bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypervariable Noncoding Sequences in Saccharomyces cerevisiaeSequence data from this article have been deposited with the EMBL/GenBank Data Libraries under accession nos. AY942206, AY942556.
Authors: Fay Justin C , Benavides Joseph A
Published: June 2005

Compared to protein-coding sequences, the evolution of noncoding sequences and the selective constraints placed on these sequences is not well characterized. To compare the evolution of coding and noncoding sequences, we have conducted a survey for DNA polymorphism at five randomly chosen loci among a diverse collection of 81 strains of Saccharomyces cerevisiae. Average rates of both polymorphism and divergence are 40% lower at noncoding sites and 90% lower at nonsynonymous sites in comparison to synonymous sites. Although noncoding and coding sequences show substantial variability in ratios of polymorphism to divergence, two of the loci, MLS1 and PDR10, show a higher rate of polymorphism at noncoding compared to synonymous sites. The high rate of polymorphism is not accompanied by a high rate of divergence and is limited to a few small regions. These hypervariable regions include sites with three segregating bases at a single site and adjacent polymorphic sites. We show that this clustering of polymorphic sites is significantly greater than one would expect on the basis of the spacing between polymorphic fourfold degenerate sites. Although hypervariable noncoding sequences could result from selection on regulatory mutations, they could also result from transient mutational hotspots.
Identification of Genetic Loci That Interact With cut During Drosophila Wing-Margin Development
Authors: Krupp Joshua J , Yaich Lauren E , Wessells Robert J , Bodmer Rolf
Published: June 2005

The Drosophila selector gene cut is a hierarchal regulator of external sensory organ identity and is required to pattern the sensory and nonsensory cells of the wing margin. Cut performs the latter function, in part, by maintaining expression of the secreted morphogen encoded by wingless (wg). We find that Cut is required for wing-margin sensory organ specification in addition to and independently of Wg maintenance. In addition, we performed a genetic modifier screen to identify other genes that interact with cut in the regulation of wing-margin patterning. In total, 45 genetic loci (35 gain-of-function and 10 loss-of-function loci) were identified by virtue of their ability to suppress the wing-margin defects resulting from gypsy retrotransposon-mediated insulation of the cut wing-margin enhancer. Further genetic characterization identified several subgroups of candidate cut interacting loci. One group consists of putative regulators of gypsy insulator activity. A second group is potentially required for the regulation of Cut expression and/or activity and includes longitudinals lacking, a gene that encodes a family of BTB-domain zinc-finger transcription factors. A third group, which includes a component of the Brahma chromatin remodeling complex encoded by moira, affects the level of Cut expression in two opposing ways by suppressing the gypsy-mediated ctK phenotype and enhancing the non-gypsy ct53d phenotype. This suggests that the Brahma complex modulates both enhancer-controlled transcription and gypsy-mediated gene insulation of the cut locus.
Molecular Evidence for Transcription of Genes on a B Chromosome in Crepis capillaris
Authors: Leach Carolyn R , Houben Andreas , Field Bruce , Pistrick Klaus , Demidov Dmitri , Timmis Jeremy N
Published: June 2005

Dispensable, supernumerary (B) chromosomes are found in diverse eukaryotic species. The origin and genetic consequences of B chromosomes have been the subjects of speculation for more than a century. Until now, there has been no molecular evidence that B chromosome DNA is transcribed and there is no unequivocal evidence as to their origin. B chromosomes are considered to be genetically inert although they appear to cause a variety of phenotypic effects. We report that members of one of two ribosomal RNA gene families that are confined to the B chromosomes of a plant, Crepis capillaris, are transcribed—thus providing the first molecular evidence of gene activity on B chromosomes. Sequence analysis of part of the A and B chromosome rRNA genes, together with comparisons with related species, indicates that the B chromosome rRNA genes originate from the A chromosome.
Contrasting Patterns of Polymorphism and Divergence on the Z Chromosome and Autosomes in Two Ficedula Flycatcher Species
Authors: Borge Thomas , Webster Matthew T , Andersson Gunilla , Saetre Glenn-Peter
Published: June 2005

In geographic areas where pied and collared flycatchers (Ficedula hypoleuca and F. albicollis) breed in sympatry, hybridization occurs, leading to gene flow (introgression) between the two recently diverged species. Notably, while such introgression is observable at autosomal loci it is apparently absent at the Z chromosome, suggesting an important role for genes on the Z chromosome in creating reproductive isolation during speciation. To further understand the role of Z-linked loci in the formation of new species, we studied genetic variation of the two species from regions where they live in allopatry. We analyzed patterns of polymorphism and divergence in introns from 9 Z-linked and 23 autosomal genes in pied and collared flycatcher males. Average variation on the Z chromosome is greatly reduced compared to neutral expectations based on autosomal diversity in both species. We also observe significant heterogeneity between patterns of polymorphism and divergence at Z-linked loci and a relative absence of polymorphisms that are shared by the two species on the Z chromosome compared to the autosomes. We suggest that these observations may indicate the action of recurrent selective sweeps on the Z chromosome during the evolution of the two species, which may be caused by sexual selection acting on Z-linked genes. Alternatively, reduced variation on the Z chromosome could result from substantially higher levels of introgression at autosomal than at Z-linked loci or from a complex demographic history, such as a population bottleneck.
Effects of a Supervisory Education for Positive Mental Health in the Workplace: A Quasi‐Experimental Study
Authors: Tsutsumi Akizumi , Takao Soshi , Mineyama Sachiko , Nishiuchi Kyoko , Komatsu Hirokazu , Kawakami Norito
Published: June 2005

