bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of iron‐phytosiderophore complexes in soil related samples: LC‐ESI‐MS/MS versus CE‐MS
Authors: Dell'mour Madeleine , Schenkeveld Walter , Oburger Eva , Fischer Lisa , Kraemer Stephan , Puschenreiter Markus , Lämmerhofer Michael , Koellensperger Gunda , Hann Stephan
Published: March 2012

Phytosiderophores (PS) form stable complexes with various transition metals. These ligands are exuded by the roots of graminacous plants as a mechanism for mobilizing and acquiring soil iron. To investigate iron mobilization and transport, a novel LC method in combination with ESI‐MS/MS for the determination of three Fe(III)‐complexes with mugineic acid (MA), 2′‐epi‐MA and 2′‐deoxymugineic acid (DMA) has been developed. Liquid chromatographic separation was realized using a silica‐based mixed‐mode reversed phase/weak‐anion exchange type stationary phase and a 50 mM ammonium acetate buffer, pH 6.5. Baseline separation of the two complex diastereomers Fe(III)‐MA and Fe(III)‐epi‐MA could be achieved. ESI‐MS/MS detection allowed for simultaneous quantification of the complexes and the free ligands. Limits of detection were determined to be 0.001 and 0.05 μM for DMA and Fe(III)‐DMA, respectively. The analytical figures of merit of the novel method were evaluated and compared with a CE‐ESI‐MS method that we had published earlier. The LC‐ESI‐MS/MS method has been successfully applied to real samples derived from preliminary extraction experiments.
Simultaneous determination of components released from dental composite resins in human saliva by liquid chromatography/multiple‐stage ion trap mass spectrometry
Authors: Hsu Wei‐Yi , Wang Ven‐Shing , Lai Chien‐Chen , Tsai Fuu‐Jen
Published: March 2012

Dental composite resins are widely used for fixing teeth; however, the monomers used in dental composite resins have been found to be cytotoxic and genotoxic, namely triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A glycol dimethacrylate (Bis‐GMA). In this study, we incubated dental composite resins with human saliva for demonstrating the released monomers and biodegradation products. A simple saliva sample dilution method without purification or derivatization was used for quantification. We found that liquid chromatography coupled with multiple‐stage ion trap mass spectrometry (LC‐MSn) operated in selected reaction monitoring (SRM) mode was able to separate the three monomers within 10 min. The calibration curves were linear (R2>0.996) over a wide range for each monomer in saliva: TEGDMA, 5–500 ppb; UDMA, 5–100 ppb, and Bis‐GMA, 5–700 ppb. Furthermore, several biodegradation products were discovered with data‐dependent MS/MS scan techniques. Although TEGMA degradation products have previously been reported, we identified two previously unknown UDMA degradation products. The LC‐MS/MS method developed in this study was able to successfully quantify monomers and their principal biodegradation products from dental composite resins in human saliva.
The source identification and classification study of soot after combustion
Authors: Zhi Youran , Zong Ruowen , Guangxuan Liao , Liu Haiqiang , Jialei Tan
Published: March 2012

Solid phase microextraction‐gas chromatography‐mass spectroscopy technology was used to extract and analyze three kinds of accelerant soot including diesel soot, gasoline soot, and diesel–gasoline mixture soot. A total of 60 spectrograms have been obtained, analyzed, and compared. It was found that these kinds of soot were quite different with each other in the difference of major target compounds and retention time span, and could be visually identified by the profile of the corresponding spectrogram. A data matrix of 60 * 41 was reached by the characteristic substances corresponding with the retention time in all these 60 spectrograms. With principal component analysis method, two major component variables were obtained to classify the attribution of soot, with perfect classification efficiency of 100%. Hierarchical cluster analysis was further applied for the dendrogram analysis. In spite of the absence of the training set, the classification of 100% accuracy of these kinds of soot could be achieved. Copyright © 2012 John Wiley & Sons, Ltd.
Essential oil composition and chemical variability of Xanthium italicum Moretti from Corsica
Authors: Andreani Stéphane , Barboni Toussaint , Desjobert Jean‐Marie , Paolini Julien , Costa Jean , Muselli Alain
Published: March 2012

The chemical composition of Xanthium italicum Moretti essential oil was established for the first time using gas chromatography and gas chromatography–mass spectrometry. One hundred and seven compounds were identified and accounted for 98.7% of the total amount. The main compounds were limonene (35.3%), borneol (5.6%), sabinene (5.8%), germacrene‐D (2.5%), α‐bisabolol (2.4%) and α‐humulene (2.1%). Twenty‐five oil samples were investigated, and their chemical variability was analysed statistically. Two main groups of essential oils were identified in concordance with the morphological characteristics: hydrocarbon‐rich oils, which correlated with 100–120 cm plant height and oxygenated‐rich oils, which correlated with 5–20 cm plant height. The chemical composition of the oils obtained from separated organs and the concentrations of the main compounds throughout the vegetative cycle of the plant were studied. Stem and leaf oils were characterized by the occurrence of limonene (47.9% g and 22.9%, respectively) and germacrene‐D (4.6% and 15.8%, respectively). Flower oils displayed δ‐selinene and germacrene‐D as the main components (22.4% and 17.0%, respectively). X. italicum fruits yielded oil with a high amount of oxygenated compounds (72.9%), particularly sesquiterpene compounds (61.5%) such as α‐bisabolol (43.0%), α‐cadinol (5.0%) and (E,E)‐α‐farnesol (4.3%). The amount of hydrocarbon compounds remained stable throughout the vegetative cycle, whereas the amounts of oxygenated compounds increased during fructification. Copyright © 2012 John Wiley & Sons, Ltd.
Early Warning with Calibrated and Sharper Probabilistic Forecasts
Authors: Machete Reason L.
Published: March 2012

