bluuebunny/crossref_metadata_2025 huggingface dataset:
An Eficient One‐Pot Synthesis of 1,4‐Dihydropyridines Catalyzed by Magnetic Nanocrystalline Fe3O4
Authors: Yang Shu‐Hong , Zhao Fei‐Yang , Lü Hong‐Yan , Deng Jia , Zhang Zhan‐Hui
Published: October 2012

An efficient approach for one‐pot three‐component reaction of aromatic amines, α,β‐unsaturated aldehydes and β‐keto esters using magnetic nanocrystalline Fe3O4 as a catalyst has been described. The corresponding 1,4‐dihydropyridines are obtained in good yields under mild conditions. In addition, the catalyst can be recovered with a magnet and reused at least five consecutive cycles without appreciable loss of its catalytic activity.
Facile Synthesis of 4‐Substituted‐2‐quinolinone‐3‐carboxylic Acid Ethyl Esters
Authors: Zhang Lijuan , Luo Yu , Yu Shanbao , Lu Wei
Published: October 2012

An efficient route for the synthesis of 4‐substituted‐2‐quinolinone‐3‐carboxylic acid ethyl esters has been developed through Suzuki or Sonogashira reactions. The advantages of the method include high yields, operational simplicity, and suitability for medicinal modification of 4‐substituted quinolinones and their derivatives.
On the Nature of the Causal Relationships Between Foreign Direct Investment, GDP and Exports in South Africa
Authors: Akoto William
Published: October 2012

What started as a financial crisis in 2008–2009 quickly became a crisis of trade for many emerging economies. Using South Africa as a case study, this paper examines the Granger causal relationships between foreign direct investment (FDI), exports and GDP as well as the responsiveness of exports to FDI shocks. The findings indicate that in the long run, FDI has a significant impact on boosting exports. In the short run, there is bi‐directional Granger causality between GDP and exports, with uni‐directional causality from FDI to exports and FDI to GDP. However, variance decomposition analyses shows that exports are not very responsive to changes in FDI inflow. Copyright © 2012 John Wiley & Sons, Ltd.
Fast separations of intact proteins by liquid chromatography
Authors: Wang Fei , Min Yi , Geng Xindu
Published: October 2012

Scientists working in many fields require fast separations of intact proteins using liquid chromatography. The fast separations here concern not only the separation step alone but also the complete chromatographic process, including column regeneration, system equilibration, and buffer exchange, in one‐ and two‐dimensional liquid chromatography in addition to fast purification technologies predominantly on the analytical scale with some unique examples on the preparative and industrial scales. This comprehensive review discusses recent developments in methodologies, packing materials, column techniques, and purification technologies in the field of rapid liquid chromatography of intact proteins. Some typical examples are summarized in the tables.
SPE for the simultaneous determination of various isothiocyanates
Authors: Wilson Eli Adjélé , Bindler Françoise , Marchioni Eric , Bergaentzlé Martine , Benrabah Tamime , Ennahar Saïd
Published: October 2012

Several SPE sorbents were investigated for the extraction of a group of chemically diverse isothiocyanates (ITCs). They included bonded silica, carbon‐based, and polymer‐based sorbents with various functional groups. Results showed large differences in the ability of these sorbents to simultaneously extract ITCs from standard solutions. Recovery rates were on average the highest with divinylbenzene (DVB) based polymeric sorbents, especially with a DVB/N‐vinylpyrrolidone copolymer that had recovery rates ranging between 86.7 and 95.6%. These sorbents achieved the most balanced extraction efficiency between aliphatic and aromatic, polar, and nonpolar ITCs. With graphitized carbon, C18‐bonded silica, and amide‐containing sorbent, recovery levels were higher for the two least polar aromatic ITCs (benzyl ITC and phenylethyl ITC), whereas for the polar aliphatic ITCs levels were the lowest. The least retained one, was methyl ITC that is the most polar with recoveries between 0 and 31.5%. The presence of amide groups, especially in a polyamide sorbent, appeared to be particularly unsuitable for the extraction of aliphatic ITCs. A copolymer made up of DVB and N‐vinylpyrrolidone was therefore shown to be the most suited for the extraction of both aliphatic and aromatic ITCs.
Quantitative determination of amphetamine in plasma using negative ion chemical ionization GC‐MS of o‐(pentafluorobenzyl‐oxycarbonyl)‐2,3,4,5‐tetrafluorobenzoyl derivatives
Authors: Leis Hans J. , Windischhofer Werner
Published: October 2012

Quantitative determination of amphetamine in plasma by the use of a novel electrophoric derivatization reagent, o‐(pentafluorobenzyloxycarbonyl)‐2,3,4,5‐tetrafluorobenzoyl chloride is described. Amphetamine can be quantitatively measured down to 49 pg/mL plasma using only 250 μL of sample due to the extraordinary sensitivity of the derivatives under negative ion chemical ionization MS. Plasma samples were made alkaline with carbonate buffer and treated with n‐hexane and reagent solution for 20 min, which, after concentration was measured by negative ion chemical ionization GC‐MS. The method is rapid as extraction and derivatization occur in one single step. [2H5]‐Amphetamine was used as an internal standard. Validation data are given to demonstrate the usefulness of the assay, including specificity, linearity, accuracy and precision, benchtop stability, freeze–thaw stability, autosampler stability, aliquot analysis, and prospective analytical batch size accuracy.
Determination of sertraline in rat plasma by HPLC and fluorescence detection and its application to in vivo pharmacokinetic studies
Authors: Melis Virginia , Usach Iris , Peris José‐Esteban
Published: October 2012

