bluuebunny/crossref_metadata_2025_split huggingface dataset:
The spatial distribution of silicon NCs and erbium ion clusters by simultaneous high‐resolution energy filtered and Z‐contrast STEM and transmission electron tomography
Authors: Wang Xiongyao , Li Peng , Malac Marek , Lockwood Ross , Meldrum Al 
Published: January 2011

AbstractImaging the spatial distribution of silicon nanocrystals (Si‐NCs) and erbium ion clusters can assist in the development of light‐emitting erbium‐doped silicon nanocomposites. We applied simultaneous energy‐filtered and high‐angle annular dark field imaging in the scanning transmission electron microscopy (STEM) mode; the former method images the Si NCs and the latter is sensitive to the high atomic number of the Er3+ ions. Both methods were performed simultaneously so as to avoid relative image drift. In Er‐doped Si nano‐composites, we find that the Er ions are not uniformly distributed in the matrix: instead, they form clusters that appear in projection images to decorate the boundaries of the Si‐NCs. This structure may develop during sample annealing, due to the low solubility of Er in the forming Si clusters. Although multi‐detector simultaneous imaging is a good way to avoid nanometer‐scale image drift that could otherwise conceal the nanoscale spatial relationship between Si‐NCs and Er clusters, an additional difficulty relates to the projection imaging methods. Essentially, it is hard to obtain spatial information parallel to the electron beam direction, so where there is apparent overlap we cannot ascertain whether an Er cluster (for example) lies above, below, or inside a given Si‐NC. Therefore, we also report on initial electron beam tomography investigations whose goal is ultimately to generate methods for obtaining the Er and Si cluster distribution in 3D. The results can lead to improved understanding of the sensitization mechanism and optimization for Er‐doped silicon nanocomposites; the clustered nature of the Er ions near the Si NCs is certainly undesirable and may explain the typically short Er3+ photoluminescence (PL) lifetimes (compared to Er‐doped silica) and the difficulty in reliably observing stimulated emission phenomena (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton in twisted single‐walled carbon nanotube
Authors: Lü Yan , Liu Hong , Gu Bing , Duan Wenhui , Luo Chenglin 
Published: January 2011

AbstractWe study the exciton effect of twisted single‐walled carbon nanotubes (SWNTs) within the tight‐binding approximation and including the electron‐electron Coulomb interaction. We obtain an approximate relationship that can describe the variation of the band gap of SWNTs with the torsion angle. Based on this relationship, we can divide SWNTs into three kinds according to the different behaviors of band gap at the small torsion angle.Furthermore, specially for metallic SWNTs, the exciton binding energies can rapidly increase to 0.2 eV under small torsion angle, like a switch on the control of generation of exciton in metallic SWNTs. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active terahertz metamaterials: Nano‐slot antennas on VO2 thin films
Authors: Kyoung J. S. , Seo M. A. , Koo S. M. , Park H. R. , Kim H. S. , Kim B. J. , Kim H. T. , Park N. K. , Kim D. S. , Ahn K. J. 
Published: January 2011

AbstractWe demonstrate a broadband metamaterial based on nano‐slot antenna on a VO2 thin film, which transforms itself from transparent to completely extinct over a broad spectrum when the underlying VO2 thin film makes Mott‐insulator‐to‐metal phase transition. Our structure, long wavelength nano resonators inspired by log‐periodic antenna, has 2 terahertz (THz) wide spectral range with 10,000: 1 extinction ratio through thermal and photo excitation. Two of the most important demands for present metamaterials research, broadband operation and full transmission/extinction control, are met in our metamaterial. Our structure enables nano‐scale thin film technology to fully enter into long wavelength applications, and we foresee a wide range of applications in areas where perfect modulation, giant nonlinearity, switching, and filtering in broad THz bands are desired. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dependence of the modulation response of quantum dot based nanocavity devices on the number of emitters
Authors: Lorke M. , Nielsen T. R. , Mørk J. 
Published: January 2011

