bluuebunny/crossref_metadata_2025_split huggingface dataset:
A divide‐and‐conquer approach to determine the Pareto frontier for optimization of protein engineering experiments
Authors: He Lu , Friedman Alan M. , Bailey‐Kellogg Chris 
Published: October 2011

AbstractIn developing improved protein variants by site‐directed mutagenesis or recombination, there are often competing objectives that must be considered in designing an experiment (selecting mutations or breakpoints): stability versus novelty, affinity versus specificity, activity versus immunogenicity, and so forth. Pareto optimal experimental designs make the best trade‐offs between competing objectives. Such designs are not “dominated”; that is, no other design is better than a Pareto optimal design for one objective without being worse for another objective. Our goal is to produce all the Pareto optimal designs (the Pareto frontier), to characterize the trade‐offs and suggest designs most worth considering, but to avoid explicitly considering the large number of dominated designs. To do so, we develop a divide‐and‐conquer algorithm, Protein Engineering Pareto FRontier (PEPFR), that hierarchically subdivides the objective space, using appropriate dynamic programming or integer programming methods to optimize designs in different regions. This divide‐and‐conquer approach is efficient in that the number of divisions (and thus calls to the optimizer) is directly proportional to the number of Pareto optimal designs. We demonstrate PEPFR with three protein engineering case studies: site‐directed recombination for stability and diversity via dynamic programming, site‐directed mutagenesis of interacting proteins for affinity and specificity via integer programming, and site‐directed mutagenesis of a therapeutic protein for activity and immunogenicity via integer programming. We show that PEPFR is able to effectively produce all the Pareto optimal designs, discovering many more designs than previous methods. The characterization of the Pareto frontier provides additional insights into the local stability of design choices as well as global trends leading to trade‐offs between competing criteria. Proteins 2011. © 2012 Wiley Periodicals, Inc.
Experimental Testing and Computer Simulations of Ductile Fracture in Tool Steels
Authors: Randelius Mats , Krantz Therese , Melander Arne 
Published: October 2011

AbstractDuctility was determined in experimental four‐point bending tests of smooth specimens of tool steel. The tool steels had different contents of carbides and carbide sizes and with a hardness of approximately 60HRc. Two of the materials tested were produced powder metallurgically, one was spray formed and one was conventionally uphill ingot cast. Carbide size distribution analysis was performed on planar polished sections of each material. Correlation between carbide microstructure and ductility performance was obtained. The fracture mechanisms were investigated with fractography. A 3D FE‐model was used to simulate the four‐point bending tests and thereby analyse the matrix flow curve. Also the strain at failure was analysed for each material when simulations were performed based on experimental data. SEM‐images of the materials carbide microstructure were used to create 2D FE‐models. The models simulated crack initiation and propagation by removing elements in the steel matrix as the plastic strain reached a critical level. With three variants, simulations of crack initiation and propagation at carbides were investigated. That was carbides with no cohesion to matrix, carbides fixed to the matrix and carbides with internal cracks. Comparison of strains at failure for the 2D and the 3D FE‐models showed good correlation.
Aussteifung von biegedrillknickgefährdeten Biegeträgern durch zweiseitig gelagerte Trapezprofile
Authors: Seidel Frank , Lindner Joachim 
Published: October 2011

AbstractTrapezprofile werden seit langem zur Aussteifung von Biegeträgern herangezogen. Nach dem augenblicklichen Stand der Normung ist die Berücksichtigung der Scheibenwirkung in Form der Schubsteifigkeit S stets an die Ausbildung eines Schubfeldes gekoppelt, d. h. alle vier Ränder müssen mit der Unterkonstruktion verbunden sein. In vielen Fällen der Praxis ist dies jedoch nicht möglich, weil die Oberkanten von Längs‐ und Querträgern sich nicht auf gleicher Höhe befinden. Im folgenden Artikel wird die aussteifende Wirkung von nur zweiseitig gelagerten Trapezprofilen untersucht. Es wird über Großversuche berichtet, welche die Grundlage für ein FEM‐Modell bilden, mit dem sowohl die bekannten Schubfeldwerte als auch die Großversuche nachgerechnet werden. Aus umfangreichen Parameteruntersuchungen ergab sich ein vereinfachtes Balkenmodell, mit dem die Schubsteifigkeiten von zweiseitig gelagerten Trapezprofilen ermittelt werden können.Stiffening of beams in bending by trapezoidal sheeting connected with the substructure at two edges only. The stiffening effect of trapezoidal sheeting had been used for a long period of time. If according to the present state of standardization the shear stiffness S is considered the construction of a shear panel is necessary. Therefore all four edges of the trapezoidal sheeting must be connected to the substructure. That might cause difficulties in construction especially in industrial buildings where main beams and secondary beams are often not present at the same height level. This paper deals with the problem that the trapezoidal sheeting is connected only at two edges with their substructure, e.g. I‐beams. Full scale tests were carried out on the basis of which a finite element model was developed. Extensive parameter studies using this model delivered parameters for a simplified strut model leading to the stiffening effect of a special shear stiffness S. This stiffness S may be incorporated in a calculation to show sufficient safety against lateral torsional buckling.
Statische Berechnung von verzweigten Rohrleitungen am Beispiel eines Manifolds
Authors: Ofner Robert 
Published: October 2011