A simple, rapid, and sensitive HPLC method based on 9H‐fluoren‐9‐ylmethyl chloroformate derivatization for the quantification of sertraline in rat plasma has been developed, requiring a plasma sample of only 0.1 mL, which was deproteinized and derivatized for 5 min in two single steps. The obtained derivative was stable at room temperature and was determined by HPLC using a fluorescence detector. The analytical column was a C(18) column and the mobile phase was acetonitrile and water (80:20, v/v). Calibration curves were linear in the range of 10–500 ng/mL. The limit of detection was approximately 3 ng/mL, and the lower limit of quantification was established at 10 ng/mL. The bias of the method was lower than 10%, and the within day as well as between day, relative standard deviations were lower than 12%. This analytical method was successfully applied to characterize sertraline pharmacokinetics in rats following intravenous (t1/2 = 213 ± 48 min, Cl = 43.1 ± 8.7 mL/min, Vd = 11560 ± 1861 mL) and oral (Cmax = 156 ± 76 ng/mL, tmax = 63.8 ± 16.3 min) administration of 2 and 5 mg, respectively.
Methods for characterization of biochromatography media
Authors: Hahn Rainer
Published: October 2012

Chromatographic methods represent the most powerful techniques for purification of biopharmaceutical compounds. Quite often, the question arises which chromatographic medium should be chosen for a particular purification task or which technique should be applied to obtain the required information for a process, respectively. The present review aims to guide through these questions by presenting experimental and modeling techniques that allow a detailed characterization and comparison of chromatography media as well provide a guideline of techniques for process development. The first section provides basic information on chromatographic theory, types of chromatographic media, and different types of techniques. The second section governs description of experimental techniques including some advises for laboratory practice. The third section presents and discusses selected references from literature. Within this article, the main focus is on traditional laboratory techniques but also automated high‐throughput screening methods will briefly be discussed.
Rationally Designed α‐Helical Broad‐Spectrum Antimicrobial Peptides with Idealized Facial Amphiphilicity
Authors: Wiradharma Nikken , Sng Melvin Y. S. , Khan Majad , Ong Zhan‐Yuin , Yang Yi‐Yan
Published: October 2012

A series of 12‐amino acid peptide analogs is designed using point mutation strategy based on an α‐helical peptide template. The first mutation in the series, KL12, has an idealized facial amphiphilicity. Subsequent mutations are performed to increase hydrophobic or cationic contents. Idealized facial amphiphilicity show enhanced antimicrobial activity and selectivity against most of the tested microbes. Increasing hydrophobic contents further enhance antimicrobial potency; however, selectivity of the most hydrophobic analog is impaired due to non‐specific interactions with mammalian cell membrane. This study demonstrates that facial amphiphilicity and hydrophobic content are strongly correlated with antimicrobial activity and selectivity of antimicrobial peptides.
Low dietary folate and methylenetetrahydrofolate reductase deficiency may lead to pregnancy complications through modulation of ApoAI and IFN‐γ in spleen and placenta, and through reduction of methylation potential
Authors: Mikael Leonie G. , Pancer Jill , Jiang Xinyin , Wu Qing , Caudill Marie , Rozen Rima
Published: October 2012

Scope

Genetic or nutritional disturbances in folate metabolism lead to hyperhomocysteinemia and adverse reproductive outcomes. Folate‐dependent homocysteine remethylation is required for methylation reactions and may influence choline/betaine metabolism. Hyperhomocysteinemia has been suggested to play a role in inflammation. The goal of this study was to determine whether folate‐related pregnancy complications could be due to altered expression of some inflammatory mediators or due to disturbances in methylation intermediates.

Methods and results

Pregnant mice with or without a deficiency of methylenetetrahydrofolate reductase (MTHFR) were fed control diets or folate‐deficient (FD) diets; tissues were collected at embryonic day 14.5. FD decreased plasma phosphocholine and increased plasma glycerophosphocholine and lysophosphatidylcholine. Liver betaine, phosphocholine, and S‐adenosylmethionine:S‐adenosylhomocysteine ratios were reduced in FD. In liver, spleen, and placenta, the lowest levels of apolipoprotein AI (ApoAI) were observed in Mthfr+/– mice fed FD. Increased interferon‐gamma (IFN‐γ) was observed in spleen and placentae due to FD or Mthfr genotype. Plasma homocysteine correlated negatively with liver and spleen ApoAI, and positively with IFN‐γ.

