bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Trait Loci Analysis Using the False Discovery Rate
Authors: Benjamini Yoav , Yekutieli Daniel
Published: June 2005

False discovery rate control has become an essential tool in any study that has a very large multiplicity problem. False discovery rate-controlling procedures have also been found to be very effective in QTL analysis, ensuring reproducible results with few falsely discovered linkages and offering increased power to discover QTL, although their acceptance has been slower than in microarray analysis, for example. The reason is partly because the methodological aspects of applying the false discovery rate to QTL mapping are not well developed. Our aim in this work is to lay a solid foundation for the use of the false discovery rate in QTL mapping. We review the false discovery rate criterion, the appropriate interpretation of the FDR, and alternative formulations of the FDR that appeared in the statistical and genetics literature. We discuss important features of the FDR approach, some stemming from new developments in FDR theory and methodology, which deem it especially useful in linkage analysis. We review false discovery rate-controlling procedures—the BH, the resampling procedure, and the adaptive two-stage procedure—and discuss the validity of these procedures in single- and multiple-trait QTL mapping. Finally we argue that the control of the false discovery rate has an important role in suggesting, indicating the significance of, and confirming QTL and present guidelines for its use.
The dst1 Gene Involved in Mushroom Photomorphogenesis of Coprinus cinereus Encodes a Putative Photoreceptor for Blue Light
Authors: Terashima Kazuhisa , Yuki Katsuyuki , Muraguchi Hajime , Akiyama Masashi , Kamada Takashi
Published: June 2005

The homobasidiomycete Coprinus cinereus exhibits remarkable photomorphogenesis during fruiting-body development. Under proper light conditions, fruiting-body primordia proceed to the maturation phase in which basidia in the pileus undergo meiosis, producing sexual spores, followed by stipe elongation and pileus expansion for efficient dispersal of the spores. In the continuous darkness, however, the primordia do not proceed to the maturation phase but are etiolated: the pileus and stipe tissues at the upper part of the primordium remain rudimentary and the basal part of the primordium elongates, producing “dark stipe.” In this study we genetically analyzed five strains that produce dark stipes even if light conditions promoting the maturation are given and then characterized one of them, Uar801 (dst1-1). The dst1 gene was cloned as a DNA fragment that rescues the dst1-1 mutation. Dst1 is predicted to be a protein of 1175 amino acids that contains two PAS domains, a coiled-coil structure, and a putative, glutamine-rich, transcriptional activation domain (AD). One of the PAS domains exhibits significant similarity to the LOV domains of known blue-light receptors, suggesting that Dst1 is a blue-light receptor of C. cinereus. The dst1-1 mutation is predicted to truncate the putative AD in the C-terminal region.
Neurospora Strains Harboring Mitochondrial Disease-Associated Mutations in Iron-Sulfur Subunits of Complex I
Authors: Duarte Margarida , Schulte Ulrich , Ushakova Alexandra V , Videira Arnaldo
Published: June 2005

We subjected the genes encoding the 19.3-, 21.3c-, and 51-kDa iron-sulfur subunits of respiratory chain complex I from Neurospora crassa to site-directed mutagenesis to mimic mutations in human complex I subunits associated with mitochondrial diseases. The V135M substitution was introduced into the 19.3-kDa cDNA, the P88L and R111H substitutions were separately introduced into the 21.3c-kDa cDNA, and the A353V and T435M alterations were separately introduced into the 51-kDa cDNA. The altered cDNAs were expressed in the corresponding null-mutants under the control of a heterologous promoter. With the exception of the A353V polypeptide, all mutated subunits were able to promote assembly of a functional complex I, rescuing the phenotypes of the respective null-mutants. Complex I from these strains displays spectroscopic and enzymatic properties similar to those observed in the wild-type strain. A decrease in total complex I amounts may be the major impact of the mutations, although expression levels of mutant genes from the heterologous promoter were sometimes lower and may also account for complex I levels. We discuss these findings in relation to the involvement of complex I deficiencies in mitochondrial disease.
The [URE3] Prion Is Not Conserved Among Saccharomyces Species
Authors: Talarek Nicolas , Maillet Laurent , Cullin Christophe , Aigle Michel
Published: June 2005

The [URE3] prion of Saccharomyces cerevisiae is a self-propagating inactive form of the nitrogen catabolism regulator Ure2p. To determine whether the [URE3] prion is conserved in S. cerevisiae-related yeast species, we have developed genetic tools allowing the detection of [URE3] in Saccharomyces paradoxus and Saccharomyces uvarum. We found that [URE3] is conserved in S. uvarum. In contrast, [URE3] was not detected in S. paradoxus. The inability of S. paradoxus Ure2p to switch to a prion isoform results from the primary sequence of the protein and not from the lack of cellular cofactors as heterologous Ure2p can propagate [URE3] in this species. Our data therefore demonstrate that [URE3] is conserved only in a subset of Saccharomyces species. Implications of our finding on the physiological and evolutionary meaning of the yeast [URE3] prion are discussed.
Mixed-Cell Raceway: Engineering Design Criteria, Construction, and Hydraulic Characterization
Authors: Ebeling James M , Timmons Michael B , Joiner Jeremy A , Labatut Rodrigo A
Published: June 2005