AbstractFür die Auslegung von Rohrleitungen für Flüssigkeiten und Gase werden häufig die ASME B31 Codes verwendet (American Society of Mechanical Engineers). Eine Alternative zur ASME B31 ist die europäische Norm EN 13480. Die Spannungen in komplexen Rohrleitungssystemen werden üblicherweise mit Stabmodellen berechnet. Die Steifigkeit der Bögen und lokale Spannungen an Abzweigern werden mittels Flexibilitätsfaktoren und Spannungsintensitätsfaktoren (SIF) berücksichtigt. In diesem Beitrag wird das Bemessungskonzept für verzweigte Rohrleitungen am Beispiel eines Manifolds (Verteilrohrleitung) vorgestellt. Ein Teil der Rohrstatik ist der Spannungsnachweis der Abzweigstücke.Stress analysis of branched piping systems using the example of a manifold. For the design of pressure piping systems for liquids and gas the ASME B31 Codes are commonly used (American Society of Mechanical Engineers). An alternative to the ASME B31 is the European standard EN 13480. The stresses in complex piping systems are usually analyzed with beam models. The stiffness of bends and local stresses at pipe branches are considered by flexibility factors and stress intensification factors (SIF). In this paper the stress analysis concept of piping systems is presented using the example of a manifold. One part of the pipe stress analysis is the code compliance check of pipe branches.
Neuartige Sandwichfahrbahnplatte für Eisenbahnbrücken
Authors: Herrmann Paul , Juen Lukas , Fink Josef 
Published: October 2011

AbstractAm Institut für Tragkonstruktionen, Stahlbau der TU Wien wird derzeit eine neuartige Verbundplatte mit einem Stahl‐Beton‐Stahl‐Sandwichprofil entwickelt. Diese Platte zeichnet sich durch hohe Tragfähigkeit bei gleichzeitig extrem niedriger Bauhöhe aus und ist damit originär für den Einsatz als Fahrbahnplatte für Ersatzneubauten von Eisenbahnbrücken mit offener Fahrbahn gedacht.Das Konstruktionsprinzip, das Herstellungsverfahren und die grundlegenden Tragmechanismen sowie eine Beschreibung der am Institut durchgeführten zerstörenden Versuchsreihe wurden bereits im Vorfeld vorgestellt [1], [2], [3], [4]. In den vorangegangenen Artikeln wurden außerdem die durchgeführten numerischen Analysen und analytischen Modellbildungen des Globaltragverhaltens der Platte beschrieben. Lokale Störzonen im Auflager‐ und Lasteinleitungsbereich sind in den globalen Berechnungsmodellen der gekoppelten Balken mit nachgiebiger Verbundfuge als Modellbetrachtung nicht enthalten. Im diesem Beitrag wird daher gezeigt, dass ein Stabwerkmodell existiert, mit dem das Tragverhalten einerseits im Vergleich zu den FE‐Analysen ausreichend genau beschrieben werden kann und andererseits auch lokale Effekte erfasst werden können.Development of an Innovative Composite Deck Slab for Railway Bridges. The Institut für Tragkonstruktionen‐Stahlbau at the TU Wien is currently developing a new and innovative steel‐concrete‐steel‐sandwich plate. This plate provides a high load bearing capacity with an extremely slender construction height and was therefore originally intended for the use in replacement works of old railway bridges without ballast bed.Earlier papers ([1], [2], [3], [4]) already described the principles of construction and fabrication as well as the basic load‐bearing mechanism. Further, the numerical simulations and the analytical models which describe the global load‐bearing behaviour were presented. These analytical models, the so called elastic shear connection models of two elastically coupled beams, do not include local effects in disturbance areas like the bearings or the areas of load application. Hence the actual paper will describe the derivation of a strut and tie model for a proper mechanical description of local effects in these areas.
Nestin- and Doublecortin-Positive Cells Reside in Adult Spinal Cord Meninges and Participate in Injury-Induced Parenchymal Reaction
Authors: Decimo Ilaria , Bifari Francesco , Rodriguez Francisco Javier , Malpeli Giorgio , Dolci Sissi , Lavarini Valentina , Pretto Silvia , Vasquez Sandra , Sciancalepore Marina , Montalbano Alberto , Berton Valeria , Krampera Mauro , Fumagalli Guido 
Published: October 2011

