bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistent organic pollutants in the diet of harbor seals (Phoca vitulina) inhabiting puget sound, washington (USA), and the strait of Georgia, British Columbia (Canada): A food basket approach
Authors: Cullon Donna L. , Jeffries Steven J. , Ross Peter S. 
Published: October 2005

Abstract
Harbor seals (Phoca vitulina) inhabiting Puget Sound (WA, USA) recently were found to be seven times more contaminated with polychlorinated biphenyls (PCBs) than those inhabiting the adjacent Strait of Georgia (BC, Canada). We carried out a food basket approach to approximate realistic dietary exposures of both new (e.g., polybrominated diphenyl ethers [PBDEs]) and legacy (e.g., dichlorodiphenyltrichloroethane [DDT]) persistent organic pollutants (POPs) for these harbor seals. Food basket homogenates, each consisting of over 200 individual prey items, were constructed using documented dietary preferences for harbor seals in these basins, and analyzed for organochlorine pesticides, flame retardants, and other persistent contaminants. Concentration rankings for the major contaminant classes in the Puget Sound food basket were sumPCBs &gt; sumPBDEs &gt; sumDDT, and for the Strait of Georgia food basket were sumPCBs &gt; sumDDT &gt; sumPBDEs, highlighting the emergence of PBDEs as a significant concern in the regional environment. Consistent with observations in harbor seals, PCB concentrations in the Puget Sound food basket were seven times higher than in its Strait of Georgia counterpart. Based on our food basket results, the estimated daily intake of sumPCB toxic equivalents to dioxin by Puget Sound harbor seals exceeds some wildlife consumption guidelines for PCBs. Our results indicate that both legacy and new POPs present a health risk to these marine mammals.
Effects of maternally transferred organochlorine contaminants on early life survival in a freshwater fish
Authors: Johnston Thomas A. , Miller Loren M. , Whittle D. Michael , Brown Scott B. , Wiegand Murray D. , Kapuscinski Anne R. , Leggetta William C. 
Published: October 2005

Abstract
Laboratory research has shown that female fish can pass toxic organochlorines (OCs) from their bodies to their eggs, killing their offspring if sufficient quantities are transferred. We conducted a controlled incubation study using gametes from a wild, OC-contaminated walleye (Sander vitreus) population (Bay of Quinte, Lake Ontario, Canada) in order to assess among-female variation in offspring early life survival in relation to ova concentrations of planar OCs (polychlorinated dibenzo-p-dioxins and furans and planar polychlorinated biphenyls) and a suite of other maternal and ova characteristics. Equal volumes of ova from each female were fertilized, pooled, and incubated together as an experimental cohort. Relative survival of each female's offspring was estimated as the proportion of surviving larvae (at ∼5 d posthatch) that she contributed to the cohort as determined by microsatellite DNA parentage assignment. Total planar OC concentration (expressed as toxic equivalency of 2,3,7,8-tetrachloro-dibenzo-p-dioxin) of ova was positively related to maternal age and size and to ova lipid content. However, early life survival did not decline with increasing ova planar OC concentrations. Similarly, we observed no significant relationships between early life survival and ova thiamine content, ova fatty acid composition, or maternal age or size. Early life survival was more strongly correlated with date of spawn collection, thyroid hormone status of the ova, and ovum size. Maternally transferred planar OCs do not appear to negatively influence female reproductive success in this walleye population.
Complex mixture toxicity for single and multiple species: Proposed methodologies
Authors: de Zwart Dick , Posthuma Leo 
Published: October 2005