A prototype raceway was constructed in a research greenhouse at the Conservation Fund's Freshwater Institute to study engineering design criteria and the hydraulics of a large mixed-cell raceway. The raceway measured 16.3 × 5.44 × 1.22 m and was constructed of structural lumber with a high-density polyethylene liner. The basic rationale of a mixed-cell raceway is to be able to operate it as a series of square or octagonal tanks, each having a center drain for continuous removal of solids and sludge. A series of vertical manifolds along the sidewalls directed the water through orifice discharges parallel and perpendicular to the walls to establish the desired rotary circulation. This was then combined with the concept of the “Cornell-type” dual-drain system, where 10–20% of the total flow into a tank is removed from a center bottom drain and 80–90% of the flow is removed from the side upper drain. Settlable wastes and sludge are then removed from the center drains and collected in a settling sump. Velocities were measured in three dimensions in representative cells at three depths (5–10 cm off the bottom, middepth, and 10 cm below the water surface) on a 0.5-m grid pattern over the raceway floor. The raceway mean rotational velocity was 5–6% of the inlet jet velocities. The results from this study can be used to further refine the engineering design criteria and demonstrate the potential for employing mixed cells as a new design concept both for production systems and for retrofits of existing raceway systems.
Molecular cloning and functional characterization of a type-I neurotensin receptor (NTR) and a novel NTR from the bullfrog brain
Authors: Li J H , Sicard F , Salam M A , Baek M , LePrince J , Vaudry H , Kim K , Kwon H B , Seong J Y
Published: June 2005

Neurotensin (NT) is a tridecapeptide that functions as a neurotransmitter and neuromodulator in the nervous system. To date, three different types of NT receptor (NTR), NTR1, NTR2 and NTR3, have been identified only in mammalian species. In the present study we isolated the cDNAs for an NTR1 and a novel NTR in the bullfrog brain, designated bfNTR1 and bfNTR4 respectively. bfNTR1 and bfNTR4 encode 422- and 399-amino acid residue proteins respectively. bfNTR1 has a 64% amino acid identity with mammalian NTR1, and 34–37% identity with mammalian NTR2. bfNTR4 exhibits 43% and 45–47% identity with mammalian NTR1 and NTR2 respectively. Both receptors are mainly expressed in the brain and pituitary. bfNTR1 triggers both CRE-luc, a protein kinase A (PKA)-specific reporter, and c-fos-luc, a PKC-specific reporter, activities, indicating that bfNTR1 can activate PKA- and PKC-linked signaling pathways. However, bfNTR4 appears to be preferentially coupled to the PKA-linked pathway as it induces a higher CRE-luc activity than c-fos-luc activity. bfNTRs exhibit different pharmacological properties as compared with mammalian NTRs. Mammalian NTR1 but not NTR2 responds to NT, whereas both bfNTR1 and bfNTR4 show a high sensitivity to NT. SR 48692 and SR 142948A, antagonists for mammalian NTR1 but agonists for mammalian NTR2, function as antagonists for both bfNTR1 and bfNTR4. In conclusion, this report provides the first molecular, pharmacological and functional characterization of two NTRs in a non-mammalian vertebrate. These data should help to elucidate the phylogenetic history of the G protein-coupled NTRs in the vertebrate lineage as well as the structural features that determine their pharmacological properties.
Cloning, heterologous expression and pharmacological characterization of a kappa opioid receptor from the brain of the rough-skinned newt, Taricha granulosa
Authors: Bradford C Samuel , Walthers Eliza A , Searcy Brian T , Moore Frank L
Published: June 2005

A full-length cDNA that encodes a kappa (κ) opioid receptor has been isolated from the brain of a urodele amphibian, the rough-skinned newt Taricha granulosa. The deduced protein contains 385 amino acids and possesses features commonly attributed to G protein-coupled receptors, such as seven putative transmembrane domains. The newt κ receptor has 75% sequence identity to κ opioid receptors cloned from mammals, and 66% sequence identity to the κ opioid receptor reported for the zebrafish, with the greatest divergence in the extracellular N-terminus, the second and third extracellular loops and the intracellular C-terminus. Membranes isolated from COS-7 cells expressing the newt κ receptor possessed a single, high-affinity (Kd =1.5 nM) binding site for the κ-selective agonist U69593. In competition binding assays, the expressed newt κ receptor displayed high affinity for the κ-selective agonists GR89696, dynorphin A(1–13), U69593, U50488 and BRL52537, as well as the κ-selective antagonist nor-binaltorphimine and the non-selective antagonist naloxone. Rank order potencies and affinity constants were similar in competition binding studies that used either whole brain homogenates or membranes isolated from COS-7 cells expressing the newt κ receptor. The expressed receptor displayed essentially no affinity for the δ-selective agonist DPDPE ([d-penicillamine, d-penicillamine]enkephalin), but showed moderate affinity for the μ-selective agonist DAMGO ([d-Ala-MePhe, Gly-ol]enkephalin) and moderately high affinity for nociceptin (orphanin FQ), the endogenous ligand for the opioid receptor-like (ORL)1 receptor. These findings support the conclusions that a gene for the κ opioid receptor is expressed in amphibians and that the pharmacology of the newt κ receptor closely matches mammalian κ opioid receptors. However, the functional dichotomy between the classic opioid receptors (κ, δ, μ) and ORL1 appears less strict in amphibians than in mammals.
Signaling cross-talk between IGF-binding protein-3 and transforming growth factor-β in mesenchymal chondroprogenitor cell growth
Authors: O’Rear L , Longobardi L , Torello M , Law B K , Moses H L , Chiarelli F , Spagnoli A
Published: June 2005

