bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homochiral, Supramolecular Frameworks Built from a Zinc(II) Tetramer or Cadmium(II) Dimer Containing Enantiopure Carboxylate Ligands Functionalized with a Strong π···π Stacking Synthon
Authors: Reger Daniel L. , Debreczeni Agota , Smith Mark D. 
Published: December 2011

AbstractThe enantiopure ligand (S)‐2‐(1,8‐naphthalimido)propanoate (Lala–) forms a tetrameric zinc(II) complex [Zn4(Lala)6(OH)2(MeOH)4]·3(CH2Cl2)·2(MeOH) (1) and a dimeric cadmium(II) complex [Cd2(Lala)4(DMF)3(MeOH)] (2). Bridging κ2‐carboxylate and hydroxide ligands link the four zinc centers in 1. The strong π···π‐stacking 1,8‐naphthalimide supramolecular synthons organize the tetramers into a 3D architecture that contains linked, homochiral helical chains. In the structure, each chain is connected to four other chains by the π···π‐stacking interactions of the naphthalimide rings. The structure is open with two types of channels filled with ordered and disordered solvent molecules. The two cadmium centers in 2 are linked by two κ2‐carboxylate ligands. The π···π‐stacking interactions of the naphthalimide rings organize the structure into 2D sheets, which lack complex chiral features. The naphthalimide rings in these d10 metal complexes promote blue (1) and green (2) emission in the solid state.
The Solution Structure and Dynamics of MRI Probes Based on Lanthanide(III) DOTA as Investigated by DFT and NMR Spectroscopy
Authors: Platas‐Iglesias Carlos 
Published: December 2011

AbstractParamagnetic lanthanide(III) complexes stable in aqueous solutions have gained increasing interest in the recent years due to their importance as contrast agents in magnetic resonance imaging (MRI). Lanthanide(III) complexes with macrocyclic ligands derived from 1,4,7,10‐tetraazacyclododecane (cyclen) are widely used for the design of MRI probes because of their high thermodynamic stability and kinetic inertness. The rational design of more efficient contrast agents requires a better understanding of the structure and dynamics of these systems in solution. This contribution reviews the work of the author and his collaborators on the solution structure and dynamics of lanthanide(III) complexes with different cyclen‐based ligands and closely related systems. DFT calculations provide molecular geometries and relative energies of the different stereoisomers of these complexes in good agreement with the experimental data. The conformational analysis performed with the aid of density functional theory (DFT) calculations was validated with the investigation of the YbIII‐induced 1H NMR paramagnetic shifts, which encode information on the position of the observed NMR nuclei with respect to the LnIII ion. Additionally, DFT calculations provide a better understanding of the dynamic processes responsible for the interconversion between the square‐antiprismatic (SAP) and twisted‐square‐antiprismatic (TSAP) isomers of these complexes in solution, which might proceed through the inversion of the cyclen unit or the rotation of the pendant arms. The activation barriers obtained from theoretical calculations show a good agreement with the experimental values obtained from variable‐temperature NMR spectroscopy. The work presented in this paper shows that DFT calculations in combination with NMR spectroscopy provide detailed information on the structure and dynamics of lanthanide(III) complexes at the molecular level and represent a powerful tool for the characterization of lanthanide(III) complexes relevant to the field of MRI contrast agents.
Synthesis of Fluorinated Ketoheptoses as Specific Diagnostic Agents
Authors: Waschke Daniel , Leshch Yevgeniy , Thimm Julian , Himmelreich Uwe , Thiem Joachim 
Published: December 2011

AbstractThe straightforward syntheses of six regioisomeric mono‐ and difluorinated D‐manno‐heptulose and Kamusol analogues, which use electrophilic or nucleophilic fluorinaton, are reported. D‐manno‐Heptulose shows attractive pharmacological properties in vivo, such as antitumour activity, as well as binding to and accumulating in pancreatic beta cells to induce hyperglycemia. The synthesised analogues represent promising probes for the detection and quantification of beta cells in vivo by 19F MRI techniques, which could help to investigate disease progression. In addition, they are potential candidates for the inhibition of tumour growth.
Discriminatory peer aggression among children as a function of minority status and group proportion in school context
Authors: Durkin Kevin , Hunter Simon , Levin Kate A. , Bergin Dermot , Heim Derek , Howe Christine 
Published: December 2011