Given a nonlinear model, a probabilistic forecast may be obtained by Monte Carlo simulations. At a given forecast horizon, Monte Carlo simulations yield sets of discrete forecasts, which can be converted to density forecasts. The resulting density forecasts will inevitably be downgraded by model misspecification. In order to enhance the quality of the density forecasts, one can mix them with the unconditional density. This paper examines the value of combining conditional density forecasts with the unconditional density. The findings have positive implications for issuing early warnings in different disciplines including economics and meteorology, but UK inflation forecasts are considered as an example. Copyright © 2012 John Wiley & Sons, Ltd.
A Markowitz Optimization of Commodity Futures Portfolios
Authors: You Leyuan , Daigler Robert T.
Published: March 2012

We examine the diversification benefits of using individual futures contracts instead of simply a commodity index. We determine the ex‐ante, ex‐post, and stability results for optimal Markowitz portfolios, investigate the instability between the ex‐ante and ex‐post results, and compare our results to traditional and naïve portfolios. The ex‐ante complete futures portfolio dominates the traditional and naive portfolios and the ex‐post portfolio outperforms the naïve portfolio. The instability between the ex‐ante and ex‐post results is primarily driven by the time‐varying returns of the individual assets rather than by risk. Finally, the Sharpe portfolio results are essentially identical to the Markowitz results. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark 33:343‐368, 2013
Cyclin E1 controls proliferation of hepatic stellate cells and is essential for liver fibrogenesis in mice
Authors: Nevzorova Yulia A. , Bangen Jörg-Martin , Hu Wei , Haas Ute , Weiskirchen Ralf , Gassler Nikolaus , Huss Sebastian , Tacke Frank , Sicinski Piotr , Trautwein Christian , Liedtke Christian
Published: March 2012

Liver fibrogenesis is associated with the transition of quiescent hepatocytes and hepatic stellate cells (HSCs) into the cell cycle. Exit from quiescence is controlled by E-type cyclins (cyclin E1 [CcnE1] and cyclin E2 [CcnE2]). Thus, the aim of the current study was to investigate the contribution of E-type cyclins for liver fibrosis in man and mice. Expression of CcnE1, but not of its homolog, CcnE2, was induced in fibrotic and cirrhotic livers from human patients with different etiologies and in murine wild-type (WT) livers after periodical administration of the profibrotic toxin, CCl4. To further evaluate the potential function of E-type cyclins for liver fibrogenesis, we repetitively treated constitutive CcnE1−/− and CcnE2−/− knock-out mice with CCl4 to induce liver fibrosis. Interestingly, CcnE1−/− mice were protected against CCl4-mediated liver fibrogenesis, as evidenced by reduced collagen type I α1 expression and the lack of septum formation. In contrast, CcnE2−/− mice showed accelerated fibrogenesis after CCl4 treatment. We isolated primary HSCs from WT, CcnE1−/−, and CcnE2−/− mice and analyzed their activation, proliferation, and survival

in vitro
. CcnE1 expression in WT HSCs was maximal when they started to proliferate, but decreased after the cells transdifferentiated into myofibroblasts. CcnE1−/− HSCs showed dramatically impaired survival, cell-cycle arrest, and strongly reduced expression of alpha smooth muscle actin, indicating deficient HSC activation. In contrast, CcnE2-deficient HSCs expressed an elevated level of CcnE1 and showed enhanced cell-cycle activity and proliferation, compared to WT cells.

Conclusions
: CcnE1 and CcnE2 have antagonistic roles in liver fibrosis. CcnE1 is indispensable for the activation, proliferation, and survival of HSCs and thus promotes the synthesis of extracellular matrix and liver fibrogenesis.
Multicultural Training Intervention to Address American Indian Stereotypes
Authors: Steinfeldt Jesse A. , Steinfeldt Matthew Clint
Published: March 2012

This article describes a multicultural training intervention that addresses American Indian stereotypes perpetuated through the use of American Indians and corresponding imagery as mascots by schools and athletic teams. With the Association for Multicultural Counseling and Development's tripartite model of multicultural competence (awareness, knowledge, skills) as a framework, this intervention's description is organized into three components: perspective‐taking to facilitate awareness of attitudes about Native‐themed mascots, specific knowledge about race‐based mascots, and social justice skills that can empower counselors to become advocates for change. This training intervention can help counseling programs provide enhanced multicultural competency training on issues salient to American Indian communities.
The Presentation of Self in Letters of Application: A Mixed‐Method Approach
Authors: Soroko Emilia
Published: March 2012

The application letter, as the first phase of employment‐seeking, is an opportunity for a job applicant to make a favorable impression on a potential employer. In the current study, the author used a mixed‐method approach to empirically explore strategies for self‐presentation in job application letters and determine the methods used in the letters and their lexical content. An array of self‐presentation strategies, both structural (relating to the formal aspect of the letters) and tactical (involving specific tactics or strategies), were identified and discussed. Job candidates’ self‐evaluation strategies in application letters may contribute to a more accurate assessment of interpersonal and intrapersonal competencies. The results suggest that lexical and meaning levels of analysis in letters of application should be treated as distinct.
Unemployed Adults’ Career Thoughts, Career Self‐Efficacy, and Interest: Any Similarity to College Students?
Authors: Bullock‐Yowell Emily , Andrews Lindsay , McConnell Amy , Campbell Michael
Published: March 2012

