bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symposium‐in‐Print: Singlet Oxygen Invited Review
Authors: Redmond Robert W. , Kochevar Irene E. 
Published: June 2006

ABSTRACTSinglet oxygen (1O2) is unique amongst reactive oxygen species formed in cells in that it is an excited state molecule with an inherent upper lifetime of 4 μs in water. Whether the lifetime of 1O2 in cells is shortened by reactions with cellular molecules or reaches the inherent maximum value is still unclear. However, even with the maximum lifetime, the diffusion radius is only ?220 nm during three lifetimes (?5%1O2 remaining), much shorter than cellular dimensions indicating that the primary reactions of 1O2 will be subcellularly localized near the site of 1O2 formation. This fact has raised the question of whether spatially resolved cellular responses to 1O2 occur, i.e. whether responses can be initiated by generation and reaction of 1O2 at a particular subcellular location that would not have been produced by 1O2 generation at other subcellular sites. In this paper, we discuss examples of spatially resolved responses initiated by 1O2 as a function of distance from the site of generation of 1O2. Three levels are recognized, namely, a molecular level where the primary oxidation product directly modifies the behavior of a cell, an organelle level where the initial photo‐oxidation products initiate mechanisms that are unique to the organelle and the cellular level where mediators diffuse from their site of formation to the target molecules that initiate the response. These examples indicate that, indeed, spatially resolved responses to 1O2 occur in cells.
Nutrient and Trace Element Leaching following Mine Reclamation with Biosolids
Authors: Stehouwer Richard , Day Rick L. , Macneal Kirsten E. 
Published: June 2006

ABSTRACTMine reclamation with biosolids increases revegetation success but nutrient addition well in excess of vegetation requirements has the potential to increase leaching of NO3 and other biosolids constituents. A 3‐yr water quality monitoring study was conducted on a Pennsylvania mine site reclaimed with biosolids applied at the maximum permitted and standard loading rate of 134 Mg ha−1 Zero‐tension lysimeters were installed at 1‐m depth 1 yr before reclamation: three in the biosolids application area, one in a control area (no biosolids). Before reclamation, all water samples had pH in the range 4.7 to 6.2, acidity <20 mg L−1, and very low levels of all other measured parameters. Following reclamation, percolate water in the biosolids‐treated area had lower pH and greater acidity than the control area. Acidity was greatest during the first winter following biosolids application, decreased during the spring, and showed a similar pattern but with much smaller concentrations the second year. Maximum first‐ year leachate NO3 concentrations were ∼300 mg L−1 and half as large the second year. Estimated inorganic N leaching loss during the first 2 yr after biosolids application was 2327 kg N ha−1 Aluminum, Mn, Cu, Ni, Pb, and Zn followed similar leaching patterns as did acidity, and their mobilization appeared to be the result of the increased acidity. These results indicate that large applications of low‐C/N‐ratio biosolids could negatively impact area water quality and that biosolids reclamation practices should be modified to reduce this possibility.
Comparison of Escherichia coli and Campylobacter jejuni Transport in Saturated Porous Media
Authors: Bolster Carl H. , Walker Sharon L. , Cook Kimberly L. 
Published: June 2006

ABSTRACTDue to the difficulties in testing for specific pathogens, water samples are tested for the presence of nonpathogenic indicator organisms to determine whether a water supply has been contaminated by fecal material. An implicit assumption in this approach is that where pathogenic microorganisms are present fecal indicator organisms are present as well; yet surprisingly few studies have been conducted that directly compare the transport of indicator organisms with pathogenic organisms in ground water environments. In this study we compared the cell properties and transport of Escherichia coli, a commonly used indicator organism, and Campylobacter jejuni, an important enteropathogen commonly found in agricultural wastes, through saturated porous media. Differences in cell properties were determined by measuring cell geometry, hydrophobicity, and electrophoretic mobility. Transport differences were determined by conducting miscible displacement experiments in laboratory columns. Under the experimental conditions tested, C. jejuni was much more negatively charged and more hydrophobic than E. coli In addition, C. jejuni cells were slightly longer, narrower, and less spherical than E. coli The variations in cell properties, primarily surface charge, resulted in significant differences in transport between these two microorganisms, with the transport of C. jejuni exceeding that of E. coli when conditions favored low attachment rates, thus calling into question the usefulness of using E. coli as an indicator organism for this important pathogen.
3,4‐Dimethylpyrazol Phosphate Effect on Nitrous Oxide, Nitric Oxide, Ammonia, and Carbon Dioxide Emissions from Grasslands
Authors: Menéndez S. , Merino P. , Pinto M. , González‐Murua C. , Estavillo J. M. 
Published: June 2006

