bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using a Geographic Information System to identify areas with potential for off-target pesticide exposure
Authors: Pfleeger Thomas G. , Olszyk David , Burdick Connie A. , King George , Kern Jeffrey , Fletcher John 
Published: July 2006

AbstractIn many countries, numerous tests are required as part of the risk assessment process before chemical registration to protect human health and the environment from unintended effects of chemical releases. Most of these tests are not based on ecological or environmental relevance but, rather, on consistent performance in the laboratory. A conceptual approach based on Geographic Information System (GIS) technology has been developed to identify areas that are vulnerable to nontarget chemical exposure. This GIS-based approach uses wind speed, frequency of those winds, pesticide application rates, and spatial location of agricultural crops to identify areas with the highest potential for pesticide exposure. A test scenario based on an incident in Idaho (USA) was used to identify the relative magnitude of risk from off-target movement of herbicides to plants in the conterminous United States. This analysis indicated that the western portion of the Corn Belt, the central California valley, southeastern Washington, the Willamette Valley of Oregon, and agricultural areas bordering the Great Lakes are among those areas in the United States that appear to have the greatest potential for off-target movement of herbicides via drift. Agricultural areas, such as the Mississippi River Valley and the southeastern United States, appears to have less potential, possibly due to lower average wind speeds. Ecological risk assessments developed for pesticide registration would be improved by using response data from species common to high-risk areas instead of extrapolating test data from species unrelated to those areas with the highest potential for exposure.
Tests of bioaccumulation models for polychlorinated biphenyl compounds: A study of young-of-the-year bluefish in the Hudson River estuary, USA
Authors: LeBlanc Lawrence A. , Buckel Jeffrey A. , Conover David O. , Brownawell Bruce J. 
Published: July 2006

Abstract
A field-based study regarding uptake of polychlorinated biphenyl compounds (PCBs) by young-of-the-year (YOY) bluefish (Pomatomus saltatrix) was initiated to test a steady-state model of bioaccumulation and trophic transfer in a rapidly growing fish. Determination of prey composition as well as size-dependent growth and specific consumption rates for YOY bluefish from separate field and laboratory studies enabled the input of these species-specific parameters into the model. Furthermore, the time and duration of the exposure of YOY bluefish to dissolved PCBs from a well-characterized system (Hudson River, USA) was well known. Patterns of accumulation of individual PCB congeners differed relative to the accumulation of total PCBs, with the greatest net accumulation occurring for the higher-molecular-weight congeners. Comparison of lipid-normalized bioaccumulation factors (BAFs) with the octanol–water partition coefficients of individual PCB congeners revealed bluefish to be above the BAFs predicted by lipid-based equilibrium partitioning, suggesting that uptake from food is an important source of PCBs in YOY bluefish. Comparison of measured BAFs with values predicted by a steady-state, food-chain model showed good first-order agreement.
Perchlorate induces hermaphroditism in threespine sticklebacks
Authors: Bernhardt Richard R. , von Hippel Frank A. , Cresko William A. 
Published: July 2006

AbstractRecently, concern regarding perchlorate contamination has arisen in many contexts. Perchlorate has many military, commercial, and domestic applications, and it has been found in milk, drinking and irrigation water, and produce. Perchlorate is harmful at low levels, yet it remains unregulated in the United States while the U.S. Environmental Protection Agency attempts to establish acceptable exposure levels. The present study investigated potential reproductive effects on vertebrates using a model fish species, the threespine stickleback (Gasterosteus aculeatus). Sticklebacks were raised from syngamy through sexual maturity in untreated water and in three target concentrations of sodium perchlorate–treated water. Perchlorate was found to interfere with the expression of nuptial coloration, courtship behavior, and normal sexual development. Genetic testing revealed that some females were masculinized to the extent that they produced both sperm and eggs, and histological analysis showed that these individuals had intersexual gonads (ovotestes) containing both oocytes and cells undergoing spermatogenesis. In vitro fertilizations revealed that those gametes were capable of self- and cross-fertilization. However, crosses using sperm derived from genetic females died either during the blastula phase or near the onset of organogenesis. Sperm derived from genetic males produced viable fry when crossed with eggs derived from genetic females from all treatments. To our knowledge, the present study provides the first evidence that perchlorate produces androgenic effects and is capable of inducing functional hermaphroditism in a nonhermaphroditic vertebrate.
Differential roles of humic acid and particulate organic matter in the equilibrium sorption of atrazine by soils
Authors: Yu Zhiqiang , Sharma Samriti , Huang Weilin 
Published: July 2006

