bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid extraction and analysis method for the simultaneous determination of 21 bioflavonoids in Siegesbeckia pubescens Makino
Authors: Yao Yaqi , Liang Xiao , Sun Xiaoqi , Yin Lina , He Hai , Guo Xingjie , Jiang Zhen 
Published: January 2015

A novel and rapid microwave extraction and ultra high performance liquid chromatography coupled with a triple quadrupole‐linear ion trap mass spectrometry method was developed and validated for the determination of 21 bioflavonoids in Siegesbeckia pubescens Makino. The optimal conditions for the extraction of flavonoids from Siegesbeckia pubescens Makino involved the use of methanol as the extraction solvent, a microwave temperature of 70°C, an extraction time of 11 min, and a solvent‐to‐solid ratio of 40 mL/g. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column(100 × 2.1 mm, 1.7 μm) with a gradient mobile phase (A: 0.3% v/v aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. All calibration curves showed good linearity (r > 0.999) within the test ranges. The method developed was validated with acceptable sensitivity, intra‐ and interday precision, reproducibility, and extraction recoveries. The validated method was successfully applied to determine the contents of 21 bioflavonoids in Siegesbeckia pubescens Makino from different sources.
Training in the Implementation of Prolonged Exposure Therapy: Provider Correlates of Treatment Outcome
Authors: Eftekhari Afsoon , Crowley Jill J. , Ruzek Josef I. , Garvert Donn W. , Karlin Bradley E. , Rosen Craig S. 
Published: January 2015

AbstractThe authors examined the degree to which provider characteristics, such as profession, treatment orientation, prior experience in treating posttraumatic stress disorder (PTSD), prior experience with prolonged exposure (PE) therapy, and attitudes about PE, were related to the clinical outcomes of veterans receiving care from clinicians participating in the national Department of Veterans Affairs (VA) PE Training Program. Positive patient outcomes were achieved by providers of every profession, theoretical orientation, level of clinical experience treating PTSD, and prior PE training experience. With 1,105 providers and 32 predictors (13 provider variables), power was at least 90% power to detect an effect of β = .15. Profession was the only provider characteristic significantly related to outcomes, but the mean effect (a 2 point difference on the PTSD Checklist) was too small to be clinically meaningful. The results support the intensive training model used in the VA PE training program and demonstrate that clinicians of varying backgrounds can be trained using interactive training workshops followed by case consultation to deliver PE effectively.
Social Control in Online Communities of Consumption: A Framework for Community Management
Authors: Sibai Olivier , de Valck Kristine , Farrell Andrew M. , Rudd John M. 
Published: January 2015

ABSTRACTOnline communities of consumption (OCCs) represent highly diverse groups of consumers whose interests are not always aligned. Social control in OCCs aims to effectively manage problems arising from this heterogeneity. Extant literature on social control in OCCs is fragmented as some studies focus on the principles of social control, while others focus on the implementation. Moreover, the domain is undertheorized. This article integrates the disparate literature on social control in OCCs providing a first unified conceptualization of the topic. The authors conceptualize social control as a system, or configuration, of moderation practices. Moderation practices are executed during interactions operating under different governance structures (market, hierarchy, and clan) and serving different purposes (interaction initiation, maintenance, and termination). From this conceptualization, important areas of future research emerge and research questions are developed. The framework also serves as a community management tool for OCC managers, enabling the diagnosis of social control problems and the elaboration of strategies and tactics to address them.
Motivational Drivers of Content Contribution to Company‐ Versus Consumer‐Hosted Online Communities
Authors: Teichmann Karin , Stokburger‐Sauer Nicola E. , Plank Andreas , Strobl Andreas 
Published: January 2015

