bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Abnormalities at Neuromuscular Synapses Lacking Multiple Syntrophin Isoforms
Authors: Adams Marvin E. , Kramarcy Neal , Fukuda Taku , Engel Andrew G. , Sealock Robert , Froehner Stanley C.
Published: November 2004

The syntrophins are modular adapter proteins that function by recruiting signaling molecules to the cytoskeleton via their direct association with proteins of the dystrophin protein family. We investigated the physiological function of β2-syntrophin by generating a line of mice lacking this syntrophin isoform. The β2-syntrophin null mice show no overt phenotype, or muscular dystrophy, and form structurally normal neuromuscular junctions (NMJs). To determine whether physiological consequences caused by the lack of β2-syntrophin were masked by compensation from the α-syntrophin isoform, we crossed these mice with our previously described α-syntrophin null mice to produce mice lacking both isoforms. The α/β2-syntrophin null mice have NMJs that are structurally more aberrant than those lacking only α-syntrophin. The NMJs of the α/β2-syntrophin null mice have fewer junctional folds than either parent strain, and the remaining folds are abnormally shaped with few openings to the synaptic space. The levels of acetylcholine receptors are reduced to 23% of wild type in mice lacking both syntrophin isoforms. Furthermore, the α/β2-syntrophin null mice ran significantly shorter distances on voluntary exercise wheels despite having normal neuromuscular junction transmission as determined by micro-electrode recording of endplate potentials. We conclude that both α-syntrophin and β2-syntrophin play distinct roles in forming and maintaining NMJ structure and that each syntrophin can partially compensate for the loss of the other.
Evolutionary Approaches to Psychopathology and Cognitive Therapy
Authors: Gilbert Paul
Published: November 2004

This opening article outlines some key themes of an evolutionary approach to psychopathology, and explores possible implications for cognitive therapy. Evolutionary psychology suggests that many of our mental mechanisms are designed to promote survival and reproduction, not happiness, or even mental health, as such. This article focuses on the concept of evolved strategies and their phenotypic expressions, to fit specific niches. It suggests that evolved strategies and their phenotypic expressions partly operate through two psychobiological systems, called the defense and safeness systems, which detect and respond to threats and punishments, and safeness and potential rewards, respectively. Various cognitive schemas, rules and automatic thoughts, especially those linked to psychopathology, are often products of the linkages in strategies as coded in defense and safeness systems. The latter part of the article gives a brief exploration of the view that self-to-self relationships (self-evaluations and “self-talk”) evolved from social cognitions and behavior. Negative self-evaluations, self-criticism, and self-attacking are viewed as internalized interactions between a hostile, dominant part of self, and an appeasing, subordinate part of self. One way of undermining this interaction is to introduce the notion of compassion for the self. A brief consideration is given to the development of “compassionate mind” in work with shame-prone people as expressed in high self-criticalness and/or self-hating. Throughout the text the main problems addressed are those of the more chronic, emotional difficulties often associated with some degree of what is called personality disorder.
Rumination, Depression, and Alcohol Use: Tests of Gender Differences
Authors: Nolen-Hoeksema Susan , Harrell Zaje A.
Published: November 2004

We examined the relationships between rumination and depressive symptoms and rumination and alcohol-related coping and problems as a function of gender. Rumination was associated with more depressive symptoms for both women and men in both cross-sectional and longitudinal analyses. Similarly, for both women and men, rumination was associated with a greater tendency to turn to alcohol and other drugs to cope in cross-sectional analyses. Longitudinal analyses showed that rumination was a significant predictor of alcohol-related problems in women, but not in men, although the gender difference in the strength of this relationship was not significant. We discuss these results in light of the social conditions and pressures associated with gender role norms.
Similarities and Differences Between Rational Emotive Behavior Therapy and Cognitive Therapy
Authors: Ellis Albert
Published: November 2004

The main theoretical and practical applications of Rational Emotive Behavior Therapy (REBT) and Cognitive Therapy (CT) are examined and found to be similar to each other in most respects, but REBT bases its concepts of improved treatment of neurotic disorders and of severe personality dysfunctioning largely on philosophical, existential, and humanistic bases, while CT tends to align them with empirical results of outcome studies. Both REBT and CT, however, use philosophic and empirical outcome studies to construct and validate their theories.
Minimizing Sample Size When Using Exploratory Factor Analysis for Measurement
Authors: Sapnas Kathryn G. , Zeller Richard A.
Published: November 2004

Traditional protocol for the determination of an adequate sample size is power analysis. Such a protocol is not useful when the primary hypothesis focuses on psychometric measurement properties. Traditional psychometrics advises that there should be 10 respondents per item. Both hypothetical and real research examples illustrate the usefulness of sub-sample analysis in determining that a sample size of at least 50 and not more than 100 subjects is adequate to represent and evaluate the psychometric properties of measures of social constructs. The “10 respondents per item” advice builds a sample size disincentive into the research design; it also represents “sample size overkill.” Sample-size overkill occurs when the research design specifies a number of cases needed, which is in excess of the number actually needed for a desired inference.
Evaluation of the Diabetes Self Care Scale: An Illustration of the Rasch Model of Measurement
Authors: Lee Nantawadee P. , Fisher, William P.
Published: November 2004

