33 research outputs found

    Institutional and policy analysis of river basin management: the Murray Darling River Basin, Austrialia

    Get PDF
    The authors describe and analyze management in the Murray-Darling basin of Australia, long regarded as a model for integrated river basin management. This interior basin of over 1 million km2 in semi-arid southeastern Australia is defined by the catchment areas of the Murray and Darling Rivers and their tributaries. Water management issues include allocation, quality, and dryland salinity. Because of Australia's federal governmental structure, institutional development has been more a matter of integrating state and local endeavors than decentralization of national authority. The Australian national government has little constitutional power over water resources. The five states in the basin make policy regarding water rights, discharge permits, fees, and the construction and operation of physical structures. River management began on the Murray River in the 1920s under the terms of a tri-state agreement. As the scope of management widened to the entire basin, more states were added and the national government supported the creation of new arrangements for integrated water resource management, with some provision for stakeholder participation. The dynamics of state-national authority over water policy, and the emergence in recent years of numerous local-level catchment organization, contribute to some uncertainty about the future course of basin management in this internationally renowned site.Water and Industry,Water Conservation,Water Resources Law,Environmental Economics&Policies,Water Supply and Systems,Town Water Supply and Sanitation,Drought Management,Water and Industry,Water Conservation,Water Supply and Sanitation Governance and Institutions

    Consumer\u27s Guide to Regulatory Impact Analysis: Ten Tips for Being an Informed Policymaker

    Get PDF
    Regulatory impact analyses (RIAs) weigh the benefits of regulations against the burdens they impose and are invaluable tools for informing decision makers.We offer 10 tips for nonspecialist policymakers and interested stakeholders who will be reading RIAs as consumers. Core problem: Determine whether the RIA identifies the core problem (compelling public need) the regulation is intended to address. Alternatives: Look for an objective, policy-neutral evaluation of the relative merits of reasonable alternatives. Baseline: Check whether the RIA presents a reasonable “counterfactual” against which benefits and costs are measured. Increments: Evaluate whether totals and averages obscure relevant distinctions and trade-offs. Uncertainty: Recognize that all estimates involve uncertainty, and ask what effect key assumptions, data, and models have on those estimates. Transparency: Look for transparency and objectivity of analytical inputs. Benefits: Examine how projected benefits relate to stated objectives. Costs: Understand what costs are included. Distribution: Consider how benefits and costs are distributed. Symmetrical treatment: Ensure that benefits and costs are presented symmetrically

    Effects of Timber Harvest on Amphibian Populations: Understanding Mechanisms from Forest Experiments

    Get PDF
    Accompanying appendix may be accessed at: http://hdl.handle.net/10355/1365Harvesting timber is a common form of land use that has the potential to cause declines in amphibian populations. It is essential to understand the behavior and fate of individuals and the resulting consequences for vital rates (birth, death, immigration, emigration) under different forest management conditions.We report on experimental studies conducted in three regions of the United States to identify mechanisms of responses by pond-breeding amphibians to timber harvest treatments. Our studies demonstrate that life stages related to oviposition and larval performance in the aquatic stage are sometimes affected positively by clearcutting, whereas effects on juvenile and adult terrestrial stages are mostly negative

    Pacific Atmospheric Sulfur Experiment (PASE): dynamics and chemistry of the south Pacific tropical trade wind regime

    Get PDF
    The Pacific Atmospheric Sulfur Experiment (PASE) was a comprehensive airborne study of the chemistry and dynamics of the tropical trade wind regime (TWR) east of the island of Kiritibati (Christmas Island, 157Âș, 20â€Č W, 2Âș 52â€Č N). Christmas Island is located due south of Hawaii. Geographically it is in the northern hemisphere yet it is 6–12Âș south of the intertropical convergence zone (ITCZ) which places it in the southern hemisphere meteorologically. Christmas Island trade winds in August and September are from east south east at 3–15 ms−1. Clouds, if present, are fair weather cumulus located in the middle layer of the TWR which is frequently labeled the buffer layer (BuL). PASE provided clear support for the idea that small particles (80 nm) were subsiding into the tropical trade wind regime (TWR) where sulfur chemistry transformed them to larger particles. Sulfur chemistry promoted the growth of some of these particles until they were large enough to activate to cloud drops. This process, promoted by sulfur chemistry, can produce a cooling effect due to the increase in cloud droplet density and changes in cloud droplet size. These increases in particle size observed in PASE promote additional cooling due to direct scattering from the aerosol. These potential impacts on the radiation balance in the TWR are enhanced by the high solar irradiance and ocean albedo of the TWR. Finally because of the large area involved there is a large factional impact on earth’s radiation budget. The TWR region near Christmas Island appears to be similar to the TWR that persists in August and September, from southwest of the Galapagos to at least Christmas Island. Transport in the TWR between the Galapagos and Christmas involves very little precipitation which could have removed the aerosol thus explaining at least in part the high concentrations of CCN (≈300 at 0.5% supersaturation) observed in PASE. As expected the chemistry of sulfur in the trade winds was found to be initiated by the emission of DMS into the convective boundary layer (BL, the lowest of three layers). However, the efficiency with which this DMS is converted to SO2 has been brought into further question by this study. This unusual result has come about as result of our using two totally different approaches for addressing this long standing question. In the first approach, based on accepted kinetic rate constants and detailed steps for the oxidation of DMS reflecting detailed laboratory studies, a DMS to SO2 conversion efficiency of 60–73% was determined. This range of values lies well within the uncertainties of previous studies. However, using a completely different approach, involving a budget analysis, a conversion value of 100% was estimated. The latter value, to be consistent with all other sulfur studies, requires the existence of a completely independent sulfur source which would emit into the atmosphere at a source strength approximately half that measured for DMS under tropical Pacific conditions. At this time, however, there is no credible scientific observation that identifies what this source might be. Thus, the current study has opened for future scientific investigation the major question: is there yet another major tropical marine source of sulfur? Of equal importance, then, is the related question, is our global sulfur budget significantly in error due to the existence of an unknown marine source of sulfur? Pivotal to both questions may be gaining greater insight about the intermediate DMS oxidation species, DMSO, for which rather unusual measurements have been reported in previous marine sulfur studies. The 3 pptv bromine deficit observed in PASE must be lost over the lifetime of the aerosol which is a few days. This observation suggests that the primary BrO production rate is very small. However, considering the uncertainties in these observations and the possible importance of secondary production of bromine radicals through aerosol surface reactions, to completely rule out the importance of bromine chemistry under tropical conditions at this time cannot be justified. This point has been brought into focus from prior work that even at levels of 1 pptv, the effect of BrO oxidation on DMS can still be quite significant. Thus, as in the case of DMS conversion to SO2, future studies will be needed. In the latter case there will need to be a specific focus on halogen chemistry. Such studies clearly must involve specific measurements of radical species such as BrO

