bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective Effect of Carbon Monoxide Donor Compounds in Endotoxin-Induced Acute Renal Failure
Authors: Shiohira Shunji , Yoshida Takumi , Shirota Satsuki , Tsuchiya Ken , Nitta Kosaku
Published: July 2007

Background: Sepsis is a common cause of acute renal failure (ARF) in clinical practice. However, the precise mechanism of endotoxin-induced ARF is not fully understood. There have been several reports that inhalation of carbon monoxide (CO) gas could be protective against acute rejection in intestine, lung, and kidney transplantation. Thus, we investigated the direct effect of CO in an experimental ARF model of septic shock induced by lipopolysaccharide (LPS). Method: Mice were pretreated with [Ru(CO)3Cl2]2 (CO donor compounds) at various concentrations (0.5, 1.0 and 2.0 µg) which were intravenously injected 24 h before intraperitoneal LPS injection. Biomarkers including myeloperoxidase activity and histochemical staining were evaluated. Results: The elevation of plasma creatinine was suppressed in CO donor-pretreated mice compared with vehicle-treated mice (creatinine 0.35 vs. 0.25; p < 0.05) 24 h after LPS injection. Renal myeloperoxidase activity slightly decreased in CO donor-pretreated mice. In the histological examination, neutrophil infiltration was significantly diminished in CO donor-treated mice. Real-time polymerase chain reaction revealed significant improvements in inflammatory related genes, such as TNFα, MCP-1, RANTES and IL4. Conclusion: Our results suggest the protective effect of the CO donor against endotoxin-induced renal injury; however, further study is needed to elucidate the mechanism.
Psychological well‐being across 1 year with rheumatoid arthritis: Coping resources as buffers of perceived stress
Authors: Treharne Gareth J. , Lyons Antonia C. , Booth David A. , Kitas George D.
Published: July 2007

Objectives. Using the transactional model of stress and coping, the present study investigated whether specific coping resources act as buffers of the relationship between perceived stress and psychological well‐being among rheumatoid arthritis (RA) patients.

Design. A longitudinal observational study was carried out with assessments at baseline, 6 months and 1 year.

Methods. Measures of perceived stress, coping resources (optimism/pessimism, social support and explicit active coping strategies) and psychological well‐being (anxiety, depression and life satisfaction) were completed by 134 RA patients. Demographics, RA duration, pain, fatigue, functional disability, antidepressant use and physical comorbidities were recorded and statistically controlled for.

Results. Perceived stress had the strongest relationship with psychological well‐being at baseline, and affected anxiety after 6 months. Optimism and pessimism predicted psychological well‐being across 1 year. Active behavioural coping buffered an association of stress with depression at baseline, while baseline active cognitive coping buffered the effect of baseline stress on life satisfaction after 6 months.

Conclusion. Patients with RA under greater perceived stress who do not use active coping strategies appear to be at risk of psychological comorbidity and may therefore benefit from interventions teaching specific active coping strategies. Larger observational studies and interventions are required to confirm and extend these findings.
Femoral Neck BMD Is a Strong Predictor of Hip Fracture Susceptibility in Elderly Men and Women Because It Detects Cortical Bone Instability: The Rotterdam Study
Authors: Rivadeneira Fernando , Zillikens M Carola , De Laet Chris EDH , Hofman Albert , Uitterlinden André G , Beck Thomas J , Pols Huibert AP
Published: July 2007

We studied HSA measurements in relation to hip fracture risk in 4806 individuals (2740 women). Hip fractures (n = 147) occurred at the same absolute levels of bone instability in both sexes. Cortical instability (propensity of thinner cortices in wide diameters to buckle) explains why hip fracture risk at different BMD levels is the same across sexes.

Introduction: Despite the sexual dimorphism of bone, hip fracture risk is very similar in men and women at the same absolute BMD. We aimed to elucidate the main structural properties of bone that underlie the measured BMD and that ultimately determines the risk of hip fracture in elderly men and women.

Materials and Methods: This study is part of the Rotterdam Study (a large prospective population-based cohort) and included 147 incident hip fracture cases in 4806 participants with DXA-derived hip structural analysis (mean follow-up, 8.6 yr). Indices compared in relation to fracture included neck width, cortical thickness, section modulus (an index of bending strength), and buckling ratio (an index of cortical bone instability). We used a mathematical model to calculate the hip fracture distribution by femoral neck BMD, BMC, bone area, and hip structure analysis (HSA) parameters (cortical thickness, section modulus narrow neck width, and buckling ratio) and compared it with prospective data from the Rotterdam Study.

Results: In the prospective data, hip fracture cases in both sexes had lower BMD, thinner cortices, greater bone width, lower strength, and higher instability at baseline. In fractured individuals, men had an average BMD that was 0.09 g/cm2 higher than women (p < 0.00001), whereas no significant difference in buckling ratios was seen. Modeled fracture distribution by BMD and buckling ratio levels were in concordance to the prospective data and showed that hip fractures seem to occur at the same absolute levels of bone instability (buckling ratio) in both men and women. No significant differences were observed between the areas under the ROC curves of BMD (0.8146 in women and 0.8048 in men) and the buckling ratio (0.8161 in women and 0.7759 in men).

