bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular dynamics simulations of semicrystalline polymers: Crystallization, melting, and reorganization
Authors: Sommer Jens‐Uwe , Luo Chuanfu 
Published: September 2010

AbstractLarge‐scale molecular dynamics (MD) simulations of semicrystalline entangled polymers are carried out to explore crystallization and melting processes. Semicrystalline polymers are obtained from disordered melts via homogeneous nucleation. In the early stage of the crystallization process, the collective scattering does not show the emergence of nuclei seeds. Although the crystallization process is thermodynamically simple, the melting process is complex resulting in multiple‐peaked melting endotherms. The molecular origin is found to be the different thermal stabilities of microcrystalline domains (MCDs). Coexistence of melting and growth of different MCDs during sufficiently slow heating enlarges the difference of their thermal stabilities. An increase of stem length close to the melting point is assisted by disorder effects in particular in the surface regions of the MCDs. The number of trans–trans states is decreasing, which increases the flexibility and mobility of the crystalline stems. We have also investigated self‐seeding processes, and we show how these can be used to obtain single lamellar crystals in MD simulations. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010
The activity of recombinant human neuroglobin as an antioxidant and free radical scavenger
Authors: Li Weiguang , Wu Yonghong , Ren Changhong , Lu Yiming , Gao Yan , Zheng Xiaofei , Zhang Chenggang 
Published: September 2010

AbstractFree radicals are by‐products of metabolism and exist in a homeostasis between generation and scavenging in vivo. Excessive free radicals cause various diseases, including nervous system diseases. Neuroglobin (Ngb), a nervous system‐specific oxygen‐binding protein, has been suggested to be a potential free radical scavenger in the nervous system in vivo; however, its underlying mechanism remains unclear. In this study, we investigated the antioxidant potential and free radical scavenging properties of recombinant human Ngb (rhNgb) in vitro. Interestingly, we found that the rhNgb protein itself has a direct and distinct antioxidant capacity and can efficiently scavenge a variety of free radicals, including the [2,2′‐azino‐di‐(3‐ethyl‐benzthiazoline‐6‐sulfonic acid)] (ABTS) cation, superoxide anion, hydrogen peroxide, and hydroxyl radical. The capacity of rhNgb to scavenge the superoxide anion and hydrogen peroxide was even comparable to that of vitamin C. In addition, rhNgb had Fe2+ chelating activity but hemoglobin did not. In conclusion, our results indicated that the rhNgb protein itself has antioxidant and free radical scavenging activities, providing fundamental evidence for the neuroprotective function of Ngb. These data provide key information for the origin of the neuroprotective and physiological role of Ngb and will promote the treatment of reactive oxygen species (ROS)‐related diseases using this novel oxygen‐binding globin. Proteins 2010. © 2010 Wiley‐Liss, Inc.
An X‐ray diffraction technique for analyzing basal‐plane stacking faults in GaN
Authors: Paduano Qing S. , Weyburne David W. , Drehman Alvin J. 
Published: September 2010

AbstractAn X‐ray diffraction (XRD) technique for analyzing basal‐plane stacking faults (BSFs) is introduced and tested on GaN. The analysis considers the coexistence of multiple X‐ray broadening terms including tilt, twist, limited coherence length, and inhomogeneous strain. By measuring and fitting a series of symmetric and asymmetric reflections planes, we deduce the lattice tilt, twist, lateral coherence length, and inhomogeneous strain contributions, which allow us to determine the existence of any additional broadening in m‐plane GaN. We found that in fact certain ω‐scans do have excess broadening and that their lattice plane dependence is similar to the functional dependence of BSFs derived for powder XRD (θ/2θ‐scan). Applying such functional dependence allows us to estimate the BSF densities (I1‐ and I2‐type). The typical stacking fault density was estimated to be 1 × 106/cm in m‐plane GaN grown on m‐plane sapphire by MOCVD, while the relative densities of I1‐ and I2‐type are sample dependent. In contrast to the m‐plane GaN, stacking faults in GaN on c‐plane sapphire do not contribute significantly to Bragg peak broadening and are below the detection limit.
Correlation of geometrical and electronic properties in metallic nanowires
Authors: Pfnür H. , Tegenkamp C. , Czubanowski M. , Lükermann D. , Rönspies J. , Wießell S. 
Published: September 2010

