bluuebunny/crossref_metadata_2025 huggingface dataset:
Corporate Social Responsibility in Buyer-Supplier Relationships: Is it Beneficial for Top-Tier Suppliers to Market their Capability to Ensure a Responsible Supply Chain?
Authors: Leppelt Thomas , Foerstl Kai , Hartmann Evi
Published: March 2014

This study assesses how top-tier suppliers market their capabilities to ensure a responsible upstream supply chain to their downstream buyers, and how the marketing of corporate social responsibility (CSR)-related supply management practices affects the reputation of top-tier suppliers in business-to-business (B2B) markets. In a cross-functional multiple-case study involving marketing, purchasing, and sustainability executives of five supplier organizations in Central Europe, we explored four distinct approaches for marketing superior CSR management abilities in B2B markets that potentially foster long-term comparative advantages: (1) Fact-based communication of measurable CSR capabilities, (2) targeting of indirect customers and influencers, (3) marketing through education, and (4) marketing of CSR as a service. Moreover, our inductive results provide evidence that the effective marketing of CSR capabilities enhances a supplier’s reputation only if it sends consistent signals to the market. Therefore, a close integration of marketing and purchasing is crucial for achieving signaling consistency. Building on an established framework of purchasing-marketing integration in the particular context of CSR we developed a crossfunctional theory on the link between marketing, supply chain alignment and reputation, which is expressed in four sets of testable research propositions.
Integrated Strategic Planning of Global Production Networks and Financial Hedging under Uncertain Demands and Exchange Rates
Authors: Koberstein Achim , Lukas Elmar , Naumann Marc
Published: March 2014

In this paper, we present a multi-stage stochastic programming model that integrates financial hedging decisions into the planning of strategic production networks under uncertain exchange rates and product demands. This model considers the expenses of production plants and the revenues of markets in different currency areas. Financial portfolio planning decisions for two types of financial instruments, forward contracts and options, are represented explicitly by multi-period decision variables and a multi-stage scenario tree. Using an illustrative example, we analyze the impact of exchange-rate and demand volatility, the level of investment expenses and interest rate spreads on capacity location and dimensioning decisions. In particular, we show that, in the illustrative example, the exchange-rate uncertainty cannot be completely eliminated by financial hedging in the presence of demand uncertainty. In this situation, we find that the integrated model can result in better strategic planning decisions for a risk-averse decision maker compared to traditional modeling approaches.
The Meniscus Arrow® as a Fixation Device for the Treatment of Mallet Fractures: Results of 50 Cases
Authors: Aarts Fenne L. M. , Derks Rosalie , Wouters Diederick B.
Published: March 2014

Background

The treatment of mallet fractures is a controversial and challenging problem. Generally, mallet fractures are treated conservatively except those involving more than one third of the base of the distal phalanx. Many different surgical fixation techniques have been published. This paper describes a new fixation procedure using ultimate bioresorbable meniscal fixation nails (Meniscus Arrows®).

Methods

Mallet fractures in 50 digits of 49 patients were fixed with this nail in an outpatient surgical procedure, mostly under local (Oberst-block) anaesthesia. The average operation time was 21 min.

Results

According to the Crawford criteria, patient outcome was graded as excellent in 48 %, good in 22 %, and fair in 28 %. In one patient, the outcome was graded as poor, but the fracture was in a pre-existent arthritic joint. All fractures were consolidated without recurrent dislocation. Complications included one wound infection, which was successfully treated with antibiotics and without further consequences. No nail deformities occurred. Two times, the nail spontaneously and gradually dislocated during intensive use of the hand after, respectively, 3 and 6 months and could easily be removed under local anaesthesia without any functional sequelae.

Conclusion

The bioresorbable meniscal nail fixation technique provides a fast and successful surgical treatment for mallet fractures with a minimum of adverse events.
Outcomes Assessment of Lunate Replacement Arthroplasty with Intrinsic Carpal Ligament Reconstruction in Kienböck's Disease
Authors: Henry Mark
Published: March 2014

Background

With advanced Kienböck's disease, hyaline cartilage delamination or bone fragmentation render the lunate unsalvageable. Common surgical options are proximal row carpectomy, scaphotrapeziotrapezoid fusion, scaphocapitate fusion, or total wrist fusion. The purpose of this study was to prospectively evaluate the clinical and radiographic outcomes of one alternative: lunate prosthetic replacement arthroplasty combined with reconstruction of the scapholunate and lunotriquetral interosseous ligaments using the flexor carpi radialis tendon.