This pilot study illustrates the use of a Rasch measurement model to evaluate the psychometric properties of the Diabetes Self Care Scale (DSCS). A convenience sample of 50 adults with diabetes at two local hospitals (one for profit and one public) in southern Louisiana responded to the survey questions. The instrument is comprised of 27 items and 6 rating categories. The Bigsteps Rasch measurement software was used for all analyses. Results indicated that respondent separation reliability was low (0.63), but item separation reliability was satisfactory (0.91). Internal validity was supported. Twenty-six items measure a single construct of diabetes self care. Construct validity was supported by the meaningfulness of the item difficulty order and by the consistency of that order across respondents. Rating scale analysis revealed that middle categories were not distinct steps in the progression of increasing diabetes self care. In addition to deleting an item producing inconsistent responses and combining adjacent categories (categories 1 and 2, and categories 3, 4, and 5), four recommendations for future research are provided.
The Friedrich-Lively Instrument to Assess the Impact of Schizophrenia on Siblings (FLIISS)©: Part I—Instrument Construction
Authors: Friedrich Rose Marie , Lively Sonja , Rubenstein Linda , Buckwalter Kathleen
Published: November 2004

Siblings of persons with schizophrenia may provide primary or secondary care for their sibling and support to parents who are primary care givers. These siblings experience stress and the accompanying sequelae of decreased quality of life, grief, chronic illness, and symptoms of depression and anxiety. Comprehensive measures of sibling stress have not been published. Before interventions to help siblings can be created, health professionals need such an assessment. The Friedrich-Lively Instrument to Assess the Impact of Schizophrenia on Siblings (FLIISS) has been developed to meet the needs of both health workers and siblings. The instrument has a strong conceptual basis adapted from Pearlin’s model of stress in caregiving and was preceded by pilot work that evaluated both quantitative and qualitative data. In this article, (Part I), the development of the instrument and its relationships to the conceptual model are described. Health professionals can use the instrument for collecting information that will increase their ability to identify sources of stress faced by siblings of persons with schizophrenia, and from this assessment they may develop interventions for this underserved population.
Development and Testing of the Labor Support Scale
Authors: Sleutel Martha Rider
Published: November 2004

Nurses use interventions and supportive strategies to help mothers throughout labor, yet little research examines intrapartum nurses’ labor support techniques. The purpose of the study was to develop and test a self-report instrument, the Labor Support Scale (LSS), to describe the frequency with which nurses perform interventions and nurses’ perceptions of the helpfulness of interventions. Steps for instrument development were item generation, content validity testing, piloting, refining, and administering the questionnaire in two studies (n = 307, n = 472). Internal consistency reliability was .90 and .92 for the frequency and helpfulness portions of the instrument (respectively). Exploratory factor analysis, known groups technique, content analysis, and discriminant analysis evaluated validity. In both phases, instrument psychometrics provided evidence of content, construct, and discriminant validity.
Use of the Edmonton Research Orientation Scale With Nurses
Authors: McCleary Lynn , Brown Ted G.
Published: November 2004

Improved understanding of the determinants of research utilization is fundamental to developing and testing strategies to increase research utilization. Inconsistent findings in this field of research about research utilization may be attributable, in part, to lack of development of measures. This research tested the internal consistency and construct validity of the Edmonton Research Orientation Scale (EROS) and its four subscales (Valuing Research, Research Involvement, Being on the Leading Edge, and Evidence-Based Practice), which are promising measures of research utilization and attitudes towards research. One hundred eighty-five registered nurses in a pediatric teaching hospital completed the EROS. Nurses who reported higher levels of education, better understanding of research topics or participation in quality management or research projects also reported higher levels on the EROS and EROS subscales. The Valuing Research and Evidence-Based Practice subscales were associated with having taken courses in research design and statistics. The findings suggest that the EROS and the Valuing Research and Evidence-Based Practice subscales may be used to measure nurses’ attitudes towards research and research utilization.
A multivariate biomarker-based model predicting population-level responses of Daphnia magna
Authors: De Coen Wim M. , Janssen Colin R.
Published: November 2004

A multivariate model is proposed relating short-term biomarker measurements in Daphnia magna to chronic effects (21-d exposure) occurring at the population level (time to death, mean brood size, mean total young per female, intrinsic rate of natural increase, net reproductive rate, and growth). The results of the short-term exposure (48h-96 h) to eight model toxicants (cadmium, chromium, mercury, tributyl tin, linear alkylsulfonic acid, sodium pentachlorophenolate, lindane, and 2,4-dichloro-phenoxyacetic acid) on the following biomarkers were used for the multivariate model: digestive enzymes (amylase, cellulase, β-galactosidase, trypsin, and esterase), enzymes of the intermediary metabolism (glycogen phosphorylase, glucose-6-phosphate de-hydrogenase, pyruvate kinase, lactate dehydrogenase, and isocitrate dehydrogenase), cellular energy allocation (CEA) (protein, carbohydrate, and lipid content and electron transport activity), and DNA damage and antioxidative stress activity. Using partial least squares to latent structures (PLS), a two-component model was obtained with R2 of 0.68 and a Q2 value of 0.60 based on the combined analysis of a limited number of the 48- and 96-h biomarker responses. For the individual population-level responses, the R2 values varied from 0.66 to 0.77 and the Q2 values from 0.52 to 0.69. Energy-related biomarkers (cellular energy allocation, lipid contents, anaerobic metabolic activity—pyruvate kinase, and lactate dehydrogenase), combined with parameters related to oxidative stress (catalase) and DNA damage measured after 48 and 96 h of exposure, were able to predict long-term effects at higher levels of biological organization.
Toxicity of cadmium, endosulfan, and atrazine in adrenal steroidogenic cells of two amphibian species, Xenopus laevis and Rana catesbeiana
Authors: Goulet Benoǐt N. , Hontela Alice
Published: November 2004