Little empirical knowledge about unemployed adults exists during a time when this group needs substantial career assistance. Because there is greater empirical understanding of college student career development compared with what is known about unemployed adults, a chi square and analyses of covariance were used to compare the career thinking, self‐efficacy, and interests of 169 unemployed adults seeking public job center assistance with that of 200 college students. Additionally, a diverse sample of 2,444 unemployed adults is demographically reviewed. Unemployed adults reported a higher level of Realistic interests and similar levels of negative career thinking and career decision‐making self‐efficacy compared with college students.
Eliminating the scattering ambiguity in multifocal, multimodal, multiphoton imaging systems
Authors: Hoover Erich E. , Field Jeffrey J. , Winters David G. , Young Michael D. , Chandler Eric V. , Speirs John C. , Lapenna Jacob T. , Kim Susy M. , Ding Shi‐you , Bartels Randy A. , Wang Jing W. , Squier Jeff A.
Published: March 2012

In this work we present how to entirely remove the scattering ambiguity present in existing multiphoton multifocal systems. This is achieved through the development and implementation of single‐element detection systems that incorporate high‐speed photon‐counting electronics. These systems can be used to image entire volumes in the time it takes to perform a single transverse scan (four depths simultaneously at a rate of 30 Hz). In addition, this capability is further exploited to accomplish single‐element detection of multiple modalities (two photon excited fluorescence and second harmonic generation) and to perform efficient image deconvolution. Finally, we demonstrate a new system that promises to significantly simplify this promising technology. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wear of ceramic‐on‐carbon fiber‐reinforced poly‐ether ether ketone hip replacements
Authors: Brockett Claire L. , John Gemma , Williams Sophie , Jin Zhongmin , Isaac Graham H. , Fisher John
Published: March 2012

Total hip replacement has been a successful surgical intervention for over 50 years, with the majority of bearings using a polyethylene cup. Long‐term failure due to osteolysis and loosening has been widely documented and alternative bearings have been sought. A novel carbon fiber‐reinforced poly‐ether ether ketone (CFR‐PEEK) cup was investigated through experimental friction and wear studies. Friction studies demonstrated the bearings operated in a boundary lubrication condition, with friction factors higher than those for other hip replacement bearings. The wear study was conducted with 36 mm diameter bearings tested against Biolox Delta heads for a period of 10 million cycles. The mean volumetric wear rate was 0.3 mm3/Mc, indicating the ceramic‐on‐CFR‐PEEK bearing to be a very low wearing option for total hip replacement. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 1459–1465, 2012.
Nickel/Poly(o‐aminophenol) Film Prepared in Presence of Sodium Dodecyl Sulfate: Application for Electrocatalytic Oxidation of Carbohydrates
Authors: Ojani Reza , Raoof Jahan‐Bakhsh , Fathi Shahla
Published: March 2012

Poly(o‐aminophenol) (POAP) was formed by successive cyclic voltammetry in monomer solution in the presence of sodium dodecyl sulfate (SDS) on the surface of a carbon paste electrode (CPE). Ni(II) ions were incorporated into the electrode by immersion of the polymeric modified electrode having amine groups in 0.1 M Ni(II) ion solution. Electrochemical study of this modified electrode shows a good redox behavior of the Ni(III)/Ni(II) couple. The electrocatalytic oxidations of glucose and other carbohydrates at the surface of the Ni/SDS‐POAP/CPE were studied in a 0.1 M NaOH solution. Compared to POAP/CPE, the SDS‐POAP/CPE significantly enhanced the catalytic efficiency of Ni ions for carbohydrates oxidation. Finally, using chronoamperometric method, the catalytic rate constants (k) for carbohydrates were calculated.
Synthesis and Esterification of 3‐Ferrocenyl Acrylic Acid in Ionic Liquid
Authors: Zhang Wen‐Sheng , Xu Wen‐Jing , Zhang Fei , Wang Yu‐Zhe , Li Jun , Wang Bao‐An , Li Yan
Published: March 2012

3‐Ferrocenyl acrylic acid, synthesized from ferrocenecarboxaldehyde and propandioic acid in water‐insoluble ionic liquid (1‐butyl‐3‐methylimidazolium hexafluorophosphate, [BMIM]PF6) at 85 °C in high yield, was transformed to a series of 3‐ferrocenyl acrylate of alcohols and phenols in water‐soluble ionic liquid (1,3‐dimethylimidazolium dimethylphosphate, [DMIM]Me2PO4) at room temperature in the presence of dicyclohexylcarbodiimide (DCC) and 4‐dimethylaminopyridine (DMAP).
Solid Phase Extraction of Trace Amounts of Cadmium with Cetyltrimethylammonium Bromide‐Coated Magnetic Nanoparticles Prior to Its Determination by Flame Atomic Absorption Spectrometry
Authors: Baghban Neda , Haji Shabani Ali Mohammad , Dadfarnia Shayessteh
Published: March 2012

