bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual Effects of Compost and Plowing on Phosphorus and Sediment in Runoff
Authors: Wortmann Charles S. , Walters Daniel T. 
Published: September 2007

AbstractManure application can lead to excessive soil test P levels in surface soil, which can contribute to increased P concentration in runoff. However, manure application often results in reduced runoff and sediment loss. Research was conducted to determine the residual effects of previously applied compost, plowing of soil with excessive soil test P, and application of additional compost after plowing on volume of runoff and loss of sediment and P in runoff. The research was conducted in 2004 and 2005 under natural rainfall events with plots of 11‐m length where low‐P and high‐P compost had been applied during April 1998 to January 2001. During this initial application period, Bray‐P1 in the surface 5‐cm of depth was increased from 14 to 553 mg kg−1for the high‐P compost. Inversion plowing in the spring of 2004 greatly decreased P levels in the surface soil and over the following year reduced runoff by 35% and total P losses by 51% compared with the unplowed compost treatments. Sediment loss was increased with plowing compared with the unplowed compost applied treatments but less than with the no‐compost treatment. The application of additional compost after plowing increased surface soil P and dissolved reactive P (DRP) in runoff but did not increase particulate P in runoff. Unplowed compost‐amended soil continued to reduce sediment loss but exhibited increased DRP loss even 5 yr after the last application. Plowing to invert excessively high‐P surface soil was effective in reducing runoff and DRP loss.
Prediction of Microbial Accessibility of Carbon‐14‐Phenanthrene in Soil in the Presence of Pyrene or Benzo[a]pyrene using an Aqueous Cyclodextrin Extraction Technique
Authors: Papadopoulos Apostolos , Reid Brian J. , Semple Kirk T. 
Published: September 2007

AbstractTraditionally, solvent extractions are routinely used in the assessment of contaminated land. However, vigorous solvent extractions only give total concentrations rather than that relating to the bioaccessible fraction. Recently, less harsh, aqueous‐based extraction methods have been shown to be a better estimate of the microbial degradation of polycyclic aromatic hydrocarbons (PAHs). The aqueous‐based hydroxypropyl‐β‐cyclodextrin (HPCD) extraction technique was tested using 14C‐PAHs in soils and compared against indigenous microbial mineralization (a measure of bioaccessibility) of 14C‐phenanthrene in the presence of pyrene or benzo[a]pyrene (B[a]P) over a range of concentrations (0, 5, 10, or 50 mg kg−1) and aged for 0, 25, 50, and 100 d in four soils. At each time point, the total loss, extractability, and mineralization of 14C‐phenanthrene was measured in each of the soils. The presence of the other PAHs had little effect on the behavior of 14C‐phenanthrene in any of the soils. Comparisons between the amounts of 14C‐phenanthrene extracted using HPCD and mineralized were made and showed that there was a correlation (1:1). This study demonstrates that HPCD extraction is able to predict the microbial accessibility fraction of 14C‐phenanthrene in the presence of other PAHs in a range of soils, further supporting the applicability of this technique.
Rye Cover Crop and Gamagrass Strip Effects on NO3Concentration and Load in Tile Drainage
Authors: Kaspar T.C. , Jaynes D.B. , Parkin T.B. , Moorman T.B. 
Published: September 2007