The effects of cadmium, endosulfan, and atrazine on corticosterone secretion and viability of adrenal cells of African clawed frog (Xenopus laevis) and bullfrog (Rana catesbeiana) were assessed in vitro using a new bioassay. The bioassay relies on stimulation with adrenocorticotropic hormone (ACTH), the endogenous secretagogue for corticosterone secretion, and with dibutyryl cyclic adenosine monophosphate (dbcAMP), an analogue of cAMP, to pinpoint the site of action of the xenobiotics within the steroidogenic cell. To compare the test toxicants according to their endocrine-disrupting potential, the lethal concentration needed to kill 50% of the cells:effective concentration of 50% (LC50:EC50) ratio was calculated, with LC50 as the concentration that kills 50% of the steroidogenic cells and the EC50 as the concentration that impairs corticosterone secretion by 50%. The higher the ratio, the higher the potential for endocrine disruption. Atrazine had no affect on cell viability and on corticosterone secretion in X. laevis, but its endocrine-disrupting potential was high in R. catesbeiana. The LC50:EC50 ratio for cadmium and endosulfan in X. laevis was 26.07 and 1.23, respectively, and for atrazine, cadmium, and endosulfan in R. catesbeiana it was 909, 41, and 3, respectively. The dbcAMP did not restore corticosterone secretion in the cells exposed to the test toxicants in both species. Our study suggests that the secretory capacity of adrenal cells of amphibians can be impaired by environmental chemicals, especially atrazine in the bullfrog, and that these adrenotoxicants disrupt the enzymatic pathways leading to corticosterone secretion downstream from the step-generating cAMP.
Assessment of the freshwater annual fish Cynopoecilus melanotaenia as a toxicity test organism using three reference substances
Authors: Arenzon Alexandre , Pinto Régis Fontana , Colombo Patrick , Raya-Rodriguez Maria Teresa
Published: November 2004

This study presents a preliminary evaluation of the use of the Brazilian fish Cynopoecilus melanotaenia as a test organism in toxicity tests. The cryptobiotic stage presented by the eggs of fish C. melanotaenia can overcome the difficulty of continuously keeping cultures and recruiting healthy animals in sufficient numbers to be used in toxicity tests. In order to determine the applicability of this species as a test organism, three different reference substances were evaluated in 96-h acute toxicity tests: Copper sulfate (CuSO4·5H2O), sodium dodecil sulfate (C12H25NaO4S), and sodium chloride (NaCl). Sensitivity ranged as follows: copper sulfate (0.05-0.13 mg/L), sodium dodecil sulfate (10.7-19.0 mg/L), and sodium chloride (1.44-1.96 g/L). We conclude that C. melanotaenia shows potential as a test organism in toxicity tests; however, further research should be conducted with other substances and should be compared with the research on other species before we can reach more conclusive results.
Effects of pore-water ammonia on in situ survival and growth of juvenile mussels (;Lampsilis cardium); in the St. Croix Riverway, Wisconsin, USA
Authors: Bartsch Michelle R. , Newton Teresa J. , Allran John W. , O'Donnell Jonathan A. , Richardson William B.
Published: November 2004

We conducted a series of in situ tests to evaluate the effects of pore-water ammonia on juvenile Lampsilis cardium in the St. Croix River (WI, USA). Threats to this river and its associated unionid fauna have accelerated in recent years because of its proximity to Minneapolis–St. Paul, Minnesota, USA. In 2000, caged juveniles were exposed to sediments and overlying water at 12 sites for 10 d. Survival and growth of juveniles was significantly different between sediment (mean, 47%) and water column (mean, 86%) exposures; however, these effects were unrelated to pore-water ammonia. During 2001, juveniles were exposed to sediments for 4, 10, and 28 d. Pore-water ammonia concentrations ranged from 0.3 to 62.0 μg NH3-N/L in sediments and from 0.5 to 140.8 μg NH3-N/L within exposure chambers. Survival (mean, 45, 28, and 41% at 4, 10, and 28 d, respectively) and growth (range, 3–45 μm/d) of juveniles were highly variable and generally unrelated to ammonia concentrations. Although laboratory studies have shown unionids to be quite sensitive to ammonia, further research is needed to identify the route(s) of ammonia exposure in unionids and to understand the factors that contribute to the spatial variability of ammonia in rivers.
Growth and nitrite and nitrous oxide accumulation of Paracoccus denitrificans ATCC 19367 in the presence of selected pesticides
Authors: Sáez Florentina , Pozo Clementina , Gómez Miguel Angel , Rodelas Belén , Gónzalez-López Jesús
Published: November 2004