Conclusion

Low dietary folate or Mthfr deficiency during pregnancy may result in adverse pregnancy outcomes by altering expression of the inflammatory mediators ApoAI and IFN‐γ in spleen and placenta. Disturbances in choline metabolism or methylation reactions may also play a role.
Living Anionic Polymerization of tert‐Butyl Acrylate in a Flow Microreactor System and Its Applications to the Synthesis of Block Copolymers
Authors: Nagaki Aiichiro , Takahashi Yusuke , Akahori Kana , Yoshida Jun‐ichi
Published: October 2012

Living anionic polymerization of tert‐butyl acrylate initiated by 1,1‐diphenylhexyllithium is conducted in a flow microreactor system in the presence of lithium chloride. A high degree of control over the molecular weight distribution is achieved under easily accessible conditions, for example at −20 °C. The subsequent reaction of a reactive polymer chain end with an alkyl methacrylate in an integrated flow micoreactor system leads to the formation of a block copolymer with a narrow molecular weight distribution.

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Understanding Entheseal Changes: Definition and Life Course Changes
Authors: Villotte S. , Knüsel C. J.
Published: October 2012

Over the past two decades, many articles have been published on entheseal changes (usually called ‘Musculoskeletal Stress Markers’) as activity markers in past societies. Over‐simplified methods and over‐interpretation of past activities have generated strong critiques of research results in this area of enquiry. While some significant improvements regarding the recording systems for entheseal changes have been applied more recently, many bioarchaeologists appear not yet to be fully aware of the multi‐factorial aetiology of these alterations. In this article, we review the anatomical and clinical literature to discuss some of the difficulties associated with the recording of entheseal changes and the multiple factors leading to their appearance in the human skeleton. Thus far, fibrocartilaginous entheses appear to hold more promise for activity‐related reconstruction than do fibrous ones, but these relationships remain an area of active research interest. Copyright © 2012 John Wiley & Sons, Ltd.
Toward a new institutional strategy framework for political marketing
Authors: Winther Nielsen Sigge
Published: October 2012

The present literature on political marketing strategy has provided important knowledge about how the material context of technologies, polls or competitors influences strategy formulation. However, less attention has been directed to the constraints facing a political organization from the social context related to habits, norms or social conventions. This article thus aims at bringing organizational new institutional theory into the field of political marketing strategy. Accordingly, it is investigated how political organizations when initiating marketing strategies act or react toward institutionalized demands in their environment, such as issues or ideas that are considered socially appropriate. As such, a strategy framework consisting of a phase model and a typology is developed. The phase model is drawn from extant literature within organizational new institutional theory stating that decision makers will (1) scan information from their environment, (2) interpret this incoming information in available cognitive categories and (3), finally, select a strategy premised on their cognitive interpretations. On this ground, we build a novel typology that specifies which political marketing strategy decision makers will select under different cognitive framings of their environment. Here, we delineate four ideal type political marketing strategies—conformity, decoupling, defense and entrepreneurial—that correspond to how organizational decision makers interpret their institutional surroundings. Copyright © 2012 John Wiley & Sons, Ltd.
Correlation of nanostructural parameters and macromechanical behaviour of hyperbranched‐modified polypropylene using time‐resolved small‐angle X‐ray scattering measurements
Authors: Sari Morteza Ganjaee , Stribeck Norbert , Moradian Siamak , Zeinolebadi Ahmad , Bastani Saeed , Botta Stephan
Published: October 2012

Polypropylene (PP) is modified utilizing a poly(ester amide)‐based hyperbranched polymer (PS). A maleic‐modified PP is used to enhance the compatibility. Usual tensile experiments are carried out. The nanocrystalline structure is studied using small‐angle X‐ray scattering (SAXS) while a uniaxial mechanical load is simultaneously applied. SAXS patterns are analysed using procedures written in PV‐WAVE. The chord distribution function (CDF) is calculated and nanostructural parameters such as long period (lp) and nanodeformation (ϵNano) are extracted. The correlations between macromechanical parameters and nanostructures are studied. Mechanical results show that PS has a plasticizing effect. Reactively blended samples demonstrate enhanced mechanical properties. SAXS patterns reveal a well‐known structure of PP as a peculiar architecture of the nanostructure. Crystalline branching occurs in a geometry that is known as a mother–daughter crystal lamellar structure, also called a crosshatching structure. It is concluded that adding PS distorts the stacking of crystalline domains. The structural information from SAXS patterns in reciprocal space is visualized in real space in the calculated CDFs. The CDFs indicate that in simple blends, lp of the crystalline stacks increases compared to blank PP. Nevertheless, reactively blended samples show an increase of lp compared to blank PP; however, they possess smaller lp compared to simple blends. © 2012 Society of Chemical Industry
Identifying protein complexes in protein–protein interaction networks by using clique seeds and graph entropy
Authors: Chen Bolin , Shi Jinhong , Zhang Shenggui , Wu Fang‐Xiang
Published: October 2012