Methods

Eligible patients with advanced Kienböck's disease and an unsalvageable lunate were included in this prospective study on a self-selected basis, forming a study group of 13 consecutive patients, 6 males and 7 females with a mean age of 40. Clinical and radiographic measurements were compared at a mean follow-up of 30.3 months from surgery with a paired, single-tailed, Student's t test using a p value of 0.05 as statistically significant.

Results

Mean preoperative/postoperative clinical measurements were as follows: wrist flexion 29.2°/43.3°, wrist extension 24.2°/53.3°, absolute value grip strength 12.3/31.5 kg, grip strength vs. contralateral 36.5/85.2 %, and DASH scores 39.1/7.7. Mean initial/immediate postoperative/final ***radiographic measurements were the following: scapholunate angle 64.2°/46.7°/46.4°, radioscaphoid angle 64.6°/42.1°/45°, and modified carpal height ratio 1.20/1.62/1.59. Preoperative to postoperative differences were all statistically significant.

Conclusions

Although these subjective and objective results reflect substantial improvement, there remain recognizable deficiencies in both prosthetic design and surgical strategy that require further modification.
Down‐regulation of miRNA‐204 by LMP‐1 enhances CDC42 activity and facilitates invasion of EBV‐associated nasopharyngeal carcinoma cells
Authors: Ma Lei , Deng Xubin , Wu Minhua , Zhang Gong , Huang Jianqing
Published: March 2014

Nasopharayngeal carcinoma (NPC) is an Epstein–Barr virus (EBV)‐associated malignancy. It is known that microRNAs are implicated in the progression of NPC. However, the role of miR‐204 in NPC is poorly understood. In this study, we found that miR‐204 was down‐regulated in NPC cells and tissues. Low‐level expression of miR‐204 was significantly associated with a more aggressive and poor prognostic phenotype of NPC. We further found that EBV‐encoded latent membrane protein 1 (LMP‐1) suppressed miR‐204 expression by activating Stat‐3. Cdc42 was identified as a direct target of miR‐204. Mir‐204 inhibited EBV positive C666‐1 cell invasion and metastasis partly through targeting cdc42.
Crystal structure analysis of EstA from Arthrobacter sp. Rue61a – an insight into catalytic promiscuity
Authors: Wagner Ulrike Gabriella , DiMaio Frank , Kolkenbrock Stephan , Fetzner Susanne
Published: March 2014

In this article we analyze the reasons for catalytic promiscuity of a type VIII esterase with β‐lactamase fold and the ability to cleave β‐lactams. We compared the structure of this enzyme to those of an esterase of the same type without any lactamase ability, an esterase with moderate lactamase ability, and a class C β‐lactamase with similar fold. Our results show that for these enzymes, the difference in the substrate specificity is sterically driven.
MicroRNA‐23b is an independent prognostic marker and suppresses ovarian cancer progression by targeting runt‐related transcription factor‐2
Authors: Li Weiping , Liu Zhongyu , Chen Li , Zhou Li , Yao Yuanqing
Published: March 2014

Our previous study found that runt‐related transcription factor‐2 (RUNX2) was upregulated in human epithelial ovarian cancer (EOC) tissues and may be involved in tumor progression and prognosis. The aim of this study was to investigate the mechanism by which RUNX2 is aberrantly expressed in EOC. We firstly confirmed that miRNA‐23b directly targets RUNX2 in EOC. Then, ectopic expression of miR‐23b significantly inhibited ovarian cancer cell proliferation and tumorigenicity by regulating the expression of RUNX2. Furthermore, the down‐regulation of miR‐23b was significantly correlated with tumor aggressiveness and poor prognosis of patients with EOC. Collectively, miR‐23b may function as tumor suppressor through inhibiting the upregulation of RUNX2, and may be a potential prognostic marker for EOC.
Homer in Stone
Authors: Petrain David
Published: March 2014

The Tabulae Iliacae are a group of carved stone plaques created in the context of early Imperial Rome that use miniature images and text to retell stories from Greek myth and history - chief among them Homer's Iliad and the fall of Troy. In this book, Professor Petrain moves beyond the narrow focus on the literary and iconographic sources of the Tabulae that has characterized earlier scholarship. Drawing on ancient and modern theories of narrative, he explores instead how the tablets transfer the Troy saga across both medium and culture as they create a system of visual storytelling that relies on the values and viewing habits of Roman viewers. The book comprehensively situates the tablets in the urban fabric of Augustan Rome. New photographs of the tablets, together with re-editions and translations of key inscriptions, offer a new, clearer view of these remarkable documents of the Roman appropriation of Greek epic.
The Emergence of Islam in Late Antiquity
Authors: Al-Azmeh Aziz
Published: March 2014

