bluuebunny/crossref_metadata_2025 huggingface dataset:
Corporate Strategies for Managing Climate Risks
Authors: Weinhofer Georg , Busch Timo
Published: July 2012

This paper focuses on organizations and their management of climate risks. Climate risks stem from continued changes in climate means and the increase in frequency and intensity of extreme weather events. We ask whether companies also apply the usual process of corporate risk management to climate risks. In seeking to answer this question, we review several literature streams in order to set out an initial theoretical reflection. Based on this we conducted an exploratory case study with 11 electric utilities. Our results illustrate that these companies perceive climatic changes as a material issue for their business. However, management has restricted knowledge about such climatic changes and thus cannot precisely determine the potential negative impacts on business activities. As a consequence, the companies have implemented a climate risk management that does not differ from the usual process of managing other business risks. Our results further illustrate that there is some variation in how individual firms manage climate risks: While risk identification and risk assessment are equally important for all electric utilities, there are differences in how management determines the direction of the individual response to climate risks. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
The Effects of SCILL Catalyst Modification on the Competitive Hydrogenation of 1‐Octyne and 1,7‐Octadiene versus 1‐Octene
Authors: Miller Stuart F. , Friedrich Holger B. , Holzapfel Cedric W.
Published: July 2012

Competitive hydrogenation of mixtures of related unsaturated compounds remains a challenging problem. Recently, solid catalysts with an ionic liquid layer (SCILL) have shown potential for increased catalyst selectivity under batch conditions. Our results for the continuous flow competitive hydrogenation of 1‐octyne and 1,7‐octadiene versus 1‐octene with a nickel SCILL catalyst indicate improved catalyst selectivity under trickle bed conditions. Different ionic liquids ([MMIM][MeOSO3], [MMIM][OcOSO3], [MMIM][NTf2], [MePsec‐Bu3 ][MeOSO3], and [Et3S][NTf2]; MMIM=1,3‐dimethylimidazole and Tf=trifluoromethanesulfonyl) with varying catalyst loadings were investigated. The results highlight the importance of potential site‐specific interactions by the ionic liquid. They also indicate the importance of the cation for these effects.
Infrared Absorption Spectroscopy of Adsorbed CO: New Applications in Nanocatalysis for an Old Approach
Authors: Zaera Francisco
Published: July 2012

In this minireview, the power of using a well‐established approach, CO infrared absorption spectroscopy, as a probe for the characterization of novel nanostructured catalysts is discussed. It is argued that the peak positions of the CO stretching mode in IR spectra can be used not only to differentiate between adsorption on metals catalysts and oxide supports, but also to provide information on the oxidation state of the metal, on the surface planes available for adsorption, and on the adsorption bonding modes possible. Perhaps more basic but more important for nanocatalysis applications is the usefulness of the information provided by CO IR spectroscopy to identify and quantify the sites accessible to reactants in the catalytic surfaces of complex nanoarchitectures. A number of examples are provided here from studies by our group to illustrate these points, including the characterization of catalysts based on dendrimer‐ and mesoporous‐silica‐encapsulated metal nanoparticles and on core@shell and yolk@shell nanostructures.
Atomic Polarizability Dominates the Electronic Properties of Peptide Bonds upon Thioxo or Selenoxo Substitution
Authors: Huang Yun , Jahreis Günther , Fischer Gunter , Lücke Christian
Published: July 2012

The amide bond as peptide linkage plays an important role in protein structure and function. A large number of theoretical and experimental studies have focused on the specific nature of the peptide bond. Little attention, however, has been paid to their chalcogen‐substituted congeners, although experimental data on thioamides revealed inconsistencies with the conventional view of amide resonance theory. Here, we employed thioxo and selenoxo substitution to determine experimentally how heavier chalcogens affect the properties of the peptide bond and adjacent atoms. NMR data revealed pronounced deshielding of heteronuclei within a three‐bond distance to the chalcogen atom; this indicates an enhanced electron‐withdrawing potential of the heavier chalcogens despite their lower electronegativities compared to oxygen. Interestingly, linear correlations were observed between chalcogen atomic polarizability and the chemical shift values of those neighboring heteronuclei as well as several physicochemical properties, such as electronic excitation energy, CN rotation barrier, dipole moment and amide proton dissociation. We conclude that the chalcogen polarizability, which relates to the charge capacity, is the dominant factor that determines the electronic properties of peptide bonds substituted with heavier chalcogens.
Synthesis and Anticoagulant Activity of Bioisosteric Sulfonic‐Acid Analogues of the Antithrombin‐Binding Pentasaccharide Domain of Heparin
Authors: Herczeg Mihály , Lázár László , Bereczky Zsuzsanna , Kövér Katalin E. , Timári István , Kappelmayer János , Lipták András , Antus Sándor , Borbás Anikó
Published: July 2012