A solid‐phase extraction (SPE) method has been presented for the selective separation and preconcentration of trace amounts of cadmium using cetyltrimethylammonium bromide (CTAB)‐coated Fe3O4 nanoparticles (NPs). The method is based on the sorption of cadmium as CdI42− complex on the positively charged surface of the CTAB‐coated Fe3O4 NPs. The preconcentrated cadmium is then desorbed from the surface of the sorbent and is determined by flame atomic absorption spectrometry. The influences of the experimental parameters including pH of the solutions, amount of surfactant, iodide concentration, sample volume, eluent type and volume on the recovery of the analyte ions were investigated. Under the optimum conditions by the extraction of 500 mL of aqueous samples, a preconcentration factor of 250 was achieved. The detection limit (3s) was 0.06 μg L−1, and the relative standard deviations at 0.5 and 5 μg L−1 levels of cadmium (n = 10) were 3.2 and 1.9% respectively. The proposed method was successfully applied to the determination of cadmium in water samples. The accuracy was evaluated through the recovery experiments and independent analysis by the graphite furnace atomic absorption spectrometry (GFAAS).
New Synthesis and Magnetic Properties of NiFe2O4/SiO2 and Co0.5Zn0.5Fe2O4/SiO2 Nanocomposites Using Tetraglycolatosilane as Precursor
Authors: Gharagozlou Mehrnaz
Published: March 2012

In this work the new synthesis and magnetic properties of NiFe2O4/SiO2 and Co0.5Zn0.5Fe2O4/SiO2 nanocomposites using a water‐soluble silica precursor, tetraglycolatosilane (THEOS), by the sol‐gel method were reported. Nanocomposite were obtained by the thermal decomposition of the organic part at different annealing temperatures varying from 400 to 900 °C. Studies carried out using XRD, FT‐IR, TEM, STA (TG‐DTG‐DTA) and VSM techniques. XRD patterns show that NiFe2O4 and Co0.5Zn0.5Fe2O4 have been formed in an amorphous silica matrix at annealing temperatures above 600 and 400 °C, respectively. It is found that when the annealing temperature is up to 900 °C NiFe2O4/SiO2 and Co0.5Zn0.5Fe2O4/SiO2 samples show almost superparamagnetic behavior with a magnetization 4.66 emu/g and ferromagnetic behavior with a magnetization 10.11 emu/g, respectively. The magnetization and coercivity values of nanocomposites using THEOS were considerably less than previous reports using TEOS. THEOS as a silica matrix network provides an ideal nucleation environment to disperse ferrite nanoparticles and thus to confine them to aggregate and coarsen. By using THEOS over the currently used TEOS and TMOS, organic solvents are not needed due to the entire solubility of THEOS in water. Synthesized nanocomposites with adjustable particle sizes and controllable magnetic properties make the applicability of ferrites even more versatile.
Electrodeposited Cu‐Au Alloy Nanoparticles for Uric Acid Electrochemical Biosensor with Quick Response
Authors: Zhang Hongfang , He Yaping , Zheng Jianbin
Published: March 2012

A uric acid (UA) electrochemical biosensor based on the Cu‐Au alloy nanoparticles (NPs) and uricase was developed. The electrodeposition technique of Cu‐Au alloy NPs was selected to be a convenient potentiostatic method at –0.8 V in a single solution containing both Au(III) and Cu2+. Cyclic voltammetry and scanning electron microscopy proved the successful deposition of Cu‐Au alloy NPs. EIS demonstrated the good conductivity of Cu‐Au alloy NPs. The enzyme was immobilized on the surface of Cu‐Au alloy NPs modified electrode by casting with chitosan solution. The ultimate biosensor showed linear amperometric response towards UA in the concentration range of 3.0 to 26.0 μM with a detection limit of 0.8 μM. The main feature of the biosensor was its short response time, which was attributed to the good conductivity of Cu‐Au alloy NPs. Furthermore, the biosensor could avoid the interference of ascorbic acid and oxygen.
DETERMINANTS OF CREDIT UNION SAVINGS IN GHANA
Authors: Adusei Michael
Published: March 2012

The study explores the determinants of credit union (CU) savings in Ghana and finds that credit risk, assets (size) and female membership are significant determinants of CU savings. Whereas a rise in CU credit risk increases CU savings, a rise in female membership as well as CU assets is characterised by a fall in CU savings. The study, therefore, argues that CUs in Ghana could maximise their savings if they target their savings‐ mobilisation campaigns at income‐earning men with higher marginal propensity to save coupled with the adoption of an effective and efficient asset management policy. Copyright © 2012 John Wiley & Sons, Ltd.
Emotional intelligence and resilience as predictors of leadership in school administrators
Authors: Maulding Wanda S. , Peters Gary B. , Roberts Jalynn , Leonard Edward , Sparkman Larry
Published: March 2012

This mixed‐method study of 48 P–12 school administrators across three southeastern states was done to begin investigation of the impact of nontraditional leadership factors. As evidenced by the results, there is a strong correlation between the factors of emotional intelligence and resilience and leadership success.
Leadership, governance, and perceptions of trust in the higher education industry
Authors: Migliore Laura‐Ann
Published: March 2012

This article presents a trust‐centered, integrated model for achieving educational excellence in the higher education industry with focus on governing boards and strategies for academic quality and financial performance. The discussion includes leadership themes and strategies on development of teacher‐leaders, creating a culture of shared leadership and effective governance for performance outcomes, robust evaluations of student‐learning assessments for continuous improvement, and strategic leadership in the implementation of high‐quality programs. Perceptions of trust form the foundation of the integrated model with influences of personality, culture, motivation, values, reliability, competence, and intuition. Trust among board trustees is essential for creating collaborative environments for innovative change and educational performance excellence. Collaborative environments promote a sense of shared leadership and governance to encourage innovation and performance excellence at all levels within the educational institution.
Symposium Introduction
Authors: Johnston Elizabeth , Kortens Anthony , Schonhofen Michael , Ben
Published: March 2012

