bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting single and mixture toxicity of petrogenic polycyclic aromatic hydrocarbons to the copepod Oithona davisae
Authors: Barata Carlos , Calbet Albert , Saiz Enric , Ortiz Laura , Bayona Josep Maria 
Published: October 2005

Abstract
In the present study, the acute toxicity of 10 polycyclic aromatic hydrocarbons (PAH) associated with the Prestige fuel oil spill (Spain, 2002) were evaluated, either as single substances or in mixtures, in adults of the copepod Oithona davisae. All but dimethylphenanthrene had negative effects on O. davisae survival at concentrations below their water solubility, with 48-h median lethal concentrations for naphthalene and pyrene of 56.1 and 0.8 μmol/L, respectively, making these the least and most toxic compounds. Polycyclic aromatic hydrocarbons had narcotic effects on copepods, as evidenced by the lack of motility at lower concentrations than those causing death. Naphthalene showed the greatest narcotic effects, and phenanthrene showed minor effects. Acute toxicity of the tested PAHs was inversely related (r2 = 0.9) with their octanol—water partition coefficient, thereby confirming the validity of the baseline quantitative structure—activity regression models for predicting the toxicity of PAH compounds in copepod species. When supplied in mixtures, the toxic effect of PAHs was additive. These results indicate that the many PAHs in an oil spill can be considered unambiguous baseline toxicants (class 1) acting additively as nonpolar narcotics in copepods; hence, their individual and combined toxicity can be predicted using their octanol—water partition coefficient.
Movement of Diuron and Hexazinone in Clay Soil and Infiltrated Pond Water
Authors: Prichard Terry , Troiano John , Marade Joe , Guo Fengmao , Canevari Mick 
Published: October 2005

ABSTRACTPre‐emergence herbicide residues were detected in domestic wells sampled near Tracy, CA. This study sought to determine the source of contamination by comparing soil distribution of diuron [N′‐(3,4‐dichlorophenyl)‐N,N‐dimethylurea] and hexazinone [3‐cyclohexyl‐6‐(dimethylamino)‐1‐methyl‐1,3,5‐triazine‐2,4(1H,3H)‐dione] in an agricultural field where the soil was a cracking clay to infiltration of residues in water captured by an adjacent holding pond. Diuron and hexazinone were applied in December to a 3‐yr‐old alfalfa (Medicago sativa L.) crop. Water content of soil taken after major rainfall but before irrigation at 106 d after application was elevated at the lowest depth sampled centered at 953 mm, indicating water was available for percolation. Herbicide residues (reporting limit 8 μg kg−1) were confined above the 152 mm soil depth, even after subsequent application of two border‐check surface irrigations. The pattern of distribution and concentration of residues in the soil were similar to results obtained from the LEACHM model, suggesting that macropore flow was limited to a shallow depth of soil. Herbicide residues were measured in runoff water at the first irrigation at 20 μg L−1 for diuron and 1 μg L−1 for hexazinone. Runoff water captured in the pond rapidly infiltrated into the subsurface soil, causing a concomitant rise in ground water elevation near the pond. Herbicide residues were also detected in the sampled ground water. We concluded that the pond was the predominant source for movement to ground water. Since addition of a surfactant to the spray mixture did not reduce concentrations in runoff water, mitigation methods will focus on minimizing infiltration of water from the pond.
Multivariate Statistical Characterization of Water Quality in Lake Lanier, Georgia, USA
Authors: Zeng Xiaoqing , Rasmussen Todd C. 
Published: October 2005

ABSTRACTWatershed monitoring programs depend on water quality characterization data collected for many parameters, at many times and places, and with limited resources. Our objective is to present a strategy that reduces the measured parameters, locations, and frequency without compromising the quality of the monitoring program. One year of twice‐monthly (growing season) and monthly (dormant season) water quality data collected from 17 lake and 10 tributary sites are used in conjunction with multivariate statistical techniques to improve the utility of collected data by identifying key parameters and monitoring locations. Factor analysis shows that tributary water quality data consists of three components—stormwater runoff, municipal and industrial discharges, and ground water—which can be distinguished using total suspended solids, total dissolved solids, and alkalinity plus soluble reactive P, respectively. Lake water quality characterization is more ambiguous than tributary water quality characterization, but factor analysis indicates that anoxia associated with lake stratification is the largest source of lake water quality variation, followed by nutrient abundance, and finally by biomass abundance. Cluster analysis suggests that tributary and lake monitoring stations can be consolidated. Reducing the number of parameters and stations frees up resources for increased monitoring elsewhere.
Is the Transfer Factor a Relevant Tool to Assess the Soil‐to‐Plant Transfer of Radionuclides under Field Conditions?
Authors: Centofanti T. , Penfield R. , Albrecht A. , Pellerin S. , Flühler H. , Frossard E. 
Published: October 2005