AbstractThis study investigates discriminatory peer aggression among primary school aged children as a function of minority status (based on nationality, ethnicity, religion) of the target and the relative proportions of minority and majority children in the school. Participants were 925 8‐ to 12‐year‐olds attending schools in Britain. Children of minority status were no more likely than children of majority background to experience peer aggression in general. However, minority children were more likely to experience being the victims of discriminatory aggression. Two contrasting predictions were tested: that discriminatory aggression would be more likely when the minority group was relatively small in number or, alternatively, that as the proportions of children of minority backgrounds increased across schools, discriminatory aggression would be greater. The latter hypothesis was supported. Findings also revealed that in schools with a lower minority presence, discriminatory aggression experienced by majority children was significantly lower than that reported by minority children. When the school minority rate exceeded 81%, discriminatory aggression was more commonly experienced among majority children than among minority children. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular and microscopic assessment of the effects of caffeine, acetaminophen, diclofenac, and their mixtures on river biofilm communities
Authors: Lawrence John R. , Zhu Bin , Swerhone George D.W. , Roy Julie , Tumber Vijay , Waiser Marley J. , Topp Ed , Korber Darren R. 
Published: December 2011

Abstract
The authors examined effects of three common contaminants, caffeine (CF), acetaminophen (AC), and diclofenac (DF), as well as their mixtures on the development, functioning, and biodiversity of river biofilm communities. Biofilms were cultivated in rotating annular reactors. Treatments included AC, CF, DF, AC + CF, AC + DF, CF + DF, AC + CF + DF at 5 µg/L, and their molar equivalent as carbon and nutrients. Incubations using 14C-labeled AC, DF, and CF indicated that 90% of the CF, 80% of the AC, and less than 2% of the DF were converted to CO2. Digital imaging revealed a variety of effects on algal, cyanobacterial, and bacterial biomass. Algal biomass was unaffected by AC or CF in combination with DF but significantly reduced by all other treatments. Cyanobacterial biomass was influenced only by the AC + DF application. All treatments other than AC resulted in a significant decrease in bacterial biomass. Diclofenac or DF + CF and DF + AC resulted in increases in micrometazoan grazing. The denaturing gradient gel electrophoresis of Eubacterial community DNA, evaluated by principal component analysis and analysis of similarity, indicated that relative to the control, all treatments had effects on microbial community structure (r = 0.47, p &lt; 0.001). However, the AC + CF + DF treatment was not significantly different from its molar equivalent carbon and nutrient additions. The Archaeal community differed significantly in its response to these exposures based on community analyses, confirming a need to integrate these organisms into ecotoxicological studies. Environ. Toxicol. Chem. 2012;31:508–517. © 2011 SETAC
Humic acid-mediated transport of tetracycline and pyrene in saturated porous media
Authors: Zhang Lunliang , Zhu Dongqiang , Wang He , Hou Lei , Chen Wei 
Published: December 2011

Abstract
The authors observed that humic acid (HA) mediates transport of tetracycline and pyrene in saturated porous media via distinctively different mechanisms. The presence of HA (20–80 mg C/L) in the influent consistently enhances the transport of tetracycline, whereas for pyrene a critical HA concentration exists (about 10 mg C/L), below which transport is inhibited but above which transport is enhanced. The difference in the HA effect stems from the difference in relative sorption affinity to HA and sand between these two compounds. Because sorption of pyrene is driven primarily by hydrophobic effect, pyrene exhibits much stronger sorption to HA than on sand. Accordingly, pyrene in the influent (or mobile phase) is predominantly associated with HA, and its transport is controlled by the partition of HA between mobile phase and sand. For the polar, ionic, and highly hydrophilic tetracycline, sorption is driven mainly by surface complexation and ligand exchange, so tetracycline exhibits relatively strong adsorption on sand, but has much weaker sorption to HA than pyrene does. For tetracycline, the effect of HA on transport is likely the competition of HA for the available adsorption sites on sand. In addition, tetracycline and pyrene exhibit markedly different breakthrough profiles, both in the presence and in the absence of HA; this can be attributed to the greater degree of adsorption nonequilibrium of tetracycline on sand. Environ. Toxicol. Chem. 2012;31:534–541. © 2011 SETAC
Deposition and accumulation of airborne organic contaminants in Yosemite National Park, California
Authors: Mast M. Alisa , Alvarez David A. , Zaugg Steven D. 
Published: December 2011

Abstract
Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub–parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms. Environ. Toxicol. Chem. 2012;31:524–533. © 2011 SETAC
Effects of a glucocorticoid receptor agonist, dexamethasone, on fathead minnow reproduction, growth, and development
Authors: LaLone Carlie A. , Villeneuve Daniel L. , Olmstead Allen W. , Medlock Elizabeth K. , Kahl Michael D. , Jensen Kathleen M. , Durhan Elizabeth J. , Makynen Elizabeth A. , Blanksma Chad A. , Cavallin Jenna E. , Thomas Linnea M. , Seidl Sara M. , Skolness Sarah Y. , Wehmas Leah C. , Johnson Rodney D. , Ankley Gerald T. 
Published: December 2011