ABSTRACTIntensively managed grasslands are potentially a large source of NH3, N2O, and NO emissions because of the large input of nitrogen (N) in fertilizers. Addition of nitrification inhibitors (NI) to fertilizers maintains soil N in ammonium form. Consequently, N2O and NO losses are less likely to occur and the potential for N utilization is increased, and NH3volatilization may be increased. In the present study, we evaluated the effectiveness of the nitrification inhibitor 3,4‐dimethylpyrazol phosphate (DMPP) on NH3, N2O, NO, and CO2emissions following the application of 97 kg N ha−1as ammonium sulfate nitrate (ASN) and 97 kg NH4+–N ha−1as cattle slurry to a mixed clover–ryegrass sward in the Basque Country (northern Spain). After slurry application, 16.0 and 0.7% of the NH4+–N applied was lost in the form of N2O and NO, respectively. The application of DMPP induced a decrease of 29 and 25% in N2O and NO emissions, respectively. After ASN application 4.6 and 2.8% of the N applied was lost as N2O and NO, respectively. The application of DMPP with ASN (as ENTEC 26; COMPO, Münster, Germany) unexpectedly did not significantly reduce N2O emissions, but induced a decrease of 44% in NO emissions. The amount of NH4+–N lost in the form of NH3following slurry and slurry + DMPP applications was 7.8 and 11.0%, respectively, the increase induced by DMPP not being statistically significant. Levels of CO2emissions were unaffected in all cases by the use of DMPP. We conclude that DMPP is an efficient nitrification inhibitor to be used to reduce N2O and NO emissions from grasslands.
Using Surface Water Application to Reduce 1,3‐Dichloropropene Emission from Soil Fumigation
Authors: Gao Suduan , Trout Thomas J. 
Published: June 2006

ABSTRACTHigh emissions from soil fumigants increase the risk of detrimental impact on workers, bystanders, and the environment, and jeopardize future availability of fumigants. Efficient and cost‐effective approaches to minimize emissions are needed. This study evaluated the potential of surface water application (or water seal) to reduce 1,3‐dichloropropene (1,3‐D) emissions from soil (Hanford sandy loam) columns. Treatments included dry soil (control), initial water application (8 mm of water just before fumigant application), initial plus a second water application (2.6 mm) at 12 h, initial plus two water applications (2.6 mm each time) at 12 and 24 h, standard high density polyethylene (HDPE) tarp, initial water application plus HDPE tarp, and virtually impermeable film (VIF) tarp. Emissions from the soil surface and distribution of 1,3‐D in the soil‐gas phase were monitored for 2 wk. Each water application abruptly reduced 1,3‐D emission flux, which rebounded over a few hours. Peak emission rates were substantially reduced, but total emission reduction was small. Total fumigant emission was 51% of applied for the control, 46% for initial water application only, and 41% for the three intermittent water applications with the remaining water treatment intermediate. The HDPE tarp alone resulted in 45% emission, while initial water application plus HDPE tarp resulted in 38% emission. The most effective soil surface treatment was VIF tarp (10% emission). Surface water application can be as effective, and less expensive than, standard HDPE tarp. Frequent water application is required to substantially reduce emissions.
Effect of Methodology in Estimating and Interpreting Water‐Extractable Phosphorus in Animal Manures
Authors: Vadas P. A. , Kleinman P. J. A. 
Published: June 2006