AbstractA significant portion of the NO3from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or “tiles.” Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3concentrations in subsurface drainage to acceptable levels; therefore, additional approaches need to be devised. We compared two cropping system modifications for NO3concentration and load in subsurface drainage water for a no‐till corn (Zea maysL.)‐soybean (Glycine max[L.] Merr.) management system. In one treatment, eastern gamagrass (Tripsacum dactyloidesL.) was grown in permanent 3.05‐m‐wide strips above the tiles. For the second treatment, a rye (Secale cerealeL.) winter cover crop was seeded over the entire plot area each year near harvest and chemically killed before planting the following spring. Twelve 30.5 × 42.7‐m subsurface‐drained field plots were established in 1999 with an automated system for measuring tile flow and collecting flow‐weighted samples. Both treatments and a control were initiated in 2000 and replicated four times. Full establishment of both treatments did not occur until fall 2001 because of dry conditions. Treatment comparisons were conducted from 2002 through 2005. The rye cover crop treatment significantly reduced subsurface drainage water flow‐weighted NO3concentrations and NO3loads in all 4 yr. The rye cover crop treatment did not significantly reduce cumulative annual drainage. Averaged over 4 yr, the rye cover crop reduced flow‐weighted NO3concentrations by 59% and loads by 61%. The gamagrass strips did not significantly reduce cumulative drainage, the average annual flow‐weighted NO3concentrations, or cumulative NO3loads averaged over the 4 yr. Rye winter cover crops grown after corn and soybean have the potential to reduce the NO3concentrations and loads delivered to surface waters by subsurface drainage systems.
Effects of Initial Solute Distribution on Contaminant Availability, Desorption Modeling, and Subsurface Remediation
Authors: Haws Nathan W. , Ball William P. , Bouwer Edward J. 
Published: September 2007

AbstractLow permeability regions in which solute movement is governed by diffusion reduce the availability of pollutants for remediation and can function as long‐term sources of groundwater contamination. The inherent difficulty in understanding mass transfer from these regions of sequestered contamination is further complicated by unknown solute distributions within the low‐permeability regions (sequestering regions). When models are calibrated to reproduce temporal histories of solute release from a sequestering region (desorption), the fitted parameter values are used to infer the physical or chemical characteristics of the media; however, the calibrated parameters also reflect the case‐specific initial conditions (i.e., the solute distribution within the sequestering region domain at the onset of desorption). This phenomenon is demonstrated using model simulations of solute diffusion from hypothetical solids with characteristics similar to those of the well studied Borden, Ontario aquifer system. Solute release from the solids is simulated using a batch diffusion model under different initial solute distributions within the solids. The results of these model simulations are used to calibrate parameters of a multiple first‐order rate desorption model (MRM) to illustrate how the fitted MRM parameters increase or decrease depending on the initial “aging” of the solids. Further numerical simulations are conducted for a one‐dimensional flow system under steady‐state and variable‐rate hydraulic flushing. These simulations show that although aging reduces desorptive mass flux during early stages of flushing, aged sites have greater desorptive mass flux (greater solute availability) than “freshly” contaminated media during the later stages of remediation. Overall, the results demonstrate why the physicochemical meaning of observed desorption rates cannot be accurately deduced without first understanding the initial solute distribution within the media.
Differential Responses of Eubacterial, Mycobacterium, and Sphingomonas Communities in Polycyclic Aromatic Hydrocarbon (PAH)‐Contaminated Soil to Artificially Induced Changes in PAH Profile
Authors: Uyttebroek Maarten , Spoden Astrid , Ortega‐Calvo Jose‐Julio , Wouters Katinka , Wattiau Pierre , Bastiaens Leen , Springael Dirk 
Published: September 2007

AbstractRecent reports suggest that Mycobacterium is better adapted to soils containing poorly bioavailable polycyclic aromatic hydrocarbons (PAHs) compared to Sphingomonas To study this hypothesis, artificial conditions regarding PAH profile and PAH bioavailability were induced in two PAH‐contaminated soils and the response of the eubacterial, Mycobacterium, and Sphingomonas communities to these changed conditions was monitored during laboratory incubation. Soil K3663 with a relatively high proportion of high molecular weight PAHs was amended with phenanthrene or pyrene to artificially change the soil into a soil with a relatively increased bioavailable PAH contamination. Soil AndE with a relatively high proportion of bioavailable low molecular weight PAHs was treated by a single‐step Tenax extraction to remove the largest part of the easily bioavailable PAH contamination. In soil K3663, the added phenanthrene or pyrene compounds were rapidly degraded, concomitant with a significant increase in the number of phenanthrene and pyrene degraders, and minor and no changes in the Mycobacterium community and Sphingomonas community, respectively. However, a transient change in the eubacterial community related to the proliferation of several γ‐proteobacteria was noted in the phenanthrene‐amended soil. In the extracted AndE soil, the Sphingomonas community initially developed into a more diverse community but finally decreased in size below the detection limit. Mycobacterium in that soil never increased to a detectable size, while the eubacterial community became dominated by a γ‐proteobacterial population. The results suggest that the relative bioavailability of PAH contamination in soil affects bacterial community structure but that the behavior of Mycobacterium and Sphingomonas in soil is more complex than prospected from studies on their ecology and physiology.
The Release of Phosphorus to Porewater and Surface Water from River Riparian Sediments
Authors: Surridge Ben W. J. , Heathwaite A. L. , Baird Andrew J. 
Published: September 2007