Abstract
Adult spinal cord has little regenerative potential, thus limiting patient recovery following injury. In this study, we describe a new population of cells resident in the adult rat spinal cord meninges that express the neural stem/precursor markers nestin and doublecortin. Furthermore, from dissociated meningeal tissue a neural stem cell population was cultured in vitro and subsequently shown to differentiate into functional neurons or mature oligodendrocytes. Proliferation rate and number of nestin- and doublecortin-positive cells increased in vivo in meninges following spinal cord injury. By using a lentivirus-labeling approach, we show that meningeal cells, including nestin- and doublecortin-positive cells, migrate in the spinal cord parenchyma and contribute to the glial scar formation. Our data emphasize the multiple roles of meninges in the reaction of the parenchyma to trauma and indicate for the first time that spinal cord meninges are potential niches harboring stem/precursor cells that can be activated by injury. Meninges may be considered as a new source of adult stem/precursor cells to be further tested for use in regenerative medicine applied to neurological disorders, including repair from spinal cord injury.
The evolving sophistication of ambush marketing: A typology of strategies
Authors: Chadwick Simon , Burton Nicholas 
Published: October 2011

AbstractAt sporting mega‐events, there is increasingly intense competition off the field of play as well as on it, with big brands battling it out for the attention of consumers. Some of these brands are associated with official event sponsors; others are associated with commercial rivals that have no official association with events such as the Olympic Games or the Fédération Internationale de Football Association (FIFA) World Cup. The latter group is increasingly engaging in what is termed “ambush marketing”‐for instance, by seeking to deliberately persuade or mislead consumers into thinking they have an official association with a sporting mega‐event. The emergence of ambush marketing emanates from the centrally controlled sale of a small number of rights packages by bodies such as the International Olympic Committee (IOC) and FIFA, which effectively exclude non‐rights holders from associating with an event. Brands that have no official legal right of association often therefore seek to access similar benefits to official sponsors by engaging in a range of activities, including targeted promotions and the creation of rival tournament properties. The focus of this article is fourfold: (1) to explain how ambushing has emerged, (2) to define ambush marketing, (3) to identify various types of ambushing, and (4) to discuss some of the management issues and challenges posed by ambush marketing. © 2011 Wiley Periodicals, Inc.
Practical implications and future research directions for international sports management
Authors: Ratten Vanessa 
Published: October 2011

AbstractInternational sports management is a unique area of academic and practitioner interest, as it is an important part of the global economy. Sport is an international product and service that influences businesses on a global scale. While there is a lot of global media attention on sport in general, there is a gap in the literature on international sports management. The aim of this article is to discuss practical implications and future research directions for international sports management. Therefore, the purpose of this article is to integrate the international management and sports management areas of study. The role of entrepreneurial sports management in different countries is discussed, as it highlights the changes that have occurred in the global business environment. Different areas of international sports management (sports internationalization, sports entrepreneurship, sports branding, sport and corporate social responsibility, sports tourism, regional development of sport, sports marketing, and international action sports) are discussed in terms of practical implications and future research directions. This article demonstrates how businesses compete in the international marketplace and how there is a large potential for entrepreneurial international sport ventures. The major finding of this article is that international sports management is a unique area of study that deserves more attention. © 2011 Wiley Periodicals, Inc.
Efficacy of proximity loggers for detection of contacts between maternal pairs of white‐tailed deer
Authors: Walrath Ryan , Van Deelen Timothy R. , VerCauteren Kurt C. 
Published: October 2011