Based on epigraphic and other material evidence as well as more traditional literary sources and critical review of the extensive relevant scholarship, this book presents a comprehensive and innovative reconstruction of the rise of Islam as a religion and imperial polity. It reassesses the development of the imperial monotheism of the New Rome, and considers the history of the Arabs as an integral part of Late Antiquity, including Arab ethnogenesis and the emergence of what was to become Muslim monotheism, comparable with the emergence of other monotheisms from polytheistic systems. Topics discussed include the emergence and development of the Muhammadan polity and its new cultic deity and associated ritual, the constitution of the Muslim canon, and the development of early Islam as an imperial religion. Intended principally for scholars of Late Antiquity, Islamic studies and the history of religions, the book opens up many novel directions for future research.
Clowning and Authorship in Early Modern Theatre
Authors: Preiss Richard
Published: March 2014

To early modern audiences, the 'clown' was much more than a minor play character. A celebrity performer, he was a one-man sideshow whose interactive entertainments - face-pulling, farce interludes, jigs, rhyming contests with the crowd - were the main event. Clowning epitomized a theatre that was heterogeneous, improvised, participatory, and irreducible to dramatic texts. How, then, did those texts emerge? Why did playgoers buy books that deleted not only the clown, but them as well? Challenging the narrative that clowns were 'banished' by playwrights like Shakespeare and Jonson, Richard Preiss argues that clowns such as Richard Tarlton, Will Kemp, and Robert Armin actually made playwrights possible - bridging, through the publication of their routines, the experience of 'live' and scripted performance. Clowning and Authorship tells the story of how, as the clown's presence decayed into print, he bequeathed the new categories around which theatre would organize: the author, and the actor.
Estimating rheumatic fever incidence in New Zealand using multiple data sources
Authors: OLIVER J. , PIERSE N. , BAKER M. G.
Published: March 2014

Rheumatic fever (RF) is an important public health problem in New Zealand (NZ). There are three sources of RF surveillance data, all with major limitations that prevent NZ generating accurate epidemiological information. We aimed to estimate the likely RF incidence using multiple surveillance data sources. National RF hospitalization and notification data were obtained, covering the periods 1988–2011 and 1997–2011, respectively. Data were also obtained from four regional registers: Wellington, Waikato, Hawke's Bay and Rotorua. Coded patient identifiers were used to calculate the proportion of individuals who could be matched between datasets. Capture–recapture analyses were used to calculate the likely number of true RF cases for the period 1997–2011. A range of scenarios were used to correct for likely dataset incompleteness. The estimated sensitivity of each data source was calculated. Patients who were male, Māori or Pacific, aged 5–15 years and met the Jones criteria, were most likely to be matched between national datasets. All registers appeared incomplete. An average of 113 new initial cases occurred annually. Sensitivity was estimated at 80% for the hospitalization dataset and 60% for the notification dataset. There is a clear need to develop a high-quality RF surveillance system, such as a national register. Such a system could link important data sources to provide effective, comprehensive national surveillance to support both strategy-focused and control-focused activities, helping reduce the incidence and impact of this disease. It is important to remind clinicians that RF cases do occur outside the well-characterized high-risk group.
A review of invasiveHaemophilus influenzaedisease in the Indigenous populations of North America
Authors: TSANG R. S. W. , BRUCE M. G. , LEM M. , BARRETO L. , ULANOVA M.
Published: March 2014

Historically, the highest incidence rates of invasiveHaemophilus influenzaedisease in the world were found in North American and Australian Indigenous children. Although immunization againstH. influenzaetype b (Hib) led to a marked decrease in invasive Hib disease in countries where it was implemented, this disease has not been eliminated and its rates in Indigenous communities remain higher than in the general North American population. In this literature review, we examined the epidemiology of invasiveH. influenzaedisease in the pre-Hib vaccine era, effect of carriage on disease epidemiology, immune response toH. influenzaeinfection and Hib vaccination in Indigenous and Caucasian children, and the changing epidemiology after Hib conjugate vaccine has been in use for more than two decades in North America. We also explored reasons behind the continued high rates of invasiveH. influenzaedisease in Indigenous populations in North America.H. influenzaetype a (Hia) has emerged as a significant cause of severe disease in North American Indigenous communities. More research is needed to define the genotypic diversity of Hia and the disease burden that it causes in order to determine if a Hia vaccine is required to protect the vulnerable populations.
Linking TEM Analytical Spectroscopies for an Assumptionless Compositional Analysis
Authors: Kothleitner Gerald , Grogger Werner , Dienstleder Martina , Hofer Ferdinand
Published: March 2014