Abstract
Synthetic glucocorticoids are pharmaceutical compounds prescribed in human and veterinary medicine as anti-inflammatory agents and have the potential to contaminate natural watersheds via inputs from wastewater treatment facilities and confined animal-feeding operations. Despite this, few studies have examined the effects of this class of chemicals on aquatic vertebrates. To generate data to assess potential risk to the aquatic environment, we used fathead minnow 21-d reproduction and 29-d embryo–larvae assays to determine reproductive toxicity and early-life-stage effects of dexamethasone. Exposure to 500 µg dexamethasone/L in the 21-d test caused reductions in fathead minnow fecundity and female plasma estradiol concentrations and increased the occurrence of abnormally hatched fry. Female fish exposed to 500 µg dexamethasone/L also displayed a significant increase in plasma vitellogenin protein levels, possibly because of decreased spawning. A decrease in vitellogenin messenger ribonucleic acid (mRNA) expression in liver tissue from females exposed to the high dexamethasone concentration lends support to this hypothesis. Histological results indicate that a 29-d embryo–larval exposure to 500 µg dexamethasone/L caused a significant increase in deformed gill opercula. Fry exposed to 500 µg dexamethasone/L for 29 d also exhibited a significant reduction in weight and length compared with control fry. Taken together, these results indicate that nonlethal concentrations of a model glucocorticoid receptor agonist can impair fish reproduction, growth, and development. Environ. Toxicol. Chem. 2012;31:611–622. © 2011 SETAC
Food chain model based on field data to predict westslope cutthroat trout (Oncorhynchus clarkii lewisi) ovary selenium concentrations from water selenium concentrations in the Elk Valley, British Columbia
Authors: Orr P. L. , Wiramanaden C. I. E. , Paine M. D. , Franklin W. , Fraser C. 
Published: December 2011

Abstract
Previous studies conducted in the Elk River watershed showed that selenium concentrations are higher in aquatic biota in lentic compared to lotic habitats of the system having similar water selenium concentrations. Studies have also shown that water selenium concentrations have increased over time (∼10% per year) and recent annual average concentrations have ranged up to 0.044 mg/L in areas downstream from mine discharges. For the present study, trophic transfer of selenium was characterized in lotic versus lentic habitats using concentrations measured in field-collected samples and assuming a three-step food chain of water to the base of the food web (biofilm), to benthic invertebrates, and then to westslope cutthroat trout (WCT) ovaries. Food chain models were developed for each habitat type (lotic and lentic) by combining linear regression equations for the three transfer relationships, allowing for prediction of fish ovary concentrations from water concentrations. Greater accumulation of selenium in lentic areas was mostly attributable to greater uptake at the base of the food chain compared to lotic areas. Enrichment/trophic transfer factors for selenium at all levels of the lotic and lentic food chains decreased and then became near constant as exposure concentrations increased. The lotic model predicted little increase in WCT ovary selenium concentrations over an eightfold increase in water concentrations (∼0.005–0.040 mg/L), accounting for the lack of observed increase in within-area fish tissue concentrations over time despite increasing trends in water concentrations. Environ. Toxicol. Chem. 2012;31:672–680. © 2011 SETAC
Domain versus boundary computation of flow sensitivities with the continuous adjoint method for aerodynamic shape optimization problems
Authors: Lozano Carlos , Andrés Esther , Martín Mario , Bitrián Pablo 
Published: December 2011

SUMMARYThis paper considers the computation of flow sensitivities that arise in the context of design optimization. The scheme is based on the solution of a continuous adjoint problem, for which two complementary, although analytically equivalent, approaches have been routinely used for some time now, yielding expressions for the sensitivities that contain, respectively, boundary and domain integrals. These concepts are clarified in a unified framework and their equivalence at the continuous level is demonstrated through appropriate algebraic manipulations. Equivalence at the discrete level is assessed through numerical testing for various aerodynamic shape‐optimization problems. Copyright © 2011 John Wiley & Sons, Ltd.
The influence of investment in workplace learning on learning outcomes and organizational performance
Authors: Park Yoonhee , Jacobs Ronald L. 
Published: December 2011

AbstractAlthough the importance of workplace learning has been recognized in research and practice, there is little empirical support that describes how workplace learning, including both formal and informal learning, is linked to organizational performance. This study investigated the influence of investment in workplace learning on learning outcomes and organizational performance using the 2005 and 2007 Human Capital Corporate Panel survey of South Korean companies. The data were analyzed using structural equation modeling. The study found that investment in workplace learning influences organizational performance through the outcomes of workplace learning. Implications for human resource development research and practice are discussed.
Fast macromolecular proton fraction mapping from a single off‐resonance magnetization transfer measurement
Authors: Yarnykh Vasily L. 
Published: December 2011