Effects of a Supervisory Education for Positive Mental Health in the Workplace: A Quasi‐Experimental Study: Akizumi Tsutsumi, et al. Okayama University School of Medicine and Dentistry, Social and Environmental Life Sciences, Social Medicine and Longevity Sciences, Hygiene and Preventive Medicine—Single‐session supervisory education was developed in conjunction with the Japanese national guidelines for the promotion of employee mental health. Totally 267 voluntary supervisors in a prefectural office were presented with comprehensive information on the role they had to fulfill to promote mental health in the workplace. Totally 864 office employees (53%) were evaluated to determine whether education had had an effect on their psychological distress and job performance. The findings from the departments in which more than one‐third of the supervisors had attended education were compared to those from the departments in which no more than one‐third of the supervisors had attended education. Three months after the education, the levels of psychological distress and, to a lesser extent, self‐reported job performance improved among employees in the departments in which at least one‐third of the supervisors attended the education compared to those from departments with lower attendance rates of the supervisors. For the psychological outcome, the positive educational effect was supported by statistically significant interaction terms between time and department category with adjustment for the confounders. Favorable changes were noted among supervisors who received the education in knowledge, attitude, and behavior regarding mental health practices. The behavioral changes were related to decreasing workplace problems and referral of employees to the liaison office and associated medical institutions. Despite several limitations, the findings suggest that providing supervisors with appropriate information has a positive effect on employee psychological well‐being.
Thirteen‐week Inhalation Toxicity of p‐Dichlorobenzene in Mice and Rats
Authors: Aiso Shigetoshi , Arito Heihachiro , Nishizawa Tomoshi , Nagano Kasuke , Yamamoto Seigo , Matsushima Taijiro
Published: June 2005

Thirteen‐week Inhalation Toxicity of p‐Dichlorobenzene in Mice and Rats: Shigetoshi Aiso, et al. Japan Bioassay Research Center, Japan Industrial Safety and Health Association— Subchronic inhalation toxicity of p‐dichlorobenzene (p‐DCB) was examined by exposing BDF1 mice and F344 rats of both sexes (6 h/d and 5 d/wk) to inhalation of 25, 55, 120, 270 or 600 ppm (v/v) p‐DCB vapor for 13 wk. The exposure to p‐DCB vapor retarded the growth rate in the male mice, and induced hepatotoxicity in the mice and rats of both sexes and renal and hematological toxicity in the male rats. Hepatotoxicity was characterized by increased liver weight, hepatocellular hypertrophy, and increased serum levels of total cholesterol. Liver necrosis and increased serum levels of AST and ALT were observed in the exposed mice, whereas these changes, which indicate hepatocellular death, did not occur in any of the exposed rats. p‐DCB‐induced renal lesions occurred only in the male rats. Hyaline droplets were observed in the proximal tubular epithelial cells, and were stained positively with anti‐α2ν‐globulin, suggesting excessive accumulation of α2ν‐globulin in the epithelial cells. Granular casts were formed in the tubular lumen, resulting from the necrotic desquamation of the renal tubular epithelium. Papillary mineralization in the renal pelvis and increased serum levels of BUN and creatinine were noted. These renal changes indicated α2ν‐globulin nephropathy. Decreases in red blood cell counts, hemoglobin concentration, hematocrit and mean corpuscular volume and increased spleen weight occurred in the exposed male rats. The NOAEL was 120 ppm for the hepatic endpoint in mice and for the renal endpoint in rats. The maximum tolerated dose for a 2‐yr bioassay inhalation study of rodent carcinogenicity was estimated to be 300 ppm, based on the present results.
Derivation and Growing Human Embryonic Stem Cells on Feeders Derived from Themselves
Authors: Wang Qian , Fang Zhen F. , Jin Fan , Lu Yong , Gai Hui , Sheng Hui Z.
Published: June 2005

Human embryonic stem cells (hESCs) are pluripotent. They have the potential to differentiate into every cell type of an organism. Since many human somatic cell types have the ability to support the growth of hESCs, cells differentiated from hESCs may also be able to support the growth of themselves. We tested this hypothesis by growing hESCs on feeders derived from themselves and demonstrated that such feeders did constitute an environment suitable for the derivation and long-term growth of hESCs. hESCs maintained in this system expressed all the markers indicative of the undifferentiated state and gave rise to cell types representative of all three primary germ layers upon differentiation. By modifying the genome of hESCs, feeders with special features can be derived and mass produced. The system will facilitate large-scale production of hESCs in a standardized animal pathogen-free environment.
Disruption of the murine PIASx gene results in reduced testis weight
Authors: Santti H , Mikkonen L , Anand A , Hirvonen-Santti S , Toppari J , Panhuysen M , Vauti F , Perera M , Corte G , Wurst W , Jänne O A , Palvimo J J
Published: June 2005

