391 research outputs found
Soil nitrogen affects phosphorus recycling: foliar resorption and plant–soil feedbacks in a northern hardwood forest
Previous studies have attempted to link foliar resorption of nitrogen and phosphorus to their respective availabilities in soil, with mixed results. Based on resource optimization theory, we hypothesized that the foliar resorption of one element could be driven by the availability of another element. We tested various measures of soil N and P as predictors of N and P resorption in six tree species in 18 plots across six stands at the Bartlett Experimental Forest, New Hampshire, USA. Phosphorus resorption efficiency (P , 0.01) and proficiency (P ¼ 0.01) increased with soil N content to 30 cm depth, suggesting that trees conserve P based on the availability of soil N. Phosphorus resorption also increased with soil P content, which is difficult to explain based on single-element limitation, but follows from the correlation between soil N and soil P. The expected single-element relationships were evident only in the O horizon: P resorption was high where resin-available P was low in the Oe (P , 0.01 for efficiency, P , 0.001 for proficiency) and N resorption was high where potential N mineralization in the Oa was low (P , 0.01 for efficiency and 0.11 for proficiency). Since leaf litter is a principal source of N and P to the O horizon, low nutrient availability there could be a result rather than a cause of high resorption. The striking effect of soil N content on foliar P resorption is the first evidence of multiple-element control on nutrient resorption to be reported from an unmanipulated ecosystem
Comment Letter to the U.S. Treasury Department Concerning the Regulatory Structure for Financial Institutions
This comment letter was submitted to the U.S. Treasury Department in connection with that Department\u27s review of proposals for changes in the regulatory structure for financial institutions. The comment letter presents the following policy recommendations: (1) the thrift charter should be eliminated, existing thrifts should be required to convert into banks, and the Office of Thrift Supervision should be merged with the Office of the Comptroller of the Currency (OCC); (2) the dual banking system should be preserved and strengthened in order to promote innovation in banking regulation and to support the community bank sector; (3) at least one federal agency that is separate and independent from the OCC should be designated as the primary federal regulator for state-chartered banks; (4) the existing statutory limits on bank mergers and acquisitions should be maintained, including the 10% nationwide deposit cap and the 30% statewide deposit cap; (5) greater scrutiny and special conditions should be required for large bank mergers; (6) Congress should establish federal consumer protection standards for all home mortgage lenders, credit card lenders, and other providers of consumer credit; (7) Congress should prohibit the OCC from issuing regulations that preempt state law, except in specific areas where Congress has given the OCC explicit authority to adopt preemptive rules; (8) Congress should establish a separate and independent federal authority to enforce federal consumer protection laws against all providers of financial services, including national banks; (9) Congress should recognize the authority of state attorneys general to enforce applicable state laws against all financial service providers, including national banks, (10) Congress should provide the Federal Reserve Board (FRB) with direct oversight over all significant financial conglomerates that control FDIC-insured banks; (11) Congress should prohibit the FDIC\u27s deposit insurance fund from making any payments to uninsured depositors or other uninsured claimants; and (12) all responsibility for protecting uninsured creditors of too big to fail (TBTF) financial institutions should be assigned to the FRB, and the FRB should impose assessments on significant financial conglomerates to recover the FRB\u27s cost of providing financial assistance to TBTF institutions
Reliability of Automated Biochemical Identification of Burkholderia pseudomallei Is Regionally Dependent
Misidentifications of Burkholderia pseudomallei as Burkholderia cepacia by Vitek 2 have occurred. Multidimensional scaling ordination of biochemical profiles of 217 Malaysian and Australian B. pseudomallei isolates found clustering of misidentified B. pseudomallei isolates from Malaysian Borneo. Specificity of B. pseudomallei identification in Vitek 2 and potentially other automated identification systems is regionally dependent
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The Cloud Feedback Model Intercomparison Project (CFMIP) contribution to CMIP6
The primary objective of CFMIP is to inform future assessments of cloud feedbacks through improved understanding of cloud-climate feedback mechanisms and better evaluation of cloud processes and cloud feedbacks in climate models. However, the CFMIP approach is also increasingly being used to understand other aspects of climate change, and so a second objective has now been introduced, to improve understanding of circulation, regional-scale precipitation, and non-linear changes. CFMIP is supporting ongoing model inter-comparison activities by coordinating a hierarchy of targeted experiments for CMIP6, along with a set of cloud-related output diagnostics. CFMIP contributes primarily to addressing the CMIP6 questions "How does the Earth system respond to forcing?" and "What are the origins and consequences of systematic model biases?" and supports the activities of the WCRP Grand Challenge on Clouds, Circulation and Climate Sensitivity. A compact set of Tier 1 experiments is proposed for CMIP6 to address this question: (1) what are the physical mechanisms underlying the range of cloud feedbacks and cloud adjustments predicted by climate models, and which models have the most credible cloud feedbacks? Additional Tier 2 experiments are proposed to address the following questions. (2) Are cloud feedbacks consistent for climate cooling and warming, and if not, why? (3) How do cloudradiative effects impact the structure, the strength and the variability of the general atmospheric circulation in present and future climates? (4) How do responses in the climate system due to changes in solar forcing differ from changes due to CO2, and is the response sensitive to the sign of the forcing? (5) To what extent is regional climate change per CO2 doubling state-dependent (non-linear), and why? (6) Are climate feedbacks during the 20th century different to those acting on long-term climate change and climate sensitivity? (7) How do regional climate responses (e.g. in precipitation) and their uncertainties in coupled models arise from the combination of different aspects of CO2 forcing and sea surface warming? CFMIP also proposes a number of additional model outputs in the CMIP DECK, CMIP6 Historical and CMIP6 CFMIP experiments, including COSP simulator outputs and process diagnostics to address the following questions. 1. How well do clouds and other relevant variables simulated by models agree with observations? 2. What physical processes and mechanisms are important for a credible simulation of clouds, cloud feedbacks and cloud adjustments in climate models? 3. Which models have the most credible representations of processes relevant to the simulation of clouds? 4. How do clouds and their changes interact with other elements of the climate system
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