ABSTRACTThe radiological impact of radionuclides released to the terrestrial environment is usually predicted with mathematical models in which the transfer of radionuclides from soil to the plant is described with the transfer factor (TF). This paper questions the validity of the protocols proposed by the International Atomic Energy Agency to measure TF in the field and in greenhouses conditions. We grew maize (Zea maysL.) both in the field after a surface application of radionuclides (54Mn,57Co,65Zn, and134Cs) and in a greenhouse with the same soil that has received the same fertilization and that had been previously sieved and homogeneously labeled with the same radionuclides before being repacked in pots. The analysis of the displacement of radionuclides in the field soil profile showed a higher concentration of the surface‐applied radionuclides in the preferential flow path (PFP) in comparison to the soil matrix indicating that they infiltrated heterogeneously in the soil profile due to the structure‐induced non‐uniform water flow. A significantly higher recovery of57Co and134Cs was observed in the plants grown in the field soil, whereas no differences in the recovery of54Mn and65Zn between the two experiments were detected. These results suggest that (i) under field conditions the soil‐to‐plant transfer of radionuclides that co‐exist as stable elements present at low concentrations in the soil and in the plant is higher than that measured under greenhouse conditions and (ii) the implicit assumption made when calculating the TF (that radionuclides are homogeneously distributed in the soil profile) is not valid, thereby preventing the calculation of an average concentration to obtain the TF parameter.
Denitrification as a Nitrogen Removal Mechanism in a Vermont Peatland
Authors: Hayden Melissa J. , Ross Donald S. 
Published: October 2005

ABSTRACTAtmospheric deposition of nitrogenous compounds to ombrotrophic peatlands (i.e., those that have peat layers higher than their surroundings and receive nutrients and minerals exclusively by precipitation) has the potential to significantly alter ecosystem functioning. This study utilized the acetylene inhibition technique to estimate the relative importance of denitrification in nitrogen removal from a primarily ombrotrophic peatland, in an attempt to estimate the threat of increased nitrogen loadings to these areas. Estimates of mean rates of denitrification ranged from −2.76 to 84.0 ng N2O‐N cm−3 h−1 (equivalent to −150 to 4800 μg N2O‐N m−2 h−1) using an ex situ core technique and from −8.30 to 5.98 μg N2O‐N m−2 h−1 using an in situ chamber technique. Core rates may have been elevated over natural field levels due to effects of disturbance on substrate availability, and chamber rates may have been low due to diffusional constraints on acetylene and N2O. Net nitrification was also measured in an attempt to evaluate this process as a source of nitrate for denitrifiers. The low rates of net nitrification measured, in combination with the low rates of in situ denitrification and the very low amounts of free nitrate measured in this peatland, suggests that inorganic N turnover in this wetland is low. Results showed that nitrate was a limiting factor for denitrification in this peatland, with mean rates from nitrate‐amended cores ranging from 13.1 to 260 ng N2O‐N cm−3 h−1, and it is expected that increases in nitrogen loadings will increase denitrification rates in this ecosystem.
Evaluation of Simplifying Assumptions on Pesticide Degradation in Soil
Authors: Beulke Sabine , van Beinum Wendy , Brown Colin D. , Mitchell Matthew , Walker Allan 
Published: October 2005