Abstract
Methods for the assessment of ecological risks associated with exposure to defined mixtures of toxicants are reviewed and formalized for single-species toxicity. Depending on the modes of action of toxicants in a mixture, these methods apply either the model for concentration additivity (CA) or the model for response additivity (RA). For complex mixtures, the present paper advocates the use of a new, two-step, mixed-model approach as a logical extension of model selection: Mixture toxicity for individual modes of action is evaluated with the CA model, and the toxicities of different modes of action are combined using the RA model. Using comparable mixture toxicity strategies in combination with the concept of species-sensitivity distributions, we develop a method to address and predict the risk for direct effects on the composition of species assemblages and biodiversity. The data needed for modeling can be obtained from existing databases, and lack of data can, in part, be addressed by the use of toxicity patterns in those databases. Both single- and multiple-species methods of mixture risk prediction are useful for risk management, because they allow ranking of polluted sites and affected species as well as identification of the most hazardous contaminants, at least in a comparative way. Validation of the proposed methods is feasible but currently limited because of a lack of appropriate data.
1,3-dinitrobenzene toxicity in the least shrew, Cryptotis parva
Authors: Mock Orin B. , Casteel Stan W. , Darmani Nissar A. , Shaddy James H. , Besch-Williford Cynthia , Towns Lex C. 
Published: October 2005

Abstract
Shrews are abundant in most areas of toxic chemical contamination and bioaccumulate pollutants at much higher rates than sympatric rodent species. As a part of studies to provide information concerning the toxicity of 1,3-dinitrobenzene (DNB) in least shrews (Cryptotis parva), groups of 10 females and 10 males received DNB at O (control), 0.7, 2.9, 11.6, and 46.3 μl/L (equivalent mean daily dosage of 0, 0.26, 1.06, 4.26, and 17.0 mg/kg body wt in each sex) in their diet for 14 d. Leukocytosis present at the 0.26 mg/kg body weight/d dosage established the lowest-observed-adverse effect level (LOAEL). Adrenal enlargement was noted at the 1.06 mg/kg body weight/d level. Splenic enlargement and reductions in hematocrit and hemoglobin values occurred at the 4.26 mg/kg body weight/d treatment. Enlargements in the liver and heart and reductions in brown fat weight, granulocyte numbers, and alanine aminotransferase levels were present at high dose levels. Histopathologic examinations showed Kupffer's cell hemosiderosis and suggested testicular damage at the two highest tested doses but failed to confirm brain lesions. Least shrews do not follow standard scaling estimates for lifespan or metabolic rates. The LOAEL calculated from the standard terrestrial screening benchmark equation was higher than our findings, suggesting that these estimates must be viewed with caution.
Comparison of Cd, Cu, and Zn toxic effects on four marine phytoplankton by pulse-amplitude-modulated fluorometry
Authors: Miao Ai-Jun , Wang Wen-Xiong , Juneau Philippe 
Published: October 2005

Abstract
The toxic effects of Cd, Cu, and Zn on four different marine phytoplankton, Dunaliella tertiolecta, Prorocentrum minimum, Synechococcus sp., and Thalassiosira weissflogii, were examined by comparing the cell-specific growth rate, pulse-amplitude-modulated (PAM) parameters (maximum photosystem II quantum yield ϕM and operational quantum yield ϕ'M), chlorophyll a content, and cellular metal concentration, over a 96-h period. The calculated no-observed-effect concentration (NOEC) based on both cell-specific growth rate and two PAM parameters (ϕM and ϕ'M) were mostly identical. Thus, these PAM parameters and cell-specific growth rate were comparable in their sensitivities as the biomarkers for trace metal toxicity to marine phytoplankton. The cyanobacteria Synechococcus sp. was the most sensitive species among the four algal species tested because of its higher cell surface to volume ratio. The toxicity of the three tested metals followed the order of Cd &gt; Cu &gt; Zn based on the cellular metal concentration of the four algae at the NOEC. The cellular metal bioaccumulation followed the same Freundlich isotherm for each metal regardless of the algal species, indicating that the metal accumulation was a nonmetabolic process under high ambient metal concentrations and that the cell surface metal binding was comparable among the different species. For all the algae examined in our study, the bioaccumulation potentials of Cu and Zn were similar to each other, while the Cd bioaccumulation was much lower under environmentally realistic metal concentration.
New organochlorine contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) from the Norwegian Arctic
Authors: Verreault Jonathan , Letcher Robert J. , Muir Derek C.G. , Chu Shaogang , Gebbink Wouter A. , Gabrielsen Geir W. 
Published: October 2005

