bluuebunny/crossref_metadata_2025 huggingface dataset:
Model Order Reduction and Error Estimation for the Parameter‐Dependent Eddy Current Equation
Authors: Jung Nadine
Published: December 2011

In design optimization many simulations are performed of the same physical phenomena. Using model order reduction methods these physical phenomena can be efficiently computed for various geometries, but there is an error compared to the full order solution. This error is estimated by error estimators in different norms. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Invariance Entropy
Authors: Kawan Christoph
Published: December 2011

In this paper, the concept of invariance entropy for continuous‐time control systems is introduced. This quantity measures the minimal data rate necessary to render a compact subset of the state space invariant by a coder‐controller device. Invariance entropy is an intrinsic quantity of the open‐loop system and shares several properties with the classical entropy quantities in the field of dynamical systems. Some of these properties, in particular relations to Lyapunov exponents, are pointed out. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Integrated design and optimization of a complex nonlinear hybrid electric powertrain including simulations in time domain
Authors: Marx Matthias , Sacher Oliver , Söffker Dirk
Published: December 2011

This paper deals with the design and optimization of hybrid electric powertrains. Therefore basic relations of the behavior of hybrid electric powertrain systems and the controller design are introduced. Based on models of typical hybrid electric system components principal optimization approaches with respect to performance parameters like efficiency, availability, lifetime, etc. are shown. Hereby an optimization algorithm based on a global optimization technique is applied. Using the example of a fuel cell based hybrid electric powertrain system the approaches are introduced and compared to each using time‐domain simulations integrated in optimization algorithms. The results show that both approaches are appropriate to design the system as well as the controllers. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Feedforward Control for a Non‐Uniform Euler‐Bernoulli Beam
Authors: Meurer Thomas , Schröck Johannes , Kugi Andreas
Published: December 2011

Flatness‐based motion planning is considered for an Euler‐Bernoulli beam with viscous damping by introducing a systematic spectral approach, which is based on the Riesz spectral properties of the system operator. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Frequency compensation for a class of DAE's arising in electrical circuits
Authors: Hennig Eckhard , Krauße Dominik , Schäfer Eric , Sommer Ralf , Trunk Carsten , Winkler Henrik
Published: December 2011

Structured perturbations of regular pencils of the form $sE-A,E,A \in {\rm I\!R}^{n\times n},\; s \in {\rm I\!\!\!C}$, are considered which model the addition of a capacitance c in an electrical circuit in order to improve the frequency response. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Control Strategy of Hardware‐in‐the‐Loop Simulator EPOS 2.0 for Autonomous Docking Verification
Authors: Zebenay Melak , Lampariello Roberto , Boge Toralf , Krenn Rainer
Published: December 2011

This paper briefly describes the hybrid simulator system called European Proximity Operation Simulator (EPOS 2.0) and the development of the hardware‐in‐the‐loop (HIL) docking simulation concept. A critical requirement for the docking simulation of this HIL simulator is that the 6‐DOF robots in the loop have to exactly mimic the dynamic response of the two satellites during a contact operation. The main challenges to meet this requirement are in the stiffness of the robots, which is unlike that of the satellites, as well as the time delay in the HIL simulator. The paper mainly presents the impedance parameter identification concept for matching the impedance between the satellites impact model and the EPOS robots. Finally it presents the preliminary results and future work. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multivariate Interpolation with Fundamental Splines of Fractional Order
Authors: Forster Brigitte , Massopust Peter
Published: December 2011

Fractional B‐splines Bσ, σ ≥ 1, are piecewise polynomials of fractional degree that interpolate the classical Schoenberg splines $B_n, n \in {\rm I\!N}$, with respect to the degree. As the Schoenberg splines of order ≥ 3, they in general do not satisfy the interpolation property $B_\sigma(n-k) = \delta_{n,k},n,k \in {\rm Z\!\!Z}$. However, the application of the interpolation filter $1/\sum_{k\in{\rm Z\!\!Z}} \hat{B}_{\sigma}(\omega-2 \pi k)$—if well‐defined—in the frequency domain yields a fundamental spline of fractional order that does satisfy the interpolation property. We extend these result via ridge functions to multivariate fractional B‐splines. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Uncertainties Quantification and Data Compression in numerical Aerodynamics
Authors: Litvinenko Alexander , Matthies Hermann G.
Published: December 2011

We research how uncertainties in the angle of attack, in the Mach number and in the geometry of the airfoil propagate in the solution (pressure, density, velocity etc). To compute different statistical functionals of the solution we build a low‐rank response surface. The building algorithm is working on the fly, is based on the QR‐decomposition, has drastically reduced memory requirements and linear complexity. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic simulation of particle‐filled hollow spheres
Authors: Steinle Tobias , Vrabec Jadran , Walther Andrea
Published: December 2011

We are simulating a new lightweight material that could potentially be used in several technical applications, such as machine casings to rapidly damp vibrations, reducing wear and tear. This is achieved by employing embedded hollow spheres that are filled with a granular material, such as a ceramic powder. Energy is dissipated via friction caused by the interaction of particles with each other and with the sphere wall. The present dynamic simulation is based on a leapfrog algorithm, a time integration method used in molecular dynamics. Modifications, such as reflecting boundary conditions, are introduced to adapt the scheme to the field of granular materials. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear fractional transformations of Stieltjes functions
Authors: Behrndt Jussi , Hassi Seppo , de Snoo Henk , Wietsma Rudi , Winkler Henrik
Published: December 2011