ABSTRACTThere is evidence that degradation of pesticides in simple laboratory systems may differ from that in the field, but it is not clear which of the simplifications inherent in laboratory studies present serious shortcomings. Laboratory experiments evaluated several simplifying assumptions for a clay loam soil and contrasting pesticides. Degradation of cyanazine [2‐(4‐chloro‐6‐ethylamino‐1,3,5‐triazin‐2‐ylamino)‐2‐methylpropiononitrile] and bentazone [3‐isopropyl‐1H‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide] at fluctuating temperature and moisture was predicted reasonably well based on parameters derived from degradation under constant conditions. There was a tendency for slower degradation of cyanazine and bentazone in soil aggregates of 3 to 5 mm in diameter (DT50 at 15°C and 40% maximum water holding capacity of 25.1 and 58.2 d, where DT50 is the time for 50% decline of the initial pesticide concentration) than in soil sieved to <3 mm (DT50 of 19.1 and 37.6 d), but the differences were not significant for most datasets. Degradation of cyanazine, isoproturon [3‐(4‐isopropylphenyl)‐1,1‐dimethylurea], and chlorotoluron [3‐(3‐chloro‐p‐tolyl)‐1,1‐dimethylurea] was measured in soil amended with different amounts of lignin. The effect of lignin on degradation was small despite considerable differences in sorption. The DT50 values of cyanazine, isoproturon, and chlorotoluron were 16.2, 18.6, and 33.0 d, respectively, in soil without lignin and 19.0, 23.4, and 34.6 d, respectively, in soil amended with 2% lignin. Degradation of bentazone and cyanazine in repacked soil columns was similar under static and flow conditions with 50.1 and 47.2% of applied bentazone and 74.7 and 73.6% of applied cyanazine, respectively, degraded within 20 d of application. Thus, the assumptions underpinning laboratory to field extrapolation tested here were considered to hold for our experimental system. Additional work is required before general conclusions can be drawn.
Rapid Removal of Nitrate and Sulfate in Freshwater Wetland Sediments
Authors: Whitmire Stefanie L. , Hamilton Stephen K. 
Published: October 2005

ABSTRACTAnaerobic microbial processes play particularly important roles in the biogeochemical functions of wetlands, affecting water quality, nutrient transport, and greenhouse gas fluxes. This study simultaneously examined nitrate and sulfate removal rates in sediments of five southwestern Michigan wetlands varying in their predominant water sources from ground water to precipitation. Rates were estimated using in situ push–pull experiments, in which 500 mL of anoxic local ground water containing ambient nitrate and sulfate and amended with bromide was injected into the near‐surface sediments and subsequently withdrawn over time. All wetlands rapidly depleted nitrate added at ambient ground water concentrations within 5 to 20 h, with the rate dependent on concentration. Sulfate, which was variably present in porewaters, was also removed from injected ground water in all wetlands, but only after nitrate was depleted. The sulfate removal rate in ground water–fed wetlands was independent of concentration, in contrast to rates in precipitation‐fed wetlands. Sulfate production was observed in some sites during the period of nitrate removal, suggesting that the added nitrate either stimulated sulfur oxidation, possibly by bacteria that can utilize nitrate as an oxidant, or inhibited sulfate reduction by stimulating denitrification. All wetland sediments examined were consistently capable of removing nitrate and sulfate at concentrations found in ground water and precipitation inputs, over short time and space scales. These results demonstrate how a remarkably small area of wetland sediment can strongly influence water quality, such as in the cases of narrow riparian zones or small isolated wetlands, which may be excluded from legal protection.
Nitrogen Fertilizer Recommendations for Corn Grown on Soils Amended with Oily Food Waste
Authors: Rashid M. T. , Voroney R. P. 
Published: October 2005

ABSTRACTSoil and plant indices of soil fertility status have traditionally been developed using conventional soil and crop management practices. Data on managing N fertilizer for corn (Zea maysL.) produced on soils amended with C‐rich organic materials, such as oily food waste (OFW) is scarce. Identification of a reliable method for making N fertilizer recommendations under these conditions is imperative. The objective of this research was to evaluate soil NO3–N (0‐ to 30‐cm depth) at preplant and presidedress (PSNT) times of sampling for predicting N requirements for corn grown on fields receiving OFW. Experiments were conducted at two locations in Ontario, Canada over 3 yr (1995–1997) where OFW was applied at different rates (0, 10, and 20 Mg ha−1), times (fall and spring), and slope positions (upper, mid, and lower) within the same field. Presidedress soil NO3–N contents were higher compared with preplant time of sampling under all OFW management conditions. Corn grain yields were significantly affected by OFW management and N fertilizer application rates. Maximum economic rate of N application (MERN) varied depending on OFW management conditions. Presidedress soil NO3–N contents had a higher inverse relationship with MERN (r= −0.88) compared with soil NO3–N at preplant (r= −0.74) time of sampling. A linear regression model (Y= 180.1 − 8.22 NO3–N at PSNT) is proposed for making N fertilizer recommendations to corn grown on soils amended with OFW in this geographical region.
Autoclaving Soil Samples Affects Algal‐Available Phosphorus
Authors: Anderson Brandon H. , Magdoff Frederick R. 
Published: October 2005