The effects of the application of eight pesticides (aldrin, lndane, dimetoate, methylparathion, methidation, atrazine, simazine, and captan) on growth, respiratory activity (as CO2 production), denitrifying activity (as N2O released), and nitrite accumulation in the culture medium by Paracoccus denitrificans strain ATCC 19367 were studied. The fungicide captan totally inhibited growth and biological activity of P. denitrificans, while the rest of the tested pesticides delayed the growth and CO2 release of P. denitrificans but did not drastically affect the bacterial growth or respiratory capacity after 96 h of culture. The denitrifying activity of P. denitrificans ATCC 19367 (as N2O released) was negatively affected by all tested pesticides. The release of N2O was strongly inhibited by several organochlorinated and organophosphorated insecticides (aldrin, lindane, dimetoate, and methidation), which led to high accumulation of nitrite in the surrounding medium. Atrazine decreased N2O release after 48 h of culture because of negative effects on growth, and methylparathion and simazine delayed the onset of N2O release by P. denitrificans. These three pesticides reduced the accumulation of NO2 compared to unamended control cultures.
Reduced nicotinamide adenine dinucleotide phosphate and the higher incidence of pollution-induced liver cancer in female flounder
Authors: Koehler Angela , Van Noorden Cornelis J. F.
Published: November 2004

In biological effect monitoring programs, induction of biotransformation and detoxification enzymes is used as a biomarker for pollution. Yet sex differences are usually neglected in the availability of reduction equivalents needed in these metabolic pathways and may affect biomarker responses. For example, female flounder have a threefold higher incidence of macroscopic liver nodules than males of the same age class in polluted environments of the North Sea that progress toward carcinomas, whereas tumors in males virtually never develop into cancer. Evidence is presented in this review that NADPH plays a significant role in this sex-related response to xenobiotics in liver of flounder. The NADPH is needed for biosynthesis, particularly of lipids and lipoproteins, and detoxification processes such as one-electron and two-electron biotransformation and conjugation and, therefore, its availability as substrate determines biomarker responses. Biotransformation of xenobiotics is more strongly induced and conjugation processes are less affected in male flounder liver during exposure. In female liver, NADPH is required for production of the yolk precursor protein vitellogenin for oocyte production. The latter process has a higher priority than the NADPH-requiring detoxification processes because reproductive success is more relevant in evolutionary perspectives than the survival of the individual female. The data reviewed here suggest that these sex-related differences in NADPH metabolism are a major cause of the higher incidence of liver cancer in female flounder in polluted environments.
A microscaled mercury saturation assay for metallothionein in fish
Authors: Shaw-Allen Patricia , Elliott Muriel , Jagoe Charles H.
Published: November 2004

A mercury (Hg) saturation assay for measuring metallothionein (MT) in fish liver was modified by optimizing binding conditions to minimize the mercury and tissue consumed. The revised method uses stable Hg at low concentrations instead of 203Hg. At the reduced Hg concentrations used, MT concentrations in livers homogenized in saline appeared to increase systematically with dilution in both bluegill sunfish (Lepomis macrochirus) and largemouth bass (Micropterus salmoides). This error suggested a binding limitation due to sulfhydryl oxidation or competition for and removal of mercury by non-MT proteins. Homogenizing tissues in trichloroacetic acid (TCA) eliminated the interference. To further evaluate the method, the protocol was tested in the laboratory and field. Metallothionein in bluegill injected with 0.6 mg/kg zinc chloride increased at a rate of 0.03 nmole MT/g liver/ h (r2 = 0.53, p = 0.001). Linearity improved when data were corrected for protein content (r2 = 0.74, p < 0.0001). Metallothionein levels in bluegill from a coal ash-contaminated environment were significantly increased over that of hatchery-reared sunfish (F = 20.17, p = 0.0003). The microscaled procedure minimizes concerns related to radioisotope use and waste generation while retaining the high sensitivity of the 203Hg assay.
Effects of carbaryl on green frog (Rana clamitans) tadpoles: Timing of exposure versus multiple exposures
Authors: Boone Michelle D. , Bridges Christine M.
Published: November 2004

The majority of studies on pesticide impacts have evaluated the effects of single exposures. However, multiple exposures to a pesticide may be more prevalent. The objective of our study was to determine how multiple exposures versus single exposure at different times during development affected survival to metamorphosis, tadpole survival, tadpole mass, and tadpole developmental stage of green frog (Rana clamitans) tadpoles reared at low and high density in outdoor cattle tank ponds. Tadpoles were exposed to carbaryl zero, one, two, or three times at 14-d intervals. We applied single doses of carbaryl at one of three times, specifically during early, mid, or late development. Overall, we found that multiple exposures had a greater impact than single exposures during development. More individuals reached metamorphosis in ponds exposed to multiple doses of carbaryl compared with controls, indicating that the presence of carbaryl stimulated metamorphosis. The presence of carbaryl in the aquatic environment also resulted in more developed tadpoles compared with controls. Tadpoles in control ponds did not reach metamorphosis and were less developed than individuals exposed to carbaryl; this effect indicates that, under ideal conditions, green frogs could overwinter in ponds so that greater size could be attained before metamorphosis in the following spring or summer. Our study demonstrated the importance of including realistic application procedures when evaluating the effects of a pesticide and that multiple exposures to a short-lived pesticide are more likely to affect an amphibian population.
Effect of low salinity on cadmium accumulation and calcium homeostasis in the shore crab (carcinus maenas) at fixed free Cd2+ concentrations
Authors: Burke Jonathan , Handy Richard D. , Roast Stephen. D.
Published: November 2004