Two pentasaccharide sulfonic acids that were related to the antithrombin‐binding domain of heparin were prepared, in which two or three primary sulfate esters were replaced by sodium‐sulfonatomethyl moieties. The sulfonic‐acid groups were formed on a monosaccharide level and the obtained carbohydrate sulfonic‐acid esters were found to be excellent donors and acceptors in the glycosylation reactions. Throughout the synthesis, the hydroxy groups to be methylated were masked in the form of acetates and the hydroxy groups to be sulfated were masked with benzyl groups. The disulfonic‐acid analogue was prepared in a [2+3] block synthesis by using a trisaccharide disulfonic acid as an acceptor and a glucuronide disaccharide as a donor. For the synthesis of the pentasaccharide trisulfonic acid, a more‐efficient approach, which involved elongation of the trisaccharide acceptor with a non‐oxidized precursor of the glucuronic acid followed by post‐glycosidation oxidation at the tetrasaccharide level and a subsequent [1+4] coupling reaction, was elaborated. In vitro evaluation of the anticoagulant activity of these new sulfonic‐acid derivatives revealed that the disulfonate analogue inhibited the blood‐coagulation‐proteinase factor Xa with outstanding efficacy; however, the introduction of the third sulfonic‐acid moiety resulted in a notable decrease in the anti‐Xa activity. The difference in the biological activity of the disulfonic‐ and trisulfonic‐acid counterparts could be explained by the different conformation of their L‐iduronic‐acid residues.
Nanosheet‐Enhanced Enantioselectivity in the Vanadium‐Catalyzed Asymmetric Epoxidation of Allylic Alcohols
Authors: Zhao Li‐Wei , Shi Hui‐Min , Wang Jiu‐Zhao , He Jing
Published: July 2012

The use of suitable chiral ligands is an efficient means of producing highly enantioselective transition‐metal catalysts. Herein, we report a facile, economic, and effective strategy for the design of chiral ligands that demonstrate enhanced enantioselectivity and catalytic efficacy. Our simple strategy employs naturally occurring or synthetic inorganic nanosheets as huge and rigid planar substituents for, but not limited to, naturally available α‐amino‐acid ligands; these ligands were successfully used in the vanadium‐catalyzed asymmetric epoxidation of allylic alcohols. The crucial role of the inorganic nanosheets as planar substituents in improving the enantioselectivity of the reaction was clearly revealed by relating the observed enantiomeric excess with the distribution of the catalytic centers and the accessibility of the substrate molecules to the catalytic sites. DFT calculations indicated that the LDH layer improved the enantioselectivity by influencing the formation and stability of the catalytic transition states, both in terms of steric resistance and H‐bonding interactions.
Enhanced Optical Nonlinearity in Noncovalently Functionalized Amphiphilic Graphene Composites
Authors: He Tingchao , Qi Xiaoying , Chen Rui , Wei Jun , Zhang Hua , Sun Handong
Published: July 2012

The good solubility of graphene‐based materials in various solvents without sacrificing their intrinsic properties is a prerequisite for their further applications. In particular, it is important for application as a practical optical limiter. A comprehensive study was conducted on the nonlinear optical property of a rationally designed amphiphilic graphene composite (PEG‐OPE‐rGO). By taking advantages of the unique energy diagram of this graphene composite, the optical limiting (OL) performances of PEG‐OPE‐rGO, which is either dissolved in solvents with moderate polarity or fabricated into thin solid films, are beyond the reported results for other graphene composites. Importantly, the main factors for the enhanced OL response of PEG‐OPE‐rGO are the multiphoton absorption and Förster resonance energy transfer process, instead of the nonlinear scattering mechanism observed for common nanostructured materials. The excellent OL response of PEG‐OPE‐rGO allows it to be one of the best candidates in practical optical limiters. Moreover, the mechanism analysis provides the deep insight for further optimization of the design of promising OL materials.
The Role of the Board in the Dissemination of Integrated Corporate Social Reporting
Authors: Frias‐Aceituno José V. , Rodriguez‐Ariza Lazaro , Garcia‐Sanchez I.M
Published: July 2012

The stakeholder theory recognizes that, besides shareholders and creditors, there exists a broad range of agents who are interested in companies' attitudes towards sustainability. Through corporate social reporting, the social and environmental effects of companies' economic actions are communicated to interest groups. However, the information contained in financial and social reports tends to be presented quite separately from that in the others, and this may lead to confusion among users. Therefore, several major companies have introduced an integrated reporting system, which coherently summarizes the information available, thus making stakeholders participants in business management.

Corporate governance mechanisms such as the Board of Directors play an important role in good practices of corporate social responsibility, implementing policies of stakeholder engagement, including processes to achieve holistic transparency.

The aim of this paper is to demonstrate the influence played by certain features of the Board of Directors in the degree of information integration presented by leading non‐financial multinational firms. Specifically, we examined 568 companies from 15 countries, for the period 2008–2010. The results obtained show that growth opportunities, the size of a company and its management bodies, together with gender diversity, are the most important factors in the integrated dissemination of information. This effect has been confirmed for the Anglo‐Saxon, Germanic and Latin models of corporate governance. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment
Both IFN‐γ and IL‐17 are required for the development of severe autoimmune gastritis
Authors: Tu Eric , Ang Desmond K.Y. , Bellingham Shayne A. , Hogan Thea V. , Teng Michele W. L. , Smyth Mark J. , Hill Andrew F. , van Driel Ian R.
Published: July 2012