AbstractA microscopic theory is used to study the dynamical properties of semiconductor quantum dot based nanocavity laser systems. The carrier kinetics and photon populations are determined using a fully quantum mechanical treatment of the light‐matter coupling.In this work, we investigate the dependency of the modulation response in such devices on the number of emitters coupled to the cavity mode. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generation of coherent LO phonons in optically driven biased quantum wells
Authors: Papenkort Thomas , Kuhn Tilmann , Axt Vollrath Martin 
Published: January 2011

AbstractWe present a theoretical analysis and numerical simulations of the resonant generation of coherent LO phonons in an electrically biased quantum well. The system is driven by a laser pulse short enough to simultaneously excite two transitions, which leads to a quantum beat that can resonantly create coherent phonons. The generation of incoherent phonons is also calculated on a quantum kinetic level and found to be dominant in terms of the energy transferred to the lattice.The simulations successfully reproduce the main features found in recent experiments [Mizoguchi et al., Appl. Phys. Lett. 94, 171105 (2009)]. Depending on the excitation conditions different generation mechanisms can be discerned. We discuss their characteristics and their relative efficiency in the special case of the quantum well model under consideration. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational study toward understanding the photodissociation mechanism of sarin
Authors: Xu Cai‐Xia , Zuo Guo‐Min , Cheng Zhen‐Xing , Han Juan 
Published: January 2011

AbstractThe potential energy surface for sarin (C4H10FO2P) dissociation into (CH3)2CHO+PO(F)(CH3), CH3+(CH3)2CHOPO(F), and F+(CH3)2CHOPO(CH3) in the T1 and S1 states were investigated at the complete‐active‐space self‐consistent field (CASSCF) with the 6‐31G** and aug‐cc‐PVDZ basis sets. The different reaction pathways are characterized on the basis of the computed potential energy surface and surface crossing point, the time‐dependent density functional theory (TD‐DFT) was used to calculate the vertical energies based on the CAS(8,7)/6‐31G** optimized excited structures, which may provide some new insights into the mechanism of the ultraviolet photo‐degradation of sarin molecules. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Explanatory parent–child conversation predominates at an evolution exhibit
Authors: Tare Medha , French Jason , Frazier Brandy N. , Diamond Judy , Evans E. Margaret 
Published: January 2011

AbstractTo investigate how parents support children's learning at an exhibit on evolution, the conversations of 12 families were recorded, transcribed, and coded (6,263 utterances). Children (mean age 9.6 years) and parents visited Explore Evolution, which conveyed current research about the evolution of seven organisms. Families were engaged with the exhibit, staying an average of 44 minutes. Parents' and children's explanatory, nonexplanatory, and evolutionary conversation was coded. Overall, substantive explanatory conversation occurred in 65% of parent utterances, whereas nonexplanatory conversation occurred in 21% of the utterances. We found substantial use of exhibit text by parents (12.9% of utterances) who read it aloud and reframed the text for their children. Parents also used evolutionary terms and evolutionary concepts (10.2%), showing that such an exhibit is a valuable way to introduce this difficult topic to elementary‐school–aged children. Parents' use of explanatory conversation positively related to their children's use of explanatory and evolutionary conversation, indicating that a dialogic interchange was occurring. Parents' attitudes toward the exhibit content, particularly the issue of human evolution, related to the museum experience. Overall, this analysis shows that parents and children are having nuanced discussions and illustrates the potential of informal experiences in supporting children's learning of a complex topic. © 2011 Wiley Periodicals, Inc. Sci Ed 95:720–744, 2011
A two‐part model for reference curve estimation subject to a limit of detection
Authors: Zhang Z. , Addo O. Y. , Himes J. H. , Hediger M. L. , Albert P. S. , Gollenberg A. L. , Lee P. A. , Louis G. M. Buck 
Published: January 2011