This symposium's focus is on connections that might be forged between leadership theory and practice, leadership development, and the theory and practice of design. Our intent in exploring the narratives of and literature about designers is to understand and appreciate how the design leadership crucible might forge more effective research approaches, generative pedagogical experience, and produce more effective leaders who can address adaptive problems. The guest editors and authors for the symposium are Elizabeth Johnston and Anthony Kortens. The symposium includes an introduction to the topic of design using current literature, incorporating a report on a series of conversations with two individuals who have enjoyed long and successful careers in design and leadership. These individuals, Michael Schonhofen and Ben Shaw, were contributing partners who shared their experiences as designers and leaders, as well as tirelessly reviewed the symposium documents and offered insights, interpretations, and suggestions.
Anti‐integrase abzymes from the sera of HIV‐infected patients specifically hydrolyze integrase but nonspecifically cleave short oligopeptides
Authors: Odintsova Elena S. , Baranova Svetlana V. , Dmitrenok Pavel S. , Calmels Christina , Parissi Vincent , Andreola Marie‐Line , Buneva Valentina N. , Nevinsky Georgy A.
Published: March 2012

In contrast to canonical proteases, total immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies (Abs) from HIV‐infected patients hydrolyze effectively only HIV integrase (IN), reverse transcriptase (RT), human casein, and serum albumin. Anti‐IN IgG and IgM isolated by chromatography on IN‐Sepharose hydrolyze specifically only IN but not many other tested proteins. Total Abs from HIV‐infected patients hydrolyze not only globular proteins but also different specific and nonspecific tri‐, tetra‐, and 20‐ to 25‐mer oligopeptides (OPs) with a higher rate than anti‐IN Abs isolated using IN‐Sepharose. A similar situation was observed for IgG from patients with multiple sclerosis and HIV‐infected patients, which after purification on myelin basic protein (MBP)–Sepharose and RT‐Sepharose specifically hydrolyze only MBP and RT, respectively. The active sites of all anti‐protein abzymes are localized on their light chains, whereas the heavy chain is responsible for the affinity of protein substrates. Interactions of intact globular proteins with both light and heavy chains of abzymes provide the specificity of protein hydrolysis. The affinity of anti‐IN and anti‐MBP abzymes for intact IN and MBP is approximately 102‐ to 105‐fold higher than for short and long specific and nonspecific OPs. The data suggest that all OPs interact mainly with the light chain of different Abs, which possesses a lower affinity for substrates, and therefore, depending on the OP sequences, their hydrolysis may be less specific or completely nonspecific. The data indicate that the relative activity of Abs not fractionated on specific protein sorbents in the hydrolysis of specific and nonspecific OPs can correspond to an average proteolytic activity of light chains of polyclonal Abs directed against many different proteins. Copyright © 2012 John Wiley & Sons, Ltd.
The reactivity of human serum albumin toward trans‐4‐hydroxy‐2‐nonenal
Authors: Liu Qingyuan , Simpson David C. , Gronert Scott
Published: March 2012

Mass spectrometry was used to probe the preferred locations of trans‐4‐hydroxy‐2‐nonenal (HNE) addition to the cysteine, histidine, and lysine residues of human serum albumin (HSA). Considering only those modified peptides supported by high mass accuracy Orbitrap precursor ion measurements (high confidence hits), with HNE:HSA ratios of 1:1 and 10:1, 3 and 15 addition sites, respectively, were identified. Using less stringent criteria, a total of 34 modifications were identified at the higher concentration. To gain quantitative data, iTRAQ labeling studies were completed. Previous work had identified Cys34, the only free cysteine, as the most reactive residue in HSA, and we have found that Lys199, His242/7, and His288 are the next most reactive residues. Although the kinetic data indicate that the lysines and histidines can react at relatively similar rates, the results show that lysine addition is much less favorable thermodynamically; under our reaction conditions, lysine addition generally does not go to completion. This suggests that under physiological conditions, HNE addition to lysine is only relevant in situations where unusually high HNE concentrations or access to irreversible secondary reactions are found. Copyright © 2012 John Wiley & Sons, Ltd.
Heparin Interacting Protein Mediated Assembly of Nano‐Fibrous Hydrogel Scaffolds for Guided Stem Cell Differentiation
Authors: Tan Huaping , Zhou Qixin , Qi Haifeng , Zhu Dan , Ma Xiaoxue , Xiong Dangsheng
Published: March 2012

A new methodology is developed to conjugate hyaluronic acid (HA) hydrogel with novel nano‐fibrous architectures via non‐covalent assembly that specifically allows for targeted adipose‐derived stem cells (ASCs) differentiation and soft tissue engineering. The assembly of non‐covalently associated hydrogel network produced via the interaction of a low molecular weight heparin (LMWH) modified HA derivative and heparin interacting protein (HIP). The multifunctional star poly(ethylene glycol) (PEG) and HIP copolymer has the capability to mediate the non‐covalent assembly of nano‐fibrous HA hydrogel networks via affinity interactions with LMWH. The effect of the HIP mediation on in vitro gelation, rheological characteristics, degradation, equilibrium swelling, adipose‐derived stem cells (ASCs) proliferation and differentiation of nano‐fibrous hydrogel is examined. The results suggest the potential utility of this unique design of the bioactive nano‐fibrous HA hydrogel in directing the differentiation of ASCs and adipogenesis in ECM‐mimetic scaffolds in vitro. These studies demonstrate that this nano‐fibrous HA hydrogel can render the formulation of a therapeutically effective platform for in vitro adipogenesis applications.

