377 research outputs found
Distribution and Efficiency of Hydrocarbon-Oxidizing Bacteria in a Freshwater Reservoir
Hydrocarbon-oxidizing bacteria were identified from three stations on DeGray Reservoir, Arkansas. The organisms were primarily gram-negative rods representing 9 taxa and 37 biotypes Pseudomonas spp. were the most common isolates. The largest populations were found in areas most frequently used by boaters, although seasonal fluctuations were apparent during the spring and fall. The degradation of outboard motor oil by the five most rapidly growing isolates was studied. Each species had a different decomposition profile, and substrate oxidation rates were variable Acinetobacter calcoaceticus var. anitratus was the most efficient decomposer
Social-Ecological Change, Resilience, and Adaptive Capacity in the McKenzie River Valley, Oregon
This study explores perceptions of long-term residents regarding links between governance, landscape, and community change in the McKenzie River Valley (MRV) in western Oregon and provides a general assessment of factors affecting resilience and adaptive capacity. Residents interviewed indicated that dramatic changes driven by market competition, timber industry changes, increased regulation, and rural restructuring have occurred in both the landscape and community. The changes that have transpired have redefined the relationship between the community and the landscape, moving away from local dependence on timber harvests to an economy focused on tourism and other ecosystem services. In doing so the community has transitioned from one with a logging community identity to one that has begrudgingly become a retirement and vacation community. We found that the social-ecological system (SES) in the MRV is still in the midst of reorganization in the wake of the 1990s Timber Wars. As a result of low institutional capacity, the system is vulnerable to exogenous drivers of change. Using a modified version of Ostrom’s (2009) framework for SES analysis, this study recommends policymakers and policy entrepreneurs take three key steps to facilitate enhanced resilience and adaptive capacity: 1) support transboundary management strategies that transcend landownership classifications; 2) tighten system feedbacks to include more local influence; and 3) develop local multilayered institutions organized vertically and horizontally. Future research should explore the potential for collaborative forestry and stewardship contracting to enhance social-ecological resilience in this valley
Oxidative stress, mitochondrial perturbations and fetal programming of renal disease induced by maternal smoking
© 2015 Elsevier Ltd. An adverse in-utero environment is increasingly recognized to predispose to chronic disease in adulthood. Maternal smoking remains the most common modifiable adverse in-utero exposure leading to low birth weight, which is strongly associated with chronic kidney disease (CKD) in later life. In order to investigate underlying mechanisms for such susceptibility, female Balb/c mice were sham or cigarette smoke-exposed (SE) for 6 weeks before mating, throughout gestation and lactation. Offspring kidneys were examined for oxidative stress, expression of mitochondrial proteins, mitochondrial structure as well as renal functional parameters on postnatal day 1, day 20 (weaning) and week 13 (adult age). From birth throughout adulthood, SE offspring had increased renal levels of mitochondrial-derived reactive oxygen species (ROS), which left a footprint on DNA with increased 8-hydroxydeoxyguanosin (8-OHdG) in kidney tubular cells. Mitochondrial structural abnormalities were seen in SE kidneys at day 1 and week 13 along with a reduction in oxidative phosphorylation (OXPHOS) proteins and activity of mitochondrial antioxidant Manganese superoxide dismutase (MnSOD). Smoke exposure also resulted in increased mitochondrial DNA copy number (day 1-week 13) and lysosome density (day 1 and week 13). The appearance of mitochondrial defects preceded the onset of albuminuria at week 13. Thus, mitochondrial damage caused by maternal smoking may play an important role in development of CKD at adult life
L-carnitine reverses maternal cigarette smoke exposure-induced renal oxidative stress and mitochondrial dysfunction in mouse offspring
© 2015 the American Physiological Society. Maternal smoking is associated with metabolic disorders, renal underdevelopment, and a predisposition to chronic kidney disease in offspring, yet the underlying mechanisms are unclear. By exposing female Balb/c mice to cigarette smoke for 6 wk premating and during gestation and lactation, we showed that maternal smoke exposure induced glucose intolerance, renal underdevelopment, inflammation, and albuminuria in male offspring. This was associated with increased renal oxidative stress and mitochondrial dysfunction at birth and in adulthood. Importantly, we demonstrated that dietary supplementation of L-carnitine, an amino acid shown to increase antioxidant defenses and mitochondrial function in numerous diseases, in smoke-exposed mothers during pregnancy and lactation significantly reversed the detrimental maternal impacts on kidney pathology in these male offspring. It increased SOD2 and glutathione peroxidase 1, reduced ROS accumulation, and normalized levels of mitochondrial preprotein translocases of the outer membrane, and oxidative phosphorylation complexes I–V in the kidneys of mouse progeny after intrauterine cigarette smoke exposure. These findings support the hypothesis that oxidative stress and mitochondrial dysfunction are closely linked to the adverse effects of maternal smoking on male offspring renal pathology. The results of our study suggest that L-carnitine administration in cigarette smokeexposed mothers mitigates these deleterious renal consequence
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Precision Dual-Aquifer Dewatering at a Low Level Radiological Cleanup in New Jersey