Linear fractional transformations of Stieltjes (and inverse Stieljes) functions, which appear naturally in the extension theory of nonnegative symmetric operators with defect one in Hilbert spaces, are investigated. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear process machine interaction in tool grinding
Authors: de Payrebrune Kristin M. , Kröger Matthias
Published: December 2011

The manufacturing of high performance cutting tools, like drills and chamfers, is done by a deep grinding process. This tool grinding process shows nonlinear relations between predefined process parameters, as cutting depth, feed speed and cutting speed, and the process characteristics, as process forces, surface properties and stability. Within an interdisciplinary research project a process model is built up to represent the process machine interaction and to predict process forces, deformation of the workpiece and geometry errors caused by this deformation. In this paper, the process model and the coupling of the included submodules will be described. The focus is thereby on the explanation of the contact module and the implementation in the dynamical model. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational mechanics‐based modeling of size‐dependent hardening in polycrystals
Authors: Bargmann Swantje , Ekh Magnus
Published: December 2011

It has been well‐known for a number of years that the macroscopic material response of polycrystalline metals is influenced by the size and morphology of grains. Different size effects may occur, one of which is the Hall‐Petch effect. The key aim of this contribution is the computational modeling of grain‐size‐dependent hardening in polycrystals using a microstructural approach. Here, the focus is on the influence of the microscopic grain boundary conditions on the simulation results. In particular, micro‐flexible boundary conditions are discussed and compared to micro‐hard and micro‐free assumptions. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bio‐inspired cationic polymerization of isoprene and analogues: state‐of‐the‐art
Authors: Ouardad Samira , Bakleh Marc‐Elias , Kostjuk Sergei V. , Ganachaud François , Puskas Judit E. , Deffieux Alain , Peruch Frédéric
Published: December 2011

Natural rubber (NR), which is polyisoprene about 100% 1,4‐cis of high molar mass, > 106 g mol−1, is mainly produced in southeast Asia and represents around 40%–45% of total worldwide elastomer consumption. Whereas more than 2500 plant species are able to produce polyisoprenoids, the only established commercial source of NR is Hevea braziliensis. NR presents high performance properties that are so far not matched by synthetic rubbers. As a consequence, NR is irreplaceable in many applications (aircraft tires, surgery gloves etc.). Nature and synthetic polymer chemists start from different substrates to synthesize polyisoprenes, i.e. isopentenyl pyrophosphate (IPP), which is a universal building brick utilized by plants and animals, and isoprene monomer, respectively. Nevertheless, we proposed that the elementary processes involved in the biosynthesis of NR are very similar to those of cationic polymerization. In the course of a study on bio‐inspired cationic polymerization of isoprene and IPP analogues, it appeared that cationic polymerization of isoprene proceeds readily and leads mainly to its 1,4‐trans addition; such a process nevertheless remains difficult to control due to the occurrence of many side reactions (transfer, protic initiation, branching, cyclization). The present paper describes our understanding of the cationic polymerization of isoprene and its analogues catalyzed by different Lewis acids, in solution and aqueous dispersions. Copyright © 2011 Society of Chemical Industry
Evaluation of an oil dispersion formulation of imidacloprid as a drench against Rhynchophorus ferrugineus (Coleoptera, Curculionidae) in young palm trees
Authors: Llácer Elena , Negre María , Jacas Josep A
Published: December 2011

BACKGROUND: The red palm weevil, Rhynchophorus ferrugineus (Olivier), is a phytophagous insect that feeds on soft succulent tissues of most palm species and is considered the main palm pest in the Middle East and the Mediterranean Basin. The aim of this study was to test the efficacy of imidacloprid oil dispersion (OD) as a drench in preventive and curative treatments against R. ferrugineus in Phoenix canariensis, Washingtonia robusta, Washingtonia filifera and Trachycarpus fortunei.

RESULTS: Levels of infestation were highest in P. canariensis. There was no infestation in W. filifera. Mean efficacies of 100 and 94% were obtained in preventive and curative treatments respectively. High efficacies in preventive treatments (mean 95.4%) lasted for up to 45 days after application.

CONCLUSION: The high efficacies and persistence of imidacloprid OD applied as a drench in young palms show the potential of this product for the management of R. ferrugineus. Copyright © 2011 Society of Chemical Industry
The current status of pesticide resistance in Australian populations of the redlegged earth mite (Halotydeus destructor)
Authors: Umina Paul A , Weeks Andrew R , Roberts John , Jenkins Sommer , Mangano G Peter , Lord Alan , Micic Svetlana
Published: December 2011

BACKGROUND: The redlegged earth mite, Halotydeus destructor Tucker, is an important pest of broad‐acre farming systems in Australia, New Zealand and South Africa. In 2006, high levels of resistance to synthetic pyrethroids were discovered in this species in Western Australia.

RESULTS: Between 2007 and 2010, the authors monitored resistance in field populations and found it had spread considerably within the state of Western Australia. Twenty‐six paddocks from 15 individual properties were identified with resistance, and these paddocks ranged over 480 km. To date, resistance has not been detected in any other Australian state. Resistance in H. destructor appears to be found across the entire pyrethroid group, but not to other chemical classes such as organophosphates and carbamates, or other chemistries with novel modes of action.