AbstractReference curves are commonly used to identify individuals with extreme values of clinically relevant variables or stages of progression which depend naturally on age or maturation. Estimation of reference curves can be complicated by a technical limit of detection (LOD) that censors the measurement from the left, as is the case in our study of reproductive hormone levels in boys around the time of the onset of puberty. We discuss issues with common approaches to the LOD problem in the context of our pubertal hormone study, and propose a two‐part model that addresses these issues. One part of the proposed model specifies the probability of a measurement exceeding the LOD as a function of age. The other part of the model specifies the conditional distribution of a measurement given that it exceeds the LOD, again as a function of age. Information from the two parts can be combined to estimate the identifiable portion (i.e. above the LOD) of a reference curve and to calculate the relative standing of a given measurement above the LOD. Unlike some common approaches to LOD problems, the two‐part model is free of untestable assumptions involving unobservable quantities, flexible for modeling the observable data, and easy to implement with existing software. The method is illustrated with hormone data from the Third National Health and Nutrition Examination Survey. Published in 2011 by John Wiley & Sons, Ltd.
Towards evolvable software architectures based on systems theoretic stability
Authors: Mannaert Herwig , Verelst Jan , Ven Kris 
Published: January 2011

SUMMARYIn today's increasingly volatile environments, evolvability is quickly becoming the most desirable characteristic of information systems. Current information systems still struggle to provide these high levels of evolvability. Based on the concept of stability from systems theory, we require that information systems should be stable with respect to a set of anticipated changes in order to exhibit high evolvability. This requires that information systems should be free from so‐called combinatorial effects. Combinatorial effects occur when the impact of a change is dependent on the size of the information system. To eliminate these combinatorial effects, we propose four theorems that are constraints on the modular structure of software architectures. The theorems are prescriptive and ensure that stable information systems are built, thereby guaranteeing high evolvability. We further present five higher level modular structures called elements. These elements provide the core functionality of information systems and comply fully with the stringent constraints implied by the four theorems. The internal structure of these elements is described by design patterns which are eligible for automatic code generation. These design patterns offer a constructive proof that it is possible to build information systems in practice by applying this set of theorems. Copyright © 2011 John Wiley & Sons, Ltd.
Satisfying quality requirements in the design of a partition‐based, distributed stock trading system
Authors: Yang Xiaohu , Zhao Liping , Wang Xinyu , Wang Ye , Sun Jie , Cristoforo Albert Jerry 
Published: January 2011

SUMMARYAlthough quality requirements (QRs) have become a major drive in today's software development, there have been very few real‐world examples in the literature that demonstrate how to meet these requirements. This paper presents such an example. Specifically, the paper describes the design of a partition‐based distributed stock trading service system that satisfies a set of QRs related to resource utilization, performance, scalability and availability. The paper evaluates this design through detailed experiments and discusses some design alternatives and the lessons learned. Central to this design are a static load distribution strategy and a dynamic load balancing strategy. The first strategy is to achieve an initial balanced workload on the system's server cluster during the system initialization time, whereas the second strategy is to maintain this balanced workload throughout the system execution time. Together, these two strategies work in unison to ensure that the server resources are efficiently utilized; the user requests are processed with the required speed; the application is partitioned with sufficient room to scale; and the system is highly available. Copyright © 2011 John Wiley & Sons, Ltd.
Metaphor in action in an academic battlefield
Authors: Basten Florence M. R. C. 
Published: January 2011

AbstractHow to explain an academic community that theorises about knowledge intensive organizations whilst creating practical knowledge about living in this community that negates these theories? I constructed a learning history of an academic business school and found some answers. Confronting the collective narrative of the organization about itself with analyses and recommendations written for others, I found little correspondence between the two. To find out why, I deconstructed the organizational narrative and searched for dominant metaphors that guided everyday practice. I found that a battlefield metaphor was used to make sense of what happened since the start of the organization, which as a sense‐making device evolved from collective to individual survival. I will present the metaphor, demonstrate its evolution and outline what it meant for staff to be writing about ideal organizations while not being able to produce one themselves. Copyright © 2011 John Wiley & Sons, Ltd.
Methamphetamine‐mediated modulation of MOR expression in the SH‐SY5Y neuroblastoma cell line
Authors: Langsdorf Erik F. , Chang Sulie L. 
Published: January 2011