AbstractThe structure on the atomic scale was found to be directly correlated with the electronic and transport properties of ultra‐thin metallic wires. We present examples of both self‐organized and artificially structured nanowires in the system Pb/Si(557). We demonstrate that artificial structuring on the nanoscale allows identification and determination of the electrical transport properties of atomic size defects, using Si(557) as a quasi‐insulating substrate and a Si double step in a monolayer high Pb nanowire as an example. One‐dimensional (1D) properties with strong electron correlation and various instabilities in metallic chains or ribbons generated by metal adsorption of sub‐monolayers on insulating substrates like Si(111) or Si(557) turn out to always be modified by the unavoidable coupling to 2D and 3D. The wealth of new and partly unexpected phenomena is exemplified here again in monolayers of Pb on Si(557), which forms wire‐like arrays. We identify structural self‐stabilization as the origin of 1D electronic transport and show that a new 1D state is generated by step decoration. Magnetoconductance measurements yield even deeper insight into mechanisms of electronic transport, as also exemplified in this specific system.
Organic solar cells with very high fill factor and voltage using tetrapropyl‐tetraphenyl‐diindenoperylene as green donor
Authors: Meiss Jan , Hummert Markus , Ziehlke Hannah , Leo Karl , Riede Moritz 
Published: September 2010

AbstractWe present 2,3,10,11‐tetrapropyl‐1,4,9,12‐tetraphenyl‐diindeno[1,2,3‐cd:1′,2′,3′‐lm]perylene (P4‐Ph4‐DIP) as new green donor for small molecule organic solar cells (SMOSC). P4‐Ph4‐DIP absorbs in the green spectral range of 490–580 nm and thus is a decisive building block towards broad coverage of the sun spectrum. SMOSC with P4‐Ph4‐DIP as donor and C60 as blue‐absorbing acceptor display very high fill factors FF > 76% and open circuit voltages of 0.99 V, reaching η = 1.92% for 12 nm P4‐Ph4‐DIP. Current voltage and external quantum efficiency spectra suggest that an exciton diffusion length ED < 20 nm is the main limiting factor. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of open‐ended TiO2 nanotube arrays by a simple two‐step anodization
Authors: Zhang Zhi‐Kun , Guo Deng‐Zhu , Xing Ying‐Jie , Zhang Geng‐Min 
Published: September 2010

AbstractWe report a two‐step anodizing approach for the fabrication of large‐scale open‐ended TiO2 nanotube arrays (TNAs) on a conductive Au layer. In this method, a deposited Ti/Au bilayer film is initially anodized under a high potential to form and shape the TNAs. A following low potential is then in situ applied at a suitable time to slowly eliminate the remaining barrier layer at the bottom of the TNAs without further treatment. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ethical considerations in industry‐sponsored Multiregional clinical trials
Authors: Ibia Ekopimo , Binkowitz Bruce , Saillot Jean‐Louis , Talerico Steven , Koerner Chin , Ferreira Irene , Agarwal Anupam , Metz Craig , Maman Marianne 
Published: September 2010

AbstractDuring the last several decades, the scientific and ethics communities have addressed important ethical issues in medical research, resulting in the elaboration and adoption of concepts, guidelines, and codes.Ethical issues in the conduct of Multiregional Clinical Trials have attracted significant attention mainly in the last two decades. With the globalization of clinical research and the rapid expansion to countries with a limited tradition of biomedical research, sponsors must proactively address local ethical issues, the adequacy of oversight as well as the applicability and validity of data, and scientific conclusions drawn from diverse patient populations.This paper highlights some core ethical principles and milestones in medical research, and, from an industry perspective, it discusses ethical issues that the clinical trial team may face when conducting Multiregional Clinical Trials (MRCT, clinical trials conducted at sites located across multiple geographic regions of the world). This paper further highlights the areas of consensus and controversies and proposes points to consider. Copyright © 2010 John Wiley & Sons, Ltd.
A high‐performance, safer and semi‐automated approach for the δ18O analysis of diatom silica and new methods for removing exchangeable oxygen
Authors: Chapligin B. , Meyer H. , Friedrichsen H. , Marent A. , Sohns E. , Hubberten H.‐W. 
Published: September 2010