    Case fatality risk of the SARS-CoV-2 variant of concern B.1.1.7 in England, 16 November to 5 February.

    Get PDF
    The SARS-CoV-2 B.1.1.7 variant of concern (VOC) is increasing in prevalence across Europe. Accurate estimation of disease severity associated with this VOC is critical for pandemic planning. We found increased risk of death for VOC compared with non-VOC cases in England (hazard ratio: 1.67; 95% confidence interval: 1.34-2.09; p < 0.0001). Absolute risk of death by 28 days increased with age and comorbidities. This VOC has potential to spread faster with higher mortality than the pandemic to date

    Cross-Cancer Genome-Wide Analysis of Lung, Ovary, Breast, Prostate, and Colorectal Cancer Reveals Novel Pleiotropic Associations

    Get PDF
    Identifying genetic variants with pleiotropic associations can uncover common pathways influencing multiple cancers. We took a two-stage approach to conduct genome-wide association studies for lung, ovary, breast, prostate, and colorectal cancer from the GAME-ON/GECCO Network (61,851 cases, 61,820 controls) to identify pleiotropic loci. Findings were replicated in independent association studies (55,789 cases, 330,490 controls). We identified a novel pleiotropic association at 1q22 involving breast and lung squamous cell carcinoma, with eQTL analysis showing an association with ADAM15/THBS3 gene expression in lung. We also identified a known breast cancer locus CASP8/ALS2CR12 associated with prostate cancer, a known cancer locus at CDKN2B-AS1 with different variants associated with lung adenocarcinoma and prostate cancer, and confirmed the associations of a breast BRCA2 locus with lung and serous ovarian cancer. This is the largest study to date examining pleiotropy across multiple cancer-associated loci, identifying common mechanisms of cancer development and progression. Cancer Res; 76(17); 5103-14. ©2016 AACR

    Global Synthesis of Air-Sea CO2 Transfer Velocity Estimates From Ship-Based Eddy Covariance Measurements

    Get PDF
    The air-sea gas transfer velocity (K-660) is typically assessed as a function of the 10-m neutral wind speed (U-10n), but there remains substantial uncertainty in this relationship. Here K-660 of CO2 derived with the eddy covariance (EC) technique from eight datasets (11 research cruises) are reevaluated with consistent consideration of solubility and Schmidt number and inclusion of the ocean cool skin effect. K-660 shows an approximately linear dependence with the friction velocity (u*) in moderate winds, with an overall relative standard deviation (relative standard error) of about 20% (7%). The largest relative uncertainty in K-660 occurs at low wind speeds, while the largest absolute uncertainty in K-660 occurs at high wind speeds. There is an apparent regional variation in the steepness of the K-660-u* relationships: North Atlantic >= Southern Ocean > other regions (Arctic, Tropics). Accounting for sea state helps to collapse some of this regional variability in K-660 using the wave Reynolds number in very large seas and the mean squared slope of the waves in small to moderate seas. The grand average of EC-derived K-660 ( - 1.47 + 76.67 u * + 20.48 u *(2) o r 0.36 + 1.203 U-10n + 0.167 U (2)(10n) ) is similar at moderate to high winds to widely used dual tracer-based K-660 parametrization, but consistently exceeds the dual tracer estimate in low winds, possibly in part due to the chemical enhancement in air-sea CO2 exchange. Combining the grand average of EC-derived K-660 with the global distribution of wind speed yields a global average transfer velocity that is comparable with the global radiocarbon (C-14) disequilibrium, but is similar to 20% higher than what is implied by dual tracer parametrizations. This analysis suggests that CO2 fluxes computed using a U-10n (2) dependence with zero intercept (e.g., dual tracer) are likely underestimated at relatively low wind speeds
    corecore