Cartilage formation is driven by mesenchymal chondroprogenitor cells (MCCs) that proliferate and differentiate into chondrocytes. The molecular mechanisms by which growth factors regulate MCC fate are not well defined. Insulin-like growth factor binding protein-3 (IGFBP-3) has intrinsic bioactivity that is independent of IGF binding. We previously reported that IGFBP-3 has IGF-independent antiproliferative and apoptotic effects in MCCs, and requires STAT-1 activation to mediate its apoptotic effect. Transforming growth factor-β (TGF-β) is a key chondroinductive growth factor. The objective of the study is to define the interactions between IGFBP-3 and TGF-β in MCC growth and their intracellular signaling pathways. We used the RCJ3•1C5•18 mesenchymal chondrogenic cells that without biochemical or oncogenic transformation progress in culture from MCCs to differentiated chondrocytes. Cell proliferation was assessed in MCCs treated with IGFBP-3 or transfected with IGFBP-3, in the presence or absence of TGF-β. To demonstrate that IGFBP-3 effects were IGF-independent an IGFBP-3 analog that lacks IGF binding was used (GGG-IGFBP-3). To determine the functional roles of the TGF-β-mediated signaling and the STAT-1 pathway, cells were either stably transfected with a dominant negative TGF-β type II receptor (MCC-DNTβRII) or treated with a STAT-1 morpholino antisense oligonucleotide. We found that in MCCs, TGF-β antagonized the antiproliferative effect of IGFBP-3. IGFBP-3 increased the cyclin-dependent kinase inhibitor p21 expression and this effect was abolished by TGF-β. Furthermore, TGF-β inhibited STAT-1 phosphorylation induced by IGFBP-3. Similarly to TGF-β, STAT-1 antisense oligonucleotide inhibited the IGFBP-3 antiproliferative action. Although TGF-β in MCC-DNTβRII lacked Smad-mediated signaling, it persistently antagonized the IGFBP-3 antiproliferative action. However, TGF-β even in MCC-DNTβRII cells induced ERK1/2 phosphorylation, and treatment with MEK inhibitor, UO126, inhibited the antagonistic effects of TGF-β on IGFBP-3. Furthermore, UO126 blocked the TGF-β inhibition of STAT-1 phosphorylation induced by IGFBP-3. Collectively, these results demonstrate cross-talk between the IGFBP-3-dependent STAT-1 signaling and the TGF-β-dependent ERK pathway that regulates MCC proliferation.
Expression of prolactin-releasing peptide and prolactin in the euryhaline mudskippers (Periophthalmus modestus): prolactin-releasing peptide as a primary regulator of prolactin
Authors: Sakamoto T , Amano M , Hyodo S , Moriyama S , Takahashi A , Kawauchi H , Ando M
Published: June 2005

Prolactin (PRL)-releasing peptide (PrRP) is a strong candidate stimulator of pituitary PRL transcription and secretion in teleosts. However, the role in control of extrapituitary PRL expression is unclear even in mammals. To study the possible presence of PrRP–PRL axes not only in the brain-pituitary but also in peripheral organs, the expression patterns of PrRP, PRL and growth hormone (GH) were characterized in amphibious euryhaline mudskippers (Periophthalmus modestus). PrRP mRNA is abundantly expressed not only in the brain but also in the liver, gut and ovary, while less abundant expression was also detected in the skin and kidney. Corresponding to the distribution of PrRP mRNA, PRL mRNA was also detectable in these organs. During adaptation to different environments, the changes in mRNA levels of PrRP paralleled those in PRL in the brain-pituitary, liver and gut in an organ-specific manner. Brain PrRP mRNA and the pituitary PRL mRNA increased under freshwater and terrestrial conditions (P<0.05); expression of PrRP and PRL in the gut of freshwater fish was higher (P<0.05) than those in sea-water fish although there were no changes in fish kept out of water; no significant change was seen in the liver. Expressions of GH were not correlated with PrRP. In the gut, PrRP and PRL appear to be co-localized in the mucosal layer, especially in the mucous cells. Thus, PrRP may also be a local modulator of extrapituitary PRL expression and the PrRP–PRL axes in various organs may play an organ-specific role during environmental adaptation.
Presleep Cognitive Activity and Thought Control Strategies in Insomnia
Authors: Bélanger Lynda , Morin Charles M. , Gendron Linda , Blais France C.
Published: June 2005

The aim of this study was to examine presleep cognitive activity and thought control strategies used by individuals with insomnia, with and without comorbid generalized anxiety disorder (GAD), and by good sleepers. Fifty participants were divided into the following comparison groups: (a) individuals with insomnia alone (n = 14), (b) individuals with insomnia and comorbid GAD (n = 16), and (c) good sleepers (n = 20). Participants completed a standardized evaluation including interviews and questionnaires on insomnia, anxiety, presleep cognitive activity, and thought control strategies. Results showed that individuals with insomnia and comorbid GAD reported greater presleep cognitive arousal than individuals with insomnia alone, who in turn reported greater cognitive arousal than good sleepers. Results also showed that individuals with insomnia and comorbid GAD used avoidance as a mean of controlling disturbing presleep cognitions more frequently than the other two groups. Both groups of individuals with insomnia evaluated their presleep thought control strategies as being less effective than good sleepers did. These results support the assertion that higher presleep cognitive arousal plays a role in insomnia and, by distinguishing individuals with insomnia alone (i.e., without comorbid anxiety disorders) from individuals with comorbid GAD, this study further suggests that higher cognitive arousal in individuals with insomnia is not necessarily accounted for by high rates of comorbidity between insomnia and GAD. The main clinical implication of these findings is that the evaluation and treatment of insomnia should consider these cognitive features in order to optimize outcome.
Cognitive-Behavioral Treatment for Generalized Anxiety Disorder: Current Status and Future Directions
Authors: Dugas Michel J. , Koerner Naomi
Published: June 2005