AbstractThe determination of the oxygen isotope composition of diatom silica in sediment cores is important for paleoclimate reconstruction, especially in non‐carbonate sediments, where no other bioindicators such as ostracods and foraminifera are available. Since most currently available analytical techniques are time‐consuming and labour‐intensive, we have developed a new, safer, faster and semi‐automated online approach for measuring oxygen isotopes in biogenic silica. Improvements include software that controls the measurement procedures and a video camera that remotely records the reaction of the samples under BrF5 with a CO2 laser. Maximum safety is guaranteed as the laser‐fluorination unit is arranged under a fume hood in a separate room from the operator. A new routine has been developed for removing the exchangeable hydrous components within biogenic silica using ramp degassing. The sample plate is heated up to 1100°C and cooled down to 400°C in ∼7 h under a flow of He gas (the inert Gas Flow Dehydration method – iGFD) before isotope analysis. Two quartz and two biogenic silica samples (∼1.5 mg) of known isotope composition were tested. The isotopic compositions were reproducible within an acceptable error; quartz samples gave a mean standard deviation of <0.15‰ (1σ) and for biogenic silica <0.25‰ (1σ) for samples down to ∼0.3 mg. The semi‐automated fluorination line is the fastest method available at present and enables a throughput of 74 samples/week. Copyright © 2010 John Wiley & Sons, Ltd.
A robotic system for monitoring carp in Minnesota lakes
Authors: Tokekar Pratap , Bhadauria Deepak , Studenski Andrew , Isler Volkan 
Published: September 2010

AbstractRobotic sensor networks (RSNs) find increasing use in environmental monitoring as they can collect data from obscure, hard‐to‐reach places over long periods of time. This work reports progress in building a network of small, lightweight robotic rafts that will be used to monitor common carp tagged with radio transmitters across Minnesota lakes. We describe the design and architecture of the robotic raft and demonstrate the robustness of our waypoint navigation algorithm through field tests conducted in various lakes. We also present results from experiments aimed at localizing tagged fish. © 2010 Wiley Periodicals, Inc.
Model selection procedure for high‐dimensional data
Authors: Zhang Yongli , Shen Xiaotong 
Published: September 2010

AbstractFor high‐dimensional regression, the number of predictors may greatly exceed the sample size but only a small fraction of them are related to the response. Therefore, variable selection is inevitable, where consistent model selection is the primary concern. However, conventional consistent model selection criteria like Bayesian information criterion (BIC) may be inadequate due to their nonadaptivity to the model space and infeasibility of exhaustive search. To address these two issues, we establish a probability lower bound of selecting the smallest true model by an information criterion, based on which we propose a model selection criterion, what we call RICc, which adapts to the model space. Furthermore, we develop a computationally feasible method combining the computational power of least angle regression (LAR) with that of RICc. Both theoretical and simulation studies show that this method identifies the smallest true model with probability converging to one if the smallest true model is selected by LAR. The proposed method is applied to real data from the power market and outperforms the backward variable selection in terms of price forecasting accuracy. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 350‐358, 2010
A novel framework for detecting maximally banded matrices in binary data
Authors: Alqadah Faris , Bhatnagar Raj , Jegga Anil 
Published: September 2010

AbstractBinary data occurs often in real‐world applications ranging from social networks to bioinformatics. As such, extracting patterns from binary data has been a fundamental task of data mining. Recently, the utility of banded structures in binary matrices has been pointed out for applications such as paleontology, bioinformatics, and social networking. A binary matrix has a banded structure if both the rows and columns can be permuted so that the 1s exhibit a staircase pattern down the rows, along the leading diagonal. Natural interpretations of banded structures include overlapping communities in social networks, patterns of species occurring in spatially correlated sites, and overlapping roles of genes in various diseases. In this paper, we show the correspondence between formal concept analysis and banded structure; as a direct result of this correspondence a novel framework for discovering banded structures is presented. Utilizing the framework, the MMBS algorithm (mine maximally banded submatrices) is developed. The current state‐of‐the‐art algorithm, MBS, only allows for the discovery of a single band and assumes a fixed‐column permutation. On the other hand, MMBS facilitates the discovery of multiple bands that may possibly be overlapping or segmented. Our experimental results, presented here, clearly indicate the advantage of MMBS over MBS with both, synthetic and real datasets. Copyright © 2010 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 431‐445, 2010
Secrecy coding for the binary symmetric wiretap channel
Authors: Chen Yanling , Han Vinck A. J. 
Published: September 2010