CONCLUSION: The high levels of resistance occurring in Western Australia have caused considerable economic losses due to ineffective chemical applications and mortality of crop plants at seedling establishment. These findings highlight the need for a comprehensive resistance surveillance programme to be developed for H. destructor within Australia. Growers need to consider non‐chemical approaches for pest control and should be encouraged to implement pesticide resistance management programmes for H. destructor. Copyright © 2011 Society of Chemical Industry
A non‐destructive method for testing two components of the behaviour of soil‐applied agricultural chemicals over a long period
Authors: Guglielmi Marie‐Anne , Rocher Françoise , Legros Sandrine , Bonnemain Jean‐Louis , Chollet Jean‐François
Published: December 2011

BACKGROUND: Owing to the complexity of soil composition, accurate predictions of both apoplastic systemicity of lipophilic xenobiotics and their leaching from the soil are made difficult. Therefore, a non‐destructive method to assess directly these two components of the spatial behaviour of soil‐applied phytochemicals is needed.

RESULTS: The plant selected was a dwarf tomato, which can exude an abundant apoplastic fluid through large stomata for several months. The feasibility and reliability of the method were assayed using three triazoles exhibiting different log D values. HPLC‐MS analyses indicated that triadimenol (log D = 2.97) was clearly the most mobile compound within the apoplast, especially its diastereoisomer A. Propiconazole (log D = 3.65) and penconazole (log D = 4.64) exhibited a similar low systemicity. The data remained the same when the three fungicides were applied together on the soil. Long time‐course studies (1.5 months) of penconazole behaviour indicated that, in contrast to leaching, which decrease sharply, root‐to‐shoot translocation remained almost unchanged during the whole experiment, in spite of the high lipophilicity of this fungicide.

CONCLUSION: This method must contribute to a better knowledge of the behaviour of commercial soil‐applied phytochemicals. It can also be used to screen new xenobiotics within strategies to satisfy environmental requirements. Copyright © 2011 Society of Chemical Industry
Deposition of thin films by sputtering cold isostatically pressed powder targets: A case study
Authors: Boydens Francis , Leroy Wouter , Persoons Rosita , Depla Diederik
Published: December 2011

Powders of copper and aluminium with a maximum grain size of 50 µm are mixed in different ratios. The mixtures are cold isostatically pressed into two‐inch circular targets which are mounted in a conventional magnetron set‐up and used to deposit both metallic Cu–Al as well as oxygen rich Cu–Al–O thin films. In both cases the thin film composition is analysed and related to the target composition. Crystallographic properties of the deposited films are presented as well. The influence of the target composition on the reactive behaviour is studied by hysteresis measurements. Furthermore, the effective sputter yields of elemental powder targets were measured. Depending on the material, the sputter yields of the powder target either increased or decreased compared to the sputter yields of solid targets. This can be qualitatively explained by an analysis of the target roughness. For the fast scanning of the compositional influence on material properties, the use of powder targets shows to be a suitable and valuable approach.
Curtailed two‐stage designs with two dependent binary endpoints
Authors: Chen Chia‐Min , Chi Yunchan
Published: December 2011

When phase I clinical trials were found to be unable to precisely estimate the frequency of toxicity, Brayan and Day [1] proposed incorporating toxicity considerations into two‐stage designs in phase II clinical trials. Conaway and Petroni [2] further pointed out that it is important to evaluate the clinical activity and safety simultaneously in studying cancer treatments with more toxic chemotherapies in a phase II clinical trial. Therefore, they developed multi‐stage designs with two dependent binary endpoints. However, the usual sample sizes in phase II trials make these designs difficult to control the type I error rate at a desired level over the entire null region and still have sufficient power against reasonable alternatives. Therefore, the curtailed sampling procedure summarized by Phatak and Bhatt [3] will be applied to the two‐stage designs with two dependent binary endpoints in this paper to reduce sample sizes and speed up the development process for drugs. Copyright © 2011 John Wiley & Sons, Ltd.
The Effects of Commercial Preparations of Herbal Supplements Commonly Used by Women on the Biotransformation of Fluorogenic Substrates by Human Cytochromes P450
Authors: Ho Shirley H. Y. , Singh Mohini , Holloway Alison C. , Crankshaw Denis J.
Published: December 2011

The study set out to determine the potential for commercially available preparations of black cohosh (Actaea racemosa), chaste tree berry (Vitex agnus‐castus), crampbark (Viburnum opulus) and false unicorn (Chamaelirium luteum) to inhibit the major human drug metabolizing enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 as well as CYP1A1 which activates some carcinogens. In vitro microplate‐based assays using cDNA‐expressed CYP450 isoforms and fluorogenic substrates were used. Components of the commercial herbal preparations interfered with the assays and limited the concentration ranges that could be tested. Nevertheless, the fluorogenic assays were robust, reproducible and easy to perform and thus are still useful for initial screening for potential herb – drug interactions. None of the preparations affected CYPs 1A1 or 2C9 at the concentrations tested but all preparations inhibited some of the enzymes with potencies around 1 μg/mL. The three most potent interactions were: chaste tree berry and CYP2C19 (IC50 0.22 μg/mL,); chaste tree berry and CYP3A4 (IC50 0.3 μg/mL); black cohosh and CYP2C19 (IC50 0.37 μg/mL,). Thus, the study successfully identified the potential for the commercial herbal preparations to inhibit human drug metabolizing enzymes. Whether this potential translates into clinically significant herb – drug interactions can only be confirmed by appropriate in vivo studies. Copyright © 2011 John Wiley & Sons, Ltd.
Hepatoprotective Effect of Flavonoid Glycosides from Lespedeza cuneata against Oxidative Stress Induced by tert‐Butyl Hyperoxide
Authors: Kim Sang Min , Kang Kyungsu , Jho Eun Hye , Jung Yu‐Jin , Nho Chu Won , Um Byung‐Hun , Pan Cheol‐Ho
Published: December 2011