Increased Cd toxicity at low salinity has been attributed to increased free Cd2+ ion concentration ([Cd2+]sw), but transfer to dilute seawater also stimulates physiological ionic regulation in crabs. In this study, Cd accumulation and Ca homeostasis in the shore crab (Carcinus maenas) were explored at fixed [Cd2+]sw to reveal the physiological events during sublethal Cd exposure. Crabs were exposed to 3.4 or 34 μg/L [Cd2+]sw in both 100% seawater (SW) and 33% SW for up to 10 d and sampled for hemolymph composition as well as gill and hepatopancreas Ca, Cd, and Ca-ATPase activity. Cadmium exposure ameliorated the expected fall in hemolymph osmotic pressure and NaCl at low salinity and generally protected tissue Ca from decline. Cadmium exposure alone (within salinity) inhibited Ca-ATPase, but this was offset by stimulation of Ca-ATPase at low salinity. The Ca-ATPase activity in the anterior and posterior gills showed different responses to Cd/low salinity stress. Crabs were more sensitive to a 10-fold increase in [Cd2+]sw at low salinity. Overall, we conclude that exposure to a fixed sublethal [Cd2+]sw reveals a compensatory physiological response that is driven primarily by salinity rather than Cd2+ free ion concentration. Physiological responses are therefore important during low-level Cd exposure in dilute seawater.
Assessment of the mutagenic potency of sewage sludges contaminated with polycyclic aromatic hydrocarbons by an Ames fluctuation assay
Authors: Pérez Assay Sandra , Reifferscheid Georg , Eichhorn Peter , Barceló Damià
Published: November 2004

The mutagenicity of crude extracts and subfractions of two samples of a reference sewage sludge material and two sewage sludges from two wastewater treatment plants (WWTP), one urban and the other one urban mixed with industrial, was assessed using an Ames fluctuation assay based on 384-well microtiter plates with liquid cultures. Crude extracts of sludges were obtained by ultrasonic extraction with dichloromethane/methanol, and further column fractionation yielded two fractions, one of which containing mutagenic polycyclic aromatic hydrocarbons (PAHs). Quantitative analysis performed by gas chromatographymass spectrometry gave sum concentrations of the 16 PAHs listed as priority pollutants by the U.S. Environmental Protection Agency at levels between 1,305 and 2,442 μg/kg. Subjecting crude extracts and column fractions to the mutagenicity assay with Salmonella strains TA98 and TA100 provided good qualitative correlation between the presence of mutagenic PAH and the induction of gene mutations. In general, the crude extracts and the PAH-fractions induced positive responses in the assay with both bacterial strains on metabolic activation by S9 rat-liver homogenate, whereas direct-acting mutagens were not detectable. In the assay with the real sludge samples of two different WWTPs, TA98 proved to be more sensitive than TA100; however, similar sensitivities of the tester strains were observed for two reference sewage sludge materials of the same origin. The outcomes of the Ames fluctuation assay demonstrated its performance as a cost-effective and relatively rapid screening tool to assess the genotoxic potential of complex environmental samples.
A protocol to estimate the release of anthropogenic hydrocarbons from contaminated soils
Authors: Loehr Raymond C. , Lamar Michael R. , Poppendieck Dustin G.
Published: November 2004

An operational protocol, appropriate for a tier 1 or tier 2 type relative risk evaluation of a site that has polycyclic aromatic hydrocarbon (PAH) or petroleum hydrocarbon impacted soils, was developed to estimate the fraction of anthropogenic hydrophobic hydrocarbons that will be released rapidly from such soils. The development of this protocol used over 400 datasets from 40 different field samples to establish and verify the operational protocol. The datasets resulted from four-month kinetic desorption studies of these field samples. Based on the chemicals evaluated, the protocol has greatest application to two, three, and four ring-PAH and to diesel range aliphatic hydrocarbons. The protocol is a simple batch desorption analysis that uses established methods and is conducted for 7 d. The protocol results were verified with specific correlation relationships (r2 = 0.81 to 0.96) to estimate the rapidly releasing fraction (F value) that is obtained in a full, four-month chemical release evaluation.
Influence of dissolved organic matter source on silver toxicity to Pimephales promelas
Authors: VanGenderen Eric J. , Ryan Adam C. , Tomasso Joseph R. , Klaine Stephen J.
Published: November 2004

In the environment, the formation of organic and inorganic silver complexes can decrease Ag bioavailability (toxicity) to aquatic organisms. However, current water quality regulations do not consider the protective effects of water quality parameters such as dissolved organic carbon (DOC) concentration. To determine the effect of DOC concentration and source on silver toxicity, nine different natural organic matter isolates were used in 96-h static-renewal toxicity tests with fathead minnow (Pimephales promelas). The 96-h dissolved silver median lethal concentrations (LC50) among different sources of dissolved organic matter varied by up to fivefold (4.5–23.3 μg/L). Further, toxicity tests with organic matter from the site with the lowest 96-h LC50 value suggested only limited additional attenuation of silver toxicity when DOC concentration was increased from 5.1 to 14.0 mg/L. With this site excluded, we found little more than a twofold difference among 96-h dissolved Ag LC50s for the remaining sources (10.1–23.3 μg/L). However, significant toxicological differences among sites remained. It was apparent that organic matter from different sources varied both chemically and toxicologically, but no conclusions could be drawn that related compositional variation to observed Ag toxicity for these isolates.
Evaluation of polychlorinated biphenyl bioaccumulation patterns in white sea urchins (Lytechinus pictus) using multiple approaches
Authors: Noblet James A. , Zeng Eddy Y. , Ritter Kerry J.
Published: November 2004