AbstractIn this paper, we investigate the binary symmetric wiretap channel. We show that the secrecy capacitycan be achieved by using random linear codes. The random coding scheme gives insight into the structure of secrecy capacity achieving code but unfortunately involves a rather impractical decoder. We further explore the coset‐coding schemeconstructed by linear codes. As a result, we give an upper bound on the total information loss, which sheds light on the design of the applicable coset codes for the secure transmission with limited information leakage. Copyright © 2010 John Wiley & Sons, Ltd.
Several methods to assess improvement in risk prediction models: Extension to survival analysis
Authors: Chambless Lloyd E. , Cummiskey Christopher P. , Cui Gang 
Published: September 2010

AbstractRisk prediction models have been widely applied for the prediction of long‐term incidence of disease. Several parameters have been identified and estimators developed to quantify the predictive ability of models and to compare new models with traditional models. These estimators have not generally accounted for censoring in the survival data normally available for fitting the models. This paper remedies that problem. The primary parameters considered are net reclassification improvement (NRI) and integrated discrimination improvement (IDI). We have previously similarly considered a primary measure of concordance, area under the ROC curve (AUC), also called the c‐statistic. We also include here consideration of population attributable risk (PAR) and ratio of predicted risk in the top quintile of risk to that in the bottom quintile. We evaluated estimators of these various parameters both with simulation studies and also as applied to a prospective study of coronary heart disease (CHD). Our simulation studies showed that in general our estimators had little bias, and less bias and smaller variances than the traditional estimators. We have applied our methods to assessing improvement in risk prediction for each traditional CHD risk factor compared to a model without that factor. These traditional risk factors are considered valuable, yet when adding any of them to a risk prediction model that has omitted the one factor, the improvement is generally small for any of the parameters. This experience should prepare us to not expect large values of the risk prediction improvement evaluation parameters for any new risk factor to be discovered. Copyright © 2010 John Wiley & Sons, Ltd.
Understanding the Photothermal Conversion Efficiency of Gold Nanocrystals
Authors: Chen Huanjun , Shao Lei , Ming Tian , Sun Zhenhua , Zhao Chunmei , Yang Baocheng , Wang Jianfang 
Published: September 2010

AbstractPlasmon‐based photothermal therapy is one of the most intriguing applications of noble metal nanostructures. The photothermal conversion efficiency is an essential parameter in practically realizing this application. The effects of the plasmon resonance wavelength, particle volume, shell coating, and assembly on the photothermal conversion efficiencies of Au nanocrystals are systematically studied by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance. The temperature of Au nanocrystal solutions reaches the maximum at ∼75°C when the plasmon resonance wavelength of Au nanocrystals is equal to the illumination laser wavelength. For Au nanocrystals with similar shapes, the larger the nanocrystal, the smaller the photothermal conversion efficiency becomes. The photothermal conversion can also be controlled by shell coating and assembly through the change in the plasmon resonance energy of Au nanocrystals. Moreover, coating Au nanocrystals with semiconductor materials that have band gap energies smaller than the illumination laser energy can improve the photothermal conversion efficiency owing to the presence of an additional light absorption channel.
Interaction of Hypoxia-Inducible Factor-1α and Notch Signaling Regulates Medulloblastoma Precursor Proliferation and Fate
Authors: Pistollato Francesca , Rampazzo Elena , Persano Luca , Abbadi Sara , Frasson Chiara , Denaro Luca , D'Avella Domenico , Panchision David M. , Puppa Alessandro Della , Scienza Renato , Basso Giuseppe 
Published: September 2010