ABSTRACTUnwanted microbial interference in samples used for biological assays of P availability has routinely been eliminated by autoclaving samples before inoculation with algae. Twenty‐three soils were selected to evaluate the relationship between algal growth in P‐deficient solutions containing small quantities of soil and the level of P determined by a variety of tests used to evaluate P availability in soils and sediments. Soils were either autoclaved or not before addition to flasks containing P‐starved algae in a nutrient solution without P. Compared to non‐autoclaved samples, autoclaving soil resulted in approximately 60% more available P as estimated by increased algal growth. However, algal growth in the presence of autoclaved soil was highly correlated with growth in the presence of non‐autoclaved samples. There was no consistent change in the correlations (r) between autoclaving or non‐autoclaving samples in the relationships of algal numbers with P extracted by a number of soil tests. The effect of autoclaving soil on soluble P was also evaluated for a subset of six soils. Autoclaved soils had significantly greater concentrations of soluble P than non‐autoclaved soils, with 78% more orthophosphate monoesters, 60% more orthophosphate diesters, and 54% more soluble inorganic P. Inhibition of algal growth may have occurred with two high‐Zn soils that produced relatively low numbers of algae despite being very high in estimated available P by all extraction methods. Removing those samples from the calculations dramatically improved correlations between soil P measured by various methods and algal growth. With these two soils removed from calculations, algal growth with autoclaved soil was most highly correlated with Olsen P (r= 0.95), with other correlations as follows: Fe‐oxide strip (r= 0.80), Mehlich 3 (r= 0.75,), modified Morgan (r= 0.61), and Bray–Kurtz 1 (r= 0.57).
Antibiotic Uptake by Plants from Soil Fertilized with Animal Manure
Authors: Kumar K. , Gupta S. C. , Baidoo S. K. , Chander Y. , Rosen C. J. 
Published: October 2005

ABSTRACTAntibiotics are commonly added to animal feed as supplements to promote growth of food animals. However, absorption of antibiotics in the animal gut is not complete and as a result substantial amounts of antibiotics are excreted in urine and feces that end up in manure. Manure is used worldwide not only as a source of plant nutrients but also as a source of organic matter to improve soil quality especially in organic and sustainable agriculture. Greenhouse studies were conducted to determine whether or not plants grown in manure‐applied soil absorb antibiotics present in manure. The test crops were corn (Zea maysL.), green onion (Allium cepaL.), and cabbage (Brassica oleraceaL. Capitata group). All three crops absorbed chlortetracycline but not tylosin. The concentrations of chlortetracycline in plant tissues were small (2–17 ng g−1fresh weight), but these concentrations increased with increasing amount of antibiotics present in the manure. This study points out the potential human health risks associated with consumption of fresh vegetables grown in soil amended with antibiotic laden manures. The risks may be higher for people who are allergic to antibiotics and there is also the possibility of enhanced antimicrobial resistance as a result of human consumption of these vegetables.
Temporal and Spatial Development of Surface Soil Conditions at Two Created Riverine Marshes
Authors: Anderson Christopher J. , Mitsch William J. , Nairn Robert W. 
Published: October 2005

ABSTRACTThe amount of time it takes for created wetlands to develop soils comparable to natural wetlands is relatively unknown. Surface soil changes over time were evaluated in two created wetlands (approximately 1 ha each) at the Olentangy River Wetland Research Park in Columbus, Ohio. The two wetlands were constructed in 1993 to be identical in size and geomorphology, and maintained to have the same hydrology. The only initial difference between the wetlands was that one was planted with native macrophytes while the other was not. In May 2004, soil samples were collected (10 yr and 2 mo after the wetlands were flooded) and compared to samples collected in 1993 (after the wetlands were excavated but before flooding) and 1995 (18 mo after the wetlands were flooded). In all three years, soils were split into surface (0–8 cm) and subsurface (8–16 cm) depths and analyzed for soil organic matter, total C, total P, available P, exchangeable cations, and pH. Soils in the two wetlands have changed substantially through sedimentation and organic accretion. Between 1993 and 1995, soils were most influenced by the deposition of senescent macroalgae, the mobilization of soluble nutrients, and the precipitation of CaCO3 Between 1995 and 2004, soil parameters were influenced more by the deposition of organic matter from colonized macrophyte communities. Mean percent organic matter at the surface increased from 5.3 ± 0.1% in 1993, 6.1 ± 0.2% in 1995, to 9.5 ± 0.2% in 2004. Mean total P increased from 493 ± 18 μg g−1 in 1993, 600 ± 23 μg g−1 in 1995, to 724 ± 20 μg g−1 in 2004. Spatial analyses of percent organic matter (a commonly used indicator of hydric soil condition) at both wetlands in 1993, 1995, and 2004 showed that soil conditions have become increasingly more variable. High spatial structure (autocorrelation) between data points was detected in 1993 and 2004, with data in 2004 exhibiting a much higher overall variance and narrower range of spatial structure than in 1993.
Cover Picture: Closing the Gap Between Self‐Assembly and Microsystems Using Self‐Assembly, Transfer, and Integration of Particles (Adv. Mater. 20/2005)
Authors: Kraus T. , Malaquin L. , Delamarche E. , Schmid H. , Spencer N. D. , Wolf H. 
Published: October 2005