In this article, we present a cognitive-behavioral model and treatment of generalized anxiety disorder (GAD). In the first section, we review a model of GAD that includes four main components: intolerance of uncertainty, positive beliefs about worry, negative problem orientation, and cognitive avoidance. Next we present the GAD assessment tools used at our clinic, which include standardized interviews and self-report questionnaires of GAD symptoms and underlying cognitive-behavioral processes. We then provide a step-by-step description of a treatment that is based on the aforementioned model of GAD, and that has six core components: presentation of treatment rationale (learning to cope with uncertainty); worry awareness training; reevaluation of the usefulness of worrying; problem-solving training; cognitive exposure; and relapse prevention. Following the treatment description, we summarize the efficacy data from our completed randomized clinical trials, and present some preliminary findings from our ongoing trial comparing our treatment to applied relaxation and wait-list control. In the final section, we present an in-depth discussion of future directions for the study and treatment of GAD, with a focus on the approach-avoidance nature of GAD. Given the movement in the field favoring the expansion of cognitive-behavioral treatments, we also comment on the possible implications of the newest integrative therapies for our existing treatment.
Development and Psychometric Testing of the Coping With Breast Cancer Threat Instrument
Authors: Lancaster Diane R.
Published: June 2005

Women with a positive family history of breast cancer have a higher relative breast cancer risk. Research pertinent to this “at-risk” population has focused primarily on the early detection measures of breast self-exam, clinical breast exam, and mammography. Other specific primary prevention coping behaviors have received little research attention and, while there are instruments that measure general coping behaviors in the face of illness threat, there are no known instruments that measure coping behaviors specific to dealing with breast cancer threat. This study tested the psychometric properties of the Coping with Breast Cancer Threat instrument (CBCT). The CBCT was designed to measure primary prevention and early detection coping strategies used by women with family histories of breast cancer in response to their appraised breast cancer threat. The tool’s format was modeled after the Jalowiec Coping Scale (JCS) and included use and effectiveness scales. Internal consistency reliabilities and content and construct validity of the CBCT were assessed in a sample of 209 women with a family history of breast cancer. Alpha coefficients for the CBCT’s total use and effectiveness scales were .70 and .76, respectively. Principal components factor analysis with a varimax rotation revealed three conceptually relevant subcales that accounted for 52% of the variance in breast cancer threat coping behaviors. The CBCT was shown to be a reliable and valid measure of coping with breast cancer threat in a well-educated, European Amercian sample of middle-aged women.
Nurse Codependency: Instrument Development and Validation
Authors: Allison Sarah
Published: June 2005

This study developed and evaluated the Nurse Codependency Questionnaire (NCQ) and generated initial estimates of the stability and internal consistency of responses for the questionnaire. An initial pool of 95 items, reflective of four domains of codependency, was generated from the codependency literature using a domain-referenced approach. Seven expert judges from the nursing and codependency fields calculated the content validity index (CVI) as > .80. Items were critiqued for relevance, clarity, and predicted direction of each item’s correlation with the total codependency score. A convenience sample of 547 male and female nurses from Texas was recruited from a variety of professional settings to test the NCQ. Evidence of reliability and validity was sought through the use of principal factor analysis (PFA) techniques and correlation analysis. The specific domains of “codependent caretaking” and “lack of voice” represented two of the four hypothesized domains that were supported by factor analysis. Data screening and item analysis resulted in a final sample of 24 items. Test-retest reliability was .90 and internal consistency reliability was .80 for the entire scale. Reliability estimates for the “codependent caretaking” and “lack of voice” scales were .65 and .59, respectively for test-retest; and .81 and .64, respectively for internal consistency. Known groups validity was supported by each of the factors’ ability to discriminate between binge and nonbinge eaters. The NCQ may be useful for identifying codependency within the nursing profession. Research is needed to determine the external factors that influence the overt expression of nurse codependency. Screening for nurse codependency may contribute to the health of the profession by providing a means for anticipatory guidance and early intervention.
The Asthma Belief Survey: Development and Testing
Authors: Velsor-Friedrich Barbara , Pigott Therese D. , Srof Brenda , Froman Robin
Published: June 2005