AbstractContact frequency and duration estimates between individuals are important to understanding the behavioral ecology of wildlife species and the epidemiology of infectious diseases. A new technology uses proximity data loggers to record time and duration of contacts. We conducted an experiment at Sandhill Wildlife Management Area, located near Babcock, Wisconsin (USA) to compare probabilities of detecting intraspecific contacts among white‐tailed deer (Odocoileus virginianus) maternal pairs (dams/fawns) based on detections from proximity loggers deployed on collars versus those obtained from direct observation. We defined 5 discrete probabilities of detection of a contact in terms of P (probability of detection by a single proximity logger) and V (probability of detection by visual observer) and estimated P and V by minimizing the Kullback–Liebler distance between distributions of theoretical probabilities and observed distributions in experimental data. We used parametric jackknifing to estimate means and variances for P and V. Mean estimates of P and V were 0.64 (95% CI = 0.62–0.67) and 0.34 (0.32–0.35), respectively. Estimates of P and V enabled the calculation of the probability that an encounter was undetected by both proximity loggers and the visual observer, which was 0.09 (95% CI = 0.073–0.094). Estimates of P and V provide estimates of nondetection bias for future studies that use proximity loggers to estimate frequencies of encounters and help quantify the usefulness of this technology relative to visual observation. Management concerns such as chronic wasting disease and bovine tuberculosis could be better understood and addressed by using proximity loggers because they are better able to quantify close contact than conventional methods such as radiotelemetry or Global Positioning System telemetry. © 2011 The Wildlife Society.
Geometric Variations and Electron Localizations in Intermetallics: The Case of La2Sb Type Compounds
Authors: Nuss Jürgen , Wedig Ulrich , Jansen Martin 
Published: October 2011

AbstractThe structural relations of La2Sb type compounds and their oxygen stuffed variants, like e.g. Eu4Sb2O (anti‐K2NiF4 type), are discussed. In the course of these investigations, the crystal structures of La2Sb, Pr2Sb, Sm2Sb, Nd2Bi, and Sm4Bi2O were determined and refined from single crystal data. Band structures have been calculated in the framework of density functional theory, and the bonding properties of the individual compounds are compared on the basis of the Electron Localization Function (ELF). Based on specific geometrical parameters, the La2Sb type compounds are arranged in a structure field map. Three distinct areas arise: insulating K2NiF4 type compounds, semiconducting, oxygen stuffed variants and oxygen‐free metallic compounds. La2Sb is found in the latter area, ruling out oxygen content, which is confirmed by high resolution single‐crystal X‐ray diffraction. The electronic structures of the compounds are related to the valence electron count. Pnictides of tri‐valent metals are metallic and feature local multicenter metal–metal bonds, di‐valent metals form oxygen stuffed variants. Samarium is the only element which is found in both areas of the structure field map, displaying an oxygen free and a stuffed variant.
Crystal Structure and Spectroscopic Properties of trans‐Dibromidobis(propane‐1, 3‐diamine)chromium(III) Perchlorate
Authors: Choi Jong‐Ha , Subhan Md Abdus , Ng Seik Weng 
Published: October 2011

AbstractThe structure of trans‐[Cr(tn)2Br2]ClO4 (tn = propane‐1, 3‐diamine) has been determined by a single‐crystal X‐ray diffraction study at 100 K. The complex crystallizes in the space group P$\bar{1}$ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 6.8220(4), b = 8.86199(9), c = 12.6644(8) Å and α = 77.859(7)°, β = 81.765(6)°, and γ = 77.764(7)°. The chromium atom is in a slightly distorted octahedral environment coordinated by four nitrogen atoms of two tn ligands and two bromine atoms in trans positions. The two six‐membered chelate rings in the complex cations are oriented in an anti chair‐chair conformation with respect to each other. The mean Cr–N(tn) and Cr–Br bonds are 2.093(3) and 2.4681(4) Å, respectively. The crystal packing is stabilized by hydrogen bonds. The infrared and electronic absorption spectral properties are consistent with the result of X‐ray crystallography. It is confirmed that the nitrogen atoms of the tn ligand are strong σ‐donors, but the bromido ligands have weak σ‐ and π‐donor properties toward the chromium(III) ion.
Li2Sr4Al2Ta2N8O, a Nitridoalumotantalate with BCT‐Zeolite Type Structure
Authors: Pust Philipp , Schnick Wolfgang 
Published: October 2011