The aerial parts of Lespedeza cuneata G. Don, perennial legume native to Eastern Asia, have been used therapeutically in traditional Asian medicine to protect the function of liver, kidneys and lungs. However, little is known about the pharmaceutical effect of extracts from this plant. In the present study, the aerial parts of L. cuneata were used to prepare an ethanol extract, which was then tested for hepatoprotective effects against injury by tert‐butyl hyperoxide (t‐BHP). At a dose of 20 μg/mL, the ethanol extract significantly protected HepG2 cells against the cytotoxicity of t‐BHP. Further fractionation of the extract with ethyl acetate allowed the isolation of five flavonoid compounds that were structurally identified by 1H and 13C NMR spectroscopy as isovitexin, hirsutrin, trifolin, avicularin and quercetin. Hirsutrin, avicularin and quercetin (10 μm) showed clear hepatoprotective activity against injury by t‐BHP in HepG2 cells, whereas isovitexin and trifolin showed no protective effects. The observed hepatoprotective effect of the investigated compounds showed a high correlation with radical scavenging activity, which followed the structure–activity relationships of the flavonoid aglycones. Copyright © 2011 John Wiley & Sons, Ltd.
Evodiamine Inhibits 12‐O‐Tetradecanoylphorbol‐13‐acetate‐induced Activator Protein 1 Transactivation and Cell Transformation in Human Hepatocytes
Authors: Chao De‐Cheng , Lin Li‐Jen , Hsiang Chien‐Yun , Li Chia‐Cheng , Lo Hsin‐Yi , Liang Ji‐An , Kao Shung‐Te , Wu Shih‐Lu , Ho Tin‐Yun
Published: December 2011

Evodia rutaecarpa has been used to treat inflammatory digestive disorders in Asian countries. However, little is known about the antitumor activities of E. rutaecarpa and its bioactive constituent evodiamine (EVO). The aim of this study was to characterize the antitumor mechanisms of E. rutaecarpa and EVO in human hepatocytes. Human Chang liver cells were transfected with activator protein 1 (AP‐1)‐luciferase reporter gene and designated as Chang/AP‐1 cells. The Chang/AP‐1 cells were treated with E. rutaecarpa and its bioactive constituents, and challenged with the AP‐1 stimulator 12‐O‐tetradecanoylphorbol‐13‐ acetate (TPA). The present study showed that the methanol extract of E. rutaecarpa decreased the TPA‐induced AP‐1 transactivation in Chang/AP‐1 cells, with an EC50 value of 24.72 μg/mL. EVO inhibited the TPA‐induced AP‐1 transactivation and colony formation, with EC50 values of 82 μm and 8.2 μm, respectively. Moreover, EVO significantly diminished the TPA‐induced phosphorylation of extracellular signal‐regulated kinases (ERKs). These results suggested that EVO treatment suppressed the TPA‐induced AP‐1 activity via the ERKs pathway. In conclusion, EVO inhibited the AP‐1 activity and cellular transformation in human hepatocytes, suggesting that EVO was a potential agent for antitumor therapy. Copyright © 2011 John Wiley & Sons, Ltd.
The Effect of Ginkgo biloba Extract on Mitochondrial Oxidative Phosphorylation in the Normal and Ischemic Rat Heart
Authors: Bernatoniene Jurga , Majiene Daiva , Peciura Rimantas , Laukeviciene Ale , Bernatoniene Ruta , Mekas Tauras , Kasauskas Arturas , Kopustinskiene Dalia
Published: December 2011

Free radical‐induced myocardial damage and impairment of vascular endothelium‐dependent relaxation are amongst the most important mechanisms responsible for ischemic heart injury. Ginkgo biloba leaf extract (GE) has been reported to improve blood circulation in the brain and have a beneficial impact on the cardiovascular system but its cardioprotective effects have not been elucidated yet. Therefore, this study investigated the influence of GE in 70% ethanol (1:5) administered orally to rats on the functions of isolated heart mitochondria under normal and ischemic conditions. Wistar rats were given GE or ethanol (solvent control) at a dosage of 0.32 mL/kg in drinking water for 10 and 18 days, while the control animals received untreated drinking water. Mitochondrial respiration rates were determined oxygraphically. Pyruvate and malate, succinate or palmitoyl‐l‐carnitine and malate were used as substrates.