PIASx belongs to the PIAS protein family, the members of which modulate activities of several transcription factors and act as E3 ligases in the sumoylation pathway. The PIASx gene is highly expressed in testis, suggesting a role in spermatogenesis. To investigate the function of PIASx in vivo, we have disrupted the PIASx gene in mice. Interestingly, the knockout mice were viable and fertile. Despite the normal fertility, the testis weight of the mutant animals was reduced and their number of apoptotic testicular cells was increased. Also, the sperm count of mutant mice tended to be reduced, but the quality of their sperm cells was normal. No significant changes were observed in the serum levels of LH and FSH or in the intratesticular testosterone concentration between the knockout animals and their wild-type littermates. Compensatory increases in other PIAS protein mRNAs were not observed in the knockout mice. These results imply that PIASx is required quantitatively rather than qualitatively for normal spermatogenesis.
Identification of a heterodimer-specific epitope present in human chorionic gonadotrophin (hCG) using a monoclonal antibody that can distinguish between hCG and human LH
Authors: Gadkari R A , Roy S , Rekha N , Srinivasan N , Dighe R R
Published: June 2005

Human chorionic gonadotrophin (hCG) is secreted during early pregnancy and is required for implantation and maintenance of the pregnancy. Active or passive immunoneutralization of hCG results in termination of pregnancy and this forms the basis of the hCG-based female contraceptive vaccine. However, the β subunit of hCG possesses 85% sequence homology with the first 114 amino acids of the β subunit of pituitary human LH (hLH), which is required for ovulation and maintenance of the corpus luteum function during the menstrual cycle. Immunization against hCG or its β subunit leads to generation of antibodies that can neutralize hLH due to many shared epitopes and hence may cause abnormal menstrual cycles. Therefore, it is essential to identify epitopes that are different in the two hormones. In the present study, we report a monoclonal antibody (MAb) specific for hCG that shows no binding to the isolated subunits. Interestingly, the MAb also does not bind hLH at all. The epitope mapping analysis revealed that this antibody recognizes a unique discontinuous epitope present only in the heterodimeric hCG and is distinct from the unique C-terminal extension of hCGβ that is absent in hLHβ. The MAb, either as IgG or its recombinant single-chain variable region fragment, inhibited the response to hCG, but not to hLH. Thus, the epitope recognized by this MAb is an ideal candidate antigen for immunocontraception.
Expression of glutaredoxin (thioltransferase) in the rat ovary during the oestrous cycle and postnatal development
Authors: González-Fernández R , Gaytán F , Martínez-Galisteo E , Porras P , Padilla C A , Sánchez Criado J E , Bárcena J A
Published: June 2005

Glutaredoxins (Grxs) are low-molecular-weight proteins which participate in redox events in association with glutathione (GSH) and are involved in a variety of cellular processes. It is known that oxidative stress plays important physiological roles within the ovary. In the present study, we have prepared specific antibodies against rat Grx and have used them to localize the protein in the ovaries of rats during postnatal development and during the oestrous cycle, by immunohistochemical methods. We have also performed a quantitative analysis of Grx by ELISA and Western blotting in homogenates of whole ovaries of cycling and pseudopregnant rats. We have found a prominent presence of Grx in the oocytes and in corpora lutea (CL) during developmental and oestrous cycle changes. Grx was absent from the oocytes in the first days of postnatal life when marked oocyte degeneration takes place, but its presence was very conspicuous in the cytoplasm of oocytes in healthy and attretic follicles in rats from 10 days of age onward, independently of the day of oestrous cycle. Follicular cells were negative. Grx immunostaining in the CL was strong in infiltrating macrophages and in a population of steroidogenic cells that survived the apoptotic burst in regressing CL and in CL remnants, but was faint or absent in young CL of the current cycle and in CL during pseudopregnancy. Grx content and oxidoreductase activity in whole ovaries increased significantly during the phase transition from proestrous to oestrous along the cycle. These results support a role of Grx in the maintenance of functional oocytes and in luteal cells surviving the regression process, probably as a consequence of the demonstrated deglutathionylating function of this protein in an antioxidant and antiapoptotic context.
Five gonadotrophin-releasing hormone receptors in a teleost fish: isolation, tissue distribution and phylogenetic relationships
Authors: Moncaut Natalia , Somoza Gustavo , Power Deborah M , Canário Adelino V M
Published: June 2005

Gonadotrophin-releasing hormone (GnRH) is the main neurohormone controlling gonadotrophin release in all vertebrates, and in teleost fish also of growth hormone and possibly of other adenohypophyseal hormones. Over 20 GnRHs have been identified in vertebrates and protochoordates and shown to bind cognate G-protein couple receptors (GnRHR). We have searched the puffer fish, Fugu rubripes, genome sequencing database, identified five GnRHR genes and proceeded to isolate the corresponding complementary DNAs in European sea bass, Dicentrachus labrax. Phylogenetic analysis clusters the European sea bass, puffer fish and all other vertebrate receptors into two main lineages corresponding to the mammalian type I and II receptors. The fish receptors could be subdivided in two GnRHR1 (A and B) and three GnRHR2 (A, B and C) subtypes. Amino acid sequence identity within receptor subtypes varies between 70 and 90% but only 50–55% among the two main lineages in fish. All European sea bass receptor mRNAs are expressed in the anterior and mid brain, and all but one are expressed in the pituitary gland. There is differential expression of the receptors in peripheral tissues related to reproduction (gonads), chemical senses (eye and olfactory epithelium) and osmoregulation (kidney and gill). This is the first report showing five GnRH receptors in a vertebrate species and the gene expression patterns support the concept that GnRH and GnRHRs play highly diverse functional roles in the regulation of cellular functions, besides the “classical” role of pituitary function regulation.
A Cognitive Theory and Therapy for Chronic Insomnia
Authors: Harvey Allison G.
Published: June 2005