IL‐17, produced by a distinct lineage of CD4+ helper T (Th) cells termed Th17 cells, induces the production of pro‐inflammatory cytokines from resident cells and it has been demonstrated that over‐expression of IL‐17 plays a crucial role in the onset of several auto‐immune diseases. Here we examined the role of IL‐17 in the pathogenesis of autoimmune gastritis, a disease that was previously believed to be mediated by IFN‐γ. Significantly higher levels of IL‐17 and IFN‐γ were found in the stomachs and stomach‐draining lymph nodes of mice with severe autoimmune gastritis. Unlike IL‐17, which was produced solely by CD4+ T cells in gastritic mice, the majority of IFN‐γ‐producing cells were CD8+ T cells. However, CD8+ T cells alone were not able to induce autoimmune gastritis. T cells that were deficient in IL‐17 or IFN‐γ production were able to induce autoimmune gastritis but to a much lower extent compared with the disease induced by wild‐type T cells. These data demonstrate that production of neither IL‐17 nor IFN‐γ by effector T cells is essential for the initiation of autoimmune gastritis, but suggest that both are required for the disease to progress to the late pathogenic stage that includes significant tissue disruption.
Interaction of TAPP adapter proteins with phosphatidylinositol (3,4)‐bisphosphate regulates B‐cell activation and autoantibody production
Authors: Landego Ivan , Jayachandran Nipun , Wullschleger Stephan , Zhang Ting‐ting , Gibson Ian W. , Miller Angela , Alessi Dario R. , Marshall Aaron J.
Published: July 2012

TAPP1 and TAPP2 (where TAPP is tandem PH domain containing protein) are dual PH domain adaptors that selectively bind PI(3,4)P2 (phosphatidylinositol (3,4)‐bisphosphate). PI(3,4)P2 is a lipid messenger generated by phosphoinositide 3‐kinase (PI3K) and SHIP, both of which are critical regulators of B‐cell activation. To determine the functional role of TAPP‐PI(3,4)P2 interactions, we utilized a double knock‐in (KI) mouse bearing mutations within the PI‐binding pocket of both TAPP1 and TAPP2. TAPP KI mice show evidence of altered B‐cell development, but generate phenotypically normal mature B‐cell populations. Total serum immunoglobulin IgM and IgG levels were found to be markedly elevated in TAPP KI mice. B cells purified from TAPP KI mice were hyper‐responsive to antigen receptor cross‐linking, showing increased proliferation, CD86 expression, and Akt phosphorylation on Ser473 and Thr308. Female TAPP KI mice developed elevated levels of anti‐DNA and antinuclear antibodies with age, associated with IgG deposition in kidneys and significant glomerulonephritis pathology. Together our results indicate that interaction of TAPPs with PI(3,4)P2 mediates feedback inhibition impacting on BCR signaling, with functional significance for control of autoreactive B cells.
Predominance of heterosubtypic IFN‐γ‐only‐secreting effector memory T cells in pandemic H1N1 naive adults
Authors: Sridhar Saranya , Begom Shaima , Bermingham Alison , Ziegler Thedi , Roberts Kim L. , Barclay Wendy S. , Openshaw Peter , Lalvani Ajit
Published: July 2012

The 2009/10 pandemic (pH1N1) highlighted the need for vaccines conferring heterosubtypic immunity against antigenically shifted influenza strains. Although cross‐reactive T cells are strong candidates for mediating heterosubtypic immunity, little is known about the population‐level prevalence, frequency, and cytokine‐secretion profile of heterosubtypic T cells to pH1N1. To assess this, pH1N1 sero‐negative adults were recruited. Single‐cell IFN‐γ and IL‐2 cytokine‐secretion profiles to internal proteins of pH1N1 or live virus were enumerated and characterised. Heterosubtypic T cells recognising pH1N1 core proteins were widely prevalent, being detected in 90% (30 of 33) of pH1N1‐naïve individuals. Although the last exposure to influenza was greater than 6 months ago, the frequency and proportion of the IFN‐γ‐only‐secreting T‐cell subset was significantly higher than the IL‐2‐only‐secreting subset. CD8+ IFN‐γ‐only‐secreting heterosubtypic T cells were predominantly CCR7−CD45RA− effector‐memory phenotype, expressing the tissue‐homing receptor CXCR3 and degranulation marker CD107. Receipt of the 2008–09 influenza vaccine did not alter the frequency of these heterosubtypic T cells, highlighting the inability of current vaccines to maintain this heterosubtypic T‐cell pool. The surprisingly high prevalence of pre‐existing circulating pH1N1‐specific CD8+ IFN‐γ‐only‐secreting effector memory T cells with cytotoxic and lung‐homing potential in pH1N1‐seronegative adults may partly explain the low case fatality rate despite high rates of infection of the pandemic in young adults.
Expansion of follicular helper T cells in the absence of Treg cells: Implications for loss of B‐cell anergy
Authors: Leonardo Steven M. , De Santis Jessica L. , Gehrand Ashley , Malherbe Laurent P. , Gauld Stephen B.
Published: July 2012

The maintenance of B‐cell anergy is essential to prevent the production of autoantibodies and autoimmunity. However, B‐cell extrinsic mechanisms that regulate B‐cell anergy remain poorly understood. We previously demonstrated that regulatory T (Treg) cells are necessary for the maintenance of B‐cell anergy. We now show that in Treg‐cell‐deficient mice, helper T cells are necessary and sufficient for loss of B‐cell tolerance/anergy. In addition, we show that the absence of Treg cells is associated with an increase in the proportion of CD4+ cells that express GL7 and correlated with an increase in germinal center follicular helper T (GC‐TFH) cells. These GC‐TFH cells, but not those from Treg‐cell‐sufficient hosts, were sufficient to drive antibody production by anergic B cells. We propose that a function of Treg cells is to prevent the expansion of TFH cells, especially GC‐TFH cells, which support autoantibody production.
Kinetic Resolution in Chiral Phosphoric Acid Catalyzed Aldol Reactions: Enantioselective Robinson‐Type Annulation Reactions
Authors: Yamanaka Masahiro , Hoshino Masaya , Katoh Takuya , Mori Keiji , Akiyama Takahiko
Published: July 2012