ABSTRACTThis research investigates the effect of the type of community host (consumer‐hosted versus company‐hosted communities) in the relationship between motivational drivers and content contribution to online communities. By presenting a typology of motivational drivers of content contribution and classifying prior research on motivational drivers accordingly, this article offers an integrated, in‐depth literature review. Four motivational self‐ versus other‐oriented and extrinsic versus intrinsic drivers were included in an empirical study of three online communities, with more than 800 community members. The results reveal that opinion leadership, self‐presentation, and enjoyment positively affect content contribution; altruism negatively affects content contribution. In company‐hosted online communities, the positive drivers are stronger than in consumer‐hosted online communities. To encourage members’ contribution, community managers should seek to attract opinion leaders, provide room for self‐presentation, and enhance members’ feelings of pleasure and comfort. A qualitativepost hocanalysis also explicates the negative effect of altruism. Overall, this study provides a fruitful basis for several important theoretical and managerial implications.
Brand Communication Success in Online Consumption Communities: An Experimental Analysis of the Effects of Communication Style and Brand Pictorial Representation
Authors: Steinmann Sascha , Mau Gunnar , Schramm‐Klein Hanna 
Published: January 2015

ABSTRACTOnline communities are often focused on consumption‐related consumer interests and offer marketers the opportunity to actively engage and cooperate with consumers, foster customer relationships, and easily spread information about new products and services. In spite of this enormous potential, it is surprising that to date, little is known about how such communities can be designed to positively influence consumers’ evaluation of a brand and further marketing‐related outcome variables. Previous studies have shown that the success of online communities might depend on the communication style that is used to interact with the members as well as on the pictorial representation of the brand within an online community. To gain insights into these and further relationships, the authors conducted an online experiment in an online brand community on a social networking site and analyzed the effects of the communication style and the pictorial representation of the brand on the members’ attitudes toward the brand, their satisfaction with the community, brand recommendation, and brand purchase. The study was conducted over three months, and the participants were surveyed three times during this period. Hence, the present study further analyzed whether the proposed effects will change over time due to the member's participation in the community. The results show that communication style and brand pictorial representation in an online consumption community influence members’ evaluation of the brand as well as of the community and brand purchase.
Identification and characterization of [6]‐shogaol from ginger as inhibitor of vascular smooth muscle cell proliferation
Authors: Liu Rongxia , Heiss Elke H. , Sider Nadine , Schinkovitz Andreas , Gröblacher Barbara , Guo Dean , Bucar Franz , Bauer Rudolf , Dirsch Verena M. , Atanasov Atanas G. 
Published: January 2015

ScopeVascular smooth muscle cell (VSMC) proliferation is involved in the pathogenesis of cardiovascular disease, making the identification of new counteracting agents and their mechanisms of action relevant. Ginger and its constituents have been reported to improve cardiovascular health, but no studies exist addressing a potential interference with VSMC proliferation.Methods and resultsThe dichloromethane extract of ginger inhibited VSMC proliferation when monitored by resazurin metabolic conversion (IC50 = 2.5 μg/mL). The examination of major constituents from ginger yielded [6]‐shogaol as the most active compound (IC50 = 2.7 μM). In the tested concentration range [6]‐shogaol did not exhibit cytotoxicity toward VSMC and did not interfere with endothelial cell proliferation. [6]‐shogaol inhibited DNA synthesis and induced accumulation of the VSMC in the G0/G1 cell‐cycle phase accompanied with activation of the nuclear factor‐erythroid 2‐related factor 2 (Nrf2)/HO‐1 pathway. Since [6]‐shogaol lost its antiproliferative activity in the presence of the heme oxygenase‐1 (HO‐1) inhibitor tin protoporphyrin IX, HO‐1 induction appears to contribute to the antiproliferative effect.ConclusionThis study demonstrates for the first time inhibitory potential of ginger constituents on VSMC proliferation. The presented data suggest that [6]‐shogaol exerts its antiproliferative effect through accumulation of cells in the G0/G1 cell‐cycle phase associated with activation of the Nrf2/HO‐1 pathway.
Automatic generation of multiblock decompositions of surfaces
Authors: Fogg Harold J. , Armstrong Cecil G. , Robinson Trevor T. 
Published: January 2015