The bioaccumulation of polychlorinated biphenyls (PCBs) from three amended field-contaminated sediments (with total PCB concentrations of ∼4, 10, and 100 μg/g dry wt) by white sea urchins (Lytechinus pictus) was evaluated using multiple statistical and theoretical approaches. Similarity analysis of the PCB bioaccumulation patterns, based on the concept of ecological communities, showed that the PCB patterns in the sea urchins and source sediments were essentially identical for all three sediment concentrations. However, affinity analysis did show some preference for bioaccumulation of higher-molecular-weight and more hydrophobic congeners by the urchins. The affinity analysis also showed that within a homologous series, bioaccumulation increased with increasing hydrophobicity. The biota-sediment accumulation factor (BSAF) profiles for the two lower concentration sediments (A and B) were found to be statistically different from the high concentration sample (sediment C) by a multivariate analysis of variance (MANOVA). The relationship between the measured apparent organic carbon-normalized partition coefficients (KOC) and octanol-water partition coefficient (Kow) (log based) suggested a significant departure from thermodynamic equilibrium. A nonequilibrium, steady-state bioaccumulation model was found to correctly predict the observed experimental bioaccumulation patterns. To improve the model performance, a hydrophobic term was introduced to account for the drop-off in BSAF profiles with log Kow ≥ 6.5. This study showed that nonequilibrium, steady-state models are far superior to equilibrium partitioning-based models for understanding the bioaccumulation of organic chemicals by sea urchins.
Developmental toxicity of in ovo exposure to polychlorinated biphenyls: II. Effects of maternal or paternal exposure on second-generation nestling American
Authors: Fernie Kim , Bortolotti Gary , Drouillard Ken , Smits Judit , Marchant Tracy
Published: November 2004

The development of second-generation nestling American kestrels (Falco sparverius) was altered by in ovo exposure of only one parent to polychlorinated biphenyls (PCBs). Polychlorinated biphenyls appear to alter nestling development through both maternally and paternally mediated effects. In 1998, F0 parent kestrels consumed approximately 5 to 7 μg total PCBs/g bird/d (Aroclors® 1248:1254: 1260) for approximately 100 d prior to eggs hatching; these eggs, containing total PCB concentrations of 34.1 μg/g, produced 13 F1 offspring, which were then paired in 1999 with unexposed kestrels to examine developmental effects of maternal or paternal in ovo PCB exposure. Using a toxicokinetics model, eggs from the maternally exposed group had predicted PCB levels of 0.03 to 0.34 μg/g, with enriched higher chlorinated congeners. Polychlorinated biphenyl concentrations in eggs of all generations have recently been found in eggs and nestlings of free-ranging eagles. Consistent with the first generation, maternally exposed F2 females generally were larger, had altered growth rates, and delayed maximal growth and fledging compared with control females. Maternally exposed F2 males were heavier but had shorter bones, grew more quickly and earlier, and fledged 2 d later than control males. In the maternally exposed group, concentrations of plasma triiodothyronine were elevated in F2 females but suppressed in F2 males. Paternally exposed F2 hatchlings of both sexes were comparable in size to controls with the exception of having longer tarsi bones, but subsequently showed slower, delayed growth (both sexes) and fledging (females) and lower thyroxine concentrations (males). The alterations in thyroid hormones in the F2 generation are discussed in light of the enrichment of higher chlorinated PCB congeners and hydroxylated PCB congeners. The developmental changes in the kestrel nestlings are likely a function of several possible mechanisms involving maternal PCB deposition, parental behavior, and neurobehavioral and endocrine–thyroid function in nestlings.
Investment disputes' model treaty encourage more arbitration use
Authors: Kantor Mark
Published: November 2004

Mark Kantor of Washington, D.C., discusses more provisions of the new Draft Model U.S. bilateral investment treaty, in the second of two parts.
Preparation and Multicolor Electrochromic Performance of a WO3/Tris(2,2′‐bipyridine)ruthenium(II)/Polymer Hybrid Film
Authors: Yagi Masayuki , Sone Koji , Yamada Miki , Umemiya Saori
Published: November 2004