A remarkable kinetic resolution was achieved in a chiral phosphoric acid catalyzed intramolecular aldol reaction. Its combination with an enantioselective Michael reaction resulted in the formation of cyclohexenone derivatives with excellent enantioselectivities. DFT calculations on the intramolecular aldol reaction revealed the importance of the 3,3′‐substituents of the phosphoric acid for the high enantioselectivity in the kinetic resolution process.
Multivariate Detection of Gene‐Gene Interactions
Authors: Rajapakse Indika , Perlman Michael D. , Martin Paul J , Hansen John A. , Kooperberg Charles
Published: July 2012

Unraveling the nature of genetic interactions is crucial to obtaining a more complete picture of complex diseases. It is thought that gene‐gene interactions play an important role in the etiology of cancer, cardiovascular, and immune‐mediated disease. Interactions among genes are defined as phenotypic effects that differ from those observed for independent contributions of each gene, usually detected by univariate logistic regression methods. Using a multivariate extension of linkage disequilibrium (LD), we have developed a new method, based on distances between sample covariance matrices for groups of single nucleotide polymorphisms (SNPs), to test for interaction effects of two groups of genes associated with a disease phenotype. Since a disease‐associated interacting locus will often be in LD with more than one marker in the region, a method that examines a set of markers in a region collectively can offer greater power than traditional methods. Our method effectively identifies interaction effects in simulated data, as well as in data on the genetic contributions to the risk for graft‐versus‐host disease following hematopoietic stem cell transplantation.
Loss of astrocyte polarization upon transient focal brain ischemia as a possible mechanism to counteract early edema formation
Authors: Steiner Esther , Enzmann Gaby U. , Lin Shuo , Ghavampour Sharang , Hannocks Melanie‐Jane , Zuber Benoît , Rüegg Markus A. , Sorokin Lydia , Engelhardt Britta
Published: July 2012

Brain edema is the main cause of death from brain infarction. The polarized expression of the water channel protein aquaporin‐4 (AQP4) on astroglial endfeet surrounding brain microvessels suggests a role in brain water balance. Loss of astrocyte foot process anchoring to the basement membrane (BM) accompanied by the loss of polarized localization of AQP4 to astrocytic endfeet has been shown to be associated with vasogenic/extracellular edema in neuroinflammation. Here, we asked if loss of astrocyte polarity is also observed in cytotoxic/intracellular edema following focal brain ischemia after transient middle cerebral artery occlusion (tMCAO). Upon mild focal brain ischemia, we observed diminished immunostaining for the BM components laminin α4, laminin α2, and the proteoglycan agrin, in the core of the lesion, but not in BMs in the surrounding penumbra. Staining for the astrocyte endfoot anchorage protein β‐dystroglycan (DG) was dramatically reduced in both the lesion core and the penumbra, and AQP4 and Kir4.1 showed a loss of polarized localization to astrocytic endfeet. Interestingly, we observed that mice deficient for agrin expression in the brain lack polarized localization of β‐DG and AQP4 at astrocytic endfeet and do not develop early cytotoxic/intracellular edema following tMCAO. Taken together, these data indicate that the binding of DG to agrin embedded in the subjacent BM promotes polarized localization of AQP4 to astrocyte endfeet. Reduced DG protein levels and redistribution of AQP4 as observed upon tMCAO might therefore counteract early edema formation and reflect a beneficial mechanism operating in the brain to minimize damage upon ischemia. © 2012 Wiley Periodicals, Inc.
Expression patterns of cancer stem cell markers ALDH1 and CD133 correlate with a high risk of malignant transformation of oral leukoplakia
Authors: Liu Wei , Wu Lan , Shen Xue‐Min , Shi Lin‐Jun , Zhang Chen‐Ping , Xu Li‐Qun , Zhou Zeng‐Tong
Published: July 2012

Molecular markers for predicting oral cancer development in premalignant oral leukoplakia (OL) are urgently needed. The objective of this study was to examine the expression patterns of cancer stem cell markers ALDH1 and CD133 in samples from patients with OL, and determine their prognostic values for subsequent development of oral cancer. Immunohistochemistry for ALDH1 and CD133 was performed in samples from a cohort of 141 patients with biopsy‐proven OL who received a mean follow‐up of 5.5 years. Patient clinicopathologic and follow‐up data were analyzed. Expression of ALDH1 and CD133 was observed in 54 (38.3%) and 32 (22.7%) of 141 patients with OL, respectively. Kaplan–Meier analysis showed that 48.1% patients with ALDH1‐positivity developed oral cancer compared with 12.6% those with ALDH1‐negativity (p < 0.001). Meanwhile, 59.4% patients with CD133‐positivity developed oral cancer compared with 16.5% those with CD133‐negativity (p < 0.001). Multivariate analysis revealed that ALDH1 and CD133 expression was associated with 4.17‐fold [95% confidence interval (CI), 1.96–8.90; p < 0.001] and 2.86‐fold (95% CI, 1.48‐5.55; p = 0.002) increased risk of OL transformation, respectively. Collectively, these data demonstrated for the first time that the expression of ALDH1 and CD133 correlated with malignant transformation in a large series of patients with OL who received a long‐term follow‐up, which suggests that they may serve as predictors to identify OL with a high risk of oral cancer development.
Ostracod Assemblages in Relation to Littoral Plant Communities of a Shallow Lake (Lake Świdwie, Poland)
Authors: Szlauer‐Łukaszewska Agnieszka
Published: July 2012

