Assessment of intrinsic bioremediation of a coal-tar-affected aquifer using Two-dimensional reactive transport and Biogeochemical mass balance approaches.

Expedited site characterization and groundwater monitoring using direct-push technology and conventional monitoring wells were conducted at a former manufactured gas plant site. Biogeochemical data and heterotrophic plate counts support the presence of microbially mediated remediation. By superimposing solutions of a two-dimensional reactive transport analytical model, first-order degradation rate coefficients ((day-1) ) of various compounds for the dissolved-phase plume were estimated (i.e., benzene [0.0084], naphthalene [0.0058], and acenaphthene [0.0011]). The total mass transformed by aerobic respiration, nitrate reduction, and sulfate reduction around the free-phase coal-tar dense-nonaqueous-phase-liquid region and in the plume was estimated to be approximately 4.5 kg/y using a biogeochemical mass-balance approach. The total mass transformed using the degradation rate coefficients was estimated to be approximately 3.6 kg/y. Results showed that a simple two-dimensional analytical model and a biochemical mass balance with geochemical data from expedited site characterization can be useful for rapid estimation of mass-transformation rates.     

A Large-Eddy Simulation Study of the Convective Boundary Layer over Philadelphia during the 1999 Summer NE-OPS Campaign

This study presents a large-eddy simulation (LES) study of the convective boundary layer on August 1, 1999 over Philadelphia, PA during a summer ozone episode. The study is an evaluation of the Colorado State University's Regional Atmospheric Modeling System Version 4.3 (RAMS4.3) with the LES option using Northeast Oxidant and Particulate Study (NE-OPS) data. Simulations were performed with different imposed sensible heat fluxes at the ground surface. The model was initialized with the atmospheric sounding data collected at Philadelphia at 1230 UTC and model integrations continued till 2130 UTC. The resulting mean profiles of temperature and humidity obtained from the LES model were compared with atmospheric soundings, tethered balloon and aircraft data collected during the NE-OPS 1999 field campaign. Also the model-derived vertical profiles of virtual temperature were compared with NE-OPS Radio Acoustic Sounder System (RASS) data while the humidity profiles were compared with NE-OPS lidar data. The comparison of the radiosonde data with the LES model predictions suggests that the growth of the mixing layer is reasonably well simulated by the model. Overall, the agreement of temperature predictions of the LES model with the radiosonde observations is good. The model appears to underestimate humidity values for the case of higher imposed sensible heat flux. However, the humidity values in the mixing layer agree quite well with radiosonde observations for the case of lower imposed sensible heat flux. The model-predicted temperature and humidity profiles are in reasonable agreement with the tethered balloon data except for some small overestimation of temperature at lower layers and some underestimation of humidity values. However, the humidity profiles as simulated by the model agree quite well with the tethered balloon data for the case of lower imposed sensible heat flux. The model-predicted virtual temperature profile is also in better agreement with RASS data for the case of lower imposed sensible heat flux. The model-predicted temperature profile further agrees quite well with aircraft data for the case of lower imposed heat flux. However, the relative humidity values predicted by the model are lower compared with the aircraft data. The model-predicted humidity profiles are only in partial agreement with the lidar data. The results of this study suggest that the explicitly resolved energetic eddies seem to provide the correct forcing necessary to produce good agreement with observations for the case of an imposed sensible heat flux of 0.1 K m s^–1 at the surface.     

Climate change effects on pesticide usage reduction efforts: a case study in China

China has announced plans to stabilize its pesticide use by 2020. Yet, future climate change will possibly increase the difficulty of meeting this goal. This study uses econometric estimation to explore how climate impacts Chinese pesticide usage and subsequently to project the future implications of climate change on pesticide use. The results indicate that both atmospheric temperature and precipitation increase pesticide usage. Under current climate change projections, pesticide usage will rise by +1.1 to 2.5% by 2040, +2.4 to 9.1% by 2070, and +2.6 to 18.3% by 2100. Linearly extrapolating the results to 2020 yields an approximately 0.5 to 1.2% increase. Thus, to achieve stabilization, more severe actions are needed to address this increase. Possible actions to achieve the reductions needed include using better monitoring and early warning networks so as to permit early responses to climate change-stimulated increases, enhancing information dissemination, altering crop mix, and promoting nonchemical control means. Additionally, given that increased pesticide usage generally increases health and environmental damage, there may be a need to more widely disseminate safe application procedure information while also strengthening compliance with food safety regulations. Furthermore, pest control strategies will need to be capable of evolving as climate change proceeds. Globally, efforts could be made to (1) scale up agrometeorological services, especially in developing countries; (2) use international frameworks to better align the environmental and health standards in developing countries with those in developed countries; and (3) adapt integrated pest management practices to climate change, especially for fruits and vegetables.     