AbstractSediments can be both a source and a sink of dissolved phosphorus (P) in surface water and shallow groundwater. Using laboratory mesocosms, we studied the influence of flooding with deionized water and simulated river water on P release to solution using sediment columns taken from a riparian wetland. The mesocosm incubation results showed that rather than retaining nutrients, sediments in the riparian zone may be a significant source of P. Concentrations of dissolved P in porewater reached more than 3 mg L−1 and in surface water over 0.8 mg L−1 within a month of sediment inundation. The reductive dissolution of P‐bearing iron (Fe) oxides was the likely mechanism responsible for P release. Dissolved P to Fe molar ratios in anaerobic samples were approximately 0.45 when columns were flooded with water that simulated the chemistry of the adjacent river. This suggests there was insufficient Fe in the anaerobic samples to precipitate all P if the solutions were oxygenated or transported to an aerobic environment. If the anaerobic wetland solutions were delivered to oxygenated rivers and streams adjacent to the riparian zone, the equilibrium concentration of P in these systems could rise. The timing of P release was inversely related to the nitrate (NO3−) concentration in floodwater. This indicates that in riparian zones receiving low nitrate loads, or where NO3− loads are being progressively reduced, the risk of dissolved P release may increase. These findings present particular challenges for restoration and management in riparian areas.
Inactivation of Ascaris suum in a Biodrying Compost System
Authors: Collick Amy S. , Inglis Scott , Wright Peter , Steenhuis Tammo S. , Bowman Dwight D. 
Published: September 2007

AbstractPathogen contamination of waterways is a serious concern in dairy farming areas where livestock waste is applied to agricultural fields. As an alternative, a biodrying composting system dries collected livestock waste, reduces the strong odors, and has been proposed as a means of reducing, and even eliminating pathogens present in the waste. Therefore, the survival of pathogens in a biodrying composting system was investigated. Dairy farm livestock waste was piled in a biodrying storage shed where forced aeration and natural decomposition processes heated a major portion of the waste pile to temperatures exceeding 55°C. Ascaris suum eggs were used as the surrogate species and inoculated into special chambers and placed at three different elevations at different intervals along the length of the pile. Control chambers were stored in water at 4°C in the laboratory. Both compost and control chambers were removed at Day 4, 8, 12, 16, and 20. The eggs were extracted from the chamber medium and analyzed for viability. No viable eggs were recovered from any of the chambers removed from the compost pile, while ≥90% viability was observed in the control chambers. High temperatures and continued drying were the major contributing factors to the inactivation of the helminth eggs. The complete inactivation of A. suum eggs by the biodrying process encourages the storage and treatment of manure to high temperatures and reduced moisture conditions before field spreading to reduce the risk of harmful pathogens contaminating waterways and potential drinking water supplies.
Nitrogen Mineralization and Microbial Activity in Oil Sands Reclaimed Boreal Forest Soils
Authors: McMillan R. , Quideau S. A. , MacKenzie M. D. , Biryukova O. 
Published: September 2007