The aim of this article is to review progress toward developing a cognitive theory of and therapy for chronic insomnia. The article will begin with a brief overview of cognitive behavior therapy for insomnia (CBT-I), the current treatment of choice, which devotes approximately one session to cognitive therapy. On the basis of (a) the conclusion from a recent review of psychological treatments for insomnia that cognitive therapy has received insufficient attention and evaluation and (b) the evidence that cognitive therapy for a range of other psychological disorders has improved treatment outcome, the remainder of the article describes another approach to the treatment of insomnia: cognitive therapy for insomnia (CT-I). This treatment is derived from a cognitive model that specifies five processes that function to maintain insomnia: worry (also known as cognitive arousal), selective attention and monitoring, distorted misperception of sleep and daytime deficits, unhelpful beliefs about sleep, and counterproductive safety behaviors. The aim of the treatment is to reverse all five maintaining processes during both the dayandthe night.
Measurement Adequacy of Parenting and Children’s Functional Status in African American and Latino Families
Authors: Wong Sabrina T. , Stewart Anita L. , Gregorich Steven E.
Published: June 2005

To examine the psychometric adequacy of two existing instruments, the Functional Status Questionnaire (FS IIR) and the Parent Behavior Checklist (PBC), in two ethnic minority groups. Age-specific items that were not relevant for children ages 1 to 5 were removed from the FS IIR and PBC. Measures were administered to 196 Latino and African American parents of children aged 1 to 5. Reliability, variability, item-convergence, and factor structure were examined. The results highlight common pitfalls in using existing measures in populations other than those on which they were originally developed. Both measures were modified resulting in all scales having low or acceptable reliability. Construct validity was supported for both the FS IIR and the PBC through confirmation of hypothesized relationships. In both ethnic groups, factor analyses supported the hypothesized factor solutions for the FS IIR and the PBC. Use of measures in minority groups requires researchers to be cognizant of the issues of psychometric adequacy in all groups. The psychometric properties of the FS IIR and the PBC were generally acceptable for Hispanics and African Americans, but each had some problems in at least one psychometric characteristic in one or both groups. Different factor loadings for some items for Hispanics and African Americans suggest different interpretation of items between the two cultural groups.
Understanding Perpetrators of Nonphysical Sexual Coercion: Characteristics of Those Who Cross the Line
Authors: DeGue Sarah , DiLillo David
Published: June 2005

Sexual coercion is defined here as a form of male sexual misconduct in which nonphysical tactics (e.g., verbal pressure) are utilized to gain sexual contact with an unwilling female partner. This study compares the risk characteristics of sexually coercive (n = 81) and nonoffending college males (n = 223) across several domains. Results revealed that sexual coercers differed from nonoffenders in that they more often subscribed to rape myths, viewed interpersonal violence as more acceptable, reported greater hostility toward females, and perceived male-female relationships as more inherently adversarial. In addition, compared to nonoffenders, sexually coercive males showed stronger indicators of promiscuity and delinquency, reported more psychopathic personality traits, had more empathic deficits, and were more likely to have experienced certain forms of childhood abuse. In most respects, coercers did not differ from those who reported engaging in more severe forms of sexual assault involving the use of physical force. These results suggest important differences between nonoffending males and those who “cross the line” by engaging in sexually coercive acts. In addition, consistent parallels can be drawn between the predictors of sexual coercion identified in this study and those documented in the sexual aggression (e.g., forcible rape) literature.
Changes in productivity and contaminants in bald eagles nesting along the lower Columbia River, USA
Authors: Buck Jeremy A. , Anthony Robert G. , Schuler Carol A. , Isaacs Frank B. , Tillitt Donald E.
Published: June 2005

Previous studies documented poor productivity of bald eagles (Haliaeetus leucocephalus) in the lower Columbia River (LCR), USA, and elevated p,p′-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), dioxins, and furans in eagle eggs. From 1994 to 1995, we collected partially incubated eggs at 19 of 43 occupied territories along the LCR and compared productivity and egg contaminants to values obtained in the mid-1980s. We found higher productivity at new nesting sites along the river, yet productivity at 23 older breeding territories remained low and was not different (p = 0.713) between studies. Eggshell thickness at older territories had not improved (p = 0.404), and eggshells averaged 11% thinner than shells measured before dichlorodiphenyltrichloroethane use. Decreases in DDE (p = 0.022) and total PCBs (p = 0.0004) in eggs from older breeding areas occurred between study periods. Productivity was not correlated to contaminants, but DDE, PCBs, and dioxin-like chemicals exceeded estimated no-effect values. Some dioxin-like contaminants in eggs were correlated to nest location, with highest concentrations occurring toward the river's mouth where productivity was lowest. Although total productivity increased due to the success of new nesting pairs in the region, egg contaminants remain high enough to impair reproduction at older territories and, over time, may alter productivity of new pairs nesting near the river's mouth.
Mercury patterns in wood duck eggs from a contaminated reservoir in South Carolina, USA
Authors: Kennamer Robert A. , Stout Jason R. , Jackson Brian P. , Colwell Sheila V. , Brisbin I. Lehr , Burger Joanna
Published: June 2005