Conclusions: The buckling ratio (an index of bone instability) portrays in both sexes the critical balance between cortical thickness and bone width. Our findings suggest that extreme thinning of cortices in expanded bones plays a key role on local susceptibility to fracture. Even though the buckling ratio does not offer additional predictive value, these findings improve our understanding of why low BMD is a good predictor of fragility fractures.
Clinical Risk Factors for Fractures in Multi-Ethnic Women: The Women's Health Initiative
Authors: Cauley Jane A , Wu LieLing , Wampler Nina S , Barnhart Janice M , Allison Matthew , Chen Zhao , Jackson Rebecca , Robbins John
Published: July 2007

To identify risk factors for fractures in multi-ethnic women, we studied 159,579 women enrolled in the Women's Health Initiative. In general, risk factors for fractures were similar across ethnic groups. However, irrespective of their ethnicity, women with multiple risk factors have a high risk of fracture. Targeting these high-risk women for screening and intervention could reduce fractures.

Introduction: Fracture rates tend to be lower in minority women, but consequences may be greater. In addition, the number of fractures is expected to increase in minority women because of current demographic trends. There are limited prospective data on risk factors for fractures in minority women.

Materials and Methods: We studied 159,579 women 50–79 yr of age enrolled in the Women's Health Initiative. Information on risk factors was obtained by questionnaire or examination. Nonspine fractures that occurred after study entry were identified over an average follow-up of 8 ± 2.6 (SD) yr.

Results: Annualized rates (%) of fracture in whites, blacks, Hispanics, Asians, and American Indians were 2.0, 0.9, 1.3, 1.2, and 2.0, respectively. Significant predictors [HR (95% CI)] of fractures by ethnic group were as follows: blacks: at least a high school education, 1.22 (1.0, 1.5); (+) fracture history, 1.7 (1.4, 2.2); and more than two falls, 1.7 (1.9, 2.0); Hispanics: height (>162 cm), 1.6 (1.1, 2.2); (+) fracture history, 1.9 (1.4, 2.5); more than two falls, 1.8 (1.4, 2.3); arthritis, 1.3 (1.1, 1.6); corticosteroid use, 3.9 (1.9, 8.0); and parental history of fracture, 1.3 (1.0, 1.6); Asians: age (per 5 yr), 1.2 (1.0, 1.3); (+) fracture history, 1.5 (1.1, 2.0); current hormone therapy (HT), 0.7 (0.5, 0.8); parity (at least five), 1.8 (1.1, 3.0); more than two falls, 1.4 (1.1, 1.9); American Indian: (+) fracture history, 2. 9 (1.5, 5.7); current HT, 0.5 (0.3, 0.9). Women with eight or more risk factors had more than a 2-fold higher rate of fracture compared with women with four or fewer risk factors. Two ethnicity × risk factor interactions were identified: age and fall history.

Conclusions: Irrespective of their ethnicity, women with multiple risk factors have a high risk of fracture. Targeting these high-risk women for screening and intervention could reduce fractures.
Synthesis and characterization of the solid uranium(VI) dioxo-diacetohydroxamate complex
Authors: Gong Cynthia-May S. , Poineau Frédéric , Czerwinski Kenneth R.
Published: July 2007

A novel dry synthesis for the uranium(VI) dioxo-diacetohydroxamate (UAHA) complex has been developed. The complex was generated in >80% yield by mechanically grinding solid uranyl acetate dihydrate (UAc) with solid acetohydroxamic acid in stoichiometric amounts. The resulting UO2(AHA)2·4H2O solid is purified by washing with acetone. The stoichiometry was confirmedviacolorimetric assays for U(VI) and AHA. The analogous ferric trisacetohydroxamate complex (FeAHA) was synthesized for comparison. A novel dry synthesis for the uranium(VI) dioxo-diacetohydroxamate (UAHA) complex has been developed. The complex was generated in >80% yield by mechanically grinding solid uranyl acetate dihydrate (UAc) with solid acetohydroxamic acid in stoichiometric amounts. The resulting UO2(AHA)2·4H2O solid is purified by washing with acetone. The stoichiometry was confirmedviacolorimetric assays for U(VI) and AHA. The analogous ferric trisacetohydroxamate complex (FeAHA) was synthesized for comparison.

The UAHA solid was extensively characterized by ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), and extended X-ray absorption fine structure (EXAFS) spectroscopies. The compound did not fluoresce after laser excitation. Proton nuclear magnetic resonance (NMR) spectra were obtained of the complex in D2O, acidified acetonitrile-d3, and DMSO-d6. The solubility was determined over a range of solvents. It was determined that in the purified solid, two bidentate AHA molecules bind to uranylviathe carbonyl and hydroxamate oxygen atoms, a structure analogous to known ferric, nickel, and lanthanum AHA complexes. In an acidic environment, binding is monodentate through the hydroxamate oxygen. And in aqueous solution, the UAHA complex assumes both binding moieties, depending on the pH. This pH-dependent speciation change is demonstrated for the first time.