The GE treatment partially uncoupled mitochondrial oxidation from phosphorylation, reduced the generation of free radicals in the mitochondria, diminished the ischemia‐induced V3 decrease and the degree of respiration stimulation by exogenous cytochrome c. Thus, these results indicate that GE exerts cardioprotective effects reducing ischemia‐caused impairment of the functions of heart mitochondria. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of Matrine on Proliferation and Apoptosis in Gallbladder Carcinoma Cells (GBC‐SD)
Authors: Zhang Zhiping , Wang Xuefeng , Wu Wenguang , Wang Jianwei , Wang Yong , Wu Xiangsong , Fei Xiaozhou , Li Songgang , Zhang Jie , Dong Ping , Gu Jun , Liu Yingbin
Published: December 2011

Although matrine, a primary active component of dried Sophora flavescens root (ku shen), is known to induce apoptosis in a variety of tumor cells in vitro, the molecular mechanism of such apoptosis remains elusive. This analysis of the cell cycle and apoptosis in matrine‐treated human gallbladder carcinoma cells (GBC‐SD) showed that matrine can indeed inhibit cell proliferation and induce G1 cell cycle arrest and apoptosis in a dose‐ and time‐dependent manner. An additional western blot analysis of matrine‐treated cells also showed caspase‐3 and Bcl‐2 activation, as well as cyclinE down‐regulation. Overall, the results indicate that matrine perturbs gallbladder cancer cell progression during the G1 phase by down‐regulating cyclinE and induces apoptosis by decreasing the expression of the antiapoptotic protein Bcl‐2 and increasing expression of the proapoptotic protein Bax. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of Panax notoginseng Saponins on the Activities of CYP1A2, CYP2C9, CYP2D6 and CYP3A4 in Rats In Vivo
Authors: Liu Rui , Qin Mengnan , Hang Pengzhou , Liu Yan , Zhang Zhiren , Liu Gaofeng
Published: December 2011

The aim of this study was to assess the influence of the Panax notoginseng saponins (PNS) on the activities of the drug‐metabolizing enzymes cytochrome P450 (CYP450) 1A2, 2 C9, 2D6 and 3A4 in rats. The activities of CYP1A2, 2 C9, 2D6 and 3A4 were measured using specific probe drugs. After pretreatment for 1 week with PNS or physiological saline (control group), probe drugs caffeine (10 mg/kg; CYP1A2 activity), tolbutamide (15 mg/kg; CYP2C9 activity), metoprolol (20 mg/kg; CYP2D6 activity) and dapsone (10 mg/kg; CYP3A4 activity) were administered to rats by intraperitoneal injection. The blood was then collected at different times for ultra performance liquid chromatography/tandem mass spectrometry (UPLC‐MS/MS) analysis. The data showed that PNS exhibited an induction effect on CYP1A2 by decreasing caffeine Cmax (36.3%, p < 0.01) and AUC0‐∞ (22.77%, p < 0.05) and increasing CL/F (27.03%, p < 0.05) compared with those of the control group. Western blot analysis was used to detect the effect of PNS on the protein level of CYP1A2, and the results showed that PNS could upregulate the protein expression of CYP1A2. However, no significant changes in CYP2C9, 2D6 or 3A4 activities were observed. In conclusion, the results indicate that PNS could induce CYP1A2, which may affect the disposition of medicines primarily dependent on the CYP1A2 pathway. Our work may be the basis of related herb–drug interactions in the clinic. Copyright © 2011 John Wiley & Sons, Ltd.
Improving Product Quality and Reliability with Customer Experience Data
Authors: Brombacher Aarnout , Hopma Eva , Ittoo Ashwin , Lu Yuan , Luyk Ilse , Maruster Laura , Ribeiro Joël , Weijters Ton , Wortmann Hans
Published: December 2011

Advance technology development and wide use of the World Wide Web have made it possible for new product development organizations to access multi‐sources of data‐related customer complaints. However, the number of customer plaints of highly innovative consumer electronic products is still increasing; that is, product quality and reliability is at risk. This article aims to understand why existing solutions from literature as well as from industry to deal with these increasingly complex multiple data sources are not able to manage product quality and reliability. Three case studies in industry are discussed. On the basis of the case study results, this article also identifies a new research agenda that is needed to improve product quality and reliability under this circumstance. Copyright © 2011 John Wiley & Sons, Ltd.
A pilot study for the intrinsic labeling of egg proteins with 15N and 13C
Authors: Fromentin Claire , Sanders Pascal , Nau Françoise , Anton Marc , Fromentin Gilles , Tomé Daniel , Thibault Jean‐Noël , Gaudichon Claire
Published: December 2011

The aim of this study was to produce intrinsically and uniformly doubly 15N‐13C‐labeled proteins. These proteins can be used as intrinsic tracers of dietary amino acids, both α‐amino groups and carbon skeletons, during postprandial metabolic utilization. Two (Rhodes) laying hens were fed for 16 days with a standard poultry diet supplemented with 0, 0.2% or 0.4% of a mixture of 20 doubly 15N‐13C‐labeled AAs. A third hen was given a non‐enriched diet, as the control. The eggs laid were collected over 24 days, from 3 days before to 4 days after supplementation. The 15N and 13C enrichments in proteins from white and yolk were measured by EA‐IRMS and GC‐C‐IRMS for enrichment in individual amino acids. After 10 days of supplementation, the 15N enrichment reached an isotopic plateau at 1500 to 3000 ‰, depending on the supplementation level, in both white and yolk while the 13C enrichment was 220 to 650 ‰ in white and was 100 to 250 ‰ in yolk. The 15N enrichment was similar among the amino acids, except for the aromatic ones in which the enrichment was lower. The δ13C values were variable among amino acids in both white and yolk, ranging from 77 ‰ for tyrosine to 555 ‰ for proline with the 0.2 % supplementation level. In conclusion, the incorporation of 0.2 % labeled amino acids in the hen diet allowed us to achieve sufficient enrichment for metabolic studies. However, due to the non‐homogeneity of the 13C labeling, adequate 13C enrichment of individual amino acids must be considered depending on the investigated metabolic pathway. Copyright © 2011 John Wiley & Sons, Ltd.
High‐performance thin‐layer chromatography plate blotting for liquid microjunction surface sampling probe mass spectrometric analysis of analytes separated on a wettable phase plate
Authors: Walworth Matthew J. , Stankovich Joseph J. , Van Berkel Gary J. , Schulz Michael , Minarik Susanne
Published: December 2011