The aims of this study included: specifying values of ecological parameters and Ostracoda species characteristic for different types of plant habitats occurring in lake systems, determining the impact of mud presence on the taxonomic structure and density of the ostracods, tracing seasonal changes in the structures of Ostracoda assemblages identifying the species typical of particular seasons. Various types of rushes and underwater meadows were taken into consideration as lake microhabitats. The research was conducted in the shallow Lake Œwidwie (NW Poland). Multivariate (constrained) ordination methods were used to analyse the relationships between species composition and environmental variables. In the lake and its margins 31 species of the Ostracoda were identified. The development of water vegetation during the vegetation season was conducive to growth in ostracod density. The accessibility of mud in plant habitats had a favourable effect on the general density of ostracods. Species which preferred a high mud content in their habitats included: Cypria ophtalmica, C. exsculpta and Physocypria kraepelini. Species typically encountered in underwater meadow habitats were: Cyclocypris ovum and Cypridopsis vidua. Underwater meadows of charophyte were characterized by the highest ostracod density in the whole lake system, with the average of 7860 ind. m–2 and the maximum of 17 470 ind. m–2. Species typically encountered in rush habitats included Notodromas monacha, Dolerocypris fasciata and Metacypris cordata. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluating nonpolarizable nucleic acid force fields: A systematic comparison of the nucleobases hydration free energies and chloroform‐to‐water partition coefficients
Authors: Wolf Maarten G. , Groenhof Gerrit
Published: July 2012

Nucleic acid force fields have been shown to reproduce structural properties of DNA and RNA very well, but comparative studies with respect to thermodynamic properties are rare. As a test for thermodynamic properties, we have computed hydration free energies and chloroform‐to‐water partition coefficients of nucleobases using the AMBER‐99, AMBER‐gaff, CHARMM‐27, GROMOS‐45a4/53a6 and OPLS‐AA force fields. A mutual force field comparison showed a very large spread in the calculated thermodynamic properties, demonstrating that some of the parameter sets require further optimization. The choice of solvent model used in the simulation does not have a significant effect on the results. Comparing the hydration free energies obtained by the various force fields to the adenine and thymine experimental values showed a very large deviation for the GROMOS and AMBER parameter sets. Validation against experimental partition coefficients showed good agreement for the CHARMM‐27 parameter set. In view of mutation studies, differences in partition coefficient between two bases were also compared, and good agreement between experiments and calculations was found for the AMBER‐99 parameter set. Overall, the CHARMM‐27 parameter set performs best with respect to the thermodynamic properties tested here. © 2012 Wiley Periodicals, Inc.
Binding energies of five molecular pincers calculated by explicit and implicit solvent models
Authors: Kessler Jiří , Jakubek Milan , Dolenský Bohumil , Bouř Petr
Published: July 2012

Molecular pincers or tweezers are designed to hold and release the target molecule. Potential applications involve drug distribution in medicine, environment technologies, or microindustrial techniques. Typically, the binding is dominated by van der Waals forces. Modeling of such complexes can significantly enhance their design; yet obtaining accurate complexation energies by theory is difficult. In this study, density functional theory (DFT) computations combined with dielectric continuum solvent model are compared with the potential of mean force approach using umbrella sampling and the weighted histogram analysis method (WHAM) with molecular dynamics (MD) simulations. For DFT, functional and basis set effects are discussed. The computed results are compared to experimental data based on NMR spectroscopic measurements of five synthesized tweezers based on the Tröger's basis. Whereas the DFT computations correctly provided the observed trends in complex stability, they failed to produce realistic magnitudes of complexation energies. Typically, the binding was overestimated by DFT if compared to experiment. The simpler semiempirical PM6‐DH2X scheme proposed lately yielded better magnitudes of the binding energies than DFT but not the right order. The MD‐WHAM simulations provided the most realistic Gibbs binding energies, although the approximate MD force fields were not able to reproduce completely the ordering of relative stabilities of model complexes found by NMR. Yet the modeling provides interesting insight into the complex geometry and flexibility and appears as a useful tool in the tweezers' design. © 2012 Wiley Periodicals, Inc.
Computation of scattering by complex targets using an efficient mixed‐order curved moment method
Authors: Deng Chu‐Qiang , Sheng Xin‐Qing , Song Wei
Published: July 2012

The goal of this paper is to develop an efficient and accurate computation scheme based on mixed‐order curved moment method for computing scattering from complex targets. To this end, the numerical performances of different kinds of higher‐order basis functions are presented and compared numerically. The formulae in the improved Duffy method for higher‐order curved moment method are derived and given explicitly. An efficient and accurate computation scheme is presented and implemented on the basis of the optimized triangular hierarchical higher‐order basis function and the improved Duffy method. Numerical experiments are performed to show accuracy and efficiency of the presented computation scheme for complex targets. Copyright © 2012 John Wiley & Sons, Ltd.
Nanoporous Ag–GaN thin films prepared by metal‐assisted electroless etching and deposition as three‐dimensional substrates for surface‐enhanced Raman scattering
Authors: Nie Bei , Duan Barrett K. , Bohn Paul W.
Published: July 2012