AbstractA new method was developed for fast quantitative mapping of the macromolecular proton fraction defined within the two‐pool model of magnetization transfer. The method utilizes a single image with off‐resonance saturation, a reference image for data normalization, and T1, B0, and B1 maps with the total acquisition time ∼10 min for whole‐brain imaging. Macromolecular proton fraction maps are reconstructed by iterative solution of the matrix pulsed magnetization transfer equation with constrained values of other model parameters. Theoretical error model describing the variance due to noise and the bias due to deviations of constrained parameters from their actual values was formulated based on error propagation rules. The method was validated by comparison with the conventional multiparameter multipoint fit of the pulsed magnetization transfer model based on data from two healthy subjects and two multiple sclerosis patients. It was demonstrated theoretically and experimentally that accuracy of the method depends on the offset frequency and flip angle of the saturation pulse, and optimal ranges of these parameters are 4–7 kHz and 600°–900°, respectively. At optimal sampling conditions, the single‐point method enables <10% relative macromolecular proton fraction errors. Comparison with the multiparameter fitting method revealed very good agreement with no significant bias and limits of agreement around ±0.7%. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
A penalty method for numerically handling dispersive equations with incompatible initial and boundary data
Authors: Flyer Natasha , Qin Zhen , Temam Roger 
Published: December 2011

AbstractThis article is the numerical counterpart of a theoretical work in progress Qin and Teman, Applicable Anal (2011), 1–19, related to the approximation of evolution hyperbolic equations with incompatible data. The Korteweg‐de Vries and Schrödinger equations with incompatible initial and boundary data are considered here. For hyperbolic equations, the lack of regularity (compatibility) is known to produce large numerical errors which propagate throughout the spatial domain, destroying convergence. In this article, we numerically test the effectiveness of the penalty‐based method proposed in Qin and Teman, Applicable Anal (2011), 1–19, which replaces the hyperbolic equations with incompatible data by a system with compatible data. We observe that convergence is increased. As explained in the text, in the case of the Schrödinger equation, the impact of incompatible (nonregular) data is most severe, and the authors are not aware of any other method that can handle such severe incompatible data. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2011
Excess activated sludge reduction by using electromagnets and ferrite particles
Authors: Kabir Mahmudul , Suzuki Masafumi , Yoshimura Noboru 
Published: December 2011

AbstractEvery year, the ratio of the sewarage treatment to population is increasing in Japan. Expansion in sewer networks is leading to the production of excess sludge which is one of the major problems in wastewater treatment plants. There are several approaches to treat the excess activated sludge. A new approach is to reduce excess sludge production by using magneto‐ferrite treatment. The Suzuki Lab of Akita University, Japan, is working on this project. We have succeeded in using magneto‐ferrite treatment in the lab scale to reduce sludge production. Ferrite particles and magnets are used in this method. Ferrite particles are nontoxic and safe for biological systems. They can be easily separated from the sludge by using magnets. However, the movement of the ferrite particles in the sludge is controlled by permanent magnets which can be made more effective by changing to electromagnets. In this paper, we describe an approach to use electromagnets instead of permanent magnets. Electromagnets can be controlled easily with an AC power supply. The results of our experiments have shown a good possibility for reduction of excess sludge. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Strategies for dephenolization of raw olive mill wastewater by means of Pleurotus ostreatus
Authors: Olivieri Giuseppe , Russo Maria Elena , Giardina Paola , Marzocchella Antonio , Sannia Giovanni , Salatino Piero 
Published: December 2011

Abstract
The reduction of polyphenols content in olive mill wastewater (OMW) is a major issue in olive oil manufacturing. Although researchers have pointed out the potential of white-rot fungus in dephenolizing OMW, the results available in the literature mainly concern pretreated (sterilized) OMW. This paper deals with the reduction of polyphenols content in untreated OMW by means of a white-rot fungus, Pleurotus ostreatus. Dephenolization was performed both in an airlift bioreactor and in aerated flasks. The process was carried out under controlled non-sterile conditions, with different operating configurations (batch, continuous, biomass recycling) representative of potential industrial operations. Total organic carbon, polyphenols concentration, phenol oxidase activity, dissolved oxygen concentration, oxygen consumption rate, and pH were measured during every run. Tests were carried out with or without added nutrients (potato starch and potato dextrose) and laccases inducers (i.e., CuSO4). OMW endogenous microorganisms were competing with P. ostreatus for oxygen during simultaneous fermentation. Dephenolization of raw OMW by P. ostreatus under single batch was as large as 70%. Dephenolization was still extensive even when biomass was recycled up to six times. OMW pre-aeration had to be provided under continuous operation to avoid oxygen consumption by endogenous microorganisms that might spoil the process. The role of laccases in the dephenolization process has been discussed. Dephenolization under batch conditions with biomass recycling and added nutrients proved to be the most effective configuration for OMW polyphenols reduction in industrial plants (42–68% for five cycles).