Cleanup of low-level radioactive wastes at the Wayne Interim Storage Site (WISS), Wayne, New Jersey during the period October, 2000 through November, 2001 required the design, installation and operation of a dual-aquifer dewatering system to support excavation of contaminated soils. Waste disposal pits from a former rare-earth processing facility at the WISS had been in contact with the water table aquifer, resulting in moderate levels of radionuclides being present in the upper aquifer groundwater. An uncontaminated artesian aquifer underlies the water table aquifer, and is a localized drinking water supply source. The lower aquifer, confined by a silty clay unit, is flowing artesian and exhibits potentiometric heads of up to 4.5 meters above grade. This high potentiometric head presented a strong possibility that unloading due to excavation would result in a ''blowout'', particularly in areas where the confining unit was < 1 meter thick. Excavation of contaminated materials w as required down to the surface of the confining unit, potentially resulting in an artesian aquifer head of greater than 8 meters above the excavation surface. Consequently, it was determined that a dual-aquifer dewatering system would be required to permit excavation of contaminated material, with the water table aquifer dewatered to facilitate excavation, and the deep aquifer depressurized to prevent a ''blowout''. An additional concern was the potential for vertical migration of contamination present in the water table aquifer that could result from a vertical gradient reversal caused by excessive pumping in the confined system. With these considerations in mind, a conceptual dewatering plan was developed with three major goals: (1) dewater the water table aquifer to control radionuclide migration and allow excavation to proceed; (2) depressurize the lower, artesian aquifer to reduce the potential for a ''blowout''; and (3) develop a precise dewatering level control mechanism to insure a vertical gradient reversal did not result in cross-contamination. The plan was executed through a hydrogeologic investigation culminating with the design and implementation of a complex, multi-phased dual-aquifer dewatering system equipped with a state of the art monitoring network
Forests and water: a state-of-the-art review for Colorado
Includes bibliographical references (pages 65-75).Forests occupy 22.6 million acres in Colorado, or 32 percent of the land area, and nearly three-quarters of the forest lands in Colorado are in public ownership. About 55 percent of the forested area is considered suitable for forest harvest. National forests comprise nearly half of the forested area and approximately 60 percent of the area is considered suitable for forest harvest. There are no significant, privately-owned, industrial forest lands in Colorado. Historic photographs, forest stand records, and other data indicate that forest density in Colorado is generally greater than in the mid to late 1800s. This increase in forest density, attributed to suppression of forest fires, reduced grazing, and lower rates of forest harvest for timber, fuel, and other products, are generally believed to have decreased annual water yields. Annual water yields from the 1.34 million acres of national forest lands in the North Platte River basin are estimated to have decreased by approximately 8 to 14 percent or 135,000 to 185,000 acre-feet per year, depending on the assumed stand history for the spruce-fir forests. Hydrologic models indicate that average annual water yields could be increased in the North Platte River basin by about 55,000 acre-feet per year if all 502,000 acres designated as suitable for timber harvest were regularly harvested on a sustained yield basis. Similar data are not available for other river basins in Colorado, although the overall trends are probably similar. This research looked at how reducing forest canopy affects the rate of spring snowmelt and water yield, how it affects evapotranspiration, what happens when the forest regrows, whether reducing forest density affects water yields if annual precipitation is a factor, the effects on water quality, and the necessity for water storage facilities to store the increased runoff. The report does not attempt to address the myriad of other issues that must be considered when evaluating various management alternatives for forested lands. Some of these issues include the numerous laws and regulations that affect land management, economic considerations, the downstream uses of water and water storage capacities, and the effects of forest management on recreation, local communities, aesthetics, and other plant and animal species.Sponsored by: Colorado River Water Conservation District, Colorado Water Resources Research Institute, Denver Water, Northern Colorado Water Conservancy District and financed in part by the U.S. Department of the Interior, Geological Survey, through the Colorado Water Resources Research Institute and Grant no. 01HQGR0077
Dynamic biospeckle analysis, a new tool for the fast screening of plant nematicide selectivity
Acute pancreatitis following medical abortion: Case report
BACKGROUND: Acute pancreatitis rarely complicates pregnancy. Although most pregnant women with acute pancreatitis have associated gallstones, less common causes such as drugs have been reported. CASE PRESENTATION: We report the case of a 34-year-old woman who underwent medical abortion with mifepristone and gemeprost and received codeine as pain-relief during the induction of abortion. She developed a severe acute necrotizing pancreatitis which required 14 days of intensive care. Other possible etiological factors, i.e. gallstone, alcohol intake and hyperlipidemia, were excluded. CONCLUSIONS: The reported case of acute pancreatitis was most likely drug-induced
The Blue Stragglers of the Old Open Cluster NGC 188
The old (7 Gyr) open cluster NGC 188 has yielded a wealth of astrophysical
insight into its rich blue straggler population. Specifically, the NGC 188 blue
stragglers are characterized by: A binary frequency of 80% for orbital periods
less than days;Typical orbital periods around 1000 days;Typical
secondary star masses of 0.5 M; At least some white dwarf companion
stars; Modestly rapid rotation; A bimodal radial spatial distribution;
Dynamical masses greater than standard stellar evolution masses (based on
short-period binaries); Under-luminosity for dynamical masses (short-period
binaries). Extensive -body modeling of NGC 188 with empirical initial
conditions reproduces the properties of the cluster, and in particular the
main-sequence solar-type binary population. The current models also reproduce
well the binary orbital properties of the blue stragglers, but fall well short
of producing the observed number of blue stragglers. This deficit could be
resolved by reducing the frequency of common-envelope evolution during Roche
lobe overflow. Both the observations and the -body models strongly indicate
that the long-period blue-straggler binaries - which dominate the NGC 188 blue
straggler population - are formed by asymptotic-giant (primarily) and red-giant
mass transfer onto main sequence stars. The models suggest that the few
non-velocity-variable blue stragglers formed from mergers or collisions.
Several remarkable short-period double-lined binaries point to the importance
of subsequent dynamical exchange encounters, and provide at least one example
of a likely collisional origin for a blue straggler.Comment: Chapter 3, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G.
Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe
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