The easy synthesis and purification of UAHA enables researchers to strictly control reaction conditions; to eliminate interfering salts and water; and to study the complex in the solid-phase.
Studies on the interaction of poly(N-vinylpyrrolidone) with no-carrier-added 61Cu, 62Zn, 66Ga, 69Ge and 71As using tracer packet technique
Authors: Sarkar Soumi , Nayak Dalia , Lahiri Susanta
Published: July 2007

Interactions of no-carrier-added radionuclides 61Cu, 62Zn, 66Ga, 69Ge and 71As with poly(N-vinylpyrrolidone) (PVP) were studied in multi-elemental environment by dialysis with the help of tracer packet technique. It has been observed that in acidic pH gallium has a high tendency for formation of Ga-PVP complex while the same is true for Cu and Zn in neutral and basic pH. Germanium is always inert towards the interaction with PVP at all pH values. No interaction of arsenic was observed in acidic and neutral pH; while in basic pH the tendency to form As-PVP complex is considerably higher. The result can be considered as a model of in-vivo interaction of PVP-Ga/Cu/Zn/As complexation.
Optimization of the decision threshold for single radioactive counting
Authors: Vivier V. , Aupiais Jean
Published: July 2007

When the activity of a sample is close to the background level, the decision threshold is classically defined by considering distributions of sample and background as being equal. Recently, the Bayesian approach has been considered in the standard ISO to refine the determination of the decision threshold by taking into account all accessible information prior to measurement such as type A and type B uncertainties. However, simplifications using Gaussian approximation and experimental values instead of true means are often used to facilitate calculations. In this paper, we develop a complete treatment without simplification, based on the Bayesian approach and Poisson distribution. Minimal informations have been considered: one single raw counting for the sample and one previously acquired background. From one single background counting, the net background probability law is calculated and then a decision threshold is deduced. In particular, we demonstrate that the decision threshold is defined for any case including very low background or even null event. Comparisons with classical approach as well as the Bayesian treatment in the new ISO 11929 have been carried out. Applications of this decision threshold for the optimisation of radioactive measurement or in case of a set of minimal detectable activities used to determine average releases are given. Bayesian treatment also gives relevant informations such as the probability for a source to be radioactive when the net number of counts is below the decision threshold.
Bifurcated CN Group in Hexacyanometallates, the Case of Cd2[Fe(CN)6]. Structure Determination from a Combination of RDF and Direct Methods
Authors: Gómez A. , Rodríguez-Hernández J. , Kycia S. , Reguera E.
Published: July 2007

The crystal structure of anhydrous cadmium hexacyanoferrate (II), Cd2[Fe(CN)6], has been solved from powder diffraction data using information extracted from low resolution radial distribution function. Such anhydrous solid is obtained by soft heating of its parent octahydrate. The radial distribution function proves to be useful for observing changes in heavy atoms interatomic distances in the structure during phase transition related to the material dehydration process. These distances were then used for guessing the heavy atom positions from the direct methods results. Cd2[Fe(CN)6] crystallizes in the hexagonal system, space group P-3 (147) and cell parameters: a = 6.32046(5) and c = 6.33786(10)Å. The structure was refined to final agreement factors of R
wp = 6.26% and S = 1.99. The proposed structural model is supported by the obtained information from Mössbauer, IR and Raman spectra.
Density, Apparent and Partial Molar Volumes, and Viscosity of Aqueous Na2CO3Solutions at High Temperatures and High Pressures
Authors: Abdulagatov Ilmutdin M. , Azizov Nazim D. , Zeinalova Adelya B.
Published: July 2007

Density of five (0.124, 0.334, 0.706, 1.055, and 1.123) mol kg-1and viscosity of seven (0.124, 0.2918, 0.334, 0.706, 0.8472, 1.055, and 1.123) mol kg-1binary aqueous Na2CO3solutions have been measured with a constant-volume piezometer and capillary flow techniques, respectively. Measurements were performed at pressures up to 52MPa for the density and 40MPa for the viscosity. The range of temperature was from 299 to 577K for density and from 293 to 478K for the viscosity. The total uncertainty of density, viscosity, pressure, temperature, and composition measurements was estimated to be less than 0.06%, 1.6%, 0.05%, 15mK, and 0.02%, respectively. Apparent molar volumes were derived using measured values of density for the solutions and for pure water calculated with IAPWS formulation. The effect of the thermodynamic variables (temperature, pressure, and concentration) on density, apparent and partial molar volumes, and viscosity of Na2CO3(aq) solutions was studied. The derived apparent molar volumes have been interpreted in terms of the Pitzer’s ion-interaction model of electrolyte solutions to accurate calculates the values of partial molar volumes at infinite dilutionV¯2∞and the second (BV) and third (CV) virial coefficients for the apparent molar volume as a function of temperature. The viscosity data have been analyzed and interpreted in terms of extended Jones–Dole equation for the relative viscosity (η/η0) of strong electrolyte solutions to accurate calculate the values of viscosityA- andB-coefficients as a function of temperature. The Arrhenius–Andrade parametersηAandb = Ea/R(whereEais the flow activation energy) were calculated using present experimental viscosity data. The effective pressuresPedue to the salt (Na2CO3) in water in the TTG (Timmann-Tait-Gibson) model were calculated from present viscosity measurements.
The Virtues and Potential Gains of Continental Trade in Eurasia
Authors: Norling Nicklas , Swanström Niklas
Published: July 2007

Trade in Eurasia is shifting to growing continental rather than regional ties at the same time as overland transports are becoming a viable option. If trade obstacles could be surmounted, this trend promises to have substantial implications for the landlocked states of Greater Central Asia and their access to world markets.
Prime Ministerial Popularity and the Changing Electoral Fortunes of Japan's Liberal Democratic Party
Authors: Patterson Dennis , Maeda Ko
Published: July 2007