Abstract
The present study investigated new or lesser-studied and legacy organochlorine (OC) contaminants and metabolites in plasma and eggs of glaucous gulls (Larus hyperboreus) collected from major breeding colonies on Bear Island in the Norwegian Arctic. Hexachlorobutadiene was below the method limit of detection (&lt;0.07 ng/g lipid wt) in all samples. The sum (sum) of 20 chlorobornane congener concentrations ranged between 294 and 986 ng/g lipid weight and 104 and 1,121 ng/g lipid weight in plasma and eggs, respectively, whereas those of ∑20polychlorinated naphthalene ranged between 1.34 and 126 ng/g lipid weight in plasma and 1.82 and 162 ng/g lipid weight in eggs. Bis(4-chlorophenyl) sulfone concentrations ranged between 5.24 and 143 ng/g lipid weight plasma, which is the first report of this contaminant in arctic biota north of Sweden. Based on 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs), partial dioxin-like toxicity varied between 3.04 and 20.8 ng TEQ/g lipid weight in plasma and 0.94 and 46.5 ng TEQ/g lipid weight in eggs, and largely was due to concentrations of non-ortho polychlorinated biphenyls (PCBs), with a very minor contribution from mono-ortho PCBs and polychlorinated naphthalenes. The major aryl sulfone metabolite in plasma was an unidentified hexachlorinated MeSO2-PCB congener (range: 13.5–551 ng/g lipid wt), whereas the pentachlorinated congeners 3′- and 4′-MeSO2-CB101 (range: 4.49–38.1 ng/g lipid wt) dominated in eggs. The predominant halogenated phenolic compound (HPC) in plasma was consistently the PCB metabolite 4-OH-CB187 (range: 0.29–17.5 ng/g wet wt), whereas in eggs, detectable HPCs were at very low and transient concentrations. As part of a complex profile of contaminant exposure, these chemical classes and metabolites may be contributing factors to enhance physiological stress in breeding glaucous gulls.
Effect-directed analysis of mutagens and ethoxyresorufin-O-deethylase inducers in aquatic sediments
Authors: Brack Werner , Schirmer Kristin , Erdinger Lothar , Hollert Henner 
Published: October 2005

Abstract
Sediment extracts from a creek in the Neckar river basin (Germany), which received the discharge of treated hospital wastewater, were found to exhibit strong aromatic hydrocarbon (Ah) receptor-mediated effects in a rainbow trout liver cell line (RTL-W1) as well as high mutagenicity in the Salmonella/microsome assay after fractionation. The crude extract did not exhibit a clear mutagenic response. Apparently, cleanup or fractionation before mutagenicity testing is necessary to minimize the risk of false-negative results. Effect-directed fractionation and analysis were applied to characterize and identify the toxicants that cause these effects. Major ethoxyresorufin-O-deethylase induction potency and mutagenicity were detected in different polyaromatic fractions, indicating different sets of toxicants that induce metabolic activation and mutagenicity. Dioxin-like halogenated aromatic hydrocarbons, including polychlorinated biphenyls, naphthalenes, dibenzo-p-dioxins and furans, and priority polycyclic aromatic hydrocarbons, contributed to Ah receptor-mediated activity only to a minor extent. Benzo[a]pyrene, benzo[a]fluoranthene, and perylene could be confirmed as important contributors to mutagenicity. The nonpriority pollutants 11H-indeno[2,1,7-cde]pyrene, a methylbenzo[e]pyrene, and a methylperylene were tentatively identified as major components, representing 82% of the peak area of a highly mutagenic fraction of the sediment extract. This suggests that hazard and risk assessment of complex environmental mixtures should make increasing attempts to identify and consider hazardous key pollutants rather than focusing on a priori-selected key pollutants alone.
Metal and oxygen uptake in the green mussel Perna viridis under different metabolic conditions
Authors: Wang Jingfeng , Chuang Chia-Ying , Wang Wen-Xiong 
Published: October 2005