A blotting method that transfers analytes separated on wettable high‐performance thin‐layer chromatography (HPTLC) plates to a hydrophobic reversed‐phase C8 HPLTC plate suitable for analysis with a liquid microjunction surface sampling probe electrospray ionization mass spectrometry system was described and demonstrated. The simple blotting procedure transfers the analyte from the wettable plate to the topmost surface of a rigidly backed, easy‐to‐mount hydrophobic substrate that already has been proven viable for analysis by this sampling probe/mass spectrometry system. The utility of the approach was demonstrated by the analysis of a four‐component peptide mixture originally separated on a ProteoChrom® HPTLC cellulose sheet and then blotted onto the reversed‐phase HPTLC plate. Published in 2011 by John Wiley & Sons, Ltd.
Identification of energy consumption and nutritional stress by isotopic and elemental analysis of urine in bonobos (Pan paniscus)
Authors: Deschner Tobias , Fuller Benjamin T. , Oelze Vicky M. , Boesch Christophe , Hublin Jean‐Jacques , Mundry Roger , Richards Michael P. , Ortmann Sylvia , Hohmann Gottfried
Published: December 2011

A mounting body of evidence suggests that changes in energetic conditions like prolonged starvation can be monitored using stable isotope ratios of tissues such as bone, muscle, hair, and blood. However, it is unclear if urinary stable isotope ratios reflect a variation in energetic condition, especially if these changes in energetic condition are accompanied by shifts in dietary composition. In a feeding experiment conducted on captive bonobos (Pan paniscus), we monitored urinary δ13C, δ15N, total C (carbon), total N (nitrogen), and C/N ratios and compared these results with glucocorticoid levels under gradually changing energy availability and dietary composition. Measurements of daily collected urine samples over a period of 31 days showed that while shifts in urinary isotope signatures of δ13C and δ15N as well as total C were best explained by changes in energy consumption, urinary total N excretion as well as the C/N ratios matched the variation in dietary composition. Furthermore, when correcting for fluctuations in dietary composition, the isotope signatures of δ13C and δ15N as well as total C correlated with urinary glucocorticoid levels; however, the urinary total N and the C/N ratio did not. These results indicate for the first time that it is possible to non‐invasively explore specific longitudinal records on animal energetic conditions and dietary compositions with urinary stable isotope ratios and elemental compositions, and this research provides a strong foundation for investigating how ecological factors and social dynamics affect feeding habits in wild animal populations such as primates. Copyright © 2011 John Wiley & Sons, Ltd.
Input‐to‐state‐stability‐type comparison principles and input‐to‐state stability for discrete‐time dynamical networks with time delays
Authors: Liu Bin , Xu Chengjie , Liu Dongnan
Published: December 2011

This paper investigates the input‐to‐state stability (ISS) issue for discrete‐time dynamical networks (DDNs) with time delays. Firstly, a general comparison principle for solutions of DDNs is proposed. Then, based on this general comparison principle, three kinds of ISS‐type comparison principles for DDNs are established, including the comparison principle for input‐to‐state ‐stability, ISS, and exponential ISS. The ISS‐type comparison principles are then used to investigate stability properties related to ISS for three kinds (linear, affine, and nonlinear) of DDNs. It shows that the ISS property of a DDN can be derived by comparing it with a linear or lower‐dimension DDN with known ISS property. By using methods such as variation of parameters, uniform M‐matrix, and the ISS‐type comparison principle, conditions of global exponential ISS for time‐varying linear DDNs with time delays are derived. Moreover, the obtained ISS results for DDNs are extended to the hybrid DDNs with time delays. As one application, the synchronization within an error bound in the sense of ISS is achieved for DDNs with coupling time delays and external disturbances. Finally, two examples are given to illustrate the results. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient and exact approach for detecting trends with binary endpoints
Authors: Shan Guogen , Ma Changxing , Hutson Alan D. , Wilding Gregory E.
Published: December 2011

Lloyd (Aust. Nz. J. Stat., 50, 329–345, 2008) developed an exact testing approach to control for nuisance parameters, which was shown to be advantageous in testing for differences between two population proportions. We utilized this approach to obtain unconditional tests for trends in 2 × K contingency tables. We compare the unconditional procedure with other unconditional and conditional approaches based on the well‐known Cochran–Armitage test statistic. We give an example to illustrate the approach, and provide a comparison between the methods with regards to type I error and power. The proposed procedure is preferable because it is less conservative and has superior power properties. Copyright © 2011 John Wiley & Sons, Ltd.
Bayesian adjusted R2 for the meta‐analytic evaluation of surrogate time‐to‐event endpoints in clinical trials
Authors: Renfro Lindsay A. , Shi Qian , Sargent Daniel J. , Carlin Bradley P.
Published: December 2011