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Conducting Metallopolymers as Precursors to Fabricate Palladium Nanoparticle/Polymer Hybrids for Oxygen Reduction
Authors: Edelman Kate R. , Stevenson Keith J. , Holliday Bradley J.
Published: March 2012

The novel conducting metallopolymer [N,N′‐((2,2′‐dimethyl)propyl)bis(5‐(2,2′‐bithiophene‐5‐yl)salcylideniminato‐palladium(II)]n prepared by electropolymerization provides a polymer matrix in which the palladium metal centers are evenly distributed. The metal centers embedded directly in the conducting metallopolymer backbone serve as seed points for size‐controlled palladium nanoparticle (NP) growth of 3.8 to 4.9 nm NPs within the conducting metallopolymer film. The palladium NP/conducting metallopolymer hybrid material has demonstrated electrocatalytic behavior toward oxygen reduction with peak current densities around 400 μA/cm2 in acidic aqueous conditions. These results demonstrate a promising new method for the production of electrocatalytically active hybrid materials.
Human mitochondrial ferritin improves respiratory function in yeast mutants deficient in iron–sulfur cluster biogenesis, but is not a functional homologue of yeast frataxin
Authors: Sutak Robert , Seguin Alexandra , Garcia‐Serres Ricardo , Oddou Jean‐Louis , Dancis Andrew , Tachezy Jan , Latour Jean‐Marc , Camadro Jean‐Michel , Lesuisse Emmanuel
Published: March 2012

We overexpressed human mitochondrial ferritin in frataxin‐deficient yeast cells (Δyfh1), but also in another mutant affected in [Fe‐S] assembly (Δggc1). Ferritin was correctly processed and expressed in the mitochondria of these cells, but the fraction of total mitochondrial iron bound to ferritin was very low, and most of the iron remained in the form of insoluble particles of ferric phosphate in these mitochondria, as evidenced by gel filtration analysis of the mitochondrial matrix (fast protein liquid chromatography [FPLC]) and by Mössbauer spectroscopy. Mutant cells in which ferritin was overexpressed still accumulated iron in the mitochondria and remained deficient in [Fe‐S] assembly, suggesting that human mitochondrial ferritin is not a functional homologue of yeast frataxin. However, the respiratory function was improved in these mutants, which correlates with an improvement of cytochrome and heme synthesis. Overexpression of mitochondrial ferritin in [Fe‐S] mutants resulted in the appearance of a small pool of high‐spin ferrous iron in the mitochondria, which was probably responsible for the improvement of heme synthesis and of the respiratory function in these mutants.
Zinc‐responsive coactivator recruitment by the yeast Zap1 transcription factor
Authors: Frey Avery G. , Eide David J.
Published: March 2012

The zinc‐responsive Zap1 transcription factor of Saccharomyces cerevisiae controls many genes involved in zinc homeostasis. Zap1 has two activation domains, AD1 and AD2, which are independently regulated by zinc. While AD1 can fully activate most Zap1 target genes, AD2 is active only on a subset of those genes. One hypothesis explaining this promoter specificity was that AD1 and AD2 recruit different coactivators. To address this question, we carried out a genetic screen to identify coactivator complexes that are required for Zap1‐mediated activation. SWI/SNF, SAGA, and Mediator complexes were implicated as playing major roles in Zap1 activation. Consistent with this conclusion, we found that these three complexes are recruited to Zap1 target promoters in a zinc‐responsive and Zap1‐dependent manner. Coactivator recruitment was highly interdependent such that mutations disrupting SAGA impaired recruitment of SWI/SNF and vice versa. Optimal Mediator recruitment was dependent on both SAGA and SWI/SNF. A comparison of the coactivators recruited by AD1 and AD2 found no obvious differences suggesting that recruitment of different coactivators is not likely the mechanism of AD specificity. Rather, our results suggest that AD2 recruits coactivators less effectively than AD1 and is therefore only functional on some promoters.
Hysteresis in the electromyography–force relationship: Toward an optimal model for the estimation of force
Authors: Kamavuako Ernest Nlandu , Rosenvang Jakob Celander
Published: March 2012

Introduction:

In this study we analyzed the presence of hysteresis in the relationship between features of electromyography (EMG) and force.

Methods:

Intramuscular EMG and surface EMG (sEMG) were recorded concurrently from the flexor digitorum profundus muscle from 0% to 100% maximum voluntary contraction (MVC) in 11 subjects. Two features, mean absolute value (MAV) and Wilson amplitude (WAMP), were computed using either the first‐order (poly1) or third‐order (poly3) polynomial.

Results:

We detected hysteresis in the EMG–force relationship for both features in all subjects. In general, the hysteresis‐based models performed better than the overall model (which does not take into account the hysteresis in the EMG–force relationship), with R2 values about 0.98 (averaged across subjects) and root mean square error around 5% of the MVC force.

Conclusion:

These results imply the existence of a path‐dependent model, which may improve the accuracy of force estimation. Muscle Nerve, 2012
Comparison of kinetic models for analysis of pyruvate‐to‐lactate exchange by hyperpolarized 13C NMR
Authors: Harrison Crystal , Yang Chendong , Jindal Ashish , DeBerardinis Ralph J. , Hooshyar M. A. , Merritt Matthew , Dean Sherry A. , Malloy Craig R.
Published: March 2012