This article explores the impact of prime ministerial popularity on the changing electoral fortunes of Japan's Liberal Democratic Party (LDP). We show that the popularity of the Japanese prime minister exerted a modest but definite impact on aggregate vote shares captured by the LDP throughout the postwar period.
U.S. Policy toward North Korea in Strategic Context: Tempting Goliath's Fate
Authors: Huntley Wade L.
Published: July 2007

Since the collapse of the U.S.-North Korea Agreed Framework in 2002, the Bush administration has failed to restrain North Korea's nuclear weapons ambitions, principally because of the constraints of highly idealized convictions. Resolution of the Korean nuclear crisis now depends on U.S. initiative beyond the boundaries of these predispositions and beyond the terms of the nuclear crisis itself.
Bovine germinal vesicle oocyte and cumulus cell proteomics
Authors: Memili E , Peddinti D , Shack L A , Nanduri B , McCarthy F , Sagirkaya H , Burgess S C
Published: July 2007

Germinal vesicle (GV) breakdown is fundamental for maturation of fully grown, developmentally competent, mammalian oocytes. Bidirectional communication between oocytes and surrounding cumulus cells (CC) is essential for maturation of a competent oocyte. However, neither the factors involved in this communication nor the mechanisms of their actions are well defined. Here, we define the proteomes of GV oocytes and their surrounding CC, including membrane proteins, using proteomics in a bovine model. We found that 4395 proteins were expressed in the CC and 1092 proteins were expressed in oocytes. Further, 858 proteins were common to both the CC and the oocytes. This first comprehensive proteome analysis of bovine oocytes and CC not only provides a foundation for signaling and cell physiology at the GV stage of oocyte development, but are also valuable for comparative studies of other stages of oocyte development at the molecular level. Furthermore, some of these proteins may represent molecular biomarkers for developmental potential of oocytes.
Gonadotrophins modulate hormone secretion and steady-state mRNA levels for activin receptors (type I, IIA, IIB) and inhibin co-receptor (betaglycan) in granulosa and theca cells from chicken prehierarchical and preovulatory follicles
Authors: Lovell Tristan M , Al-Musawi Sara L , Gladwell Richard T , Knight Philip G
Published: July 2007

Ovarian follicle development is regulated through endocrine and local mechanisms. Increasing evidence indicates roles for transforming growth factor β superfamily members, including inhibins and activins. We recently identified divergent expression of mRNAs encoding activin receptors (ActR) and inhibin co-receptor betaglycan in chicken follicles at different stages of maturation. Here, we compare the actions of LH and FSH (0, 1, 10, 100 ng/ml) on levels of mRNA for ActRI, ActRIIA, ActRIIB and betaglycan in chicken granulosa and theca cells (GC and TC) from preovulatory (F1) and prehierarchical (6–8 mm) follicles. The expression of mRNAs for LH-R and FSH-R and production of inhibin A, oestradiol and progesterone were also quantified. FSH decreased ActRIIB and ActRI mRNA levels in 6–8 mm GC, whereas LH increased the mRNA levels. Both LH and FSH enhanced ActRIIA (5- and 8.5-fold) and betaglycan mRNA expression (2- and 3.5-fold) in 6–8 mm GC. In 6–8 mm TC, LH and FSH both increased the betaglycan mRNA level (7- and 3.5-fold respectively) but did not affect ActRI, ActRIIA and ActRIIB transcript levels. In F1 GC, both LH and FSH stimulated ActRI (2- and 2.4-fold), ActRIIB (3.2- and 2.7-fold) and betaglycan (7- and 4-fold) mRNA levels, while ActRIIA mRNA was unaffected. In F1 TC, LH and FSH reduced ActRIIA (35–50%) and increased (4.5- and 7.6-fold) betaglycan mRNA, but had no effect on ActRI and ActRIIB transcript levels. Results support the hypothesis that expression of ActR and betaglycan are differentially regulated by gonadotrophins during follicle maturation in the hen. This may represent an important mechanism for fine-tuning follicle responsiveness to local and systemic activins and inhibins.
Effects of ACTH and expression of the melanocortin-2 receptor in the neonatal mouse testis
Authors: Johnston Heather , King Peter J , O’Shaughnessy Peter J
Published: July 2007

ACTH has been shown to stimulate androgen production by the fetal/neonatal mouse testis through the melanocortin type 2 receptor (MC2R). This study was designed to localize the expression of MC2R in the neonatal mouse testis and characterize the effects of ACTH on testicular androgen production. Using immunohistochemistry, MC2R was localized to the fetal-type Leydig cell population of the neonatal testis. ACTH caused a time-dependent increase in cyclic AMP (cAMP) and testosterone production by isolated cells with an increase in cAMP apparent in < 3 min. There was no additive effect of maximally stimulating doses of ACTH and human chorionic gonadotropin (hCG). Androgen production in response to ACTH and hCG was reduced by UO126 and dexamethasone, which are the inhibitors of ERK1/2 and phospholipase A2 respectively. Expression of mRNA encoding StAR was increased fourfold by both ACTH and hCG, although expression of mRNA encoding for steroidogenic enzymes was not markedly affected. The potency of N-terminal fragments of ACTH to stimulate androgen production was similar to that seen previously in the adrenal. Data indicate that both LH and ACTH, acting through their respective receptors, stimulate steroidogenesis by fetal-type Leydig cells via arachidonic acid, protein kinase A, and ERK1/2 activation of StAR.
Claudin-11 expression and localisation is regulated by androgens in rat Sertoli cells in vitro
Authors: Kaitu’u-Lino Tu’uhevaha J , Sluka Pavel , Foo Caroline F H , Stanton Peter G
Published: July 2007