A two‐stage model for evaluating both trial‐level and patient‐level surrogacy of correlated time‐to‐event endpoints has been introduced, using patient‐level data when multiple clinical trials are available. However, the associated maximum likelihood approach often suffers from numerical problems when different baseline hazards among trials and imperfect estimation of treatment effects are assumed. To address this issue, we propose performing the second‐stage, trial‐level evaluation of potential surrogates within a Bayesian framework, where we may naturally borrow information across trials while maintaining these realistic assumptions. Posterior distributions on surrogacy measures of interest may then be used to compare measures or make decisions regarding the candidacy of a specific endpoint. We perform a simulation study to investigate differences in estimation performance between traditional maximum likelihood and new Bayesian representations of common meta‐analytic surrogacy measures, while assessing sensitivity to data characteristics such as number of trials, trial size, and amount of censoring. Furthermore, we present both frequentist and Bayesian trial‐level surrogacy evaluations of time to recurrence for overall survival in two meta‐analyses of adjuvant therapy trials in colon cancer. With these results, we recommend Bayesian evaluation as an attractive and numerically stable alternative in the multitrial assessment of potential surrogate endpoints. Copyright © 2011 John Wiley & Sons, Ltd.
Data processing and analysis in real‐world traditional Chinese medicine clinical data: challenges and approaches
Authors: Liu Baoyan , Zhou Xuezhong , Wang Yinhui , Hu Jingqing , He Liyun , Zhang Runshun , Chen Shibo , Guo Yufeng
Published: December 2011

Traditional Chinese medicine (TCM) is a clinical‐based discipline in which real‐world clinical practice plays a significant role for both the development of clinical therapy and theoretical research. The large‐scale clinical data generated during the daily clinical operations of TCM provide a highly valuable knowledge source for clinical decision making. Secondary analysis of these data would be a vital task for TCM clinical studies before the randomised controlled trials are conducted. In this article, we discuss the challenges and issues, such as structured data curation, data preprocessing and quality, large‐scale data management and complex data analysis requirements, in the data processing and analysis of real‐world TCM clinical data. Furthermore, we also discuss related state‐of‐the‐art research and solutions in China. We have shown that the clinical data warehouse based on the collection of structured electronic medical record data and clinical terminology would be a promising approach for generating clinical hypotheses and helping the discovery of clinical knowledge from large‐scale real‐world TCM clinical data. Copyright © 2011 John Wiley & Sons, Ltd.
A dynamic model for the risk of bladder cancer progression
Authors: Porta Núria , Calle M. Luz , Malats Núria , Gómez Guadalupe
Published: December 2011

We propose a multistate modeling approach to describe the observed evolution of patients diagnosed with non‐muscle‐invasive bladder cancer. On the basis of data from the Spanish Bladder Cancer/EPICURO study, we adjust a multistate model taking into account the disease‐related events of interest (recurrence, progression, and disease‐related deaths) as well as competing deaths due to other causes. We then develop a dynamic predictive process for bladder cancer progression, which allows the risk of a patient to be updated whenever new information of his or her evolution is available. By using specific measures of prospective accuracy in the presence of competing risks, the proposed dynamic model has shown to improve prediction accuracy and provides a more personalized management of bladder patients. Copyright © 2011 John Wiley & Sons, Ltd.
Global hypothesis testing for high‐dimensional repeated measures outcomes
Authors: Chi Yueh‐Yun , Gribbin Matthew , Lamers Yvonne , Gregory Jesse F. , Muller Keith E.
Published: December 2011

High‐throughput technology in metabolomics, genomics, and proteomics gives rise to high dimension, low sample size data when the number of metabolites, genes, or proteins exceeds the sample size. For a limited class of designs, the classic ‘univariate approach’ for Gaussian repeated measures can provide a reasonable global hypothesis test. We derive new tests that not only accurately allow more variables than subjects, but also give valid analyses for data with complex between‐subject and within‐subject designs. Our derivations capitalize on the dual of the error covariance matrix, which is nonsingular when the number of variables exceeds the sample size, to ensure correct statistical inference and enhance computational efficiency. Simulation studies demonstrate that the new tests accurately control Type I error rate and have reasonable power even with a handful of subjects and a thousand outcome variables. We apply the new methods to the study of metabolic consequences of vitamin B6 deficiency. Free software implementing the new methods applies to a wide range of designs, including one group pre‐intervention and post‐intervention comparisons, multiple parallel group comparisons with one‐way or factorial designs, and the adjustment and evaluation of covariate effects. Copyright © 2011 John Wiley & Sons, Ltd.
Designer Hydrophilic Regions Regulate Droplet Shape for Controlled Surface Patterning and 3D Microgel Synthesis
Authors: Hancock Matthew J. , Yanagawa Fumiki , Jang Yun‐Ho , He Jiankang , Kachouie Nezamoddin N. , Kaji Hirokazu , Khademhosseini Ali
Published: December 2011