The activity of specific enzyme‐catalyzed reactions may be detected in vivo by 13 C NMR of hyperpolarized (HP) substrates. The signals from HP substrates and products, acquired over time, have been fitted to a number of different mathematical models to determine fluxes, but these models have not been critically compared. In this study, two‐pool and three‐pool first‐order models were constructed to measure flux through lactate dehydrogenase in isolated glioblastoma cells by NMR detection of lactate and pyruvate following the addition of HP [1‐13C]pyruvate. Mass spectrometry (MS) was used to independently monitor 13 C enrichment in intra‐ and extracellular lactate. Six models were evaluated using time‐dependent pyruvate C2 and lactate C1 HP NMR data acquired by the use of selective excitation pulses, plus 13 C enrichment data from intracellular and extracellular lactate measured by MS. A three‐pool bidirectional model provided the most accurate description of pyruvate metabolism in these cells. With computed values for T1 of pyruvate and lactate, as well as the effect of pulsing, the initial flux through lactate dehydrogenase was well determined by both the two‐pool bidirectional and unidirectional models when only HP data were available. The three‐pool model was necessary to fit the combined data from both MS and HP, but the simpler two‐pool exchange model was sufficient to determine the 13 C lactate concentration when the lactate appearance was measured only by HP. Copyright © 2012 John Wiley & Sons, Ltd.
Gift giving and social emotions: experience as content
Authors: Chakrabarti Ronika , Berthon Pierre
Published: March 2012

The purpose of this paper is to employ an extended notion of gift giving by showing that much of the gifts exchanged in social media are driven by social emotions. We argue that consumers have migrated from the production of services to the production of experiences and that, in social media, the primary experience of value is emotion. Web 2.0 is markedly different compared with its predecessor Web 1.0, in that it empowered social media, the fastest growing phenomenon on the Internet to occur; yet people are struggling to make money from it. Much value is created and exchanged, but most of it escapes monetization. Whereas, consumption on Web 1.0 was mostly goal‐oriented, rational, and functional, consumption on Web 2.0 is exploratory, idiosyncratic, and social. Traditional economic paradigms of market exchange have struggled to explain consumer behavior in this new dispensation: most exchange is ‘free’. So the question is, what is the currency and motivation driving social relations in Web 2.0? We argue that it is gifts and social emotions. We develop a circumplex of social emotions and show how different organizations utilize these emotions to archive their objectives. Implications for managers and researchers are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
A crisis of public affairs in Europe?
Authors: Schepers Stefan
Published: March 2012

Public affairs, in relation to European governance system, checks and balances between country interests and public affairs operations at different levels of governance. Copyright © 2012 John Wiley & Sons, Ltd.
Cellular apoptosis susceptibility (chromosome segregation 1‐like, CSE1L) gene is a key regulator of apoptosis, migration and invasion in colorectal cancer
Authors: Alnabulsi Ayham , Agouni Abdelali , Mitra Suman , Garcia‐Murillas Isaac , Carpenter Brian , Bird Steve , Murray Graeme I
Published: March 2012

Cellular apoptosis susceptibility (chromosome segregation 1‐like, CSE1L) gene maps to chromosomal region 20q13.13, a region frequently amplified in solid tumours. In this study, we investigated the roles played by CSE1L in colorectal cancer by examining CSE1L expression and clinico‐pathological parameters in colorectal cancer and investigating the effect of CSE1L on the viability, adhesion and migration of colorectal cancer cells. RT‐PCR showed that CSE1L mRNA was over‐expressed in colorectal cancer. CSE1L depletion by knock‐down with CSE1L‐specific siRNA significantly reduced viability in HCT116 cells (p = 0.004) and SW480 cells (p = 0.003) whilst significantly increasing the proportion of apoptotic HCT116 cells (p < 0.001) and SW480 cells (p < 0.001). Furthermore, CSE1L depletion significantly reduced the adhesive capacity of HCT116 (p = 0.003) and SW480 cells (p = 0.004). Analysis by qRT‐PCR following CSE1L siRNA treatment of HCT116 and SW480 cells showed significant modulation of key apoptotic (p53, p73 and BAK) and adhesive (E‐cadherin, Ep‐CAM and ICAM‐1) molecules. Immunohistochemistry of a colorectal cancer tissue microarray showed that CSE1L had a significantly increased level in colorectal cancer compared to normal colorectal epithelium (p < 0.001). There were significant decreases in both nuclear (p = 0.006) and cytoplasmic (p = 0.003) staining of CSE1L in tumours with lymph node metastasis (stage 3 tumours) compared with lymph node‐negative tumours (stage 1 and 2 tumours). In lymph node‐negative patients, poor survival was associated with increased CSE1L cytoplasmic expression (p = 0.042). These results indicate that CSE1L is associated with viability and apoptosis, cellular adhesion and invasion, thus implicating CSE1L in the progression of colorectal cancer. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The CREB–Smad6–Runx2 axis contributes to the impaired osteogenesis potential of bone marrow stromal cells in fibrous dysplasia of bone
Authors: Fan Qi‐Ming , Yue Bing , Bian Zhen‐Yu , Xu Wen‐Ting , Tu Bing , Dai Ke‐Rong , Li Gang , Tang Ting‐Ting
Published: March 2012

Fibrous dysplasia (FD) is characterized by the replacement of normal bone with abnormal fibro‐osseous tissue. This disorder is due to activating missense mutations in the GNAS gene and resultant over‐production of cAMP. However, the signalling pathways that contribute to FD pathogenesis remain unknown. In the current study, bone marrow stromal cells (BMSCs) carrying GNAS R201H mutation were isolated from lesion site of FD patients. cAMP accumulation, enhanced proliferation and impaired osteogenesis potential were observed. Two cell models, BMSCs treated with excess exogenous cAMP and BMSCs infected with lentivirus GNAS R201H, were established to model the pathological conditions of FD and used to investigate its pathogenesis. The results suggest that the CREB‐Smad6‐Runx2 axis is involved in osteogenesis dysfunction of BMSCs with the FD phenotype. We confirmed the results in FD lesion‐derived BMSCs and observed that the impaired osteogenesis potential of BMSCs infected with lentivirus GNAS (R201H) was recovered in vitro through modulation of the CREB‐Smad6‐Runx2 axis. This study provides useful insight into the signalling pathways involved in the FD phenotype and facilitates dissection of the molecular pathogenesis of FD and testing of novel therapies. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Modeling viscoelastic secondary flows in three‐dimensional noncircular ducts
Authors: Holmes Lori T. , Fávero Jovani L. , Osswald Tim A.
Published: March 2012