Mercury contamination of wildlife populations has been documented widely in recent years as biomonitoring has become an important tool for assessing environmental contamination. Avian eggs provide an ideal assay material for Hg biomonitoring, particularly when the collection of eggs is simplified by using cavity-nesting species that nest in easily monitored nest boxes. However, studies are needed that address the dynamics of how Hg is distributed within eggs, and how Hg is deposited naturally within clutches laid by a single female and among clutches laid by different females occupying the same contaminated environment. We collected 138 eggs from 13 complete clutches of box-nesting wood ducks (Aix sponsa) during 1991 and 1992 at a contaminated reservoir of the U.S. Department of Energy's Savannah River Site in South Carolina, USA. Total Hg residues in egg components and clutches were determined, partitioning of Hg among egg components was examined, and effects of egg-laying sequence on egg component Hg levels were determined. Mean albumen Hg was 0.22 ppm wet mass, mean yolk Hg was 0.04 ppm, and mean shell Hg was 0.03 ppm. On average, 86.1% of total egg Hg was concentrated in the albumen, 11.2% in the yolk, and 2.7% in the shell. Mercury concentrations in all egg components varied significantly among clutches and between successive clutches laid by the same female in the same year. Laying sequence significantly affected Hg concentrations in the albumen and shell, but not in the yolk. Declines of albumen Hg due to laying sequence were more pronounced for clutches that contained higher average Hg levels. Our results suggest that collection of first-laid eggs may be preferable for assessing maximal Hg exposure to developing embryos, and that monitoring Hg levels through the use of empty eggshells following brood departure from nests may be valid only if the laying sequence is known.
Effects of metal and organophosphate mixtures on Ceriodaphnia dubia survival and reproduction
Authors: Mahar Amy M. , Watzin Mary C.
Published: June 2005

The toxicity of mixtures of copper, zinc, and diazinon were determined for Ceriodaphnia dubia using 7-d survival and reproduction tests. Fifteen treatments, including combinations of the chemicals at 0, 25, 50, 75, and 100% of their individual median lethal concentrations, adding up to one toxic unit (TU) were tested. The TU was then used to classify each mixture response as additive, greater than additive, or less than additive. For survival, additive responses occurred in the 75% zinc plus 25% diazinon and the 50% copper plus 25% zinc plus 25% diazinon treatments. For reproduction, additive responses occurred in the 75% copper plus 25% zinc, 75% copper plus 25% diazinon, and 75% zinc plus 25% diazinon treatments. Copper and zinc played a greater role in toxicity than diazinon did. Less-than-additive interactions were found in all remaining mixtures, perhaps because of differences in mode of action between diazinon and metals. Consideration of dose-response curves can help to explain inconsistencies regarding toxic response in treatments with different ratios of the same chemicals. As TU percentages changed, mixture components were taken from different locations on differently shaped dose-response curves. Because most responses were less than additive, however, water-quality criteria based on individual concentrations probably are protective for most metal-organophosphate mixtures.
Interseasonal variation in blood concentrations of organochlorines in great black-backed gulls (Larus marinus)
Authors: Bustnes Jan Ove , Skaare Janneche Utne , Berg Vidar , Tveraa Torkild
Published: June 2005

In two subsequent breeding seasons (2001 and 2002), we measured 12 organochlorines (OCs), including hexa-chlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), p,p′-dichlorodiphenyldichloroethylene (DDE), oxychlordane, and eight polychlorinated biphenyl congeners (PCBs), in the blood of the same 25 great black-backed gulls (Larus marinus). The wet-weight concentrations of different OCs in the blood decreased between 45 and 60% from 2001 to 2002. The main reasons for this were lower blood-lipid concentrations and higher body condition in 2002 compared to 2001. The differences in blood lipids and body condition probably resulted from changes in the availability of different prey types between the years. Despite the variation in the blood concentrations of OCs, there was a high predictability of the relative relationship among individuals between the years, especially for the most-persistent compounds (persistent PCBs, oxychlordane, and DDE); that is, individuals with high levels in 2001 still had relatively high levels compared to other individuals in 2002. This suggests that a concentration obtained from a single blood sample is a relatively reliable measurement of OC burdens for individual great black-backed gulls compared to other individuals, independent of changes in mean OC levels within the population. However, by including information about the nutritional status of individuals, more precise interference from samples in different years and locations may be made. Moreover, the great seasonal variation in OC levels within individuals may have implications for how OC monitoring should be conducted in gull populations.
Cluster analysis of contaminated sediment data: Nodal analysis
Authors: Hartwell S. Ian , Claflin Larry W.
Published: June 2005