SummaryMultiblock‐structured meshes have significant advantages over fully unstructured meshes in numerical simulation, but automatically generating these meshes is considerably more difficult. A method is described herein for automatically generating high‐quality multiblock decompositions of surfaces with boundaries. Controllability and flexibility are useful capabilities of the method. Additional alignment constraints for forcing the appearance of particular features in the decomposition can be easily handled. Also, adjustments are made according to input metric tensor fields that describe target element size properties. The general solution strategy is based around using a four‐way symmetry vector‐field, called a cross‐field, to describe the local mesh orientation on a triangulation of the surface. Initialisation is performed by propagating the boundary alignment constraints to the interior in a fast marching method. This is similar in a way to an advancing‐front or paving method but much more straightforward and flexible because mesh connectivity does not have to be managed in the cross‐field. Multiblock decompositions are generated by tracing the separatrices of the cross‐field to partition the surface into quadrilateral blocks with square corners. The final task of meshing the decomposition requires solving an integer programming problem for block division numbers. Copyright © 2015 John Wiley & Sons, Ltd.
TRAX: An approach for the time rational analysis of complex dynamic systems
Authors: Lecomte Christophe 
Published: January 2015

SummaryThis paper introduces a theoretical and algorithmic reduced model approach to efficiently evaluate time responses of complex dynamic systems. The proposed approach combines four main components: analytical expressions of the average of the system's transfer functions in the frequency domain, precise and convergent rational approximations of these exact expressions, exact evaluation of these approximations through model reduction in rational Krylov subspaces and semi‐analytical interpolation at just a few frequency points. The resulting algorithmic principles to evaluate the time response of a particular system are relatively straightforward: one first evaluates the response of the system with slight additional damping at a few frequencies and one then projects or reduces the system in the subspace spanned by these responses. The time response of the reduced model implicitly provides a precise evaluation of that of the original system. The properties of the reduced models and the precision of the proposed approach are studied, and applications on complex matrix systems are presented and discussed. While the theory and numerical algorithms are presented in a matrix context, they are also transposable in a continuous functional context. Copyright © 2015 John Wiley & Sons, Ltd.
A new hybrid boundary node method based on Taylor expansion and the Shepard interpolation method
Authors: Yan Fei , Lv Jia‐He , Feng Xia‐Ting , Pan Peng‐Zhi 
Published: January 2015

SummaryA novel meshless method based on the Shepard and Taylor interpolation method (STIM) and the hybrid boundary node method (HBNM) is proposed. Based on the Shepard interpolation method and Taylor expansion, the STIM is developed to construct the shape function of the HBNM. In the STIM, the Shepard shape function is used as the basic function, which is the zero‐level shape function, and the high‐power basic functions are constructed through Taylor expansion. Four advantages of the STIM are the interpolation property, the arbitrarily high‐order consistency, the absence of inversion for the whole process of shape function construction, and the low computational expense. These properties are desirable in the implementation of meshless methods. By combining the STIM and the HBNM, a much more effective meshless method is proposed to solve the elasticity problems. Compared with the traditional HBNM, the STIM can improve accuracy because of the use of high‐power basic functions and can also improve the computational efficiency because there is no inversion for the shape function construction process. Numerical examples are given to demonstrate the accuracy and efficiency of the proposed method. Copyright © 2015 John Wiley & Sons, Ltd.
A node‐to‐node scheme with the aid of variable‐node elements for elasto‐plastic contact analysis
Authors: Jin Seungmin , Sohn Dongwoo , Lim Jae Hyuk , Im Seyoung 
Published: January 2015

SummaryA strategy for a two‐dimensional contact analysis involving finite strain plasticity is developed with the aid of variable‐node elements. The variable‐node elements, in which nodes are added freely where they are needed, make it possible to transform the non‐matching meshes into matching meshes directly. They thereby facilitate an efficient analysis, maintaining node‐to‐node contact during the contact deformation. The contact patch test, wherein the contact patch is constructed out of variable‐node elements, is thus passed, and iterations for equilibrium solutions reach convergence faster in this scheme than in the conventional approach based on the node‐to‐surface contact. The effectiveness and accuracy of the proposed scheme are demonstrated through several numerical examples of elasto‐plastic contact analyses. Copyright © 2015 John Wiley & Sons, Ltd.
Brittle and ductile failure of rocks: Embedded discontinuity approach for representing mode I and mode II failure mechanisms
Authors: Nikolic M. , Ibrahimbegovic A. , Miscevic P. 
Published: January 2015