ABSTRACTManure water‐extractable phosphorus (WEP) data are used in indices and models to assess P transport in runoff. Methods to measure WEP vary widely, often without understanding the effect on how much P is extracted. We conducted water extractions on five dairy, swine, and poultry manures to assess single and sequential extractions, drying manures, solution to solid (cm3 g−1) extraction ratios, and P determination method. We found little difference in WEP of single or sequential extractions. Increasing extraction ratio from 10:1 to 250:1 resulted in more WEP recovered, but in a diminishing fashion so that ratios of 200:1 and 250:1 were not significantly different. Patterns of increased WEP with extraction ratio varied with manure type, presence of bedding material, and drying treatment. Fresh and air‐dried manures had similar patterns, but differed substantially from oven‐dried (90°C) manures. The differential effect of oven‐drying on WEP was greatest for dairy and poultry manure, and less for swine manure. We analyzed water extracts colorimetrically before and after digestion, to examine the potential effect of P determination by inductively coupled plasma (ICP) spectroscopy. Digested extracts always contained more P. For manures with bedding, drying decreased the difference in P measured before and after digestion. The opposite was true for manures without bedding. Results highlight the influence of methodology on manure WEP measurement and caution needed when comparing data across studies using different WEP methods. Overall, our results point to a need for a standard manure water extraction method.
Impact of Transgenic Bt Maize Residues on the Mycotoxigenic Plant Pathogen Fusarium graminearum and the Biocontrol Agent Trichoderma atroviride
Authors: Naef Andreas , Zesiger Thierry , Défago Geneviève 
Published: June 2006

ABSTRACTTransformation of maize with genes encoding for insecticidal crystal (Cry) proteins from Bacillus thuringiensis (Bt) could have an impact on the saprophytic survival of plant pathogens and their antagonists on crop residues. We assessed potential effects on the mycotoxin deoxynivalenol (DON)‐producing wheat and maize pathogen Fusarium graminearum and on the biocontrol agent Trichoderma atroviride Purified Cry1Ab protein caused no growth inhibition of these fungi on agar plates. Cry1Ab concentrations above levels common in Bt maize tissue stimulated the growth of F. graminearum The fungi were also grown on γ‐radiation‐sterilized leaf tissue of four Bt maize hybrids and their non transgenic isolines collected at maize maturity on a field trial in 2002 and 2003. Both fungi degraded the Cry1Ab protein in Bt maize tissue. Fungal biomass quantification with microsatellite‐based polymerase chain reaction (PCR) assays revealed differential fungal growth on leaf tissue of different maize varieties but no consistent difference between corresponding Bt and non‐Bt hybrids. Generally, year of maize tissue collection had a greater impact on biomass production than cultivar or Bt transformation. The mycotoxin DON levels observed in maize tissue experiments corresponded with patterns in F. graminearum biomass, indicating that Bt transformation has no impact on DON production. In addition to bioassays, maize leaf tissue was analyzed with a mass spectrometer‐based electronic nose, generating fingerprints of volatile organic compounds. Chemical fingerprints of corresponding Bt and non‐Bt leaf tissues differed only for those hybrid pairs that caused differential fungal biomass production in the bioassays. Our results suggest that Cry1Ab protein in maize residues has no direct effect on F. graminearum and T. atroviride but some corresponding Bt/non‐Bt maize hybrids differ more in composition than Cry protein content alone, which can affect the saprophytic growth of fungi on crop residues.
Experimental Oxidative Dissolution of Sphalerite in the Aznalcóllar Sludge and Other Pyritic Matrices
Authors: Hita Raúl , Torrent José , Bigham Jerry M. 
Published: June 2006