A tungsten trioxide (WO3)/tris(2,2′‐bipyridine)ruthenium(II) ([Ru(bpy)3]2+; bpy=2,2′‐bipyridine)/poly(sodium 4‐styrenesulfonate) (PSS) hybrid film was prepared by electrodeposition from a colloidal triad solution containing peroxotungstic acid (PTA), [Ru(bpy)3]2+, and PSS. A binary solution of [Ru(bpy)3]2+ and PTA (30 vol % ethanol in water) gradually gave an orange precipitate, possibly caused by the electrostatic interaction between the cationic [Ru(bpy)3]2+ and the anionic PTA. The addition of PSS to the binary PTA/[Ru(bpy)3]2+ solution remarkably suppressed this precipitation and caused a stable, colloidal triad solution to form. The spectrophotometric measurements and lifetime analyses of the photoluminescence from the excited [Ru(bpy)3]2+ ion in the colloidal triad solution suggested that the [Ru(bpy)3]2+ ion is partially shielded from electrostatic interaction with anionic PTA by the anionic PSS polymer chain. The formation of the colloidal triad made the ternary [Ru(bpy)3]2+/PTA/PSS solution much more redox active. Consequently, the rate of electrodeposition of WO3 from PTA increased appreciably by the formation of the colloidal triad, and fast electrodeposition is required for the unique preparation of this hybrid film. The absorption spectrum of the [Ru(bpy)3]2+ ion in the film was close to its spectrum in water, but the photoexcited state of the [Ru(bpy)3]2+ ion was found to be quenched completely by the presence of WO3 in the hybrid film. The cyclic voltammogram (CV) of the hybrid film suggested that the [Ru(bpy)3]2+ ion performs as it is adsorbed onto WO3 during the electrochemical oxidation. An ohmic contact between the [Ru(bpy)3]2+ ion and the WO3 surface could allow the electrochemical reaction of adsorbed [Ru(bpy)3]2+. The composition of the hybrid film, analyzed by electron probe microanalysis (EPMA), suggested that the positive charge of the [Ru(bpy)3]2+ ion could be neutralized by partially reduced WO3− ions, in addition to Cl− and PSS units, based on the charge balance in the film. The electrostatic interaction between the WO3− ion and the [Ru(bpy)3]2+ ion might be responsible for forming the electron transfer channel that causes the complete quenching of the photoexcited [Ru(bpy)3]2+ ion, as well as the formation of the ohmic contact between the [Ru(bpy)3]2+ ion and WO3. A multicolor electrochromic performance of the WO3/[Ru(bpy)3]2+/PSS hybrid film was observed, in which transmittances at 459 and 800 nm could be changed, either individually or at once, by the selection of a potential switch. Fast responses, of within a few seconds, to these potential switches were exhibited by the electrochromic hybrid film.
Reaktionskinetische Messungen an katalytisch aktivierten Filterkerzensegmenten
Authors: Hackel M. , Schaub G. , Nacken M. , Heidenreich S.
Published: November 2004

No abstracts.
Tensidbeeinflusster Metallionendurchtritt an Flüssig/Flüssig‐Phasengrenzen im elektrischen Feld
Authors: Paeslack R. , Haseneder R. , Härtel G.
Published: November 2004

No abstracts.
Bakterieninaktivierung in gefrorenen Lebensmitteln durch hochdruckinduzierte Eiskristall‐Phasenübergänge
Authors: Luscher C. , Knorr D.
Published: November 2004

No abstracts.
Macroscopic Order and Electro‐Optic Response of Dipolar Chromophore–Polymer Materials
Authors: Pereverzev Yuriy V. , Prezhdo Oleg V. , Dalton Larry R.
Published: November 2004

This Minireview considers the key factors that govern the organization of macroscopic polarization in nonlinear optical systems obtained by electric poling of organic dipolar chromophores dissolved in polymer matrices. The macroscopic electric polarization depends on the thermodynamic state of the dipole system. The dependence of the paraelectric and antiferroelectric states of dipolar chromophores on the chromophore concentration and the strength of the poling field is discussed. Phase transitions between the para‐ and antiferroelectric states are investigated within the limits of the Ising and isotropic models for the chromophore dipoles and are considered for varying chromophore concentration, poling field strength, and macroscopic shape of the sample used for poling. The macroscopic polarization and electro‐optic coefficient of the material change drastically upon phase transition. The theories are compared with the experimental data on the electro‐optic coefficient dependence on the chromophore concentration. The isotropic dipole model shows excellent agreement with experiment for the chromophore systems most commonly used in nonlinear optics.
Activating CD94:NKG2C and inhibitory CD94:NKG2A receptors are expressed by distinct subsets of committed CD8+ TCR αβ lymphocytes
Authors: Arlettaz Lionel , Villard Jean , de Rham Casimir , Degermann Sylvie , Chapuis Bernard , Huard Bertrand , Roosnek Eddy
Published: November 2004

A subset of CD8+ T cells express the natural killer cell receptors CD94:NKG2A or CD94:NKG2C. We found that although many CD8+ T cells transcribe CD94 and NKG2C, expression of a functional CD94:NKG2C receptor is restricted to highly differentiated effector cells. CD94:NKG2A is expressed by a different subset consisting of CCR7+ memory cells and CCR7– effector cells. Since NKG2A can only be induced on naive CD8+ T cells while CD94– memory cells are refractory, it is likely that commitment to the CD94:NKG2A+ subset occurs during the first encounter with antigen. CCR7+CD94:NKG2A+ T cells recirculate through lymph nodes where upon activation, they produce large quantities of IFN‐γ. These cells occur as a separate CD94:NKG2A+ T cell lineage with a distinct TCR repertoire that differs from that of the other CD8+CD94– T cells activated in situ.
CC chemokine receptor 2 regulates leukocyte recruitment and IL‐10 production during acute polymicrobial sepsis
Authors: Feterowski Carolin , Mack Matthias , Weighardt Heike , Bartsch Bernadett , Kaiser‐Moore Simone , Holzmann Bernhard
Published: November 2004