AbstractMethamphetamine (METH) has been shown to induce oxidative stress in SH‐SY5Y cells, a neuroblastic, dopaminergic cell line model. In neuronal cells, oxidation of dopamine by auto‐oxidative or enzymatic mechanisms leads to the production of reactive oxygen species (ROS). Neuronal cells treated with METH accumulate dopamine, which can ultimately lead to increased levels of ROS. ROS has been shown to mediate the expression of the mu‐opioid receptor (MOR). The goal of this in vitro study was to examine the effects of METH on the accumulation of intracellular ROS in SH‐SY5Y cells, which could, in turn, modulate MOR expression. Confocal laser scanning microscopy (CLSM) indicated that METH induced intracellular accumulation of ROS, detected as increased fluorescence of rhodamine 123, in a dose‐ and time‐dependent manner. Moreover, accumulation of ROS preceded METH‐induced expression of the MOR, which was attenuated by the free radical chelator, vitamin E. Additionally, increased MOR expression was noted following hydrogen peroxide treatment, indicating a role for ROS in mediating MOR expression. Taken together, our data show that METH's effect on MOR expression is dependent upon sublethal levels of intracellular ROS, which suggests a possible coupling of METH‐ and opiate‐mediated intracellular signaling. Synapse, 2011. © 2011 Wiley‐Liss, Inc.
Changes in the Localization of Perforated Peptic Ulcer and its Relation to Gender and Age of the Patients throughout the Last 45 Years
Authors: Wysocki Andrzej , Budzyński Piotr , Kulawik Jan , Drożdż Włodzimierz 
Published: January 2011

AbstractBackgroundThroughout recent decades there has been noticeable change in the incidence of peptic ulcer disease and its complications. The aim of the present study was to determine the character of changes over the last 45 years in the localization of perforation, in patient age, and in patient gender.MethodsA group of 881 patients admitted to the Second Department of General Surgery in Krakow, Poland, from 1962 to 2006 were included in the study and constituted the material for the analysis. The study was divided into three time periods (1962–1976, 1977–1991, and 1992–2006) to allow statistical analysis of trends.ResultsThe general incidence of perforations of peptic ulcer did not show changes; however, the percentage of women with perforated duodenal ulcer markedly increased. Patients with perforated stomach ulcer—regardless of gender—and females suffering from perforated duodenal ulcer were, on the average, about 10 years older than males with perforated duodenal ulcers. The mean age of male and female patients with perforated duodenal ulcer over the last 45 years showed an insignificant upward trend.Conclusions(1) The percentage of women with perforated duodenal ulcer continuously and statistically significantly rose. (2) Men with perforated duodenal ulcer were significantly younger than other patients. (3) The mean ages of male and female patients with perforated duodenal ulcer over the last 45 years showed an insignificant upward trend.
Mucosal Advancement Flap Anoplasty for Chronic Anal Fissure Resistant to Conservative Therapy
Authors: Ouaïssi M. , Giger U. , Sielezneff I. , Yawovi K. A. , Pamela A. , Pirro N. , Sastre B. 
Published: January 2011

AbstractBackgroundSphincter‐sparing procedures are increasingly advocated in the treatment of chronic anal fissures (CAF) resistant to conservative management. Herein, we report about our results with sphincter‐sparing transanal mucosal advancement flap anoplasty (MAAP) to treat CAF.Patients and MethodsThe present study was a retrospective single‐center analysis of patients in whom conservative management of CAF failed and who subsequently underwent MAAP between January 2003 and December 2008.ResultsA total of 26 patients with a median age of 46.5 years (range: 17–79 years) had undergone MAAP after suffering with CAF for a median period of 9 months (range: 4–36 months). Surgery was well tolerated in all patients. One patient developed a perianal abscess at the operative site 3 weeks after MAAP, which required excision. At 2, 12, and 24 months follow‐up, all patients were free of pain with no fissure recurrence or any worsening of incontinence.ConclusionsMucosal advancement flap anoplasty might be another sphincter‐sparing treatment option in patients suffering from CAF. To draw final conclusions about the value of MAAP in the treatment of CAF, more solid data are required.
On the construction of a RoboCup small size league team
Authors: Gurzoni José Angelo , Martins Murilo Fernandes , Tonidandel Flavio , Bianchi Reinaldo A. C. 
Published: January 2011