AbstractOrganic materials including a peat‐mineral mix (PM), a forest floor‐mineral mix (L/S), and a combination of the two (L/PM) were used to cap mineral soil materials at surface mine reclamation sites in the Athabasca oil sands region of northeastern Alberta, Canada. The objective of this study was to test whether LFH provided an advantage over peat by stimulating microbial activity and providing more available nitrogen for plant growth. Net nitrification, ammonification, and N mineralization rates were estimated from field incubations using buried bags. In situ gross nitrification and ammonification rates were determined using the 15N isotope pool dilution technique, and microbial biomass C (MBC) and N (MBN) were measured by the chloroform fumigation‐extraction method. All reclaimed sites had lower MBC and MBN, and lower net ammonification and net mineralization rates than a natural forest site (NLFH) used as a control, but the reclamation treatment using LFH material by itself had higher gross and net nitrification rates. A positive correlation between in situ moisture content, dissolved organic N, MBC, and MBN was observed, which led us to conduct a moisture manipulation experiment in the laboratory. With the exception of the MBN for the L/S treatment, none of the reclamation treatments ever reached the levels of the natural site during this experiment. However, materials from reclamation treatments that incorporated LFH showed higher respiration rates, MBC, and MBN than the PM treatment, indicating that the addition of LFH as an organic amendment may stimulate microbial activity as compared to the use of peat alone.
Evaluation of a turbidimetric immunoassay for measurement of plasma IgG concentration in foals
Authors: McCue Patrick M. 
Published: September 2007

Abstract
Objective—To validate a turbidimetric immunoassay (TIA) for measurement of plasma IgG concentrations in foals.
Animals—36 foals.
Procedures—Blood samples were collected from foals before suckling and at 12 and 24 to 36 hours after birth. Plasma IgG concentrations were determined via a commercial single radial immunodiffusion (RID) assay. By use of goat anti-equine IgG antiserum and a spectrophotometer, a TIA was developed to measure plasma and serum IgG concentrations; the percentage light transmission was calibrated against RID assay–determined IgG concentrations. Assay repeatability and effects of serial dilution, sample type, and ambient temperature on assay results were evaluated.
Results—Serial dilution of plasma samples from foals 12 and 24 to 36 hours of age with presuckle plasma yielded percentage light transmission results that were highly inversely correlated (r = −0.95) with IgG concentrations determined via RID assay. Measurements of IgG in plasma and serum samples via TIA did not differ. When samples were assayed multiple times, the coefficient of variation was < 5.0%. Ambient temperature did not affect TIA results. At IgG concentrations of 400 and 800 mg/dL, TIA sensitivity was > 90%; specificity was 99.1% and 70.5%, respectively; and positive and negative predictive values were 98.1% and 71.5%, respectively, and 96.4% and 91.1%, respectively.
Conclusion and Clinical Relevance—Plasma IgG concentrations in foals determined via the TIA and RID assay were highly correlated. The TIA rapidly yielded quantitative results and would be useful in clinical situations where intervention decisions are time dependent.
Pharmacokinetics and pharmacodynamics of ϵ-aminocaproic acid in horses
Authors: Ross Julie , Dallap Barbara L. , Dolente Brett A. , Sweeney Raymond W. 
Published: September 2007

Abstract
Objective—To determine the pharmacokinetics and pharmacodynamics of ϵ-aminocaproic acid (EACA), including the effects of EACA on coagulation and fibrinolysis in healthy horses.
Animals—6 adult horses.
Procedures—Each horse received 3.5 mg of EACA/kg/min for 20 minutes, IV. Plasma EACA concentration was measured before (time 0), during, and after infusion. Coagulation variables and plasma α2-antiplasmin activity were evaluated at time 0 and 4 hours after infusion; viscoelastic properties of clot formation were assessed at time 0 and 0.5, 1, and 4 hours after infusion. Plasma concentration versus time data were evaluated by use of a pharmacokinetic analysis computer program.
Results—Drug disposition was best described by a 2-compartment model with a rapid distribution phase, an elimination half-life of 2.3 hours, and mean residence time of 2.5 ± 0.5 hours. Peak plasma EACA concentration was 462.9 ± 70.1 μg/mL; after the end of the infusion, EACA concentration remained greater than the proposed therapeutic concentration (130 μg/mL) for 1 hour. Compared with findings at 0 minutes, EACA administration resulted in no significant change in plasma α2-antiplasmin activity at 1 or 4 hours after infusion. Thirty minutes after infusion, platelet function was significantly different from that at time 0 and 1 and 4 hours after infusion. The continuous rate infusion that would maintain proposed therapeutic plasma concentrations of EACA was predicted (ie, 3.5 mg/kg/min for 15 minutes, then 0.25 mg/kg/min).
Conclusions and Clinical Relevance—Results suggest that EACA has potential clinical use in horses for which improved clot maintenance is desired.
Endoscopic evaluation of bronchial morphology in rabbits
Authors: Johnson Lynelle R. , Drazenovich Tracy L. , Hawkins Michelle G. 
Published: September 2007