SummaryIn this work, we present a discrete beam lattice model with embedded discontinuities capable of simulating rock failure as a result of propagating cracks through rock mass. The developed model is a two‐dimensional (plane strain) microscale representation of rocks as a two‐phase heterogeneous material. Phase I is chosen for intact rock part, while phase II stands for pre‐existing microcracks and other defects. The proposed model relies on Timoshenko beam elements enhanced with additional kinematics to describe localized failure mechanisms. The model can properly take into account the fracture process zone with pre‐existing microcracks coalescence, along with localized failure modes, mode I of tensile opening and mode II of shear sliding. Furthermore, we give the very detailed presentation for two different approaches to capturing the evolution of modes I and II, and their interaction and combination. The first approach is to deal with modes I and II separately, where mode II can be activated but compression force may still be transferred through rock mass which is not yet completely damaged. The second approach is to represent both modes I and II being activated simultaneously at a point where complete failure is reached. A novel numerical procedure for dealing with two modes failure within framework of method of incompatible modes is presented in detail and validated by a set of numerical examples. Copyright © 2015 John Wiley & Sons, Ltd.
Coarse‐grained modeling and simulation of graphene sheets based on a discrete hyperelastic approach
Authors: Qian Dong , Zhou Zhong , Zheng Qingjin 
Published: January 2015

SummaryA discrete hyperelastic model was developed in this paper for a single atomic layer of graphene structure that was originally planar. This model can be viewed as an extension to the well‐known continuum hyperelastic model. Based on the discrete nature of the atomic structure, the notion of discrete mapping and the concept of spatial secant were introduced. The spatial secant served as a deformation measure that provided a geometric exact mapping in the discrete sense between the atomistic and continuum representations. By incorporating a physics‐based interatomic potential, the corresponding discrete hyperelastic model was then established. After an introduction of the model, the computational implementation using the Galerkin finite element and/or meshfree method was outlined. The computational framework was then applied to study of the mechanics of graphene sheets. Extensive comparisons with full‐scale molecular mechanics simulations and experimental measurement were made to illustrate the robustness of this approach. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
New prospects for PV powered water desalination plants: case studies in Saudi Arabia
Authors: Fthenakis Vasilis , Atia Adam A. , Morin Olivier , Bkayrat Raed , Sinha Parikhit 
Published: January 2015