Three‐dimensional (3D) nanoporous gallium nitride (PGaN) scaffolds are fabricated by Pt‐assisted electroless hydrofluoric acid (HF) etching of crystalline GaN followed by in situ electroless deposition of Ag nanostructures onto the interior surfaces of the nanopores, yielding a large surface area substrate for surface‐enhanced Raman scattering (SERS). The resulting 3D SERS‐active substrates have been optimized by varying reaction parameters and starting material concentration, exhibiting enhanced Raman signals 10–100× more intense than either (1) sputtered Ag‐coated porous GaN or (2) Ag‐coated planar GaN. The increase in SERS signal is attributed to a combination of the large surface area and the inherent transparency of PGaN in the visible spectral region. Overall, Ag‐decorated PGaN is a promising platform for high sensitivity SERS detection and chemical analysis, particularly for reaction and metabolic products that can be trapped inside the highly anisotropic nanoscale pores of PGaN. The potential of this sampling mode is illustrated by the ability to acquire Raman spectra of adenine down to 5 fmol. Additionally, correlated SERS and laser desorption/ionization mass spectrometry spectra can be acquired from same sample spot without further preparation, opening new possibilities for the investigation of surface‐bound molecules with substantially enhanced information content. Copyright © 2012 John Wiley & Sons, Ltd.
Optimization of ion‐pair based hollow fiber liquid phase microextraction combined with HPLC–UV for the determination of methimazole in biological samples and animal feed
Authors: Ebrahimzadeh Homeira , Asgharinezhad Ali Akbar , Adlnasab Laleh , Shekari Nafiseh
Published: July 2012

Ion‐pair based hollow fiber liquid phase microextraction (IP‐HFLPME) coupled with high performance liquid chromatography‐ultraviolet detection was applied for the preconcentration and determination of methimazole in biological samples and animal feed. Optimization of the conditions for the high extraction efficiency was studied simultaneously using the experimental design. For the first step, the Plackett–Burman design was applied to screen the significant factors on the extraction efficiency. Central composite design (CCD) was then used for the optimization of important factors and the response surface equations were obtained. The optimum experimental conditions were donor phase pH, 12.2; extraction temperature, 45°C; extraction time, 50 min; sodium perchlorate concentration, 1.5 M; cetyltrimethylammonium bromide concentration, 0.65 mM, and without salt addition in donor phase. The limit of detection and the dynamic linear range were in the range of 0.1–0.7 μg L−1 and 0.5–1000 μg L−1, respectively. Preconcentration factors were obtained in the range of 93–155 in different matrices. Finally, the performance of the proposed method was tested for the determination of trace amounts of methimazole in plasma, urine, bovine milk, and animal feed samples, and satisfactory results were obtained (RSDs < 7.1%).
Analysis of fluoroquinolones in animal feeds by liquid chromatography with fluorescence detection
Authors: Borràs Sílvia , Ríos‐Kristjánsson Juan‐Gabriel , Companyó Ramon , Prat Maria‐Dolors
Published: July 2012

An analytical method for the analysis of six fluoroquinolones (FQs) in animal feeds was developed. The sample treatment consists of a simple and rapid extraction of the analytes by manual shaking with an acetonitrile‐water mixture containing hydrochloric acid without further sample cleanup. Matrix effects were minimized by diluting the extract with water. Determination was carried out by liquid chromatography using fluorimetric detection. The method was validated in‐house in four different feed matrices (poultry, cow, pig, and lamb feed). Mean recoveries ranging from 80 to 105%, with relative standard deviations below 12%, were achieved from spiked animal feed samples on the 0.2–2.0 μg/g level. No relevant differences were observed between the studied feeds, this ensuring that the method was reliable for a wide variety of feed matrices. Decision limit and detection capability values are below 0.08 and 0.13 mg/kg, respectively, for most FQs. The results obtained demonstrate the feasibility of the analytical method developed for a routine use to control the illegal use of these substances in feeding stuffs.
Dynamic Light Scattering of Rigid Rods – A Universal Relationship on the Apparent Diffusion Coefficient as Revealed by Numerical Studies and Its Use for Rod Length Determination
Authors: Liu Tao , Xiao Zhiwei
Published: July 2012

Numerical simulations are performed to study the diffusion behaviors of rigid rods examined by dynamic light scattering (DLS). It was identified that the apparent diffusion coefficient, Dp, determined by DLS obeys a universal relationship Dp/DG = f(qL) = 1.1804 + 0.1764 × tanh [11.799× tan−1(qL) ‐17.169], where DG, L, and q are the mass‐of‐center diffusion coefficient, length of the rod, and scattering vector, respectively. This relationship delineates the DLS experiments into weak (qL < 4.0), intermediate (4.0 < qL < 20.0), and strong translation–rotation coupling regime (qL > 20.0). In weak (strong) coupling regime, Dp is a measure of DG (D// ‐ longitudinal diffusion coefficient) of the rods. In addition, if DLS is performed in the intermediate coupling regime, the rod length can be determined by solving Dp/DG = f(qL).
Rare Earth Metal‐Mediated Group Transfer Polymerization of Vinylphosphonates
Authors: Salzinger Stephan , Rieger Bernhard
Published: July 2012