The identification of protein complexes plays a key role in understanding major cellular processes and biological functions. Various computational algorithms have been proposed to identify protein complexes from protein–protein interaction (PPI) networks. In this paper, we first introduce a new seed‐selection strategy for seed‐growth style algorithms. Cliques rather than individual vertices are employed as initial seeds. After that, a result‐modification approach is proposed based on this seed‐selection strategy. Predictions generated by higher order clique seeds are employed to modify results that are generated by lower order ones. The performance of this seed‐selection strategy and the result‐modification approach are tested by using the entropy‐based algorithm, which is currently the best seed‐growth style algorithm to detect protein complexes from PPI networks. In addition, we investigate four pairs of strategies for this algorithm in order to improve its accuracy. The numerical experiments are conducted on a Saccharomyces cerevisiae PPI network. The group of best predictions consists of 1711 clusters, with the average f‐score at 0.68 after removing all similar and redundant clusters. We conclude that higher order clique seeds can generate predictions with higher accuracy and that our improved entropy‐based algorithm outputs more reasonable predictions than the original one.
Unifying protein inference and peptide identification with feedback to update consistency between peptides
Authors: Shi Jinhong , Chen Bolin , Wu Fang‐Xiang
Published: October 2012

We first propose a new method to process peptide identification reports from databases search engines. Then via it we develop a method for unifying protein inference and peptide identification by adding a feedback from protein inference to peptide identification. The feedback information is a list of high‐confidence proteins, which is used to update an adjacency matrix between peptides. The adjacency matrix is used in the regularization of peptide scores. Logistic regression (LR) is used to compute the probability of peptide identification with the regularized scores. Protein scores are then calculated with the LR probability of peptides. Instead of selecting the best peptide match for each MS/MS, we select multiple peptides. By testing on two datasets, the results have shown that the proposed method can robustly assign accurate probabilities to peptides, and have a higher discrimination power than PeptideProphet to distinguish correct and incorrect identified peptides. Additionally, not only can our method infer more true positive proteins but also infer less false positive proteins than ProteinProphet at the same false positive rate. The coverage of inferred proteins is also significantly increased due to the selection of multiple peptides for each MS/MS and the improvement of their scores by the feedback from the inferred proteins.
Molecular orientation and composition at the surface of spin‐coated polyfluorene:Fullerene blend films
Authors: Anselmo Ana Sofia , Dzwilewski Andrzej , Svensson Krister , Moons Ellen
Published: October 2012

The surface composition in spin‐coated films of polyfluorene:fullerene blends was determined quantitatively by near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. By comparing partial and total electron yield spectra, we found vertical compositional differences in the surface region. Furthermore, the orientation of the polymer chains was investigated by variable‐angle NEXAFS. Blend films of poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole] with [6,6]‐phenyl‐C61‐butyric acid methyl ester in two different blend ratios were studied. Results showed polymer enrichment of the surfaces for films with a polymer:fullerene weight ratio of 20:80 and of 50:50, spin‐coated from both chlorobenzene and chloroform solutions. The angular dependence of the NEXAFS spectra of the pure polymer films showed a preferential plane‐on orientation, which was slightly stronger in the subsurface region than at the surface. In blend films, this orientational preference was less pronounced and the difference between surface and subsurface vanished. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Viscoelasticity of nanobubble‐inflated ultrathin polymer films: Justification by the coupling model
Authors: Ngai K. L. , Prevosto Daniele , Grassia Luigi
Published: October 2012

The nanobubble inflation method is the only experimental technique that can measure the viscoelastic creep compliance of unsupported ultrathin films of polymers over the glass–rubber transition zone as well as the dependence of the glass transition temperature (Tg) on film thickness. Sizeable reduction of Tg was observed in polystyrene (PS) and bisphenol A polycarbonate by the shift of the creep compliance to shorter times. The dependence of Tg on film thickness is consistent with the published data of free‐standing PS ultrathin films. However, accompanying the shift of the compliance to shorter times, a decrease in the rubbery plateau compliance is observed. The decrease becomes more dramatic in thinner films and at lower temperatures. This anomalous viscoelastic behavior was also observed in poly(vinyl acetate) and poly (n‐butyl methacrylate), but with large variation in the change of either the Tg or the plateau compliance. By now, well established in bulk polymers is the presence of three different viscoelastic mechanisms in the glass–rubber transition zone, namely, the Rouse modes, the sub‐Rouse modes, and the segmental α‐relaxation. Based on the thermorheological complexity of the three mechanisms, the viscoelastic anomaly observed in ultrathin polymer films and its dependence on chemical structure are explained in the framework of the Coupling Model. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Low Temperature Deposition of Antibacterially Active Silicon Oxide Layers Containing Silver Nanoparticles, Prepared by Atmospheric Pressure Plasma Chemical Vapor Deposition
Authors: Beier Oliver , Pfuch Andreas , Horn Kerstin , Weisser Jürgen , Schnabelrauch Matthias , Schimanski Arnd
Published: October 2012

This study presents investigations to create antibacterially active thin films by using the atmospheric pressure plasma chemical vapor deposition technique. Silver nitrate solutions are sprayed and converted within the plasma to create and implement formed silver nanoparticles into a growing SiOx‐matrix in situ during the deposition step. Investigation of the films on their bactericidal activity using an Escherichia coli (E. coli) strain shows a strong antibacterial effect of the coatings and additionally a good stability against abrasive wear. The films are characterized by X‐ray photoelectron spectroscopy, SEM, energy dispersive X‐ray spectroscopy, and IR spectroscopy.