A simple technique is presented for controlling the shapes of micro‐ and nanodrops by patterning surfaces with special hydrophilic regions surrounded by hydrophobic boundaries. Finite element method simulations link the shape of the hydrophilic regions to that of the droplets. Shaped droplets are used to controllably pattern planar surfaces and microwell arrays with microparticles and cells at the micro‐ and macroscales. Droplets containing suspended sedimenting particles, initially at uniform concentration, deposit more particles under deeper regions than under shallow regions. The resulting surface concentration is thus proportional to the local fluid depth and agrees well with the measured and simulated droplet profiles. A second application is also highlighted in which shaped droplets of prepolymer solution are crosslinked to synthesize microgels with tailored 3D geometry.
Diameter‐Dependent Thermal Transport in Individual ZnO Nanowires and its Correlation with Surface Coating and Defects
Authors: Bui Cong Tinh , Xie Rongguo , Zheng Minrui , Zhang Qingxin , Sow Chorng Haur , Li Baowen , Thong John T. L.
Published: December 2011

A systematic study of the thermal transport properties of individual single‐crystal zinc oxide (ZnO) nanowires (NWs) with diameters in the range of ∼50–210 nm is presented. The thermal conductivity of the NWs is found to be dramatically reduced by at least an order of magnitude compared to bulk values, due to enhanced phonon‐boundary scattering with a reduction in sample size. While the conventional phonon transport model can qualitatively explain the temperature dependence, it fails to account for the diameter dependence. An empirical relationship for assessing diameter‐dependent thermal properties is observed, which shows an approximately linear dependence of the thermal conductivity on the cross‐sectional area of the NWs in the measured diameter range. Furthermore, it is found that an amorphous‐carbon layer coating on the NWs does not perturb the thermal properties of the NW cores, whereas 30 keV Ga+ ion irradiation at low dose (∼4 × 1014 cm−2) leads to a remarkable reduction of the thermal conductivity of the ZnO NWs.
Ontology patterns for service‐oriented software development
Authors: Tsai Wei‐Tek , Wu Budan , Jin Zhi , Huang Yu , Li Wu
Published: December 2011

Modern software often uses ontologies as its key component to store data and their relationships. This is different from using an ontology as a stand‐alone tool for knowledge sharing and representation. The ontology component needs to work with other software components and needs to evolve as the software evolves. Ontology design has been a research topic for years; however, most of these studies focus on using ontologies as stand‐alone applications. This paper studies ontology patterns that can be applied to design ontologies as an integral part of a service‐oriented application. The paper first briefly reviews various ontology design issues including a brief survey of existing ontology design patterns. The paper then outlines general principles for using ontologies in software applications, including the needs to incorporate ontology design process as a part of software development processes, design ontologies as a component of an overall software architecture, and use ontologies to enhance software evolution and the role that ontologies can play in software validation. The paper then proposes some common ontology patterns that can be used to design ontologies in service‐oriented applications. This is followed by examining two international projects, SENSEI and FCINT, where ontologies are used in service‐oriented applications and several ontology design patterns are used. Copyright © 2011 John Wiley & Sons, Ltd.
Vc: A C++ library for explicit vectorization
Authors: Kretz Matthias , Lindenstruth Volker
Published: December 2011

It is an established trend that CPU development takes advantage of Moore's Law to improve in parallelism much more than in scalar execution speed. This results in higher hardware thread counts (MIMD) and improved vector units (SIMD), of which the MIMD developments have received the focus of library research and development in recent years. To make use of the latest hardware improvements, SIMD must receive a stronger focus of API research and development because the computational power can no longer be neglected and often auto‐vectorizing compilers cannot generate the necessary SIMD code, as will be shown in this paper. Nowadays, the SIMD capabilities are sufficiently significant to warrant vectorization of algorithms requiring more conditional execution than was originally expected for Streaming SIMD Extension to handle. The Vc library (http://compeng.uni‐frankfurt.de/?vc) was designed to support developers in the creation of portable vectorized code. Its capabilities and performance have been thoroughly tested. Vc provides portability of the source code, allowing full utilization of the hardware's SIMD capabilities, without introducing any overhead. Copyright © 2011 John Wiley & Sons, Ltd.
A discrete force allocation algorithm for modelling wind turbines in computational fluid dynamics
Authors: Réthoré P.‐E. , Sørensen N.N.
Published: December 2011

This paper describes an algorithm for allocating discrete forces in computational fluid dynamics (CFD). Discrete forces are useful in wind energy CFD. They are used as an approximation of the wind turbine blades' action on the wind (actuator disc/line), to model forests and to model turbulent inflows. Many CFD codes are designed with collocated variables layout. Although this approach has many attractive features, it can generate a numerical decoupling between the pressure and the velocities. This issue is addressed by the Rhie–Chow control volume momentum interpolation. However, this algorithm does not address the specific cases where discrete forces are present. The velocities and pressure exhibit some significant numerical fluctuations at the position where the body forces are applied. While this issue is limited in space, it is usually critical to accurately estimate the velocity at the position of the wind turbine rotor to estimate correctly the power production and the rotor loading. The method proposed in this paper solves this issue by spreading the force on the direct neighbouring cells and applying an equivalent pressure jump at the cell faces. This can potentially open the possibility of coarsening the mesh where the forces are applied and have a considerable effect in reducing the computational cost of modelling wind turbines, wind farms and forests. This approach gives excellent results with three test cases where an analytical solution is known. This correction is also applicable in other fields of CFD that use discrete body forces. Copyright © 2011 John Wiley & Sons, Ltd.