Accurate evaluation of asthma self-efficacy is essential to the effective management of asthma. This article describes the development and testing of the Asthma Belief Survey (ABS). The instrument is a 15-item tool that uses a 5-point self-report scale to measure asthma self-efficacy in relation to daily asthma maintenance and an asthma crisis. This instrument was tested with a sample of 79 African American school children, who attended eight inner-city elementary schools. The mean age of the sample was 11.05 years with a range of 8 to 14 years. The majority of students had been diagnosed with asthma prior to the age of 5 years. The Asthma Belief Survey demonstrated good psychometric properties: good Cronbach’s α reliability coefficient (.83), coherence as a single scale measuring children’s self-efficacy in treating their own asthma, and significant relationships with scales of asthma knowledge (r= .51,p< .000) and asthma self-care practices (r= .52,p< .001). The Asthma Belief Survey has sound reliability and validity evidence to support its use to measure a child’s asthma self-management self-efficacy. The practitioner can use this instrument to assess a child’s self-efficacy in the areas of asthma health maintenance and avoidance of asthma episodes.
Synthesis of Intervention Research to Modify Physical Activity and Dietary Behaviors
Authors: Blue Carolyn L. , Black David R.
Published: June 2005

A descriptive literature review was conducted to examine conceptual and methodological issues of interventions aimed at improving both physical activity and diet behaviors according to critical elements established by Sidani and Braden (1998). The method of the review of 30 articles describing 17 intervention studies focused on the following nine elements: (a) relevance of the intervention to the targeted outcome; (b) theoretical components of the intervention; (c) intervention components; (d) complexity, strength, and integrity of the intervention; (e) extraneous factors; (f) adherence to the intervention and retention; (g) reliability and validity of the outcome measures; (h) expected outcomes; and (i) effectiveness of the intervention. The results were that the interventions were relevant and included multiple components, but most interventions lacked an explicit theoretical framework. Adherence to the intervention and retention were problems. Overall, to varying degrees and for those completing the programs, the interventions were effective for increasing physical activity, lowering dietary fat, weight loss, and reducing risk for illness. Twelve “lessons learned” evolved that have practical and research implications. One salient lesson and future priority is to incorporate theory to reveal the intervention content and mechanisms to modify physical activity and dietary behaviors concurrently so that future interventions are more efficacious and efficient. Another lesson revealed the need for more sensitive measures, and examination of ways to improve intervention adherence and retention and prevent relapse.
Global Biological Threats to Health: An Imperative for Collaboration
Authors: Salmon Marla E.
Published: June 2005

Biological threats to health are challenging governments worldwide. National strategies for preventing and managing existing and emerging threats require significant collaboration across borders, sectors, services, agencies and professions. Perhaps most important are the partnerships of key national health leaders who can develop and foster these relationships.

Government Chief Nursing Officers (CNOs) and Chief Medical Officers (CMOs), providing leadership in more than 100 countries worldwide, play crucial roles in addressing biological threats to health. However, much of this leadership is exercised without the benefit of strong collaborative relationships between these two key national leaders. Unfortunately, without functional partnerships between nurses and physicians at all levels, national and global capacity to address biological and other threats will be greatly compromised.

For these reasons, the first ever global forum for CNOs and CMOs teams was hosted by the Lillian Carter Center for International Nursing in Atlanta, in June 2004. Representatives from 70 countries focused on biological threats in relation to three key purposes: (1) gaining shared scientific and practical knowledge; (2) developing and strengthening collaboration and partnerships among CNOs and CMOs; and, (3) creating a joint plan for advancing national preparedness. This article describes the content, process and outcomes of this historic meeting.
The Lived Experience of Moral Distress: Nurses Who Assisted With Elective Abortions
Authors: Hanna Debra R.
Published: June 2005

The concept of moral distress has been studied mainly as an occupational issue and has not been developed for use in clinical practice. This study was designed to bridge prior studies of occupational moral distress with future clinical investigations of moral distress. Study aims were to discover the essence, properties, and full content domain of the concept of moral distress in order to develop a universal definition of the concept. A modified phenomenological study of nurses’ experience of a particular moral issue was conducted. A maximum variation sampling strategy was used to recruit a final sample of registered nurses (N= 10). Interior aversion is the essential act of moral distress. Five properties of the lived experience of moral distress were identified: perception, pain, valuing, altered participation, and perspective. Three types of moral distress identified in this study were: shocked, muted, and suppressed (persistent). Type of moral distress was related to situational conditions, recognition of moral ends, quality of coping processes, and temporal breadth. Negative outcomes of moral distress, which probably exist, were undetectable with this study design. The definition has been composed in universal terms, but remains tentative, since the full content domain of moral distress was largely but not definitively identified.
Genetic and Environmental Influences on Intimate Partner Aggression: A Preliminary Study
Authors: Hines Denise A. , Saudino Kimberly J.
Published: June 2005

Social learning theory posits that, because aggression against intimates runs in families, children learn how to behave aggressively through watching their parents and being reinforced for their own aggression. This theory considers only environmental influences on familial resemblance; however, familial resemblance could also be due to genetic factors. The current study uses a twin design (134 monozygotic, 41 dizygotic) to examine the extent to which genetic and environmental factors contribute to individual differences in intimate aggression. Model-fitting analyses consistently showed that shared genes explained the familial resemblance in psychological and physical intimate partner aggression; the remaining variance was explained by unique environments. Multivariate model-fitting analyses showed that most of the genetic influences responsible for the receipt of aggression were also responsible for its use, suggesting that there is a genetic predisposition to get involved in aggressive relationships. These results challenge the prevailing theory to explain familial resemblance in intimate aggression.
Sublethal effects of cadmium on prey choice and capture efficiency in juvenile brook trout (Salvelinus fontinalis)
Authors: Riddell David J. , Culp Joseph M. , Baird Donald J.
Published: June 2005