AbstractRecent studies have indicated that soil organic matter (SOM) may consist of physically and chemically different fractions, including particulate organic matter (POM), such as black carbon and unburned coal materials. The present study examined the differential roles of three different SOM fractions isolated from a peat and a topsoil in the equilibrium sorption of the herbicide atrazine (ATZ). The SOM fractions isolated from the two samples included humic acids (HAs), base-extracted humin (HM), and POM after demineralization of HM. A batch technique was employed to measure both the nonequilibrium ATZ sorption on the original and HA samples and the equilibrium ATZ sorption and desorption. The results showed that the phase-distribution relationships measured under nonequilibrium conditions were more linear and had lower sorption-capacity parameters compared with their respective isotherms measured under equilibrium conditions. The sorption isotherms were variously nonlinear, with POM exhibiting the greatest organic carbon–normalized sorption capacity. There existed apparent sorption–desorption hysteresis for each sorbent–sorbate system. It appeared that the extracted HAs could facilitate hydrolysis of ATZ when the reaction time extended to 4 d or longer. The equilibrium sorptive behavior of the HAs therefore was not examined. The present study indicated that both original samples showed lower organic carbon–normalized sorption distribution coefficients compared with their respective SOM fractions, suggesting that a fraction of sorption sites in soil aggregates were not accessed by ATZ.
Ecological hazard assessment of major veterinary benzimidazoles: Acute and chronic toxicities to aquatic microbes and invertebrates
Authors: Oh Su Jin , Park Jeongim , Lee Min Jung , Park So Young , Lee Jong-Hyeon , Choi Kyungho 
Published: July 2006

Abstract
Aquatic toxicities of six benzimidazole-based anthelmintics—namely, albendazole, thiabendazole, flubendazole, febantel, fenbendazole, and oxfendazole—were evaluated with a marine bacterium, Vibrio fischeri, and a freshwater invertebrate, Daphnia magna. Delayed and chronic toxicity tests using D. magna also were conducted for benzimidazoles with high acute toxicity. Vibrio fischeri was greater than 10-fold less sensitive to most of the benzimidazoles tested compared to daphnids. For D. magna, the most acutely toxic anthelmintic compound tested was fenbendazole (48-h median effective concentration [EC50s], 16.5 μg/L), followed by flubendazole (48-h EC50, 66.5 μg/L), albendazole (48-h EC50, 67.9 μg/L), febantel (48-h EC50, 216.5 μg/L), thiabendazole (48-h EC50, 843.6 μg/L), and oxfendazole (48-h EC50, 1,168.4 μg/L). The lipophilicity parameter, log Kow, explained the observed acute D. magna toxicity of the individual benzimidazoles (r = −0.91, p &lt; 0.01). Delayed expression of toxicity observed for 21 d after 96-h exposure to fenbendazole and flubendazole was not notable, which might result from the relatively high elimination constants for the chemicals. With chronic exposure to fenbendazole, D. magna survival, reproduction, and growth were significantly impacted at 1.25 to 4.1 μg/L (p &lt; 0.05). Hazard quotients estimated for fenbendazole, albendazole, flubendazole, and febantel were 2,770, 9.7, 4, and 1.2, respectively, suggesting a need for further investigation and a potential for environmental concerns, particularly with fenbendazole.
Bioaccumulation and trophic transfer of some brominated flame retardants in a Lake Winnipeg (Canada) food web
Authors: Law Kerri , Halldorson Thor , Danell Robert , Stern Gary , Gewurtz Sarah , Alaee Mehran , Marvin Chris , Whittle Mike , Tomy Gregg 
Published: July 2006