The objective of the present study was to explore the use of multivariate statistical methods as a means to discern relationships between contaminants and biological and/or toxicological effects in a representative data set from the National Status and Trends (NS&T) Program. Data from the National Oceanic and Atmospheric Administration, NS&T Program's Bioeffects Survey of Delaware Bay, USA, were examined using various univariate and multivariate statistical techniques, including cluster analysis. Each approach identified consistent patterns and relationships between the three types of triad data. The analyses also identified factors that bias the interpretation of the data, primarily the presence of rare and unique species and the dependence of species distributions on physical parameters. Sites and species were clustered with the unweighted pair-group method using arithmetic averages clustering with the Jaccard coefficient that clustered species and sites into mutually consistent groupings. Pearson product moment correlation coefficients, normalized for salinity, also were clustered. The most informative analysis, termed nodal analysis, was the intersection of species cluster analysis with site cluster analysis. This technique produced a visual representation of species association patterns among site clusters. Site characteristics, such as salinity and grain size, not contaminant concentrations, appeared to be the primary factors determining species distributions. This suggests the sediment-quality triad needs to use physical parameters as a distinct leg from chemical concentrations to improve sediment-quality assessments in large bodies of water. Because the Delaware Bay system has confounded gradients of contaminants and physical parameters, analyses were repeated with data from northern Chesapeake Bay, USA, with similar results.
Identification of six differentially expressed genes in response to copper exposure in the aquatic plant Lemna gibba (duckweed)
Authors: Akhtar Tariq A. , Lampi Mark A. , Greenberg Bruce M.
Published: June 2005

Aquatic plants are susceptible to metal pollution and provide an entry point for metals, such as copper, into the aquatic biosphere. Exposure of the aquatic plant Lemna gibba to copper has been associated with the production of reactive oxygen species (ROS) and oxidative damage, caused in large part by the ability of this metal to redox cycle. In particular, copper-mediated production of ROS, a known group of signaling molecules, triggers numerous defense responses in L. gibba. Therefore, the objective of the present study was to examine to what extent acute copper exposure alters gene expression. First, the kinetics of copper uptake was assessed to determine if assimilation occurred within the short exposures needed to induce gene expression. Subsequently, using differential display polymerase chain reaction, we identified six genes with expressions that were putatively altered in response to copper. Differential expression was confirmed by northern hybridization analysis and showed that copper causes an accumulation of transcripts that encode for callose synthase, heat shock protein 90, serine decarboxylase, and the biotin carboxylase subunit of acetyl-coenzyme A carboxylase. Conversely, copper caused a decline in transcript levels for genes encoding the HAP5 subunit of the heme-activated protein (HAP) transcription factor in addition to the chloroplast nucleoid DNA-binding protein CND41. Interestingly, the expressions of these genes are sensitive to cellular ROS levels. We believe that these gene products provide valuable information regarding the molecular mechanisms of copper toxicity.
Effects of dose and particle size on activated carbon treatment to sequester polychlorinated biphenyls and polycyclic aromatic hydrocarbons in marine sediments
Authors: Zimmerman John R. , Werner David , Ghosh Upal , Millward Rod N. , Bridges Todd S. , Luthy Richard G.
Published: June 2005

Recent laboratory studies show that mixing activated carbon with contaminated sediment reduces the chemical and biological availability of hydrophobic organic contaminants. In this study, we test the effects of varying the activated carbon dose and particle size in reducing the aqueous availability of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and the uptake of PCBs by two benthic organisms. We mixed PCB- and PAH-contaminated sediment from Hunters Point Naval Shipyard, San Francisco Bay (CA, USA), for one month with activated carbon, at doses of 0.34, 1.7, and 3.4% dry mass basis. We found that increasing the carbon dose increased the effectiveness in reducing PCB bioaccumulation. In 56-d uptake tests with the benthic organisms Neanthes arenaceodentata and Leptocheirus plumulosus, PCB bioaccumulation was reduced by 93 and 90%, respectively, with 3.4% carbon. Increasing the dose also increased the effectiveness in reducing PCB and PAH aqueous concentrations and uptake by semipermeable membrane devices and quiescent flux of PCBs to overlying water. Decreasing activated carbon particle size increased treatment effectiveness in reducing PCB aqueous concentration, and larger-sized activated carbon (400–1,700 μm) was ineffective with a contact period of one month. We invoke a numerical model based on intraparticle diffusion in sediment and activated carbon particles to help interpret our experimental results. This model was useful in explaining the trends for the effect of activated carbon dose and particle size on PCB aqueous concentrations in well-mixed systems.
Monitoring exposure of northern cardinals, Cardinalis cardinalis, to cholinesterase-inhibiting pesticides: enzyme activity, reactivations, and indicators of environmental stress
Authors: Maul Jonathan D. , Farris Jerry L.
Published: June 2005