Prey choice in juvenile brook trout (Salvelinus fontinalis) was investigated under sublethal Cd stress in the presence of alternative prey types. Following 30-d exposures to either 0, 0.5, or 5.0 μg/L Cd, individual fish held in artificial stream channels were presented with both motile (Baetis tricaudatus) and nonmotile (Chironomus tentans) prey items and their foraging behavior and capture success was observed. The Cd-exposed trout were found to express a significant preference for C. tentans larvae as alternative prey to B. tricaudatus nymphs. Nevertheless, these preliminary findings indicate that, irrespective of prey choice, the capture efficiency of Cd-stressed trout declined by 20 to 55% with increasing Cd concentration when compared with control fish, and the activity of individual trout increased by 25% over controls, although these responses were not statistically significant. Cadmium significantly affected fish condition factors: The condition factor of control fish increased by 34% over the 30-d period, and Cd-exposed fish declined in condition by 12 to 18%. It is hypothesized that such a switch by fish to feeding on benthic prey under natural exposure conditions and their proximity to contaminated sediment may further exacerbate the sublethal effects of Cd on these individuals by intensifying or prolonging Cd exposure through a combination of trophic transfer and altered foraging behavior.
The pesticide malathion reduces survival and growth in developing zebrafish
Authors: Cook Leslie W. , Paradise Christopher J. , Lom Barbara
Published: June 2005

Malathion is an organophosphorous pesticide widely used to control mosquitoes in urban areas and pests, such as boll weevils, in agricultural areas. Zebrafish, Danio rerio, are model organisms for developmental toxicology research because they are readily available, produce large numbers of clear embryos, and are sensitive to environmental changes. The nonlethal effects of malathion on developing zebrafish embryos, however, previously have not been analyzed quantitatively. We exposed zebrafish embryos to sublethal malathion concentrations to determine malathion's effects on a developing vertebrate. Zebrafish exposed to 0.5, 1.0, or 1.5 mg/L of malathion consistently elicited more rapid hatching from the chorion than zebrafish exposed to 2.0-, 2.5-, or 3.0-mg/L malathion concentrations. In addition, exposure to 2.0, 2.5, or 3.0 mg/L of malathion resulted in significantly shorter body length and eye diameters, indicating that malathion had teratogenic effects on zebrafish embryos. Malathion's action as an acetylcholinesterase inhibitor and the toxicity of the metabolites of malathion may be responsible for malathion's teratogenic effects on fish development.
Developmental impact of atrazine on metamorphing Xenopus laevis as revealed by nuclear analysis and morphology
Authors: Freeman Jennifer L. , Rayburn A. Lane
Published: June 2005

Atrazine is one of the major surface water contaminants in the midwestern United States. Speculations have arisen on the potential effects of atrazine contamination to anuran larvae developing in these surface waters. In this study, Xenopus laevis tadpoles were exposed to environmentally relevant concentrations of atrazine. Nuclear and morphological endpoints were used to assess the effects of atrazine on developing X. laevis. Atrazine significantly affected metamorphing X. laevis after three-weeks exposure compared to controls as revealed by flow cytometric nuclear DNA analysis. The flow cytometric analysis was reflective of developmental effects. The number of nuclei per organism also was analyzed. Nuclei number was found to be associated with X. laevis development. Nuclei counting showed significant effects of atrazine after five-weeks exposure. A third endpoint, Nieuwkoop and Faber (NF) morphological staging, also demonstrated that atrazine significantly affected development after four weeks. Atrazine was found to alter the timing of metamorphosis of X laevis using both nuclear analysis and gross morphology. The NF staging was found to be a sensitive assay to measure effects of development, whereas flow cytometry provided an impartial quantitative measure.
Phytochelatin induction, cadmium accumulation, and algal sensitivity to free cadmium ion in Scenedesmus vacuolatus
Authors: Le Faucheur Séverine , Behra Renata , Sigg Laura
Published: June 2005

Phytochelatins are small, intracellular, metal-binding polypeptides produced by algae on exposure to increased metal concentration in their environment. The aim of the present study was to examine the relationship between phytochelatin concentration, bioaccumulated metal, and sensitivity of algal growth on cadmium exposure. For that purpose, intracellular cadmium concentration and thiol (glutathione, γ-glutamylcysteine [γGluCys], and phytochelatins [PCn]) content were determined in the freshwater green alga Scenedesmus vacuolatus exposed to growth-inhibitory and noninhibitory concentrations of free Cd2+ in the range from 10−14 to 10−7 M. The algal growth rate was optimal up to a free Cd2+ concentration of 10−9 M and then decreased by 40% at higher concentrations. The intracellular cadmium content increased sharply from 0.22 to 746 amol/cell over this free Cd2+ range. At the lowest Cd2+ concentration (control), glutathione was the only detectable thiol (127 amol/cell). With increasing Cd2+, formation of γGluCys and phytochelatins from PC2 to PC6 were observed. The predominant oligomer was PC3, with 42 amol/cell at the highest Cd2+ concentration (10−7 M). The ratio of the concentration of total thiol groups to intracellular cadmium was important for maintaining optimal growth. In contrast, thiol groups from phytochelatins were never measured in excess to intracellular cadmium content.
Vitellogenin detection and chick pathology are useful endpoints to evaluate endocrine-disrupting effects in avian one-generation reproduction study
Authors: Shibuya Kazumoto , Wada Masaru , Mizutani Makoto , Sato Kazuo , Itabashi Masafumi , Sakamoto Tamami
Published: June 2005