Claudin-11 and occludin are protein components in tight junctions (TJs) between Sertoli cells which are important for the maintenance of the blood–testis barrier. Barrier formation occurs during puberty, with evidence suggesting hormonal regulation of both claudin-11 and occludin. This study aimed to investigate the regulation of claudin-11 and occludin mRNA expression by testosterone (T) and FSH and their immunolocalisation at rat Sertoli cell TJs in vitro, and to correlate any steroid regulation with the functional capacity of TJs. Sertoli cells formed functional TJs within 3 days as assessed by transepithelial electrical resistance (TER). Both T and dihydrotestosterone significantly (P < 0.01) increased TER twofold and claudin-11 mRNA two- to threefold within 3 days. FSH partially stimulated TER and claudin-11 mRNA, but estradiol had no effect. T also promoted claudin-11 localisation into extensive intercellular contacts. In contrast to claudin-11, Tand FSH did not change occludin mRNA expression, however, T promoted localisation of occludin at cell contacts in a similar manner to claudin-11. Addition of flutamide to T-stimulated cells caused a twofold decrease in both TER and claudin-11 mRNA expression, and resulted in the loss of both proteins from cell contacts. This effect was reversible following flutamide removal. It is concluded that androgens i) co-regulate claudin-11 mRNA expression and TER, implicating claudin-11 in TJ formation and ii) promote the localisation of claudin-11 and occludin at Sertoli cell contacts. Hence, the ability of androgens to maintain spermatogenesis in vivo is partly via their effects on TJ proteins and regulation of the blood–testis barrier.
Long-term sediment bioassay of lead toxicity in two generations of the marine amphipodElasmopus laevis, S.I. Smith, 1873
Authors: Ringenary Mark J. , Molof Alan H. , Tanacredi John T. , Schreibman Martin P. , Kostarelos Konstantinos
Published: July 2007

Sediments are evaluated for toxicity by measuring mortality in a single cohort of amphipods in either acute (10-d) or chronic (28-d) bioassays. This investigation differed from conventional bioassays in four ways: Sublethal effects (fecundity) were estimated; the testing period was 60+ d; two successive generations were examined; and Elasmopus laevis Smith, 1873, amphipods were employed. Four test sediments were created between 58 and 424 μg/g of lead using the 30-μg/g whole-sediment as the control. Bioaccumulated lead at 60 d varied as a linear function of lead concentration in the sediments. Fecundity, as estimated by offspringper-chamber and/or percent reproductive success, was reduced as sediment lead concentrations increased and reproduction was delayed compared with the control. The reduction in offspring production per test chamber varied significantly as an inverse function of lead sediment concentration, best described by a curvilinear exponential equation. It was concluded that E. laevis exposed to 118 μg/g and higher could not maintain a population as large as that in the control. Although the current sediment quality guideline for lead stipulates that adverse biological effects likely will occur above 218 μg/g, this study revealed a statistically significant negative reproductive response at 118 μg/g lead, and suggests that the current regulatory guideline for lead, based on lethality, should be reconsidered.
Toxicity of cadmium to early life stages of brown trout (Salmo trutta) at multiple water hardnesses
Authors: Brinkman Stephen F. , Hansen Daria L.
Published: July 2007

Toxicity of cadmium to early life stages of brown trout (Salmo trutta) was determined at multiple water hardnesses. Increasing water hardness decreased cadmium toxicity. Postswimup fry were much more sensitive than embryos and larvae. Chronic values from early life stage tests initiated with eyed embryos were 3.52, 6.36, and 13.6 μg Cd/L at water hardnesses of 30.6, 71.3, and 149 mg/L, respectively. In tests initiated with 30-d postswimup fry, chronic values were 1.02, 1.83, and 6.54 μg Cd/L at water hardnesses of 29.2, 67.6, and 151 mg/L, respectively. Higher chronic values from the early life stage tests compared to tests initiated with swimup fry likely are caused by acclimation during cadmium-tolerant embryo and larval stages. Growth was not affected by cadmium in the early life stage tests but was negatively affected in tests initiated with fry at water hardnesses of 29.2 and 67.6 mg/L. Concentrations of cadmium that reduced growth were higher than those that increased mortality. Median lethal concentrations for swimup fry after 96 h were 1.23, 3.90, and 10.1 μg Cd/L at water hardnesses of 29.2, 67.6, and 151 mg/L, respectively. Test results enable prediction of acute mortality of brown trout swimup fry based on cadmium concentration and water hardness.
Decreased toxicity to terrestrial plants associated with a mixture of methyltert-butyl ether and its metabolitetert-butyl alcohol
Authors: An Youn-Joo , Lee Woo-Mi
Published: July 2007