Abstract
Objective—To evaluate bronchial morphology endoscopically in rabbits and develop a valid nomenclature for the endobronchial branching pattern.
Animals—10 mature New Zealand White rabbits.
Procedures—Flexible bronchoscopy was performed in rabbits anesthetized with isoflurane via nasal mask. Airways were systematically evaluated from the larynx to the terminal branches accessible with a 2.5-mm–outer diameter flexible endoscope. Airway branching patterns were identified and assessed for variation among subjects.
Results—Airways of all rabbits were readily examined with the 2.5-mm flexible endoscope. Laryngeal structure and function were normal in each rabbit, and airway branching patterns in all rabbits evaluated were identical. At the carina, branching into left and right principal bronchi was evident. The left principal bronchus divided immediately into the left cranial and left caudal lobar bronchi. The left cranial lobe bronchus further divided into dorsal and ventral segmental bronchi. The left caudal lobe bronchus gave rise to branches originating dorsally, ventrally, and medially before continuing caudally. The right principal bronchus divided into the right cranial, right middle, and accessory lobar bronchi and continued distally as the right caudal lobar bronchus. The right cranial lobe bronchus also divided into dorsal and ventral segmental bronchi, and the right caudal lobe bronchus had branches that originated dorsally, ventrally, and medially.
Conclusions and Clinical Relevance—Definition of a standard nomenclature for airway branching in rabbits will allow precise localization of disease in clinical cases and accurate collection of airway samples in clinical and scientific evaluations.
Computed tomographic analysis of the effects of two inspired oxygen concentrations on pulmonary aeration in anesthetized and mechanically ventilated dogs
Authors: Staffieri Francesco , Franchini Delia , Carella Giuseppina L. , Montanaro Manuela G. , Valentini Valerio , Driessen Bernd , Grasso Salvatore , Crovace Antonio 
Published: September 2007

Abstract
Objective—To compare the effect of 2 concentrations of oxygen in inspired gas (fraction of inspired oxygen [FIO2] 1.0 or 0.4) on pulmonary aeration and gas exchange in dogs during inhalation anesthesia.
Animals—20 healthy dogs.
Procedures—Following administration of acepromazine and morphine, anesthesia was induced in each dog with thiopental and maintained with isoflurane in 100% oxygen (100% group; n = 10) or a mixture of 40% oxygen and air (40% group; 10). Dogs were placed in dorsal recumbency and were mechanically ventilated. After surgery, spiral computed tomography (CT) of the thorax was performed and PaO2, PaCO2, and the alveolar-arterial oxygen tension difference (P[A–a]O2) were assessed. The lung CT images were analyzed, and the extent of hyperinflated (−1,000 to −901 Hounsfield units [HUs]), normally aerated (−900 to −501 HUs), poorly aerated (−500 to −101 HUs), or nonaerated (−100 to +100 HUs) areas was determined.
Results—Compared with the 100% oxygen group, the normally aerated lung area was significantly greater and the poorly aerated and nonaerated areas were significantly smaller in the 40% oxygen group. The time to CT (duration of surgery) was similar in both groups. Although PaCO2 was similar in both groups, PaO2 and P(A–a)O2 were significantly higher in the 100% oxygen group. In both groups, pulmonary atelectasis developed preferentially in caudal lung fields.
Conclusion and Clinical Relevance—In isoflurane-anesthetized dogs, mechanical ventilation with 40% oxygen appeared to maintain significantly better lung aeration and gas exchange than ventilation with 100% oxygen.