The classical implementation for putting quantitative figures on maps to reveal elemental compositions in transmission electron microscopy is by analytical methods like X-ray and energy-loss spectroscopy. Typically, the technique in use often depends on whether lighter or heavier elements are present and—more practically—which calibrations are available or sample-related properties are known. A framework linking electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray (EDX) signals such that absolute volumetric concentrations can be derived without assumptions made a priori about the unknown sample, is largely missing. In order to combine both techniques and harness their respective potentials for a light and heavy element analysis, we have set up a powerful hardware configuration and implemented an experimental approach, which reduces the need for estimates on many parameters needed for quantitative work such as densities, absolute thicknesses, theoretical ionization cross-sections, etc. Calibrations on specimens with known geometry allow the measurement of inelastic mean free paths. As a consequence, mass-thicknesses obtained from the EDX ζ-factor approach can be broken up and quantities like concentrations and partial energy-differential ionization cross-sections become accessible. ζ-factors can then be used for conversion into EELS cross-sections that are hard to determine otherwise, or conversely, connecting EDXS and EELS in a quantitative manner quite effectively.
Symposium ‘Theories of Territory beyond Westphalia’
Authors: Banai Ayelet , Moore Margaret , Miller David , Nine Cara , Dietrich Frank
Published: March 2014

Is territory a trap? Does the concept of territory trap us into false assumptions of internally homogeneous, externally bounded political communities that exercise uniform sovereignty across their domain? Against the background of debates about territory and the territorial state in international relations, this symposium brings together five contributions in political theory that advance a nuanced and systemic understanding of what territory is. Taken together, they indicate that there is much to the territorial paradigm beyond the modern, sovereign, and territorial state model. There are diverse conceptions of territory, which may be relevant across different legal and political orders. The various conceptual analyses of territory in this symposium suggest that the sovereign state model is only one way in which a sovereign political authority can be territorial. These essays provide the conceptual tools to formulate (and subsequently test) the hypothesis that the transformations in statehood may not be best described in terms of the rise and decline of territorial sovereignty, but as moves from one model of territorially bounded political authority to another. In political theory, it is only in recent years that this foundational concept has received sustained attention from political theorists. This symposium aims to take forward this welcome theoretical development.
Wastewater as a point source of antibiotic-resistance genes in the sediment of a freshwater lake
Authors: Czekalski Nadine , Gascón Díez Elena , Bürgmann Helmut
Published: March 2014

Antibiotic-resistance genes (ARGs) are currently discussed as emerging environmental contaminants. Hospital and municipal sewage are important sources of ARGs for the receiving freshwater bodies. We investigated the spatial distribution of different ARGs (sul1, sul2, tet(B), tet(M), tet(W) and qnrA) in freshwater lake sediments in the vicinity of a point source of treated wastewater. ARG contamination of Vidy Bay, Lake Geneva, Switzerland was quantified using real-time PCR and compared with total mercury (THg), a frequently particle-bound inorganic contaminant with known natural background levels. Two-dimensional mapping of the investigated contaminants in lake sediments with geostatistical tools revealed total and relative abundance of ARGs in close proximity of the sewage discharge point were up to 200-fold above levels measured at a remote reference site (center of the lake) and decreased exponentially with distance. Similar trends were observed in the spatial distribution of different ARGs, whereas distributions of ARGs and THg were only moderately correlated, indicating differences in the transport and fate of these pollutants or additional sources of ARG contamination. The spatial pattern of ARG contamination and supporting data suggest that deposition of particle-associated wastewater bacteria rather than co-selection by, for example, heavy metals was the main cause of sediment ARG contamination.
Fluorescent staining of glycoproteins in sodium dodecyl sulfate polyacrylamide gels by 4H-[1]-benzopyrano[4,3-b]thiophene-2-carboxylic acid hydrazide
Authors: Zhu Zhongxin , Zhou Xuan , Wang Yang , Chi Lisha , Ruan Dandan , Xuan Yuanhu , Cong Weitao , Jin Litai
Published: March 2014