The influence of the main fuel oxygenate methyl tert-butyl ether (MTBE) and its key metabolite, tert-butyl alcohol (TBA), on the growth of a plant seedling was studied separately and in combination. The test plants were mung bean (Phaseolus radiatus), cucumber (Cucumis sativus), wheat (Triticum aestivum), sorghum (Sorghum bicolor), kale (Brassica alboglabra), Chinese cabbage (Brassica campestris), and sweet corn (Zea mays). The growth of all the plants was adversely affected by TBA and MTBE. The 5-d median effective concentration (EC50) for the plants exposed to MTBE and TBA were in the range of 680 to 1,000 mg MTBE/kg soil (dry wt) and 1,200 to 3,500 mg TBA/kg soil (dry wt), respectively. The relative order of the sensitivity rankings is almost the same for MTBE and TBA. Methyl tert-butyl ether is more toxic than TBA to most of the test species. Based on the EC50 values, MTBE is approximately 1.5 to 3 times more potent than TBA. The sum of the toxic unit (TU) at 50% inhibition of the mixture (EC50mix) was calculated from the dose (TU-based)-response relationships using the trimmed Spearman-Karber method. The combined effect of MTBE + TBA on the plant growth was less than additive because the EC50mix values were greater than 1 TU. This phenomenon may be due to the competition of MTBE and TBA in terms of their intake by plants. The combined effects of MTBE and TBA should be taken into account to assess their risk in gasoline-contaminated sites.
Interactions of silver, cadmium, and copper accumulation in green mussels (Perna viridis)
Authors: Ng Tania Y.-T. , Wang Wen-Xiong
Published: July 2007

Metal interaction is vital for assessing the use of aquatic organisms in monitoring metal contamination. The present study examined the interactions between Ag and Cd accumulation and between Ag and Cu accumulation in the green mussel (Perna viridis). Accumulation of Ag and Cd in the whole tissue of green mussels exposed to 5 μg/L of Ag and 20 μg/L of Cd for two weeks was independent; however, interaction was observed at the subcellular level. Approximately 25% of Ag shifted from the insoluble fraction (IF) to the metallothionein-like protein in the presence of Cd, which probably resulted from the competition of Cd on IF in the Ag-Cd coexposure. On the other hand, coexposure of the mussels to Ag (5 μg/L) and Cu (30 μg/L) for two weeks increased the Ag and Cu concentrations in the tissue synergistically (two- to fivefold), but Ag and Cu subcellular distributions were similar in the coexposed and the singly exposed mussels. Exposure to Ag alone increased the dietary uptake of Ag by 30%, but the effect was reduced in the presence of Cd. No interaction, however, was observed between uptake rates of metals from the dissolved phase. To conclude, a significant interaction was observed for total Ag and Cu accumulation, but not for total Ag and Cd accumulation, in the mussels. Metal interaction is more likely to be observed at the subcellular level than at the whole-tissue level.
Wastewater treatment plants as a pathway for aquatic contamination by pharmaceuticals in the Ebro river basin (Northeast Spain)
Authors: Gros Meritxell , Petrović Mira , Barceló Damià
Published: July 2007

The occurrence of 28 pharmaceuticals of major human consumption in Spain, including analgesics and anti-inflam-matories, lipid regulators, psychiatric drugs, antibiotics, antihistamines, and β-blockers, was assessed along the Ebro river basin, one of the biggest irrigated lands in that country. Target compounds were simultaneously analyzed by off-line solid-phase extraction, followed by liquid chromatography-tandem mass spectrometry. The loads of detected pharmaceuticals and their removal rates were studied in seven wastewater treatment plants (WWTPs) located in the main cities along the basin. Total loads ranged from 2 to 5 and from 0.5 to 1.5 g/d/1,000 inhabitants in influent and effluent wastewaters, respectively. High removal rates (60–90%) were achieved mainly for analgesics and anti-inflammatories. The other groups showed lower rates, ranging from 20 to 60%, and in most cases, the antiepileptic carbamazepine, macrolide antibiotics, and trimethoprim were not eliminated at all. Finally, the contribution of WWTP effluents to the presence of pharmaceuticals in receiving river waters was surveyed. In receiving surface water, the most ubiquitous compounds were the analgesics and anti-inflammatories ibuprofen, diclofenac, and naproxen; the lipid regulators bezafibrate and gemfibrozil; the antibiotics erythromycin, azithromycin, sulfamethoxazole, trimethoprim, and less frequently, ofloxacin; the antiepileptic carbamazepine; the antihistamine ranitidine; and the β-blockers atenolol and sotalol. Although levels found in WWTP effluents ranged from low μg/L to high ng/L, pharmaceuticals in river waters occurred at levels at least one order of magnitude lower (low ng/L range) because of dilution effect. From the results obtained, it was proved that WWTP are hot spots of aquatic contamination concerning pharmaceuticals of human consumption.
Analysis of glutathione endpoints for measuring copper stress in Chlamydomonas reinhardth
Authors: Stoiber Tasha L. , Shafer Martin M. , Perkins Dawn A. Karner , Hemming Jocelyn D.C. , Armstrong David E.
Published: July 2007

Glutathione (GSH) is the most abundant nonprotein thiol in eukaryotic cells and it protects cells by functioning as an antioxidant and a metal-binding ligand. Because glutathione readily undergoes oxidation-reduction reactions to combat oxidative stress, intracellular ratios of the reduced (GSH) to the oxidized (GSSG) forms of glutathione may serve as an important biomarker of exposure and effect of trace metals in eukaryotic cells. We compared sensitivity of glutathione ratios in the freshwater alga Chlamydomonas reinhardtii to the traditional endpoints of cell growth rates and chlorophyll a following exposure to Cu for periods of 6 and 24 h. A response of the GSH:GSSG ratio to Cu concentration was observed at Cu levels of 40 and 80 nM after exposure for both 6 and 24 h. The concentration of total GSH at 24 h was roughly half the value at 6 h after exposure to either 40 or 80 nM Cu. A response for cell growth rate was observed only at 24 h, whereby the average specific growth rate decreased from about 1.1 to 0.4 d−1. The total Cu concentrations eliciting a cell response of 50%, effect concentrations (EC50s), after 24 h of exposure were similar (49.2, 49.8, and 38.2 nM Cu) and not significantly different for GSH:GSSG ratio, GSH levels, and specific growth, respectively. Total cell-associated Cu concentrations after exposure for 24 h were calculated from the EC50 endpoints and ranged from 13.3 to 17.0 fg/cell. Overall, thiol ratios were indicative of toxicity resulting from exposure to Cu, but precision may be greater for the cell growth rate endpoints.
Influence of the temperature gradient in blubber on the bioaccumulation of persistent lipophilic organic chemicals in seals
Authors: Czub Gertje , McLachlan Michael S.
Published: July 2007