AbstractLi2Sr4Al2Ta2N8O was synthesized from Li3AlN2, Sr(NH2)2, LiN3, and lithium metal as fluxing agent in weld shut tantalum crucibles. Single crystals were obtained as byproduct from reaction with the ampoule material. The crystal structure (P21/n (no. 14), a = 9.4081(19), b = 10.012(2), c = 5.9832(12) Å, β = 93.44(3)°, Z = 2) was solved on the basis of single‐crystal X‐ray diffraction data. Li2Sr4Al2Ta2N8O is built up of vertex sharing AlN4 and TaN4 tetrahedra, forming a BCT‐zeolite type structure with Sr2+ ions and molecular Li2O units incorporated into the voids. Lattice energy calculations (MAPLE) confirmed the electrostatic bonding interactions and the chemical composition.
Über Fluoridhalogenide
Authors: Weidlein Johann 
Published: October 2011

AbstractIn den letzten Jahren sind zahlreiche neue Fluorierungsmittel bekannt geworden, die in ihrer Vielfalt zu interessanten, bisher unbekannten Fluorverbindungen geführt haben. Die Fluorierungsmittel ihrerseits sind durch eine Reihe neuer Synthesen zugänglich geworden, über die im folgenden berichtet werden soll. Die Fluorierungen lassen sich zum Teil von der Struktur der Fluorierungsmittel her verstehen, so daß diesem Aspekt besondere Aufmerksamkeit gewidmet wird. Anhand charakteristischer Beispiele werden die Anwendungsbereiche der verschiedenen Verfahren abgetastet.
On the Characteristic Curvature of Alkyl‐Polypropylene Oxide Sulfate Extended Surfactants
Authors: Hammond Charles E. , Acosta Edgar J. 
Published: October 2011

AbstractThe hydrophobicity of alkyl‐polypropylene oxide sulfate surfactants was evaluated via their characteristic curvature (Cc) using the hydrophilic‐lipophilic difference (HLD) framework. A close examination of the relationship between the molecular structure of the surfactants considered (structure of the alkyl group and the number of propylene oxide groups in each surfactant) and their Cc led to a group contribution model that, for the first time, takes into consideration the geometry of the alkyl tail group. Based on this group contribution model, branching at the C2 (beta‐carbon) position of the alkyl group produces the largest increase in characteristic curvature. This observation is consistent with the notion that the Cc is associated with the packing factor for anionic surfactants. Branching at the C2 position tends to produce cylindrical or inverse cone shape packing, typical of more hydrophobic (positive Cc) surfactants. This study also confirms previous observations that, different from conventional anionic surfactants, the phase behavior of alkyl polypropylene oxide sulfates is less sensitive to electrolyte concentration and that these formulations turn hydrophobic with increasing temperature, akin to the behavior of nonionic surfactants.
Chromatographic Separation of Synthesized Phenolic Lipids from Krill Oil and Dihydroxyphenyl Acetic Acid
Authors: Aziz Sarya , St‐Louis Richard , Yaylayan Varoujan , Kermasha Selim 
Published: October 2011

AbstractThe separation and characterization of novel biomolecules, phenolic lipids, obtained by the enzymatic transesterification in organic solvent‐free media of krill oil with 3,4‐dihydroxyphenylacetic acid were investigated. The experimental findings showed that by increasing the polarity of the gradient eluent and by decreasing the solvent strength of the mobile phase, from methanol to acetonitrile, a higher resolution was obtained. The use of a shorter column and smaller particle packing size resulted in an enhancement of the efficiency, with decreases in both separation time and solvent consumption. Overall, the evaporative light‐scattering detector (ELSD) showed better repeatability of the resolution (R), theoretical plate number (n), plates per meter (N) and the retention time values as compared to that of the UV detection at 210 and 280 nm. In terms of detection and repeatability, ELSD was shown to be a more appropriate tool for the quantitative analysis of the components of krill oil and its esterified phenolic lipids than UV detection. Fourier transform infrared spectroscopy analysis tentatively confirmed the nature of the separated compounds. In addition, the structural analyses of novel biomolecules by HPLC–MS–APCI/ESI suggested the formation of two phenolic monoacylglycerols.