Abstract
Coupled respirometric and radiotracer techniques were applied to simultaneously measure the rates of oxygen and metal uptake in the green mussel Perna viridis. This was performed under different metabolic conditions by varying the ambient oxygen partial pressure (Po2), temperature, air exposure, and body size. When the mussels were tested under different hypoxic and anoxic conditions, Cd and Zn uptake decreased with decreasing Po2, accompanied by a decrease in the ventilation activity of mussels. Significant reduction in metal uptake was observed at a Po2 level of 3 kPa. Under anoxic conditions, the uptake of Cd and Zn was 1.6 to 2.7 times and 2.8 times, respectively, lower than those measured under normoxia. In contrast, both the absorption efficiencies of Cd and Zn and the oxygen extraction efficiency increased significantly with decreasing Po2. There were significant correlations between the rates of Cd/Zn and O2 uptake by the mussels when quantified under various Po2 levels. The uptake of Cd and Zn was temperature dependent and increased with temperature over a range of 15 to 30°C. Significant correlations between the rates of Cd/Zn and O2 uptake were also found in the temperature experiments. With reimmersion of mussels after aerial exposure, the mussels experienced an apparent O2 debt. Metal uptake also increased within the first 15 min followed by gradual recovery to the control levels. Similarly, the quantified uptake rates of Zn were significantly correlated with the O2 uptake in experiments with different sizes of mussels. These results strongly suggest that Cd and Zn uptake are coupled with oxygen uptake in the mussels; thus, physiological processes need to be considered in studying metal accumulation.
Comparison of different androgen bioassays in the screening for environmental (anti)androgenic activity
Authors: Christiaens Valerie , Berckmans Pascale , Haelens Annemie , Witters Hilda , Claessens Frank 
Published: October 2005

Abstract
Endocrine disruptors pose a growing threat to human and wildlife health. Validated test systems are required to study the mechanisms by which chemicals may interfere with the endocrine system. In order to identify compounds with (anti)androgenic activity, we used several in vitro bioassays, based on different androgen receptor (AR) functions, including AR transactivation and interaction between the amino-terminal domain and the ligand-binding domain. The AR activity assay, based on activation of the transcription of an androgen-responsive reporter gene in the presence of androgen, proved to excel in terms of high fold induction range and low minimal detection limit. The EC50 value, defined as the concentration that leads to half the maximal response and reflecting the potency of the synthetic androgen R1881 (methyltrienolone), was found to be 250 pM, consistent with the high affinity of this ligand to the human AR. A number of environmental samples were tested in the bioassay. The bioassay also could be used to detect antiandrogenic activity, because known AR-antagonists were able to inhibit R1881-mediated transactivation.
Potential ecotoxic effects of polychlorinated biphenyls on Xenopus laevis
Authors: Qin Zhan-Fen , Zhou Jing-Ming , Cong Lin , Xu Xiao-Bai 
Published: October 2005

Abstract
We examined potential ecotoxic effects of polychlorinated biphenyl (PCB)3, PCB5, Aroclor 1254, and Aroclor 1242 on Xenopus laevis. Tadpoles were exposed to PCBs from stage 46/47 (system of Nieuwkoop and Faber) to the completion of metamorphosis. We demonstrated, to our knowledge for the first time, forelimb malformations caused by PCBs (malformation rate, &gt;70%). The malformed forelimbs were fixed in the adduction-backward rotation position and could not move. Therefore, malformed male frogs were destined to have no offspring, because they could not grasp the females with their forelimbs to mate. Alcian blue-alizarin red double-staining indicated that the forelimb malformation resulted from the shoulder abnormality. Compared with the normal shoulder joint, the proximal humerus with the humerus inter-rotated 90° in the abnormal shoulder joint. Moreover, testes from more than a third of male frogs with exposed to PCBs exhibited feminization to different degrees at gross morphology and histology, with fewer or abnormal spermatogonia and oocytes. Gonadal abnormalities would lead directly to reproductive dysfunction and population decline. These results suggest that PCBs have potentially ecotoxic effects on amphibian populations. We infer that PCBs could play roles in amphibian malformations and population declines, at least at sites that are polluted heavily with PCBs.
Factor structure of the Buss‐Perry aggression questionnaire in different samples and languages
Authors: Vigil‐Colet Andreu , Lorenzo‐Seva Urbano , Codorniu‐Raga Maria J. , Morales Fabia 
Published: October 2005

