD and uveitis and updated recommendations for managing patients with PsA and these related conditions. A multispecialty approach is essential to effectively, safely, and holistically manage such patients. Advanced therapies are not equally efficacious across these related conditions, with dosing regimens and safety varying
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