To investigate additional endpoints for screening of endocrine disruptors in birds, effects of 17β-estradiol (E2) on one-generation reproduction in the Japanese quail (Coturnix japonica) were assessed. Pairs of the 10-week-old Japanese quail were fed a low-phytoestrogen diet containing E2 at 0 (control), 10, 100, and 1,000 ppm for six weeks. In the E2 100- and 1,000-ppm groups, the parental quail represented marked toxic changes including high mortality, decreased food consumption, decreased gonad weights, gross and histologic toxic changes in the reproductive and other organs, and inhibition of the reproduction. However, no adverse effects were observed in the parental quail from the E2 10-ppm group. In the parental males, serum vitellogenin (VTG) concentrations were increased significantly in the E2 10-ppm group, disclosing that serum VTG concentration is one of the highly sensitive endpoints for evaluating estrogenic endocrine activities. In the E2 10-ppm group, number of eggs laid, number of eggs with abnormalities, eggshell strength and thickness, fertility, early and late viabilities of embryos, normal hatchling rate, and clinical signs, mortality, viability, and body weight of chicks at 14 d of age were not affected. However, histopathology of the chicks in the E2 10-ppm group revealed meaningful morphological changes in the reproductive organs, such as cystic dilatation of seminiferous tubules, increased interstitial cells in the testis, and decreased theca cells in the ovary. The present study suggests that serum VTG concentration in the parental quail and histopathology of reproductive organs in the offspring are sensitive endpoints and are useful as additional endpoints in the avian one-generation reproduction test using the Japanese quail for evaluating estrogenic endocrine-disrupting effects.
Effects of different forms of organic carbon on the partitioning and bioavailability of nonylphenol
Authors: Burgess Robert M. , Pelletier Marguerite C. , Gundersen Jennifer L. , Perron Monique M. , Ryba Stephan A.
Published: June 2005

Oxygenated nonpolar organic contaminants (NOCs) are underrepresented in studies of the partitioning and bioavailability of NOCs, including nonylphenol. In this investigation, we evaluated the toxicity, partitioning, and bioavailability of nonylphenol as affected by different forms of organic carbon. Along with organic carbon content, the role of organic carbon polarity was assessed. Toxicity of nonylphenol to a mysid and amphipod was comparable to results reported in the literature for marine organisms with median lethal concentrations (LC50s) of 82.3 and 236 μg/L, respectively. The presence of the different forms of organic carbon in every instance altered, often statistically significantly, the toxicity and bioavailability of the nonylphenol and increased the LC50 by approximately a factor of two. Partition coefficients (KPs) for nonylphenol ranged from 21.3 for cellulose to 9,770 for humic acid; log organic carbon-normalized partition coefficients (KOCs) ranged from 1.71 for cellulose to 4.71 for sediment. An exercise to predict nonylphenol effects using our toxicity data and normalized partition coefficients indicated organic carbon content was most protective and also highlighted the need for further research to better understand nonylphenol bioavailability. These data suggested that with regard to partitioning and bioavailability, the oxygenated NOC nonylphenol behaves like conventional NOCs. The data also suggest that, with refinements, polarity may have some advantages in predicting nonylphenol bioavailability.
Acute and chronic toxicity of lead in water and diet to the amphipod Hyalella azteca
Authors: Besser John M. , Brumbaugh William G. , Brunson Eric L. , Ingersoll Christopher G.
Published: June 2005

We evaluated the influence of waterborne and dietary lead (Pb) exposure on the acute and chronic toxicity of Pb to the amphipod Hyalella azteca. Test solutions were generated by a modified diluter with an extended (24-h) equilibration period. Acute (96-h) toxicity of Pb varied with water hardness in the range of 71 to 275 mg/L as CaCO3, despite similar dissolved Pb concentrations. Acute toxicity was greatest in soft test water, with less than 50% survival at the lowest dissolved Pb concentration (151 μg/L). Survival also was significantly reduced in medium-hardness water but not in hard test water. In chronic (42-d) studies, amphipods were exposed to waterborne Pb and fed either a control diet or a diet equilibrated with waterborne Pb levels. For animals fed the control diet, the median lethal concentration (LC50) for Pb was 24 μg/L (as dissolved Pb), and significant reductions in survival occurred at 16 μg/L. Exposure to Pb-treated diets significantly increased toxicity across a wide range of dissolved Pb concentrations, with a LC50 of 16 μg/L and significant reductions in growth and reproduction at 3.5 μg/L. Significant effects on growth and reproduction occurred at dissolved Pb concentrations close to the current U.S. chronic water-quality criterion. Our results suggest that both aqueous- and dietary-exposure pathways contribute significantly to chronic Pb exposure and toxic effects in aquatic biota.
Effects of ionic liquids on the survival, movement, and feeding behavior of the freshwater snail, Physa acuta
Authors: Bernot Randall J. , Kennedy Erin E. , Lamberti Gary A.
Published: June 2005