Seals constitute an important link in food webs of the Arctic environment and are an important vector of persistent lipophilic organic pollutants to top predators (e.g., polar bears) and humans. Two fugacity-based, non-steady state, mechanistic lifetime models were assembled to explore the influence of the temperature gradient in the insulating blubber on the distribution and bioaccumulation of persistent lipophilic organic pollutants in seals. The behavior of a two-compartment model that distinguishes between the gastrointestinal tract and the seal itself was compared with a three-compartment model, in which a separate blubber compartment was implemented with a temperature gradient through the insulation layer. In both models, equilibrium partitioning between the animal's tissues, blood, and milk was assumed. The models were parameterized for ringed seals (Phoca hispida) and evaluated using field data for bioaccumulation of polychlorinated biphenyls in this species. The two-compartment model resulted in predicted concentrations below reported field data. This was in particular the case for females, for which the elimination of the contaminants via milk was overpredicted by up to one order of magnitude. The three-compartment model with its consideration of the temperature gradient in blubber yielded predictions that were much more consistent with the field data. It also predicted a fractionation of polychlorinated biphenyl congeners between different blubber layers, as well as between blubber and blood or milk, which was in good qualitative agreement with observations reported in the literature. This work indicates that the temperature gradient in the blubber has an impact on the bioaccumulation of persistent lipophilic organic pollutants in seals and in marine mammals in general.
Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoil
Authors: Joner Erik Jautris , Munier-Lamy Colette , Gouget Barbara
Published: July 2007

An old mine spoil at a 19th-century mining site with considerable residues of uranium (400–800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An ecotoxicity bioassay using incorporation of [3H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO2-citrate was ≈ 120 μM as compared to 30 μM in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 μM UO2-citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bioavailable U to affect indigenous microorganisms and that bioavailable U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low.
Dynamic energy budget as a basis to model population-level effects of zinc-spiked sediments in the gastropodValvata piscinalis
Authors: Ducrot Virginie , Péry Alexandre R.R. , Mons Raphaël , Quéau Hervé , Charles Sandrine , Garric Jeanne
Published: July 2007

This paper presents original toxicity test designs and mathematical models that may be used to assess the deleterious effects of toxicants on Valvata piscinalis (Mollusca, Gastropoda). Results obtained for zinc, used as a reference toxicant, are presented. The feeding behavior, juvenile survival, growth, age at puberty, onset of reproduction, number of breedings during the life cycle, and fecundity were significantly altered when the snails were exposed to zinc-spiked sediments. Dynamic energy budget models (DEBtox) adequately predicted the effects of zinc on the V. piscinalis life cycle. They also provided estimates for life-cycle parameters that were used to parameterize a demographic model, based on a Z-transformed life-cycle graph. The effect threshold for the population growth rate (γ) was estimated at 259 mg/kg dry sediment of zinc, showing that significant changes in abundance may occur at environmental concentrations. Significant effects occurring just above this threshold value were mainly caused by the severe impairment of reproductive endpoints. Sensitivity analysis showed that the value of γ depended mainly on the juvenile survival rate. The impairment of this latter parameter may result in extinction of V. piscinalis. Finally, the present study highlights advantages of the proposed modeling approach in V. piscinalis and possible transfer to other test species and contaminants.
Application of a source apportionment model in consideration of volatile organic compounds in an urban stream
Authors: Asher William E. , Luo Wentai , Campo Kimberly W. , Bender David A. , Robinson Keith W. , Zogorski John S. , Pankow James F.
Published: July 2007

Position-dependent concentrations of trichloroethylene and methyl-tert-butyl ether are considered for a 2.81-km section of the Aberjona River in Massachusetts, USA. This river flows through Woburn and Winchester (Massachusetts, USA), an area that is highly urbanized, has a long history of industrial activities dating to the early 1800s, and has gained national attention because of contamination from chlorinated solvent compounds in Woburn wells G and H. The river study section is in Winchester and begins approximately five stream kilometers downstream from the Woburn wells superfund site. Approximately 300 toxic release sites are documented in the watershed upstream from the terminus of the study section. The inflow to the river study section is considered one source of contamination. Other sources are the atmosphere, a tributary flow, and groundwater flows entering the river; the latter are categorized according to stream zone (1, 2, 3, etc.). Loss processes considered include outflows to groundwater and water-to-atmosphere transfer of volatile compounds. For both trichloroethylene and methyl-tert-butyl ether, degradation is neglected over the timescale of interest. Source apportionment fractions with assigned values αinflow, α1, α2, α3, etc. are tracked by a source apportionment model. The strengths of the groundwater and tributary sources serve as fitting parameters when minimizing a reduced least squares statistic between water concentrations measured during a synoptic study in July 2001 versus predictions from the model. The model fits provide strong evidence of substantial unknown groundwater sources of trichloroethylene and methyl-tert-butyl ether amounting to tens of grams per day of trichloroethylene and methyl-tert-butyl ether in the river along the study section. Modeling in a source apportionment manner can be useful to water quality managers allocating limited resources for remediation and source control.
Aquatic invertebrate resting egg sensitivity to glutaraldehyde and sodium hypochlorite
Authors: Raikow David F. , Landrum Peter F. , Reid David F.
Published: July 2007