Abstract
The extent of bioaccumulation and trophic transfer of brominated diphenyl ether (BDE) congeners, hexabromocyclododecane (HBCD) diastereoisomers (α, β, and γ), decabromodiphenylethane (DBDPE), and bis(2,4,6-tribromophenoxy)ethane (BTBPE) was examined in a Lake Winnipeg (Canada) food web. Six species of fish, zooplankton, mussels, sediment, and water from the south basin of the lake were selected for study. Significant positive correlations were found between concentrations of total (Σ) polybrominated diphenylethers (PBDEs; p &lt; 0.005), ΣHBCDs (p &lt; 0.0001), BTBPE (p &lt; 0.0001), and lipid content in fish. Strong positive linear relationships also were observed from individual plots of BDE 47, BDE 209, and DBDPE concentrations (lipid wt) and trophic level (based on δ15N), suggesting that these compounds biomagnify in the Lake Winnipeg food web. Biomagnification factors varied for the chemicals studied. Plots of log bioaccumulation factors for mussel and zooplankton versus log octanol–water partition coefficient (Kow) were similar and suggest that neither mussels nor zooplankton are in equilibrium with the water. Fifteen BDE congeners were consistently detected in water (dissolved phase, n = 3), with BDE 47 having the greatest concentration (17 pg/L). The rank order of compounds in water (arithmetic mean ± standard error) were ΣPBDEs (49 ± 12 pg/L) &gt; α-HBCD (11 ± 2 pg/L) &gt; BTBPE (1.9 ± 0.6 pg/L). Concentrations of DPDPE, BDE 209, and β- and γ-HBCD isomers were below their respective method detection limits (MDLs) in water. Total PBDE concentrations in sediment (n = 4) were greater than any other brominated flame retardant examined in the present study and ranged from 1,160 to 1,610 ng/g (dry wt), with BDE 209 contributing roughly 50% of the total. The γ-HBCD isomer was detected at concentrations of 50 ± 20 pg/g (dry wt) in sediment, whereas BTBPE and DBDPE were consistently below their respective MDLs in sediment.
Assessment of estrogenic exposure in brown trout (Salmo trutta) in a Swiss midland river: Integrated analysis of passive samplers, wild and caged fish, and vitellogenin mRNA and protein
Authors: Burki Richard , Vermeirssen Etiënne L.M. , Körner Oliver , Joris Caroline , Burkhardt-Holm Patricia , Segner Helmut 
Published: July 2006

AbstractThis field study examined the vitellogenin (VTG) biomarker response under conditions of low and fluctuating activities of environmental estrogenicity. The present study was performed on immature brown trout (Salmo trutta) exposed to the small river Luetzelmurg, which is located in the prealpine Swiss midland region and receives effluents from a single sewage treatment plant (STP). To understand better factors influencing the relationship between estrogenic exposure and VTG induction, we compared VTG levels in caged (stationary) and feral (free-ranging) fish, VTG levels in fish from up- and downstream of the STP, and two different methods for quantifying VTG (enzyme-linked immunosorbent assay vs real-time reverse transcription–polymerase chain reaction), and we used passive samplers (polar organic chemical integrative sampler [POCIS]) to integrate the variable, bioaccumulative estrogenic load in the river water over time. The POCIS from the downstream site contained approximately 20-fold higher levels of bioassay-derived estrogen equivalents than the POCIS from the upstream site. In feral fish, this site difference in estrogenic exposure was reflected in VTG protein levels but not in VTG mRNA. In contrast, in caged fish, the site difference was evident only for VTG mRNA but not for VTG protein. Thus, the outcome of VTG biomarker measurements varied with the analytical detection method (protein vs mRNA) and with the exposure modus (caged vs feral). Our findings suggest that for environmental situations with low and variable estrogenic contamination, a multiple-assessment approach may be necessary for the assessment of estrogenic exposure in fish.
Partitioning of moderately hydrophobic endocrine disruptors between water and synthetic membrane vesicles
Authors: Kwon Jung-Hwan , Liljestrand Howard M. , Katz Lynn E. 
Published: July 2006