ABSTRACTAfter the collapse on 25 Apr. 1998 of the Aznalcóllar mine tailings dike in southwestern Spain, 45 km2 of the Guadiamar valley were covered by a pyritic sludge containing up to 2% sphalerite (ZnS). Later, the sludge was mechanically removed and calcium carbonate was plowed into the soil to immobilize heavy metals. By June 2001 more than 60% of the sulfides in the residual sludge had oxidized and soil Zn contents reached locally phytotoxic levels. Therefore, the oxidative dissolution of sphalerite in the sludge and other pyritic samples was examined. Flow‐through oxidation experiments showed that: (i) about 5 and 17% of the sludge Fe and Zn were in soluble form, respectively, because the sludge sample had been partly oxidized in the field; (ii) the oxidation rates of the residual pyrite and sphalerite were similar; (iii) the overall sulfide oxidation rate was relatively unaffected by the addition of calcite; and (iv) poorly crystalline Fe (hydr)oxides containing Zn in occluded form and Zn (hydroxi)carbonates were formed in the presence of calcite. The rate of oxidation of reference sphalerite greatly increased when it was incorporated in the sludge or in a reference pyrite matrix. This enhancement was due to galvanic interaction because pyrite oxidation was depressed in the presence of sphalerite. Oxidation by Fe3+ ions was less important because the oxidation rates of native sphalerite were not greater at low than at high pH. The fast oxidation rate of sphalerite in the Aznalcóllar sludge indicates a need for quick adoption of remediation measures in similar accidents elsewhere. The use of calcite amendments has little influence on the oxidation rate but does result in the accumulation of Zn in relatively insoluble forms.
Demonstration of Methods to Reduce E. coli Runoff from Dairy Manure Application Sites
Authors: Meals Donald W. , Braun David C. 
Published: June 2006

ABSTRACTContamination by bacteria is a leading cause of impairment in U.S. waters, particularly in areas of livestock agriculture. We evaluated the effectiveness of several practices in reducing Escherichia coli levels in runoff from fields receiving liquid dairy (Bos taurus) manure. Runoff trials were conducted on replicated hay and silage corn (Zea mays L.) plots using simulated rainfall. Levels of E. coli in runoff were ∼104 to 106 organisms per 100 mL, representing a significant pollution potential. Practices tested were: manure storage, delay between manure application and rainfall, manure incorporation by tillage, and increased hayland vegetation height. Storage of manure for 30 d or more consistently and dramatically lowered E. coli counts in our experiments, with longer storage providing greater reductions. Manure E. coli declined by >99% after ∼90 d of storage. On average, levels of E. coli in runoff were 97% lower from plots receiving 30‐d‐old and >99% lower from plots receiving 90‐d‐old manure than from plots where fresh manure was applied. Runoff from hayland and cornland plots where manure was applied 3 d before rainfall contained ∼50% fewer E. coli than did runoff from plots that received manure 1 d before rainfall. Hayland vegetation height alone did not significantly affect E. coli levels in runoff, but interactions with rainfall delay and manure age were observed. Manure incorporation alone did not significantly affect E. coli levels in cornland plot runoff, but incorporation could reduce bacteria export by reducing field runoff and interaction with rainfall delay was observed. Extended storage that avoids additions of fresh manure, combined with application several days before runoff, incorporation on tilled land, and higher vegetation on hayland at application could substantially reduce microorganism loading from agricultural land.
Surface and Subsurface Phosphorus Losses from Fertilized Pasture Systems in Ohio
Authors: Owens L. B. , Shipitalo M. J. 
Published: June 2006

ABSTRACTPhosphorus is an essential plant nutrient and critical to agricultural production, but it is also a problem when excessive amounts enter surface waters. Summer rotational grazing and winter feeding beef pasture systems at two fertility levels (56 and 28 kg available P ha−1) were studied to evaluate the P losses from these systems via surface runoff and subsurface flow using eight small (0.3‐1.1 ha), instrumented watersheds and spring developments. Runoff events from a 14‐yr period (1974‐1988) were evaluated to determine the relationships between event size in mm, total dissolved reactive phosphorous (TDRP) concentration, and TDRP transport. Most of the TDRP transported was via surface runoff. There were strong correlations (r2 = 0.45‐0.66) between TDRP transport and event size for all watersheds, but no significant (P = 0.05) correlations between TDRP concentration and event size. Flow‐weighted average TDRP concentrations from the pasture watersheds for the 14‐yr period ranged from 0.64 to 1.85 mg L−1 with a few individual event concentrations as high as 85.7 mg L−1 The highest concentrations were in events that occurred soon after P fertilizer application. Average seasonal flow‐weighted TDRP concentrations for subsurface flow were <0.05 mg L−1 Applying P fertilizer to pastures in response to soil tests should keep TDRP concentrations in subsurface flow at environmentally acceptable levels. Management to reduce runoff and avoidance of P fertilizer application when runoff producing rainfall is anticipated in the next few days will help reduce the surface losses of P.
Salmonella Survival in Manure‐Treated Soils during Simulated Seasonal Temperature Exposure
Authors: Holley Richard A. , Arrus Katia M. , Ominski Kimberly H. , Tenuta Mario , Blank Gregory 
Published: June 2006