Spondyloarthropathy in vertebrae of the aquatic Cretaceous snake <Emphasis Type="Italic">Lunaophis aquaticus</Emphasis>, and its first recognition in modern snakes

Inflammatory arthritis is documented for the first time in snakes. Ossification of the intervertebral capsule and zygapophyseal joints resulting in segmental vertebral fusion was observed in the aquatic Cretaceous snake Lunaophis aquaticus. Such pathologic alterations are pathognomonic for the spondyloarthropathy form of inflammatory arthritis. A survey of 2144 snakes in recent collections, performed to identify Holocene prevalence, revealed only two occurrences in extant snakes. The findings in Bitis gabonica and Elaphe taeniura were indistinguishable from those noted in Lunaophis aquaticus and identical to those previously recognized in modern varanids. The pathology likely represents a form of reactive arthritis related to enteropathic infection. While the disease probably did not affect general locomotion, its vertebral column position may have compromised mating.     

Environmental load of Cryptosporidium parvum oocysts from cattle manure in feedlots from the central and western United States

The first step in assessing the risk of water contamination by Cryptosporidium parvum oocysts from feedlot cattle (Bos taurus) production systems is to quantify the number of C. parvum oocysts present in the fecal material deposited by feedlot cattle. Our primary objective for this project was to estimate the daily environmental load of C. parvum oocysts in fecal material deposited by feedlot cattle from across the central and western USA. Our secondary goal was to genotype isolates of C. parvum from feedlot cattle to help facilitate proper identification of mammalian sources of waterborne C. parvum. Based on 5274 fecal samples from 22 feedlots in seven states (California, Washington, Colorado, Oklahoma, Texas, Nebraska, and South Dakota), we estimated a point prevalence of C. parvum of 0.99 to 1.08% in fecal material from feedlot pens from a wide range of climates and a diverse range of feedlot management systems. On average, fresh fecal material from throughout feedlot systems (recent arrivals to nearing slaughter) contained about 1.3 to 3.6 oocysts/g feces, which roughly translates to about 2.8 x 10(4) to 1.4 x 10(5) oocysts/animal per day.     

Compassionate versus consequentialist conservation

Ethical treatment of wildlife and consideration of animal welfare have become important themes in conservation, but ethical perspectives on how best to protect wild animals and promote their welfare are diverse. There are advantages to the consequentialist harms ethical framework applied in managing wild herbivores for conservation purposes. To minimize harms while achieving conservation goals, we argue that overabundant wild herbivores should in many cases be managed through consumptive in situ killing. Advantages of this policy are that the negative welfare states imposed on animals last only a short time; remaining animals are not deprived of positive welfare states (e.g., linked to rearing offspring); poor welfare states of animals in overabundant populations are avoided (e.g., starvation); negative welfare impacts on heterospecifics through resource depletion (i.e., competition) are prevented; harvesting meat reduces the number of (agricultural) animals raised to supply meat; and minimal costs maximize funding for other wildlife management and conservation priorities. Alternative ethical approaches to our consequentialist framework include deontology (containing animal rights) and virtue ethics, some of which underpin compassionate conservation. These alternative ethical approaches emphasize the importance of avoiding intentional killing of animals but, if no population reduction occurs, are likely to impose considerable unintentional harms on overabundant wildlife and indirectly harm heterospecifics through ineffective population reduction. If nonlethal control is used, it is likely that overabundant animals would be deprived of positive welfare states and economic costs would be prohibitive. We encourage conservation stakeholders to consider animal-welfare consequentialism as an ethical approach to minimize harms to the animals under their care as well as other animals that policies may affect while at the same time pursuing conservation goals.     

Quantifying structural physical habitat attributes using LIDAR and hyperspectral imagery

Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity, and riparian vegetation cover and structure. The Environmental Monitoring and Assessment Program (EMAP) is designed to assess the status and trends of ecological resources at different scales. High-resolution remote sensing provides unique capabilities in detecting a variety of features and indicators of environmental health and condition. LIDAR is an airborne scanning laser system that provides data on topography, channel dimensions (width, depth), slope, channel complexity (residual pools, volume, morphometric complexity, hydraulic roughness), riparian vegetation (height and density), dimensions of riparian zone, anthropogenic alterations and disturbances, and channel and riparian interaction. Hyperspectral aerial imagery offers the advantage of high spectral and spatial resolution allowing for the detection and identification of riparian vegetation and natural and anthropogenic features at a resolution not possible with satellite imagery. When combined, or fused, these technologies comprise a powerful geospatial data set for assessing and monitoring lentic and lotic environmental characteristics and condition.