Abstract
Medulloblastoma (MDB) is the most common brain malignancy of childhood. It is currently thought that MDB arises from aberrantly functioning stem cells in the cerebellum that fail to maintain proper control of self-renewal. Additionally, it has been reported that MDB cells display higher endogenous Notch signaling activation, known to promote the survival and proliferation of neoplastic neural stem cells and to inhibit their differentiation. Although interaction between hypoxia-inducible factor-1α (HIF-1α) and Notch signaling is required to maintain normal neural precursors in an undifferentiated state, an interaction has not been identified in MDB. Here, we investigate whether hypoxia, through HIF-1α stabilization, modulates Notch1 signaling in primary MDB-derived cells. Our results indicate that MDB-derived precursor cells require hypoxic conditions for in vitro expansion, whereas acute exposure to 20% oxygen induces tumor cell differentiation and death through inhibition of Notch signaling. Importantly, stimulating Notch1 activation with its ligand Dll4 under hypoxic conditions leads to expansion of MDB-derived CD133+ and nestin+ precursors, suggesting a regulatory effect on stem cells. In contrast, MDB cells undergo neuronal differentiation when treated with γ-secretase inhibitor, which prevents Notch activation. These results suggest that hypoxia, by maintaining Notch1 in its active form, preserves MDB stem cell viability and expansion.
Development of Multiple Power Quality Supply System
Authors: Hirose Keiichi , Fukui Akiyoshi , Matsumoto Akira , Murai Hideyuki , Takeda Takashi , Matsumura Toshiro 
Published: September 2010

AbstractThis paper describes the characteristics and performances of a multiple power quality supply system (MPQSS), which consists of power electronics‐based voltage compensators and three types of distributed generators (DGs). Its original concept of a future power delivery system having different service levels to meet each customer or load requirement at the same time was proposed as Flexible, Reliable, and Intelligent Electrical eNergy Delivery System (FRIENDS). The effectiveness of the developed power system was measured during an actual field demonstration conducted in 2007 by the New Energy and Industrial Technology Development Organization (NEDO), Sendai, Japan. Its effectiveness in feeding four classes of alternative current (AC) and one of direct current (DC) power while meeting various customer requirements was confirmed. Some sets of test data and an analysis using the data indicate that the developed system meets all the requirements for DG‐related plants and has additional benefits. The power system maintains voltage and frequency conditions without interruption in the every state, grid interconnection, islanding, and backup modes. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Panacea or paradox? Cross‐sector partnerships, climate change, and development
Authors: Forsyth Tim 
Published: September 2010

AbstractCross‐sector partnerships between representatives of state, private business, and civil society are widely proposed as means to involve non‐state actors in public policy. Yet, critics have argued partnerships contain paradoxes that prevent effective regulation or social inclusion. This paper reviews these debates and applies them to climate change policy in developing countries, and especially technology transfer and forest governance. The paper argues that debate about partnerships needs to move from rhetoric to identifying institutional designs that maximize contractual obligations and enhance local deliberation. But enhancing deliberation also implies looking at how partnerships reflect, rather than create, wider norms and advocacy coalitions, and by creating standardized means of collaboration such as free and prior informed consent. Rethinking partnerships in these ways not only accelerates climate change mitigation but also builds local adaptive capacity. Copyright © 2010 John Wiley & Sons, Ltd.This article is categorized under:

Policy and Governance > Governing Climate Change in Communities, Cities, and Regions
Use a Reduced Heston or Reduce the Use of Heston?
Authors: Guillaume Florence , Schoutens Wim 
Published: September 2010

AbstractThis paper features the calibration performance of the Heston model for two different calibration procedures. The first consists of the standard calibration on the whole parameter set and the second one, called reduced calibration, consists of a calibration on the reduced parameter set {κ, λ, ρ} where the spot variance v0 and the long run variance η are inferred beforehand from the time series of the VIX volatility index. It is shown that both calibration procedures lead to an accurate fit of the vanilla option surface. Furthermore, both the computation time and the calibration risk of the reduced calibration procedure turn out to be significantly lower, which might turn out to be a considerable advantage for practitioners. This paper also features a comparison of the price of different exotic options for the two calibration procedures.