Northern cardinals (Cardinalis cardinalis) frequently use agricultural field edges in northeast Arkansas, USA, and may be at risk of exposure to cholinesterase (ChE)-inhibiting pesticides. We monitored northern cardinal exposure to ChE-inhibiting pesticides by comparing plasma total ChE (TChE) activity to reference-derived benchmarks and TChE reactivations. Total ChE and acetylcholinesterase (AChE) were measured for 128 plasma samples from 104 northern cardinals from nine study sites. Of birds sampled from sites treated with ChE-inhibiting pesticides, 4.3% of the samples had TChE activities below the diagnostic threshold (2 standard deviations [SD] below the reference mean) and 8.7% of the samples had TChE reactivations. No difference was found in TChE (p = 0.553) and AChE (p = 0.288) activity between treated and reference sites; however, activity varied among treated sites (p = 0.003). These data do not suggest uniform exposure to individuals, but rather exposure was variable and likely influenced by mitigating factors at individual and site scales. Furthermore, monitoring of TChE reactivation appeared to be a more sensitive indicator of exposure than the diagnostic threshold. Fluctuating asymmetry (FA) was greater at agricultural sites than reference sites (p = 0.016), supporting the hypothesis that FA may be useful for assessing a combination of habitat- and contaminant-related environmental stress.
Time trends (1983–1999) for organochlorines and polybrominated diphenyl ethers in rainbow smelt (Osmerus mordax) from lakes michigan, huron, and superior, USA
Authors: Chernyak Sergei M. , Rice Clifford P. , Quintal Richard T. , Begnoche Linda J. , Hickey James P. , Vinyard Bryan T.
Published: June 2005

The U.S. Geological Service Great Lakes Science Center has archived rainbow smelt (Osmerus mordax) collected from the early 1980s to the present. These fish were collected to provide time- and site-dependent contaminant residue data needed by researchers and managers to fill critical data gaps regarding trends and behavior of persistent organic contaminants in the Great Lakes ecosystem. In the present study, data are presented for concentrations of several organochlorine (OC) contaminants in the archived smelt, including DDT, polychlorinated biphenyls (PCBs), toxaphene, and chlordanes in Lakes Michigan and Huron (MI, USA) and in Lake Superior (MN, USA). The trends for all the OCs were declining as a first-order decay over the sampled time series (1983/1985–1993/1999) with the exception of toxaphene in Lake Superior and PCBs at the Charlevoix/Little Traverse Bay site in Lake Michigan. Concentration of the emerging contaminant, polybrominated diphenyl ethers (PBDEs), also was traced from its apparent entry into this ecosystem in approximately 1980 until 1999. Time trends for the PBDEs were increasing exponentially at all sites, with concentration-doubling times varying from 1.58 to 2.94 years.
Evaluation of the ishikawa cell line bioassay for the detection of estrogenic substances from sediment extracts
Authors: Hashimoto Shinya , Akatsuka Yoko , Kurihara Ryo , Matsuoka Sumiko , Nakatsukuri Maiko , Kurokawa Yuko , Tani Yukinori , Kawai Shin'ichiro
Published: June 2005

This study examines the application of Ishikawa human endometrial adenocarcinoma cells to measure the estrogenic activity of fractionated extracts of sediments from Tokyo Bay, Japan. Estrogen stimulates alkaline phosphatase activity in this cell line. The results of these assays were compared with those of a yeast estrogen screen (YES) assay. The Ishikawa cell line bioassay showed higher sensitivity to 17β-estradiol (median effective concentration [EC50], 10.7 pM) than did the YES assay (EC50, 480 pM). Fractionation of sediment extracts (all samples collected from 5 sites) showed that the nonpolar fraction was poisonous to yeast cells; the estrogenic activity of this fraction, therefore, could not be measured by YES. However, the nonpolar fraction did not kill the Ishikawa cells. The 17β-estradiol-equivalent values of 15 extracts (3 fractions from each of 5 sediment samples) ranged from 5.7 to 697 pg/g dry weight according to the Ishikawa cell line bioassay. Chemical analysis using gas chromatography-mass spectrometry revealed that the highest concentrations of endocrine-disrupting chemicals were observed at the sampling station near the sewage treatment plant. The results support that the Ishikawa cell line bioassay is suitable for measuring the estrogenic activity of sediment samples.
A new pycnodontiform fish from the Early Cretaceous of Las Hoyas (Cuenca, Spain)
Authors: Poyato-Ariza Francisco Jose , Wenz Sylvie
Published: June 2005

Stenamara mia is a new genus and species of a rare pycnodontiform fish from the Barremian, early Cretaceous, lacustrine beds of Las Hoyas, province of Cuenca, Spain. It was previously considered Eomesodon sp., but a number of characters clearly separates it from the genus Eomesodon: lack of prognathism; absence of nuchal plates; presence of a parietal process and of only two rows of teeth in the prearticular; and peltate pattern of ossification and distribution of scales, that is, scales are present only before the level of the unpaired fins, and are complete only in the ventralmost abdominal area. The unique combination of these and other characters, plus the following autopomorphies, diagnoses the new taxon: presence of a strongly curved dorsal prominence that results in an ovoid shape of the contour of the body; body deeper than long, with maximum body height near 125% of standard length; and narrow, high cloaca formed by only two differentiated scales, the posterior one considerably longer than the anterior one. Stenamara mia nov. gen. nov. sp. is considered a primitive Pycnodontidae, pending a cladistic analysis to determine precisely its phylogenetic relationships.
Evolution des particules d'or en milieu lateritique soudano-sahelien; alluvions et colluvions dans l'environnement d'un gite filonien, Piela, Burkina Faso
Authors: Ouangrawa Mariam , Grandin Georges , Parisot Jean-Claude , Delaune Mireille
Published: June 2005