As process capabilities become more advanced, the need to predict flow phenomena at a smaller scale increases significantly. Viscoelastic secondary flows in square ducts were simulated using a finite volume approach. Single mode and multimode Giesekus and Phan‐Thien Tanner (PTT) models were implemented and were able to reproduce full three‐dimensional (3D) flow through a square duct. Results for low density polyethylene (LDPE), polystyrene, and polycarbonate are all in agreement with experiments [Dooley, Viscoelastic flow effects in multilayer polymer coextrusion, PhD Thesis, Technische Universiteit Eindhoven (2002)] as well as numerical results using a finite element method (FEM) and a meshless radial function method (RFM), [Lopez et al.,SPE ANTEC Tech. Pap.(2010)]. The mathematical model presented here has shown the potential to model full 3D flow in more complex geometries. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Phase inversion composition and domain identification by energy dispersive spectroscopy in immiscible blends of poly(trimethylene terephthalate) and polyamide6,10
Authors: Giancola Giorgiana , Lehman Richard L. , Miller Steve
Published: March 2012

Immiscible blends were prepared from polyamide6,10 and poly(trimethylene terephthalate) by extrusion with the goal of identifying the phase inversion composition and domain morphology. Broadly, we studied this system to develop new polymer blends with good engineering properties combined with a high bio‐based fraction. Earlier work has demonstrated that the polymers are suitable for melt coprocessing. In this work, we sought to bracket the phase inversion composition, to identify any elements of cocontinuity, and to characterize the domain morphology by a traditional and a novel means. After extrusion of a full range of compositions, the morphologies in the 40–60 vol% range appeared to coarsely bracket the phase inversion point and compositions in this range were selected for detailed microscopic examination. High resolution energy dispersive spectroscopy (EDS) was used to differentiate these chemically similar polymers based on the nitrogen content of the polyamide. Results show elements of cocontinuity appearing at the 50 vol% composition. The EDS mapping techniques employed in this work were successful in sharply differentiating the domains of the two polymers. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Calculation of quantitative shunt values using photoluminescence imaging
Authors: Augarten Yael , Trupke Thorsten , Lenio Martha , Bauer Jan , Weber Juergen W. , Juhl Matthias , Kasemann Martin , Breitenstein Otwin
Published: March 2012

A proof of concept study for a method of determining quantitative shunt values in silicon solar cells from photoluminescence images is presented. The method is based on interpretation of the luminescence intensity around a local shunt or recombination‐active defect in terms of the extracted current. The theoretical relationship between the photoluminescence signal and the shunt current is derived. Experimental results on specifically prepared test structures show good agreement with known shunt resistance values. Experimental data on diffused wafers are presented. The effect of the front metallisation in complete cells on the appearance and interpretation of shunts in photoluminescence images is investigated experimentally. The limitations of the method are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Fear of recurrence among head and neck cancer survivors: longitudinal trends
Authors: Ghazali Naseem , Cadwallader Ella , Lowe Derek , Humphris Gerry , Ozakinci Gozde , Rogers Simon N.
Published: March 2012

Background

Fear of recurrence (FoR) following head and neck cancer (HNC) treatment is a major patient concern but is infrequently discussed in outpatient settings and may cause significant detrimental effect on patient psychological well‐being.

Aim

The aim of this paper is to determine longitudinal trends and predictors of significant FoR.

Method

Prospective data collection was obtained in 189 post‐treatment HNC patients with 456 clinic attendances from October 2008 to January 2011. All patients completed Patient Concerns Inventory (PCI), University of Washington Quality of Life Questionnaire version 4 and the FoR questionnaires using a combination of paper and touch‐screen technology.

Results

The prevalence of significant FoR was 35%, which was stable longitudinally. Logistic regression‐delineated predictors of significant FoR were young age (<65 years), anxiety/mood and patient‐reported FoR. Conventional prognostic factors including standard clinicopathological factors, treatment modality and length of follow‐up did not predict significant FoR. Over time, 20% of patients reported significant FoR intermittently, whereas 30% experienced it consistently. The remaining 50% did not experience significant FoR.

Discussion

Patient‐related characteristics were more important than clinicopathological prognostic factors in predicting significant FoR, potentially creating a mismatch between the doctors' perception of patient's experience of FoR with what patients may experience. In the long term, FoR is expressed across a spectrum extending from ‘normal’ FoR to persistent significant FoR with an intermediate category of intermittent significant FoR. Those patients experiencing intermittent and consistent levels of significant FoR may benefit from psychological support. This study confirmed that self‐reported screening FoR using the PCI is a valuable tool in identifying significant FoR. Copyright © 2012 John Wiley & Sons, Ltd.
Comments on ‘Application of an adaptive design to a randomized phase II selection trial in gastric cancer: a report of the study design’ by Satoshi Morita and Junichi Sakamoto. Pharmaceutical Statistics
Authors: Hossain Md Monir , Chen Zhongxue
Published: March 2012

In this commentary, we show that the treatment selection probabilities in Morita and Sakamoto [1] could be different if safety information is considered. Copyright © 2012 John Wiley & Sons, Ltd.