Abstract
The Robot Soccer domain has become an important artificial intelligence test bench and a widely studied research area. It is a domain with real, dynamic, and uncertain environment, where teams of robots cooperate and face adversarial competition. To build a RoboCup Small Size League (SSL) team able to compete in the world championship requires multidisciplinary research in fields like robotic hardware development, machine learning, multi-robot systems, computer vision, control theory, and mechanics, among others.
This paper intends to provide insights about the aspects involved on the development of the RoboFEI RoboCup SSL robot soccer team and to present the contributions produced over its course. Among these contributions, a computer vision system employing an artificial neural network (ANN) to recognize colors, a heuristic algorithm to recognize partially detected objects, an implementation of the known rapidly-exploring random trees (RRT) path planning algorithm with additional rules, enabling the angle of approach of the robot to be controlled, and a layered strategy software system.
Experimental results on real robots demonstrate the high performance of the vision system and the efficiency of the RRT algorithm implementation. Some strategy functions are also experimented, with empirical results showing their effectiveness.
Sex differences in sleep pattern of rats in an experimental model of osteoarthritis
Authors: Silva Andressa , Araujo Paula , Zager Adriano , Tufik Sergio , Andersenl Monica Levy 
Published: January 2011

AbstractBackground: Osteoarthritis (OA) is a major healthcare burden with increasing incidence, and is characterised by the degeneration of articular cartilage. OA is associated with chronic pain and sleep disturbance.Objective: The current study examined and compared the long‐term effects of chronic articular pain on sleep patterns between female and male rats in an experimental model of OA.Methods: Rats were implanted with electrodes for electrocorticography and electromyography and assigned to control, sham or OA groups. OA was induced by the intra‐articular administration of (2 mg) monosodium iodoacetate into the left knee joint in male and female rats (at estrus and diestrus phases).Results: Sleep was monitored at days 1, 10, 15, 20 and 28 after iodoacetate injection during light and dark periods. The results showed that the overall sleep architecture changed in both sexes. These alterations occurred during the light and dark periods, began on D1 and persisted until the end of the study. OA rats, regardless of sex, showed a fragmented sleep pattern with reduced sleep efficiency, slow‐wave sleep and paradoxical sleep, and fewer paradoxical sleep bouts. However, the males showed lower sleep efficiency and reduced slow‐wave sleep compared to females during the dark period. Additionally, OA affected the hormonal levels in male rats, as testosterone levels were reduced in comparison to the control and sham groups. In females, progesterone and estradiol remained unchanged throughout the study.Conclusions: Our results suggest that the chronic model of OA influenced the sleep patterns in both sexes. However, males appeared to be more affected.
Unfavorable attitudes toward receiving methadone maintenance therapy and associated factors among the inmates using intravenous heroin
Authors: Yen Cheng‐Fang , Tsai Jih‐Jin , Wang Peng‐Wei , Yeh Yi‐Chun , Liu Shu‐Chun , Wang Shu‐Hui , Wang Chao‐Ching 
Published: January 2011

AbstractThe aims of this study were to examine unfavorable attitudes toward receiving methadone maintenance therapy (MMT) and associated factors among inmates using intravenous heroin in Taiwan. A total of 315 inmates using intravenous heroin were recruited. Their unfavorable attitudes toward receiving MMT after discharge from prison were evaluated using the Client Attitudes Toward Methadone Programs Scale. The associations of unfavorable attitudes toward receiving MMT with sociodemographic and drug‐using characteristics, human immunodeficiency virus serostatus, perceived family support, and depression were examined using multiple regression analysis. The results of this study showed that the mean score of unfavorable attitudes toward receiving MMT, determined on the Client Attitudes Toward Methadone Programs Scale, was 9.918 (standard deviation = 2.277, range = 5–20). Heroin‐using inmates who were young, started using heroin earlier, perceived many advantages and few disadvantages of heroin use, had never received MMT, and had severe depression, had unfavorable attitudes toward receiving MMT. Based on the results of this study, we suggest that inmates who have the factors associated with unfavorable attitudes toward receiving MMT should receive intervention and motivational interviewing to improve their attitudes toward MMT and to increase their opportunity to receive MMT after discharge from prison.