AbstractThis study aims to analyze the factorial structure of the aggression questionnaire developed by Buss and Perry [1992]. Many studies of different adaptations of the questionnaire have shown its lack of fit to the 4–factor structure proposed by Buss and Perry because of the functioning of certain items. The present study applies consensus oblimin rotation to five of these studies in an attempt to assess the degree of congruence within these factorial structures and, if necessary, to remove the problematical items. This method simultaneously rotates the loading matrices obtained in several studies to achieve a mixture of simplicity and optimal agreement between them. The factorial structures reported by Buss and Perry [1992] in English, Nakano [2001] in Japanese, Ramirez et al. [2001] in Japanese and Spanish, and Garcia‐León et al. [2002] in Spanish, were used. Results show that the congruence between the different factorial solutions is considerable, although certain items show low congruence values. The result for these items was taken into account, and a reduced version was proposed that does not include them. The results show that this reduced version of the test could be congruent among samples and languages. Aggr. Behav. 00:1–8, 2005. © 2005 Wiley‐Liss, Inc.
Cortical complexity in cetacean brains
Authors: Hof Patrick R. , Chanis Rebecca , Marino Lori 
Published: October 2005

AbstractCetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55–60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As such, cetacean brains offer a critical opportunity to address questions about how complex behavior can be based on very different neuroanatomical and neurobiological evolutionary products. Cetacean brains and primate brains are arguably most meaningfully conceived as alternative evolutionary routes to neurobiological and cognitive complexity. In this article, we summarize data on brain size and hemisphere surface configuration in several cetacean species and present an overview of the cytoarchitectural complexity of the cerebral cortex of the bottlenose dolphin. © 2005 Wiley‐Liss, Inc.
Overview of the visual system of tarsius
Authors: Collins Christine E. , Hendrickson Anita , Kaas Jon H. 
Published: October 2005

AbstractTarsiers, which are currently considered to constitute the sister group of anthropoid primates, exhibit a number of morphological specializations such as remarkably large eyes, big ears, long hind legs, and a nearly naked tail. Here we provide an overview of the current state of knowledge on the tarsier visual system and describe recent anatomical observations from our laboratory. Its large eyes notwithstanding, the most remarkable feature of the tarsier brain is the large size and distinct lamination of area V1. Based on the need of tarsier for optimal scotopic vision and acuity to detect small prey in low lighting conditions, tarsiers may have preserved a high level of visual acuity by enlarging V1 at the expense of other areas. The other classically described visual regions are present in tarsier, albeit many borders are not clearly distinct on histochemical or immunohistochemical preparations. Tarsiers also have a large number and unusual distributions of cones in the retina, with high numbers of M/L‐cones in the central retina and S‐cones surprisingly at the periphery, which may be sensitive to UV light and may be useful for prey detection. These adaptive specializations may together account for the unique nocturnal predatory requirements of tarsiers. © 2005 Wiley‐Liss, Inc.
Purinergic receptor antagonists inhibit odorant‐induced heat shock protein 25 induction in mouse olfactory epithelium
Authors: Hegg Colleen C. , Lucero Mary T. 
Published: October 2005

AbstractHeat shock proteins (HSPs) accumulate in cells exposed to a variety of physiological and environmental factors, such as heat shock, oxidative stress, toxicants, and odorants. Ischemic, stressed, and injured cells release ATP in large amounts. Our hypothesis is that noxious stimulation (in this case, strong odorant) evokes the release of ATP in the olfactory epithelium (OE). Extracellular ATP, a signal of cellular stress, induces the expression of HSPs via purinergic receptors. In the present study, in vivo odorant exposure (heptanal or R‐carvone) led to a selective induction of HSP25 in glia‐like sustentacular cells in the Swiss Webster mouse OE, as previously shown in rats (Carr et al., 2001). Furthermore, in vitro and in vivo administration of purinergic receptor antagonists suramin and pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulfonic acid (PPADS) blocked the expression of HSP25 immunoreactivity in sustentacular cells. ATP released by acutely injured cells could act as an early signal of cell and tissue damage, causing HSP expression and initiating a stress signaling cascade to protect against further damage. Sustentacular cells have a high capacity to detoxify xenobiotics and thereby protect the olfactory epithelium from airborne pollutants. Thus, the robust, rapid induction of HSPs in sustentacular cells may help maintain the integrity of the OE during exposure to toxicants. © 2005 Wiley‐Liss, Inc.