AbstractIncreased water demand and increased drought episodes in the Middle East and other regions necessitate an expansion in desalination projects and create a great market opportunity for photovoltaics (PV). PV‐powered desalination has previously been regarded as not being a cost‐competitive solution when compared with conventionally powered desalination; however, the decline in PV costs over the last few years has changed this outlook. This paper presents up‐to‐date performance and cost analysis of reverse osmosis (RO) desalination powered with PV connected to the Saudi Arabian grid. Reference cases include relatively small (i.e., producing 6550 m3 water per day) and large (i.e., 190 000 m3/day) desalination plants using seawater at a salinity of 40 000 ppm. We used data from a King Abdullah University for Science and Technology presentation and Hybrid Optimization Model for Electric Renewables 2.81 Energy Modeling Software (HOMER Energy LLC) in tandem with Desalination Economic Evaluation Program 4.0 (International Atomic Energy Agency) desalination software to analyze the techno‐economic feasibility of these plants. The first phase of our work entailed a comparison between dual‐axis high concentration PV (CPV) equipped with triple junction III/V solar cells and CdTe PV‐powered RO systems. The estimated levelized cost of electricity from CPV is $0.16/kWh, whereas that from CdTe PV is $0.10/kWh and $0.09/kWh for fixed‐tilt and one‐axis tracking systems, respectively. These costs are higher than the price of diesel‐based grid electricity in the region because diesel fuel is heavily subsidized in Saudi Arabia.In the second phase, we determined the cost of producing desalinated water from the two RO plant sizes powered with CdTe PV. Assuming that the grid acts as zero‐loss storage, the total water cost ranges from a high cost of $1.39/m3 for the small RO plant coupled with latitude‐tilt, fixed PV to $0.85/m3 for the large RO plant coupled with optimally positioned one‐axis tracking systems; these PV power plants would displace 1 158 987 and 33 579 763 l of diesel per year, respectively. Furthermore, the corresponding savings in diesel subsidies enabled by PV are $1.5m and $43.2m per year. Applying these savings to the PV system calls for a levelized cost of electricity of $0.21/kWh, justifying a feed‐in‐tariff at this level. The avoided CO2 emissions by displacing diesel fuel would be 3115 and 90 241 tonnes per year for the small and large Photovoltaics Powered Reverse Osmosis Water Desalination (PV‐RO) plants, respectively. On the basis of the results of this study, we infer that there are great business prospects associated with large deployment of PV‐RO plants in the greater Middle East, and we estimate the reduction in regional CO2 emissions from such deployment. Copyright © 2015 John Wiley & Sons, Ltd.
Fabrication of highly ordered porous membranes of cellulose triacetate on ice substrates using breath figure method
Authors: Yu Bing , Cong Hailin , Li Zejing , Yuan Hua , Peng Qiaohong , Chi Ming , Yang Shujing , Yang Ruixia , Ranil Wickramasinghe S. , Tang Jianguo 
Published: January 2015

ABSTRACTHighly ordered porous membranes of cellulose triacetate (CTA) were prepared successfully on ice substrates using breath figure method. The pore size and structure of the membrane were modulated by changing CTA concentrations and substrate materials. As the CTA concentration in the casting solution increased, the pore size in the formed membrane decreased. The regularity of the membrane cast on the ice substrate was much better than that of the membrane cast on glass substrate, because the low temperature of ice substrate slowed down the evaporation rate of organic solvent, which offered enough time for condensed water droplets to self‐organize into an ordered array dispersed in the polymer solution before their coagulation. The ordered porous CTA membrane was not only used for microfiltration, but also used for fabrication of functional microstructures. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 552–558
Ca2+ and Mg2+ modulate conformational dynamics and stability of downstream regulatory element antagonist modulator
Authors: Pham Khoa , Dhulipala Gangadhar , Gonzalez Walter G. , Gerstman Bernard S. , Regmi Chola , Chapagain Prem P. , Miksovska Jaroslava 
Published: January 2015

AbstractDownstream Regulatory Element Antagonist Modulator (DREAM) belongs to the family of neuronal calcium sensors (NCS) that transduce the intracellular changes in Ca2+ concentration into a variety of responses including gene expression, regulation of Kv channel activity, and calcium homeostasis. Despite the significant sequence and structural similarities with other NCS members, DREAM shows several features unique among NCS such as formation of a tetramer in the apo‐state, and interactions with various intracellular biomacromolecules including DNA, presenilin, Kv channels, and calmodulin. Here we use spectroscopic techniques in combination with molecular dynamics simulation to study conformational changes induced by Ca2+/Mg2+ association to DREAM. Our data indicate a minor impact of Ca2+ association on the overall structure of the N‐ and C‐terminal domains, although Ca2+ binding decreases the conformational heterogeneity as evident from the decrease in the fluorescence lifetime distribution in the Ca2+ bound forms of the protein. Time‐resolved fluorescence data indicate that Ca2+binding triggers a conformational transition that is characterized by more efficient quenching of Trp residue. The unfolding of DREAM occurs through an partially unfolded intermediate that is stabilized by Ca2+ association to EF‐hand 3 and EF‐hand 4. The native state is stabilized with respect to the partially unfolded state only in the presence of both Ca2+ and Mg2+ suggesting that, under physiological conditions, Ca2+ free DREAM exhibits a high conformational flexibility that may facilitate its physiological functions.