Chemokine receptors are important for recruiting leukocytes to sites of infection and may contribute to immune cell activation. The present study investigated the role of the chemokine receptor CCR2 in polymicrobial septic peritonitis. The results showed that peritoneal production of the CCR2 ligands CCL2 and CCL12 in septic mice was largely independent of the common Toll‐like receptor signaling adaptor MyD88. Antibody blockade of CCR2 reduced the recruitment of macrophages and neutrophils to the infected peritoneal cavities of both wild‐type and MyD88‐deficient mice, suggesting that CCR2 engagement contributes to the MyD88‐independent cellular response against polymicrobial septic peritonitis. Notably, administration of blocking CCR2 antibodies markedly increased local and systemic IL‐10 levels in septic wild‐type mice, whereas IL‐10 was not detected in MyD88‐deficient mice irrespective of whether CCR2 was blocked or not. Inhibition of CCR2 directly augmented Toll‐like receptor‐induced IL‐10, but not TNF and IL‐6, production of macrophages in vitro. Concomitant with enhanced IL‐10 production, CCR2 blockade caused impaired bacterial clearance and aggravated kidney injury in wild‐type, but not MyD88‐null mice. These results indicate that CCR2 engagement modulates the innate immune response to polymicrobial septic peritonitis by both MyD88‐dependent and ‐independent processes and suggest that a major function of CCR2 in sepsis is to attenuate IL‐10 production and IL‐10‐mediated suppression of host defense.
Effector and regulatory T cells derived from the same T cell clone differ in MHC class II‐peptide multimer binding
Authors: Nolte‐‘t Hoen Esther N. M. , Amoroso Maria Grazia , Veenstra Jetty , Grosfeld‐Stulemeyer Mayken C. , van Eden Willem , Broeren Chris P. M. , Wauben Marca H.  M.
Published: November 2004

MHC class II‐peptide multimers are a valuable tool for antigen‐specific detection of CD4+ T cells. However, it has been proposed that T cells in a hypo‐responsive state can have diminished binding of such multimers. In the present study, we investigated this phenomenon at the clonal level. We found that anergic CD4+ T cells had a reduced capacity to bind MHC class II‐peptide multimers compared to their non‐anergic counterparts. Increasing the incubation temperature, time, or MHC‐peptide valency could not equalize multimer binding by anergic and non‐anergic T cells. Neither anergic T cells nor non‐anergic T cells internalized the MHC class II‐peptide dimers efficiently, and in both cases the dimers bound to the plasma membrane at locations containing a low amount of raft‐associated lipids. Disruption of lipid rafts, however, led to decreased dimer binding by non‐anergic T cells and to a lesser extent by anergic T cells. Finally, we show that the depth of the anergic state of the T cell, which determines its ability to regulate other T cell responses, correlates with the reduced dimer binding. We here demonstrate for the first time differential MHC class II‐peptide multimer binding by regulatory (anergic) and effector T cells with identical TCR.
Imaging and analysis of nanowires
Authors: Bell David C. , Wu Yue , Barrelet Carl J. , Gradečak Silvija , Xiang Jie , Timko Brian P. , Lieber Charles M.
Published: November 2004

We used vapor‐liquid‐solid (VLS) methods to synthesize discrete single‐element semiconductor nanowires and multicomposition nanowire heterostructures, and then characterized their structure and composition using high‐resolution electron microscopy (HRTEM) and analytical electron microscopy techniques. Imaging nanowires requires the modification of the established HRTEM imaging procedures for bulk material to take into consideration the effects of finite nanowire width and thickness. We show that high‐resolution atomic structure images of nanowires less than 6 nm in thickness have lattice “streaking” due to the finite crystal lattice in two dimensions of the nanowire structure. Diffraction pattern analysis of nanowires must also consider the effects of a finite structure producing a large reciprocal space function, and we demonstrate that the classically forbidden 1/3 {422} reflections are present in the [111] zone axis orientation of silicon nanowires due to the finite thickness and lattice plane edge effects that allow incomplete diffracted beam cancellation. If the operating conditions are not carefully considered, we found that HRTEM image delocalization becomes apparent when employing a field emission transmission electron microscope (TEM) to image nanowires and such effects have been shown to produce images of the silicon lattice structure outside of the nanowire itself. We show that pseudo low‐dose imaging methods are effective in reducing nanowire structure degradation caused by electron beam irradiation. We also show that scanning TEM (STEM) with energy dispersive X‐ray microanalysis (EDS) is critical in the examination of multicomponent nanowire heterostructures. Microsc. Res. Tech. 64:373–389, 2004. © 2004 Wiley‐Liss, Inc.
Probing photonic and optoelectronic structures by Apertureless Scanning Near‐Field Optical Microscopy
Authors: Bachelot Renaud , Lerondel Gilles , Blaize Sylvain , Aubert Sebastien , Bruyant Aurelien , Royer Pascal
Published: November 2004

This report presents the Apertureless Scanning Optical Near‐Field Microscope as a powerful tool for the characterization of modern optoelectronic and photonic components with sub‐wavelength resolution. We present an overview of the results we obtained in our laboratory over the past few years. By significant examples, it is shown that this specific probe microscopy allows for in situ local quantitative study of semiconductor lasers in operation, integrated optical waveguides produced by ion exchange (single channel or Y junction), and photonic structures. Microsc. Res. Tech. 64:441–452, 2004. © 2004 Wiley‐Liss, Inc.