AbstractThe cover shows 100  μm diameter glass spheres covered by a grid of hexagonally packed polystyrene beads. Wolf and co‐workers placed the 500 nm diameter polystyrene beads onto the larger spheres using the self‐assembly, transfer, and integration (SATI) process that they report on p. 2438. The cover illustrates the capability of SATI to process uneven surfaces in addition to the planar substrates discussed in the article. The carrier that holds the smaller beads deforms during their transfer onto the larger spheres, so that on the larger spheres patterned “caps” are formed. Using this process, which is compatible with standard microfabrication techniques, a variety of particle assemblies can be achieved.
Non‐nucleoside HIV Reverse Transcriptase Inhibitors, Part 6[1]: Synthesis and Anti‐HIV Activity of Novel 2‐[(Arylcarbonylmethyl)thio]‐6‐arylthio DABO Analogues
Authors: Sun Guang‐Fu , Kuang Yun‐Yan , Chen Fen‐Er , De Clercq Erik , Balzarini Jan , Pannecouque Christophe 
Published: October 2005

Abstract2‐(Arylcarbonylmethyl)thio‐6α‐naphthylmethyl derivatives of dihydro‐alkoxy‐benzyl‐oxopyrimidines (DABO) were newly found to exhibit activity against both HIV‐1 and HIV‐2. To further explore their structure‐activity relationship, the modified S‐DABO analogues (5a–g and 6e–f) with a 1‐naphthylthio or phenylthio group at the C‐6 position were synthesized. S‐Alkylation of 5‐ethyl‐2‐thiouracil with substituted 2‐bromo‐acetophenones provided crude 2‐[(arylcarbonylmethyl)thio]‐5‐ethyl‐(3H)‐uracil 2a–e, which was directly subjected to toluenesulfonylation with TsCl to afford disulfonate 4a–e. Substitution of 4a–e with arylthiol afforded the desired S‐DABO analogues 5a–g and 6e–f. The compounds were evaluated for their in vitro anti‐HIV activity in MT‐4 cells. The IC50 values for anti‐HIV‐1 activity fall into the range 0.37–29.50 μM, and the IC50 values for anti‐HIV‐2 activity fall into the range 23.11–181.07 μM. The results indicated that these compounds are moderately active against HIV‐1 and HIV‐2.
Adaptation of DELFIATM Cortisol Kit for Determination of Salivary Cortisol Concentration
Authors: Höferl Martina , Krist Sabine , Buchbauer Gerhard 
Published: October 2005

AbstractSalivary cortisol concentration seems to be an excellent indicator of the biologically active plasma cortisol level because of the nearly absence of corticoid‐binding proteins in saliva. With regard to the easy, noninvasive, and stress‐free nature of saliva sampling, this parameter greatly facilitates studies of the HPA (hypothalamus‐pituitary‐adrenocortical) axis, especially in children. A commercially available TR‐FIA (time‐resolved fluoroimmunoassay), the DELFIATM (dissociation‐enhanced lanthanide fluoroimmunoassay) method, proposed for plasma and urine cortisol analyses, was adapted for salivary cortisol measurement by means of simple modifications of the assay protocol. The sensitivity was determined to be 0.53 nmol/L. The intra‐ and interassay coefficients of variation ranged from 5.5 to 8.2 % and from 6.0 to 10.4 %, respectively. The present findings suggest that the DELFIATM procedure provides a reliable, sensitive, and convenient alternative procedure to the assay for salivary cortisol.