Room-temperature ionic liquids (ILs) are being promoted as environmentally friendly alternatives to volatile organic solvents currently used by industry. Because ILs are novel and not yet in widespread use, their potential impact on aquatic organisms is unclear. We studied the effects of several ILs on the survivorship and behavior (movement and feeding rates) of the freshwater pulmonate snail, Physa acuta. Median lethal concentrations (LC50s) of ILs with imidazolium- and pyridinium-based cations and Br− and PF−6 as anions ranged from 1 to 325 mg/L. Toxicity was greatest for ILs with eight-carbon alkyl chains attached to both imidazolium and pyridinium rings and declined with shorter alkyl chains, indicating a positive relationship between alkyl chain length and toxicity. Compared to controls, snails moved more slowly when exposed to butyl- and hexyl-cation ILs at 1 to 3% of LC50 concentrations but were not affected at higher IL concentrations (4–10% of LC50), which is characteristic of U-shaped dose-response curves. Snail movement was not affected by ILs with octyl alkyl groups. Grazing patterns, however, indicated that snails grazed less at higher IL concentrations. Physa acuta egestion rates were reduced in the presence of ILs at 3 to 10% of LC50 concentrations. Thus, nonlethal IL concentrations affected P. acuta behaviors, potentially impacting individual fitness and food web interactions. These results provide initial information needed to assess the potential hazards of ILs should they reach freshwater ecosystems.
Datation par les foraminiferes planctoniques d'une activite volcanique d'age lutetien a Toubab Dialow (Senegal occidental)
Authors: Sarr Raphael , Ndiaue Papa Moussa , Niang-Diop Isabelle , Gueye Mamadou
Published: June 2005

A level of silicified limestones with nummulites and daucines has been discovered in Toubab Dialaw, located in the horst of Ndiass. Interbedded between the diatreme and the ferruginous lateritic crust, this level is characterized by sheath folds. The biostratigraphic analysis revealed the presence of nummulites, daucina and a planktonic association with Globigerinatheka kugleri (Bolli, Loeblich et Tappan, 1957) which characterizes P11-P13 zones of late Lutetian to early Bartonian age. This indicates that the Tertiary volcanic activity in the Cap Vert peninsula, here represented by the Toubab Dialaw diatreme, till now considered late Eocene to late Pliocene, began earlier, during the Middle Eocene and more precisely between 48 and 45 Ma. Moreover, the presence of sheath folds indicates that the sedimentary material has been subject to a submarine slide along a low slope. Finally, all the petrographical, palaeontological and structural data allow to precise the set up history of the volcanic and sedimentary formations constituting the littoral cliffs of Toubab Dialaw.
The Paleocene/Eocene-boundary interval of a Tethyan deep-sea section (Austria) and its correlation with the North Sea basin
Authors: Egger Hans , Heilmann-Clausen Claus , Schmitz Birger
Published: June 2005

The Anthering-section is one of the most expanded upper Paleocene - lower Eocene sedimentary sequences known to date and records several of the Paleocene/Eocene boundary events, including the delta 13 C isotope excursion. Within 250 m of abyssal-plain deposits, calcareous mud-turbidites originating from the basin slope alternate with hemipelagic claystones. The average rate of sedimentation for the lower part of Zone NP9 is calculated at 22.7 cm/ky and for the upper part of Zone NP9 and Zone NP10 at 9.1 cm/ky. In the lower part of Zone NP10 closely spaced bentonite layers occur which mainly display immobile element concentrations typical for alkaline basalts. However, the thickest bentonite (X1), situated at the base of the ash series, plots into the trachyte field. Dinoflagellate stratigraphy strongly suggests that the ash-series at Anthering is synchronous with the main occurrence of ash layers in the North Sea region which display a comparable chemical composition. The biostratigraphical and geochemical correspondence of both ash-series point to a common source of magma. Especially, a correlation of layer +19 of the North Sea region with layer X1 at Anthering seems probable. We therefore consider the bentonites from the Anthering-section as distal deposits of the "positive" ash-series of the North Sea region which obviously represent unique and widespread correlation tools.
Orbital control on pelagic clay sedimentology; the case of the late Albian "Amadeus Segment" (central Italy)
Authors: Tateo Fabio , Morandi Noris , Nicolai Annarita , Ripepe Maurizio , Coccioni Rodolfo , Galeotti Simone , Baudin Francois
Published: June 2005

The Amadeus Segment which falls within the Oceanic Anoxic Event 1c, is a composite stratigraphic interval of late Albian age, composed by frequent alternation of black shales characterised by organic carbon content usually lower than 1% and carbonate-richer sediments. Geochemical and clay mineral signatures indicate a coarser grain size for the black shales, and geochemical data from literature indicate a continental origin of the organic matter. Most of the geochemical variables analyzed show a record which follows an orbital cyclicity, with the exception of Mn and Ba, whose mobility after burial was identified by independent compositional criteria. The spectral analysis succeeded in identifying such compositional peculiarities, and also enabled to correlate the Amadeus Segment with the Segment-1 of the nearby Piobbico Core. The Milankovitch cyclicity (low eccentricity and obliquity) deeply affects the sedimentation of the Amadeus Segment, because orbital frequencies characterize the distribution of foraminiferal and compositional variables, which are both controlled by organic productivity and by detrital supply (dilution effect excluded). The high frequency changes from carbonate-rich layers to black shales are interpreted as changes in oceanographic regimes which in turn caused variations in the dispersal regime of continental inputs and in productivity.