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Fast and efficient combustion synthesis route to produce novel nanocarbons
Authors: Dąbrowska Agnieszka , Huczko Andrzej , Dyjak Sławomir
Published: October 2012

We report the preliminary results on simple one‐step chemical synthesis of exfoliated graphite and other carbon‐related nanostructures via a novel combustion synthesis route. We found previously that different solid carbonates could be decomposed to elements upon reducing in solid phase by using a strong reducers and the produced carbon vapors instantly condense towards 1‐D nanocarbons. Here such combustion processing is extended towards the direct heterogeneous, efficient, and autothermic high‐pressure reduction of gaseous carbon oxides (CO2 and CO) to elements using the following reducers: Li, Mg, Ca, B, Ti, Zr, and Al. The solid products (layered graphite and nanocarbides) were chemically purified and characterized using XRD, SEM, and Raman spectroscopy.

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Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3‐thiophene acetic acid) conducting polymer
Authors: Szabó T. , Magyar M. , Németh Z. , Hernádi K. , Endrődi B. , Bencsik G. , Visy Cs. , Horváth E. , Magrez A. , Forró L. , Nagy L.
Published: October 2012

A large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio‐nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3‐thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment.
A coupled energy transport and hydrological model for urban canopies evaluated using a wireless sensor network
Authors: Wang Zhi‐Hua , Bou‐Zeid Elie , Smith James A.
Published: October 2012

We propose a new surface exchange scheme coupling the transport of energy and water in urban canopies. The new model resolves the subfacet heterogeneity of urban surfaces, which is particularly useful for capturing surface exchange processes from vegetated urban surfaces, such as lawns or green roofs. We develop detailed urban hydrological models for surfaces consisting of either natural (soil and vegetation) or engineered materials with water‐holding capacity. The coupling of energy and water transport enables us to parametrize surface evaporation from different urban facets including soils, vegetation and water‐holding engineered surfaces. The new coupled model is evaluated using field measurement data obtained through a wireless sensor network deployed over the Princeton University campus. Comparison of model prediction and measured results shows that the proposed surface exchange scheme is able to predict widely varying surface temperatures for each subfacet with good accuracy. Different weather conditions and seasonal variability are found to have insignificant effect on the model performance. The new model is also able to capture the subsurface hydrological processes with reasonable accuracy, particularly for urban lawns. The proposed model is then applied to assess different mitigation strategies of the urban heat island effect.
ECOSYSTEM ENGINEERS MODULATE EXOTIC INVASIONS IN RIPARIAN PLANT COMMUNITIES BY MODIFYING HYDROGEOMORPHIC CONNECTIVITY
Authors: Corenblit D. , Steiger J. , Tabacchi E. , González E. , Planty‐Tabacchi A‐M
Published: October 2012

Patterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities; and (ii) islands and river margins disconnected from annual hydrogeomorphic disturbances and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for both vegetation types. However, significant differences in native and exotic species richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity were attained within the herbaceous vegetation type than within the woody type. These differences are most likely related to changes in local exposure to hydrogeomorphic disturbances driven by woody engineer plant species and to vegetation succession. A lower exotic species cover within the woody vegetation type than within the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation through landform construction resulted in a decrease of alpha (α) diversity at the patch scale but, in parallel, caused an increase in gamma (γ) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic acceptance of exotic species by native species at the local scale (generally <10 m2) within heterogeneous and disturbed environments. Furthermore, we suggest that in riparian contexts such as the River Tech exotic species trapp sediment at the same time as native species and thus contribute to the increase in ecosystem resistance during the biogeomorphic succession. Copyright © 2012 John Wiley & Sons, Ltd.
Who is governing whom? Executives, governance, and the structure of generosity in large U.S. firms
Authors: Marquis Christopher , Lee Matthew
Published: October 2012

We examine how organizational structure influences strategies over which corporate leaders have significant discretion. Corporate philanthropy is a strategic activity commonly managed through a specific, differentiated organizational structure—the corporate foundation—that formalizes and constrains the influence of individual senior managers and directors on corporate strategy. Our analysis of Fortune 500 firms from 1996 to 2006 shows that characteristics of senior management and directors affect corporate philanthropic contributions. We also find that organizational structure constrains the philanthropic influence of board members, but not of senior managers, a result contrary to what existing theory would predict. We discuss how these findings advance understanding of how organizational structure and corporate leadership interact and how organizations can more effectively realize the strategic value of corporate social responsibility activities.
In‐Vitro Permeability of Neutral Polystyrene Particles via Buccal Mucosa
Authors: Teubl Birgit Johanna , Meindl Claudia , Eitzlmayr Andreas , Zimmer Andreas , Fröhlich Eleonore , Roblegg Eva
Published: October 2012