AbstractThe partition coefficient between water and lipid membrane vesicles (Klipw) has been used as an alternative to the 1-octanol–water partition coefficient (Kow) between water and organic solvent, because it more closely represents actual biological membranes. Despite theoretical differences, log Klipw correlates well with log Kow for conventional nonpolar organic pollutants. In the present study, Klipw values of 11 structurally diverse endocrine-disrupting chemicals (EDCs) were measured for three different types of lipid membrane vesicles from dipalmitoylphosphatidylcholine (DPPC), DPPC/cholesterol, and palmitoyloleoylphosphatidylcholine. Correlation analyses were conducted to evaluate the effects of hydrophobicity, molar liquid volume (MLV), and polar surface area (PSA) for 20 EDCs, including nine from a previous study. Correlations that include MLV and PSA reduce the predicted value of log Klipw, suggesting that lipid membranes are less favorable than 1-octanol for a hydrophobic solute because of the higher molar volume and higher hydrogen-bonding potential. These results suggested that Kow alone has limited potential for estimating Klipw and that additional descriptors are required. In addition, Klipw values vary by as much as two orders of magnitude because of the changes in membrane fluidity and the amount of cholesterol in the lipid bilayer. Therefore, lipid components should be chosen carefully to evaluate the bioconcentration of these compounds.
Association of europium(III), americium(III), and curium(III) with cellulose, chitin, and chitosan
Authors: Ozaki Takuo , Kimura Takaumi , Ohnuki Toshihiko , Kirishima Akira , Yoshida Takahiro , Isobe Hiroshi , Francis Arokiasamy J. 
Published: July 2006

Abstract
The association of trivalent f-elements—Eu(III), Am(III), and Cm(III)—with cellulose, chitin, and chitosan was determined by batch experiments and time-resolved, laser-induced fluorescence spectroscopy (TRLFS). The properties of these biopolymers as an adsorbent were characterized based on speciation calculation of Eu(III). The adsorption study showed that an increase of the ionic strength by NaCl did not affect the adsorption kinetics of Eu(III), Am(III), and Cm(III) for all the biopolymers, but the addition of Na2CO3 significantly delayed the kinetics because of their trivalent f-element complexation with carbonate ions. It also was suggested from the speciation calculation study that all the biopolymers were degraded under alkaline conditions, leading to their masking of the adsorption of Eu(III), Am(III), and Cm(III) on the nondegraded biopolymers. The masking effect was higher for cellulose than for chitin and chitosan, indicating that of the three, cellulose was degraded most significantly in alkaline solutions. Desorption experiments suggested that some portion of the adsorbed Eu(III) penetrated deep into the matrix, being isolated in a cavity-like site. The TRLFS study showed that the coordination environment of Eu(III) is stabilized mainly by the inner spherical coordination in chitin and by the outer spherical coordination in chitosan, with less association in cellulose in comparison to chitin and chitosan. These results suggest that the association of these biopolymers with Eu(III), Am(III), and Cm(III) is governed not only by the affinity of the functional groups alone but also by other factors, such as the macromolecular steric effect. The association of degraded materials of the biopolymers also should be taken into consideration for an accurate prediction of the influence of biopolymers on the migration behavior of trivalent f-elements.
Assessment of the significance of direct and indirect pollution inputs to a major salmon-producing river using polyethylene membrane devices
Authors: Moles Adam , Holland Larry , Andersson Ole 
Published: July 2006

Abstract
Conventional passive sampling devices for monitoring pollution input often prove to be cost-prohibitive when assessing large spatial and temporal scales. The Kenai River, a major salmon-producing river in Alaska (USA), served as the perfect laboratory to test the utility of polyethylene membrane devices for assessing chronic nonpoint-source inputs to a large riverine watershed. Comparison of the relative levels of polycyclic aromatic hydrocarbons (PAHs) at a large number of locations over time allowed us to assess the significance and potential source of these compounds in the river. Concentrations of PAH were greatest near urban areas and peaked during the late winter, when streams flows and dilution were low. Vessel activity and PAH levels peaked in July and were heaviest in the lower 16 km of the river, where fishing activity was concentrated. Nearly one-third of the vessels observed on the river were powered by two-stroke engines, which release a higher proportion of unburned fuel into the water than the cleaner burning four-stroke engines. The low concentrations of hydrocarbons upriver of the boat traffic suggest very little remote delivery of these contaminants to the watershed. Polyethylene strips proved to be an excellent, low-cost tool for determining the PAH patterns in a large watershed.
Comparative evaluation of three high-performance liquid chromatography–based Kow estimation methods for highly hydrophobic organic compounds: Polybrominated diphenyl ethers and hexabromocyclododecane
Authors: Hayward Stephen J. , Lei Ying D. , Wania Frank 
Published: July 2006