On a barren bedrock, transported auriferous materials of colluvial and alluvial origin present differences in the distribution, composition and morphology of gold particles. Under Sudano-Sahelian conditions, transport processes shape evolved particles in short distances.
Trishear kinematic model of fault-propagation folding and sequential development of minor structures; the Oupia Anticline (NE Pyrenees, France) case study
Authors: Grelaud Sylvain , Buil Diego , Hardy Stuart , Frizon de Lamotte Dominique
Published: June 2005

The Oupia anticline is a fault-propagation fold located at the northeastern tip of the Pyrenees. We show that this structure is suitably modelled using the trishear kinematic model rather than the self-similar kink-band model. In particular, the trishear model accounts well for the change in forelimb dip along strike as well as for sequential overall thickening and then thinning of the forelimb deduced from microtectonic analysis.
Where should the Global Stratotype Section and Point (GSSP) for the Paleocene/Eocene boundary be located?
Authors: Aubry Marie-Pierre
Published: June 2005

The Working Group (WG) on the Paleocene/Eocene (P/E) boundary will soon have to submit a formal proposal regarding the selection of a GSSP for the boundary. Before it proceeds, a number of critical points must be considered. First, there has been dual definition of the Paleocene/Eocene boundary so that even today the boundary is placed at two different lithostratigraphic horizons by marine and vertebrate paleontologists. The former use the base of the Ypresian Stage = Mont Heribu Member in the Belgium Basin whereas the latter use the Conglomerat de Meudon believed until recently to lie at the base of the Sparnacian Argile plastique of the Paris Basin. A historical review of the definitions of the terms that have become accepted as standard chronostratigraphic units help to explain how this dual definition arose and to show that the definition accepted by most vertebrate paleontologists is spurious. The current placement of the Paleocene/Eocene boundary, i.e., defined by the base of Ypresian Stage (Ieper Clay), conforms to the definition of the Paleocene by Schimper in 1874. Second, the WG must determine whose basic chronostratigraphic procedures to follow. There has been in recent years a profound shift in chronostratigraphic procedures so that the fundamental principles recognized by the International Subcommission on Stratigraphic classification [ISSC, Hedberg, Ed, 1976; Salvador, Ed., 1994] are difficult to reconcile with the rules published by the International Commission on Stratigraphy (ICS) in recent years, based on the precept that "correlation precedes definition". For this reason the WG finds itself in a dilemma, and must weigh the risks associated with the attractive solution that would consist in defining the P/E boundary by a lithostratigraphic level where the late Paleocene carbon isotope excursion (CIE) is recorded. Four possible options that may satisfy Hedberg's principle of chronostratigraphy and/or the need for recognizing globally the Paleocene/Eocene boundary are presented. Whichever option is followed, it is important to remember that chronostratigraphy must remain objective and as arbitrary as possible, and thus independent of any aspect of Earth history, either paleobiologic, tectonic or climatic. In addition, in making a proposal for the definition of the P/E boundary, the WG must ensure that its choice will not contribute to a destabilisation of the current chronostratigraphic framework.
Calcareous nannofossil turnover around the Paleocene/Eocene transition at Alamedilla (southern Spain)
Authors: Monechi Simonetta , Angori Eugenia , von Salis Katharina
Published: June 2005

A high resolution biostratigraphic study of calcareous nannofossil assemblages has been performed on the Alamedilla section in southern Spain across the Paleocene/Eocene transition. The identification of numerous and well differentiated events together with a major calcareous nannofossil turnover suggest the Alamedilla section to represent one of the most expanded and continuous sections straddling the P/E boundary. Quantitative analyses have revealed a change in the species richness and fluctuations in abundance of important paleoecological species.
Conditions et ages 40 Ar/ 39 Ar de mise en place des granitoides de la zone externe sud du Massif central francais; exemple des granodiorites de St-Guiral et du Liron (Cevennes, France)
Authors: Najoui Khalid , Leyreloup Andre Francois , Monie Patrick
Published: June 2005

The St-Guiral and the Liron laccolithic granodiorites outcropping in the southeastern area of the French Massif Central intrude the Cambro-Ordovician low grade series of the western Cevennes. The petrological study of their contact aureoles shows that these plutons emplaced at low depth (1-2 kb; 690-700 degrees C). The laser probe 40 Ar/ 39 Ar allows us to suggest a minimum age of 324 Ma for the emplacement of the St-Guiral granodiorite. This emplacement seems synchronous with the LP-HT regional metamorphism in the western Cevennes for which the cooling ages are identical. The Liron granodiorite (310 Ma) is younger and crosscuts the thermal structures of the LP-HT regional metamorphism. Accordingly these plutons emplaced at the Namurian-early Westphalian during the extensional phases related to the generalised gravitational collapse of the previously thickened Hercynian belt. The detachment of the subducted lithosphere (slab detachment) could be related to these phenomena and could explain the granitization of the south external area of the Hercynian belt as well as the migration of the magmatism towards the south of the belt.