Recent studies have shown that poly(vinylphosphonate)s are readily accessible by rare earth metal‐mediated group transfer polymerization (GTP). This article highlights the progress in this new field and advantages of GTP in comparison to classical anionic and radical polymerization approaches. Late lanthanide metallocenes proved to be efficient initiators and highly active catalysts for vinylphosphonate polymerization yielding polymers of precise molecular weight and low polydispersity. Using this method, our group has developed a surface‐initiated GTP to prepare poly(vinylphosphonate) brushes. In combination with different ester cleavage strategies, rare earth metal‐mediated GTP is an efficient way to create well‐defined high‐molecular‐weight poly(vinylphosphonic acid).
Community Enterprises—An Institutional Innovation
Authors: Frey Bruno S. , Lüthi Roger , Osterloh Margit
Published: July 2012

Management research has focused on for‐profit firms. Recently Wikipedia and Linux have emerged that we call Community Enterprises. They are not‐for‐profit organizations producing innovation resources and making them freely available. They collide with firms, which aim at acquiring control of resources. Although contributing substantially to the economy, they suffer from not being able to quantify their contributions adequately. We analyze them as aliens in the market economy and to the theory of the firm, discussing which measures must be applied to ensure their activities, and which assumptions must be revised to encompass their potential as a source of economic value. Copyright © 2012 John Wiley & Sons, Ltd.
A Theory of Nascent Entrepreneurship and Organization
Authors: Felin Teppo , Knudsen Thorbjørn
Published: July 2012

In this paper, we develop a theory and model of organizational founding and the emergence of collective beliefs and strategies. We explicate how collective beliefs, resulting in the formation of new organizations, emerge via three social mechanisms: sorting or matching, interaction, and selection. We specifically highlight how value homophily, social processes, and threshold effects contribute to the actualization (or not) of entrepreneurial beliefs and ideas. Our theory and model highlight not only the emergence of collective beliefs but also the socially interdependent nature of belief realization, choice, and strategy in nascent organizations. Copyright © 2012 John Wiley & Sons, Ltd.
Fingerprint Kernels for Protein Structure Comparison
Authors: Fober Thomas , Mernberger Marco , Klebe Gerhard , Hüllermeier Eyke
Published: July 2012

A key task in structural biology is to define a meaningful similarity measure for the comparison of protein structures. Recently, the use of graphs as modeling tools for molecular data has gained increasing importance. In this context, kernel functions have attracted a lot of attention, especially since they allow for the application of a rich repertoire of methods from the field of kernel‐based machine learning. However, most of the existing graph kernels have been designed for unlabeled and/or unweighted graphs, although proteins are often more naturally and more exactly represented in terms of node‐labeled and edge‐weighted graphs. Here we analyze kernel‐based protein comparison methods and propose extensions to existing graph kernels to exploit node‐labeled and edge‐weighted graphs. Moreover, we propose an instance of the substructure fingerprint kernel suitable for the analysis of protein binding sites. By using fuzzy fingerprints, we solve the problem of discontinuity on bin‐boundaries arising in the case of labeled graphs.
Family Business or Social Problem? The Cost of Unreported Domestic Violence
Authors: Carrell Scott E. , Hoekstra Mark
Published: July 2012

Social interest in problems such as domestic violence is typically motivated by concerns regarding equity, rather than efficiency. However, we document that taking steps to reduce domestic violence by reporting it yields substantial benefits to external parties. Specifically, we find that although children exposed to as‐yet‐unreported domestic violence reduce the achievement of their classroom peers, these costs disappear completely once the parent reports the violence to the court. This suggests that the public has an interest in helping families to overcome their problems in general and to report domestic violence in particular. It also suggests that social and judicial interventions may help combat negative peer effects in schools.
Ordering of block copolymer/nanoparticle composite thin films
Authors: Lo Chieh‐Tsung , Lee Byeongdu , Gao Mong‐Wei , Chou Po‐Wei
Published: July 2012

The ordering behavior of polymer nanocomposites composed of gold nanoparticles confined in the polystyrene (PS) domains of PS based block copolymers was investigated. The results reveal that the self‐assembly of nanoparticles in the PS domains improved the ordering of microdomains. This is attributed to the presence of nanoparticles that reduced the degree of segregation of the system, causing slow phase separation. This facilitates the packing of the cylindrical microdomains, leading to a well‐ordered structure of the composite. When particles were incorporated into the major domains of cylindrically ordered block copolymer, the connectivity of the domains allowed particles to move to the top of the film to gain additional entropy of the system. In contrast, when particles were organized in parallel cylinders in the block copolymer, they were confined in the cylinders which prevented them from diffusing in the depth direction. The aggregation of nanoparticles was amplified when the composite was annealed in air. We believe that the results from this study will enable more understanding of the effects of nanoparticles on the ordering of block copolymer/nanoparticle composite thin films and will provide a tool in the fabrication of composite thin films. Copyright © 2012 Society of Chemical Industry
Relationship between prostate cancer gene 3 (PCA3) and characteristics of tumor aggressiveness
Authors: Augustin Herbert , Mayrhofer Katrin , Pummer Karl , Mannweiler Sebastian
Published: July 2012

BACKGROUND

Data supporting prostate cancer gene 3 (PCA3) as prognostic marker are still inconsistent. With special emphasis to Gleason pattern specific tumor volumes (TVs) the relationships between PCA3 score and different characteristics of tumor aggressiveness were meticulously analyzed.

METHODS

In 127 patients treated with radical prostatectomy for clinically localized prostate cancer, urinary PCA3 score was quantified using Progensa™ PCA3 assay. Total TV and Gleason patterns' specific tumor volumes (GPTV) were assessed by computer‐assisted planimetry. Spearman's rank correlations coefficients (r) were calculated to assess relationships between PCA3 and TV as well as GPTV. Regression analyses were performed to estimate the relationship between PCA3 and TV as well as non‐organ confined disease.