Drugs can be absorbed well in the oral cavity, which eliminates problems related to intestinal and hepatic first‐pass metabolism. Although it is well‐established that nanoparticles are small enough to penetrate/permeate epithelial barriers, there is no clear understanding of how they interact with the buccal mucosa. This work provides useful information regarding particle properties with regard to mucosal uptake and can be used for the rational design of nanocarriers. In the buccal mucosa, the uptake of neutral polystyrene nanoparticles (PP) is size‐dependent. Compared to 25 and 50 nm particles, 200 nm PP particles penetrate into deeper regions of the mucosa. This is attributed to the structure of the buccal mucosa, i.e., mucus layer and microplicae. The particles permeate the mucus layer and deposit in ridge‐like folds of superficial buccal cells. Thus, the effects of thermodynamic driving forces and/or interparticle electrostatic repulsion are enhanced and cellular uptake might be reduced for smaller particle sizes.
Formation of Reversed Austenite in High Temperature Tempering Process and its Effect on Mechanical Properties of Cr15 Super Martensitic Stainless Steel Alloyed with Copper
Authors: Ye Dong , Li Jun , Jiang Wen , Su Jie , Zhao Kunyu
Published: October 2012

Formation mechanism of the reversed austenite of Cr15 super martensitic stainless steel (SMSS) alloyed with copper after high temperature tempering was investigated by means of thermo‐calc software, transmission electron microscope (TEM), and X‐ray diffraction (XRD). The mechanical properties of the SMSS were also tested. The experimental results show that the reversed austenite with low dislocation density is formed at high temperature tempering processing. The transformation of the martensite to reversed austenite is a diffused phase transformation, and the growth of the reversed austenite is closely related to the diffusion process of Ni. The bulk reversed austenite with large amount of stacking faults is formed with the increase of the tempering temperature. The volume fraction of reversed austenite increases at first and then decreases with increasing tempering temperature, and the maximum amount of the reversed austenite is obtained at 650°C. The reversed austenite is unstable at the tempering temperature above 650°C and the martensitic phase transformation will occur at the following cooling process. The mechanical properties of Cr15 super martensitic stainless steel are significantly influenced by the volume fraction of reversed austenite.
The Effort of Being in a Fictional World: Upkeyings and Laminated Frames in MMORPGs
Authors: Linderoth Jonas
Published: October 2012

On the basis of ten months of fieldwork studying a role‐playing guild in the game World of Warcraft, this article shows that contrary to the idea that virtual worlds are seductive illusions, technology does not necessarily support players' feelings of being immersed in fictional worlds. Applying Goffman's frame theory, the author explains how role‐players in the game actively upkey elements from primary frameworks in order to create and uphold the frame of being in a fictional world. This kind of narrative immersion is rather hindered than facilitated by technology.
Kerr-AdS and its near-horizon geometry: perturbations and the Kerr/CFT correspondence
Authors: Dias Óscar J. C. , Santos Jorge E. , Stein Maren
Published: October 2012

Abstract

We investigate linear perturbations of spin-sfields in the Kerr-AdS black hole and in its near-horizon geometry (NHEK-AdS), using the Teukolsky master equation and the Hertz potential. In the NHEK-AdS geometry we solve the associated angular equation numerically and the radial equation exactly. Having these explicit solutions at hand, we search for linear mode instabilities. We do not find any (non-)axisymmetric instabilities with outgoing boundary conditions. This is in agreement with a recent conjecture relating the linearized stability properties of the full geometry with those of its near-horizon geometry. Moreover, we find that the asymptotic behaviour of the metric perturbations in NHEK-AdS violates the fall-off conditions imposed in the formulation of the Kerr/CFT correspondence (the only exception being the axisymmetric sector of perturbations).
Correlation between the Higgs decay rate to two photons and the muon g − 2
Authors: Giudice Gian F. , Paradisi Paride , Strumia Alessandro
Published: October 2012

Abstract

In the context of minimal supersymmetry with slepton mass universality we find that an enhancement in h → γγ by at least 40%, as hinted by present data, implies a deviation of the muon anomalous magnetic moment by exactly the right amount to explain the observed anomaly. The enhancement in h → γγ selects a light stau with large left-right mixing, a light Bino, and heavy higgsinos. The corresponding parameters are compatible with thermal dark matter, predict small deviations in h → Zγ and h → ττ, and measurable violations of lepton universality.
Characterization of a new alginate lyase from newly isolated Flavobacterium sp. S20
Authors: Huang Lishuxin , Zhou Jungang , Li Xiao , Peng Qiang , Lu Hong , Du Yuguang
Published: October 2012