Ballast tank treatment technologies are currently in development to reduce the risk of acquiring or transporting viable aquatic organisms that could be introduced to ecosystems and become invasive. Aquatic invertebrate resting eggs represent a challenge to such technologies because of morphological and biochemical adaptations to stress that also protect eggs from artificial stressors. To evaluate the potential efficacy of chemical biocides for ballast tank treatment, the present study examined the acute toxicity of glutaraldehyde and sodium hypochlorite on resting eggs of the freshwater cladoceran Daphnia mendotae and marine brine shrimp (Artemia sp.). Glutaraldehyde was toxic to resting eggs of Artemia sp., as indicated by a lethal concentration to 90% of organisms (LC90) of 95% confidence interval (226 ± 10 mg/L). Daphnia mendotae, in contrast, displayed erratic responses to glutaraldehyde. Sodium hypochlorite was similarly toxic to resting eggs of Artemia sp. and D. mendotae, which displayed LC90s of 86.5 ± 3.0 and 78.3 ± 1.6 mg/L, respectively. Burial in sediment protected resting eggs from toxicants. The present results corroborate those from previous investigations of resting egg sensitivity to artificial stressors, supporting the conclusions that resting eggs are less sensitive than other life stages to artificial stressors and that chemical biocide concentrations effective against other life stages may be ineffective against resting stages.
Sorption of tylosin A, D, and A-aldol and degradation of tylosin a in soils
Authors: Sassman Stephen A. , Sarmah Ajtt K. , Lee Linda S.
Published: July 2007

Heightened concerns regarding the potential impact on soil and water quality of veterinary antibiotics warrant a better understanding of the environmental fate of antibiotics in soil. Sorption of the macrolides tylosin A (TA), tylosin D, and TA-aldol was measured in several soils and evaluated with respect to soil pH, organic matter content, percentage clay, and cation-exchange capacity (CEC). Tylosin and related compounds exhibit similar sorption characteristics and generally are strongly sorbed, with sorption being well and positively correlated to surface area, clay content, and CEC. Sorption coefficients normalized by CEC were within a narrow range (104.1±0.21 L/molc) for all but one soil; however, good extraction recoveries with only methanol for most soils suggested that hydrophobic processes also contribute to sorption. Aerobic degradation of TA over a three-month period in two freshly collected agricultural soils and 60Co-irradiated soils indicated that both abiotic and microbial processes contribute to TA transformation. The abiotic process was much slower and dominated in the first two weeks, followed by rapid microbial degradation within 3 d. Three primary degradation products were identified using liquid chromatography with full-scan mass spectrometry, with unconfirmed identifications of TA having the aldehyde group oxidized to an acid (m/z = 932) in both soils and tyslosin B (m/z = 772) as well as tylosin B having the aldehyde group oxidized to an acid (m/z = 788) in the sandy soil.
Cognitive Pathology and Moral Judgment in Managers
Authors: Curlo Eleonora , Strudler Alan
Published: July 2007

We examine the moral and managerial significance of some empirical studies in cognitive psychology. We suggest that these results may plausibly be interpreted as expressing deontological commitments of experimental subjects, even though psychologists who discuss the results seem to suppose that they show that people are irrational consequentialists. We argue that the plausibility of our interpretation suggests how managers who wish to take seriously entrenched social views on morality might best craft corporate policy on corporate responsibility, and we suggest that the form of argument we employ may be regarded as a kind of appeal to reflective equilibrium.
Business, Ethics, and Carol Gilligan's “Two Voices”
Authors: White Thomas I.
Published: July 2007

This article argues that Carol Gilligan's research in moral development psychology, work which claims that women speak about ethics in a “different voice” than men do, is applicable to business ethics. This essay claims that Gilligan's “ethic of care” provides a plausible explanation for the results of two studies that found men and women handling ethical dilemmas in business differently. This paper also speculates briefly about the management implications of Gilligan's ideas.
Mutual Understanding, The State of Attention, and the Ground for Interaction in Economic Systems
Authors: Berger Lawrence A.
Published: July 2007

Neoclassical economic theory assumes that people pursue utility maximization within an objective framework, evident to all, that serves as the basis for the interaction. Agents are assumed to be detached observers who see the situation as it is in objective reality. It is argued in this article that there is no objective ground for interaction that exists apart from the understanding of economic agents. Agents have orientations that change over time depending on the way that the situation is currently understood. Depth of understanding and the extent of common ground depend on the quality of attention and the will to openness and honesty. Efforts to maintain connections with others make possible mutual understanding and visions of the common good that enable the coordinated pursuit of desired states of the world.

Thus the understanding is … itself the lawgiver of nature. Save through it, nature, that is, synthetic unity of the manifold of appearances according to rules, would not exist at all….

Immanuel Kant, Critique of Pure Reason