RESULTS

Mean patients' age was 60.8 years. Patients showed a mean PSA level of 8.1 ng/ml and a mean PCA3 score of 68.5. PCA3 was not significantly correlated with TV (r = 0.131, P = 0.142). Stratified by Gleason score groups ≤6, 7, and ≥8, PCA3 showed no significant correlations with TV. In a subgroup analysis of 50 patients with different primary and secondary Gleason patterns there was neither a correlation with the primary GPTV (r = 0.071, P = 0.626) nor with the secondary GPTV (r = 0.052, P = 0.722). The PCA3 score was neither an independent predictor for TV nor for non‐organ confined disease.

CONCLUSIONS

The PCA3 score did not show any significant correlation with TV, primary or secondary GPTV. Moreover, the PCA3 score was not an independent predictor for TV or for non‐organ confined disease. Thus, the PCA3 score had no impact for the prediction of aggressive prostate cancers. Prostate 73: 203–210, 2013. © 2012 Wiley Periodicals, Inc.
Impact of tricyclazole and azoxystrobin on growth, sporulation and secondary infection of the rice blast fungus, Magnaporthe oryzae
Authors: Kunova Andrea , Pizzatti Cristina , Cortesi Paolo
Published: July 2012

BACKGROUND: Rice blast, caused by Magnaporthe oryzae B. Couch sp. nov., is one of the most destructive rice diseases worldwide, causing substantial yield losses every year. In Italy, its management is based mainly on the use of two fungicides, azoxystrobin and tricyclazole, that restrain the disease progress. The aim of this study was to investigate and compare the inhibitory effects of the two fungicides on the growth, sporulation and secondary infection of M. oryzae.

RESULTS: Magnaporthe oryzae mycelium growth was inhibited at low concentrations of azoxystrobin and relatively high concentrations of tricyclazole, while sporulation was more sensitive to both fungicides and was affected at similarly low doses. Furthermore, infection efficiency of conidia obtained from mycelia exposed to tricyclazole was affected to a higher extent than for conidia produced on azoxystrobin‐amended media, even though germination of such conidia was reduced after azoxystrobin treatment.

CONCLUSIONS: This study presents for the first time detailed azoxystrobin and tricyclazole growth–response curves for M. oryzae mycelium growth and sporulation. Furthermore, high efficacy of tricyclazole towards inhibition of sporulation and secondary infection indicates an additional possible mode of action of this fungicide that is different from inhibition of melanin biosynthesis. Copyright © 2012 Society of Chemical Industry
Laboratory evaluation of the effects of Manilkara subsericea (Mart.) Dubard extracts and triterpenes on the development of Dysdercus peruvianus and Oncopeltus fasciatus
Authors: Fernandes Caio P , Xavier Alexandre , Pacheco João Pedro Furtado , Santos Marcelo Guerra , Mexas Rodrigo , Ratcliffe Norman A , Gonzalez Marcelo Salabert , Mello Cícero Brasileiro , Rocha Leandro , Feder Denise
Published: July 2012

BACKGROUND: Studies were carried out to evaluate the effects of Manilkara subsericea extracts and triterpenes on the development of two species of agricultural pest insects, Oncopelus fasciatus and Dysdercus peruvianus.

RESULTS: All treatments of insects with M. subsericea extracts induced mortality, delayed development and inhibited moulting. Some extracts assayed (FH, FB and FD in D. peruvianus, and FH, FB and FEA in O. fasciatus) also produced body deformities in the few adults that emerged. Other extracts (FH, FEA, FB, FD and LET in both insects), however, induced either permanent (overaged) or extranumerary nymphs, both of which were unable to achieve the adult stage and reproductive status. The insects were also treated with triterpenes (α‐ and β‐amyrin acetates) which showed high lethality at 30 days after treatment and delayed the intermoult period so that overaged nymphs were detected.

CONCLUSION: The results indicate that extracts and triterpenes from Manilkara subsericea act as potent growth inhibitors of phytophagous hemipteran nymphs. It is also concluded that the mixture of several different molecules in the extracts used produces synergic effects that do not occur after using the triterpenes (PFT) alone. These secondary metabolites in the M. subsericea extracts can potentially be used in integrated control programmes against crop pests. Copyright © 2012 Society of Chemical Industry
Static and dynamic characterization of AlN and nanocrystalline diamond membranes
Authors: Knöbber Fabian , Zürbig Verena , Heidrich Nicola , Hees Jakob , Sah Ram Ekwal , Baeumler Martina , Leopold Steffen , Pätz Daniel , Ambacher Oliver , Lebedev Vadim
Published: July 2012

In this work, AlN and nanocrystalline diamond thin films as well as multi‐layer structures on their basis are characterized towards their mechanical properties. In particular, the Young's modulus E and the residual stress σ are obtained by wafer bow measurements of thin films as well as by bulge experiments and vibration measurements of freestanding membranes. Depending on the growth conditions, the AlN thin films, deposited by reactive magnetron sputtering, revealed values of σ ∼ +300 up to +400 MPa and E ∼ 370 GPa, while the diamond films, grown by microwave plasma CVD, showed values of σ ∼ −60 to +60 MPa and E ∼ 870 up to 1000 GPa. The values and the accuracy of the characterization techniques used are discussed and their limits are demonstrated.