ABSTRACTAddition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure‐treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six‐strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (−18, 4, 10, 25°C), spring to summer (4, 10, 25, 30°C), or summer to winter (25, 10, 4, −18°C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post‐inoculation and thereafter at 15‐d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (≥180 d) in both soils during summer‐winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were ≤30 d and suggested that a 30‐d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be minimized.
Comparative pharmacokinetics of meloxicam in clinically normal horses and donkeys
Authors: Sinclair Melissa D. , Mealey Katrina L. , Matthews Nora S. , Peck Ken E. , Taylor Tex S. , Bennett Brad S. 
Published: June 2006

Abstract
Objective—To determine the disposition of a bolus of meloxicam (administered IV) in horses and donkeys (Equus asinus) and compare the relative pharmacokinetic variables between the species.
Animals—5 clinically normal horses and 5 clinically normal donkeys.
Procedures—Blood samples were collected before and after IV administration of a bolus of meloxicam (0.6 mg/kg). Serum meloxicam concentrations were determined in triplicate via high-performance liquid chromatography. The serum concentration-time curve for each horse and donkey was analyzed separately to estimate standard noncompartmental pharmacokinetic variables.
Results—In horses and donkeys, mean ± SD area under the curve was 18.8 ± 7.31 μg/mL/h and 4.6 ± 2.55 μg/mL/h, respectively; mean residence time (MRT) was 9.6 ± 9.24 hours and 0.6 ± 0.36 hours, respectively. Total body clearance (CLT) was 34.7 ± 9.21 mL/kg/h in horses and 187.9 ± 147.26 mL/kg/h in donkeys. Volume of distribution at steady state (VDSS) was 270 ± 160.5 mL/kg in horses and 93.2 ± 33.74 mL/kg in donkeys. All values, except VDSS, were significantly different between donkeys and horses.
Conclusions and Clinical Relevance—The small VDSS of meloxicam in horses and donkeys (attributed to high protein binding) was similar to values determined for other nonsteroidal anti-inflammatory drugs. Compared with other species, horses had a much shorter MRT and greater CLT for meloxicam, indicating a rapid elimination of the drug from plasma; the even shorter MRT and greater CLT of meloxicam in donkeys, compared with horses, may make the use of the drug in this species impractical.
Evaluation of isoflurane and sevoflurane vaporizers over a wide range of oxygen flow rates
Authors: Ambrisko Tamas D. , Klide Alan M. 
Published: June 2006

Abstract
Objective—To examine the accuracy and precision of isoflurane and sevoflurane anesthetic vaporizers.
Sample Population—5 identcal isoflurane and 5 identical sevoflurane vaporizers.
Procedures—Oxygen flow rates from 0.02 to 10 L/min were used with different vaporizer dial settings. Agent concentrations were measured at the common gas outlet by use of a refractometer. Accuracy was defined as the difference between measured agent concentrations, and dial settings were expressed as a percentage of the applied dial settings. Precision was defined as SD of the measured agent concentrations for each combination of dial setting and flow.
Results—Isoflurane values were generally greater than the dial settings. Accuracy of the isoflurane vaporizer was > 20% when 0.6% and 1% was dialed. Accuracy of the sevoflurane vaporizer was always within ± 20% but decreased at 0.02 L/min flow and at combinations of high flow and high dial settings. Overall precision of the isoflurane vaporizer was better than that of the sevoflurane vaporizer.
Conclusions and Clinical Relevance—A possible explanation for the inaccuracy of the isoflurane vaporizer may be that it was manufactured to be accurate with air but not oxygen, which must be accounted for when using the vaporizer with oxygen, especially with nonrebreathing systems. The sevoflurane vaporizer may not deliver accurate agent concentrations at high flow and high dial settings. Both vaporizers are suitable for clinical use with a wide range of oxygen flow rates if these precautions are properly addressed.