Alginate lyase is a promising biocatalyst because of its application in saccharification of alginate for the production of biochemicals and renewable biofuels. This study described the isolation of a new alginate metabolizing bacterium, Flavobacterium sp. S20, from sludge samples and the characterization of its alginate lyase Alg2A. The alginate lyase gene, alg2A, was obtained by constructing and screening the genomic library of the strain S20 and overexpressed in Escherichia coli. Substrate specificity assays indicated Alg2A preferred poly-α-l-guluronate as a substrate over poly-β-d-mannuronate. In the saccharification process of a high content (10 %, w/v) of sodium alginate, the recombinant alginate lyase Alg2A yielded 152 of mM the reducing sugars after 69 h of reaction, and the amounts of oligosaccharides with a different degree of polymerization (DP) generated by Alg2A gradually accumulated without significant variation in the distribution of oligosaccharide compositions. These results indicated that Alg2A possessed high enzymatic capability for saccharifying the alginate, which could be used in saccharifying the alginate biomass prior to the main fermentation process for biofuels. In addition, Alg2A had a different endolytic reaction mode from both the two commercial alginate lyases and other alginate lyases from polysaccharide lyase family 7 owing to high yields of penta-, hex-, and hepta-saccharides in the hydrolysis products of Alg2A. Thus, Alg2A could be a good tool for the large-scale preparation of alginate oligosaccharides with high DP.
Effects of elevated CO2 on the nutrient compositions and enzymes activities of Nilaparvata lugens nymphs fed on rice plants
Authors: Zeng YunYun , Huang WenKun , Su Li , Wu Gang , Zhuang Jing , Zhao WanYun , Hua HongXia , Li JunSheng , Xiao NengWen , Xiong YanFei
Published: October 2012

Elevated CO2 may reduce the tolerance of Nilaparvata lugen (N. lugens) to adverse environmental factors through the biological and physiological degeneration of N. lugens. In an artificial climate box, under 375 and 750 μL L−1 CO2 levels, the rice stems nutrient content, the nutrient content and enzyme activities of N. lugens nymph fed on rice seedlings exposed to ambient and elevated CO2 were studied. The results showed that rice stems had significantly higher protein and total amino acid levels under ambient than elevated CO2 levels. Nymphs had significantly higher protein levels in the ambient CO2 treatment, while their glucose levels were significantly lower under ambient CO2 conditions. Significantly higher trypsin activity was observed in nymphs grown in elevated CO2. Significantly lower activities of the protective enzymes total superoxide dismutase and catalase were observed in the nymphs under ambient CO2. Meanwhile, the activity of the detoxification enzyme glutathione S-transferase was significantly higher in the ambient CO2 treatment. Measuring how energy and resources were allocated to enzymes in N. lugens nymphs under elevated CO2 conditions can provide a more meaningful evaluation of their metabolic tolerances to adverse climatic conditions.
The role and clinical implications of microRNAs in hepatocellular carcinoma
Authors: Zhao Xue , Yang Zhen , Li GuangBing , Li DongKai , Zhao Yi , Wu Yan , Robson Simon C. , He Lian , Xu YiYao , Miao RuoYu , Zhao HaiTao
Published: October 2012

Hepatocellular carcinoma (HCC) is common and one of the most aggressive of all human cancers. Recent studies have indicated that miRNAs, a class of small noncoding RNAs that regulate gene expression post-transcriptionally, directly contribute to HCC by targeting many critical regulatory genes. Several miRNAs are involved in hepatitis B or hepatitis C virus replication and virus-induced changes, whereas others participate in multiple intracellular signaling pathways that modulate apoptosis, cell cycle checkpoints, and growth-factor-stimulated responses. When disturbed, these pathways appear to result in malignant transformation and ultimately HCC development. Recently, miRNAs circulating in the blood have acted as possible early diagnostic markers for HCC. These miRNA also could serve as indicators with respect to drug efficacy and be prognostic in HCC patients. Such biomarkers would assist stratification of HCC patients and help direct personalized therapy. Here, we summarize recent advances regarding the role of miRNAs in HCC development and progression. Our expectation is that these and ongoing studies will contribute to the understanding of the multiple roles of these small noncoding RNAs in liver tumorigenesis.
Feasible path planning for fixed-wing UAVs using seventh order Bézier curves
Authors: Neto Armando Alves , Macharet Douglas G. , Campos Mario F. M.
Published: October 2012

This study presents a novel methodology for generating smooth feasible paths for autonomous aerial vehicles in the three-dimensional space based on a variation of the Spatial Quintic Pythagorean Hodographs curves. Generated paths must satisfy three main constraints: (i) maximum curvature, (ii) maximum torsion and (iii) maximum climb (or dive) angle. A given path is considered to be feasible if the main kinematic constraints of the vehicle are not violated, which is accomplished in our approach by connecting different waypoints with seventh order Bézier curves. This also indirectly insures the smoothness of the vehicle’s acceleration profile between two consecutive points of the curve and of the entire path by controlling the curvature values at the extreme points of each composing Bézier curve segment. The computation of the Pythagorean Hodograph is cast as an optimization problem, for which we provide an algorithm with fast convergence to the final result. The proposed methodology is applicable to vehicles in three-dimensional environments, which can be modeled presuming the imposed constraints. Our methodology is validated in simulation with real parameters and simulated flight data of a small autonomous aerial vehicle.
Involvement of PTEN in TPA‐mediated p53‐activation in mouse skin epidermal JB6 cells
Authors: Robbins Delira , Ponville Jacquelyn , Morris Kerri , Zhao Yunfeng
Published: October 2012