Abstract
Three methods for estimating the octanol–water partition coefficient (Kow) based on its relationship with capacity factors on reversed-phase (RP) high-performance liquid chromatography (HPLC) columns were compared in terms of their applicability to highly hydrophobic compounds (HHCs). Methods based on simple isocratic elutions were found to be unsuitable, because the very high organic modifier fractions that are required to elute HHCs from RP columns challenge the basic assumption of the similarity between the octanol–water and RP–eluent systems. Compound planarity was found to exert a considerable influence on the retention of HHCs in RP columns, leading to different linear calibration curves for chlorobenzenes and chlorobiphenyls. Only an empirical exponential regression succeeded in describing the behavior of both groups of compounds during gradient elutions. In a method based on isocratic retention times at multiple temperatures, satisfactory calibration was achieved with a multivariate linear regression that included a numerical indicator of compound planarity. Considering experimental simplicity, speed, precision, and accuracy, with the latter judged by comparison with Kow values for polybrominated diphenyl ethers and polychlorinated naphthalenes as reported in the literature, a gradient elution combined with an exponential calibration curve is recommended for estimating the Kow of HHCs. To our knowledge, the first isomer-specific Kow values for hexabromocyclododecane are reported. Bearing in mind that the influence of structural characteristics on retention is likely to increase with hydrophobicity, it is not justified to judge a HPLC-based Kow estimation method as being suitable for HHCs because it is shown to work well for less hydrophobic substances. Whereas univariate linear regressions often may prove to be sufficient when dealing with substances having a log Kow of less than five, methods for HHCs need to account for the influence of structure on retention.
The Cargo of the Montserrat: Gilbertese Labor in Guatemalan Coffee, 1890-1908
Authors: McCreery David , Munro Doug 
Published: July 2006

Upon the plantations themselves the laborers are not so badly treated, for there they are the property of their owners, and men treat their own property well, especially when it is of considerable value. But they are brought from a thoroughly healthy climate, where disease is almost unknown, to a feverstricken region. Within twelve months their numbers will probably be reduced to one-third, and at the expiration of the three years a woefully diminished number will return to their lovely homes in the Western Pacific.In recent years much attention has focused on the labor migration of Pacific Islanders, and particularly Melanesians, during the second half of the nineteenth century for work on the export plantations of Fiji, Samoa, New Guinea, and Queensland. A smaller number, but a quantity nevertheless significant for the populations from which they came, went to labor in Latin America. In 1862-63, for example, vessels from Peru kidnapped perhaps 3,600 persons from the smaller islands of the eastern Pacific and ventured as far west as the Gilbert Islands, where they ensnared three hundred or more unsuspecting individuals. A larger migration from the Gilberts occurred almost thirty years later, when in 1890-92 some twelve hundred individuals signed up to work on the coffee plantations (fincas) of the Pacific piedmont (boca costa) of southern Mexico and Guatemala; this constituted almost fifteen percent of the Gilbertese who migrated for offisland labor after the middle of the century. Less than 800 of the 1890s cohort actually arrived, and perhaps a quarter to a third of these died in the first year, so that their impact on an industry which annually mobilized tens of thousands of local Indians was limited. Nevertheless, for the Guatemalan coffee elites the experience confirmed what they had long suspected, that there would be no solution to their labor problems outside of the republic itself. For the Gilbertese this was by far the largest instance of labor recruitment of the decade, a period of economic hardship and political changes in the archipelago.
The Enchanted Burro, Bayonets and the Business of Making Sugar: State, Capital, and Labor Relations in the Ingenio San Antonio, 1912-1926
Authors: Gould Jeffrey L. 
Published: July 2006

Since the 1920s, the San Antonio sugar mill in Chichigalpa, Nicaragua has been that country's largest manufacturing establishment. The ingenio (the sugar mill along with the plantation) employed close to 2,000 workers in 1920, and has since consistently employed far more workers than any other single enterprise. The owners of San Antonio were—and continue to be—the most economically powerful group within the Nicaraguan elite, In contemporary Nicaragua, the above affirmations remain valid: San Antonio is still the largest employer and economically most powerful financial group in the country.Any consideration of the development of Nicaraguan capitalism must take into account the history of the Ingenio San Antonio (ISA). In this article, I will examine the development of relations among labor, management, and the state in San Antonio from the 1890s until 1930 using archival and oral sources. Throughout this period, politics and economics were inseparable for the workers. Particularly after the U.S. Marines occupied Nicaragua in 1912 and bolstered the Conservative regime, the political Liberalism of the San Antonio workers was something of a popular revolutionary