PTEN
and
p53
colocalize
by
cosedimentation in solution
(View interaction)
Effects of endoplasmic reticulum stressors on maturation and signaling of hemizygous and heterozygous wild‐type and mutant forms of KIT
Authors: Brahimi-Adouane Sabrina , Bachet Jean-Baptiste , Tabone-Eglinger Séverine , Subra Frédéric , Capron Claude , Blay Jean-Yves , Emile Jean-François
Published: October 2012

Gain of function mutations of KIT are frequent in some human tumors, and are sensible to tyrosine kinase inhibitors. In most tumors, oncogenic mutations are heterozygous, however most in vitro data of KIT activation have been obtained with hemizygous mutation. This study aimed to investigate the maturation and activation of wild‐type (WT) and mutant (M) forms of KIT in hemizygous and heterozygous conditions. WT and two types of exon 11 deletions M forms of human KIT were expressed in NIH3T3 cell lines. Membrane expression of KIT was quantified by flow cytometry. Quantification of glycosylated forms of KIT and phosphorylated forms of AKT and ERK were performed by western blot. Simultaneous activation of WT KIT and treatment with endoplasmic reticulum (ER) inhibitors, tunicamycin or brefeldin A induced a complete inhibition of membrane expression of the 145 kDa form of KIT. By contrast activation or ER inhibitors alone, only partly inhibited this form. ER inhibitors also inhibited KIT activation‐dependent phosphorylation of AKT and ERK1/2. Brefeldin A induced a complete down regulation of the 145 kDa form in hemizygous M, and induced an intra‐cellular accumulation of the 125 kDa form in WT but not in hemizygous M. Heterozygous cells had glycosylation and response to ER inhibitors patterns more similar to WT than to hemizygous M. Phosphorylated AKT was reduced in hemizygous cells in comparison to WT KIT cells and heterozygous cells, and in the presence of brefeldin A in all cell lines. Effects of ER inhibitors are significantly different in hemizygous and heterozygous mutants. Differences in intra‐cellular trafficking of KIT forms result in differences in downstream signaling pathways, and activation of PI3K/AKT pathway appears to be tied to the presence of the mature 145 kDa form of KIT at the membrane surface.
Tectonometamorphic evolution of the Garevka polymetamorphic complex (Yenisei Ridge)
Authors: Kozlov P.S. , Likhanov I.I. , Reverdatto V.V. , Zinoviev S.V.
Published: October 2012

The Garevka metamorphic complex (GMC), located at the junction of the Central Angara and Isakovka terranes (western part of the Transangarian Yenisei Ridge), was studied in terms of its tectonometamorphic evolution and geodynamic processes in the Neoproterozoic history of the region. Geological, structural, geochronological, and petrological data permitted the recognition of two stages in the GMC evolution, which differ in thermodynamic regimes and metamorphic field gradients. These stages were related to crustal contraction and extension within the Yenisei regional shear zone, a large lineament structure in the region. Stage 1 was marked by the formation of metamorphic complexes in the middle to upper amphibolite facies moderate-pressure regional metamorphic settings at ∼ 960 Ma, P = 7.7–8.6 kbar, and T = 582–631 °C. This suggests subsidence of the area to the middle continental crust with dT/dH = 20–25 °C/km. During stage 2, the rocks experienced Late Riphean (∼ 880 Ma, SHRIMP II U–Pb and 40Ar–39Ar dating) dynamic metamorphism under epidote-amphibolite facies conditions (P = 3.9–4.9 kbar; T = 461–547 °C), indicating a metamorphic field gradient of dT/dH no greater than 10 °C/km, with the formation of blastomylonites in narrow zones of ductile and brittle deformations. In these zones, high-grade GMC blocks were exhumed to the upper continental crust and underwent low-temperature metamorphism. Comparison of the structural, geologic, and other evolutionary features (nearly identical age constraints in view of exhumation rate, similar PT-paths, and different types of metamorphism associated with different geodynamic settings, etc.) of the Garevka and Teya complexes suggests that they constitute a single polymetamorphic complex.
Petrography of Devonian and Lower Carboniferous terrigenous deposits in the southwest of the West Siberian Plate (Vagai–Ishim and Tobol–Ubagan structures)
Authors: Mizens G.A. , Kokshina L.V.
Published: October 2012

We present new data on the material composition of terrigenous deposits in the pre-Jurassic basement of the West Siberian Plate, which formed on the margin of the Kazakhstan paleocontinent. Studies of the sections of several wells drilled in the east of the Kurgan Region showed that the Middle–Upper Devonian and lower Lower Carboniferous continental and littoral deposits are graywackes rich in rock and plagioclase clastics. Quartz grains amount to no more than 3–5%. The rock clastics are mainly volcanics of basic and normal compositions, which were supplied, most likely, from acting volcanoes of the marginal belt. By genesis, these are predominantly tephroids. Along with allothigenic components of sandstones, we consider authigenic minerals, which permit treating the postsedimentational transformation of the Middle Devonian and Early Carboniferous rocks as early catagenesis. By the vitrinite reflectance, the Lower Visean sandstones correspond to gradations MC2 and MC3 (medium catagenesis).