A sensitive, specific, economic and MS compatible staining method for gel-separated glycoproteins by using BH was described and demonstrated by 1-D and 2-D SDS-PAGE, deglycosylation, glycoprotein affinity enrichment and LC-MS/MS, respectively.
Stability-indicating LC method for the determination of cephalothin in lyophilized powder for injection
Authors: Rugani Karen de Souza , Salgado Hérida Regina Nunes
Published: March 2014

A stability-indicating gradient reversed phase liquid chromatography (RP-LC) method has been developed for the quantitative determination of cephalothin (CET), an antimicrobial compound, in the presence of its impurities and degradation products generated from forced degradation studies.
O− from amorphous and crystalline CO2 ices
Authors: Davis Daly , Kundu Sramana , Prabhudesai Vaibhav S. , Krishnakumar E.
Published: March 2014

Reflection absorption infrared spectroscopy and time of flight mass spectrometry are combined to show that low energy electron induced desorption of O− from crystalline CO2 films is smaller than that from amorphous CO2 films.
On the use of thioamides as fluorescence quenching probes for tracking protein folding and stability
Authors: Petersson E. James , Goldberg Jacob M. , Wissner Rebecca F.
Published: March 2014

Our laboratory has developed thioamide analogs of the natural amino acids as minimally-perturbing fluorescence quenching probes that can be placed at many locations in a protein sequence.
N-heterocyclic carbene metal complexes: photoluminescence and applications
Authors: Visbal Renso , Gimeno M. Concepción
Published: March 2014

This review covers the advances made in the synthesis and applications of luminescent transition metal complexes containing N-heterocyclic carbene (NHC) ligands.
Preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in aqueous media with β-cyclodextrin-SO3H as a recyclable catalyst
Authors: Wu Jian , Du Xianli , Ma Juan , Zhang Yuping , Shi Qingcai , Luo Lijun , Song Baoan , Yang Song , Hu Deyu
Published: March 2014

A β-cyclodextrin-SO3H-assisted, convenient and efficient strategy for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in aqueous media is presented.
A charge-switchable, four-armed polymeric photosensitizer for photodynamic cancer therapy
Authors: Lee Chung-Sung , Park Wooram , Jo Young Um , Na Kun
Published: March 2014

A water-soluble, charge-switchable, four-armed polymeric photosensitizer (C4P-PS), in which charge switching is pH dependent, has been designed as a new class of photosensitizer for photodynamic cancer therapy.
Altering physical properties of pharmaceutical co-crystals in a systematic manner
Authors: Aakeröy Christer B. , Forbes Safiyyah , Desper John
Published: March 2014

Systematic structure–property studies on a series of co-crystals of potential cancer drugs with aliphatic dicarboxylic acids were undertaken.
Turning colour on and off using molecular disorder and proton transfer in multi-component molecular complexes
Authors: Jones Charlotte L. , Wilson Chick C. , Thomas Lynne H.
Published: March 2014

Three pairs of molecular complexes based around 4-iodoaniline and 3,5-dinitrobenzoic acid are reported. Within each pair, one complex is colourless and one red; the influences on the colour are discussed including the role of molecular disorder and proton transfer.
Probing the type of anomalous diffusion with single-particle tracking
Authors: Ernst Dominique , Köhler Jürgen , Weiss Matthias
Published: March 2014

We introduce a versatile method to extract the type of (transient) anomalous random walk from experimental single-particle tracking data.
DPT tautomerisation of the G·Asynand A*·G*synDNA mismatches: a QM/QTAIM combined atomistic investigation
Authors: Brovarets' Ol'ha O. , Hovorun Dmytro M.
Published: March 2014

The A*·G*syn↔ A·G*synDPT tautomerisation proceeds through the asynchronous concerted mechanism; the G·AsynDNA base mispair does not tautomerise at all.
Improvement of open-circuit voltage and photovoltaic properties of 2D-conjugated polymers by alkylthio substitution
Authors: Cui Chaohua , Wong Wai-Yeung , Li Yongfang
Published: March 2014

The photovoltaic properties of 2D-conjugated copolymer PBDTTTs were further improved by side chain engineering in a 2D-conjugated polymer.
Deregulation of biometal homeostasis: the missing link for neuronal ceroid lipofuscinoses?
Authors: Grubman Alexandra , Pollari Eveliina , Duncan Clare , Caragounis Aphrodite , Blom Tea , Volitakis Irene , Wong Andrew , Cooper Jonathan , Crouch Peter J. , Koistinaho Jari , Jalanko Anu , White Anthony R. , Kanninen Katja M.
Published: March 2014

Deregulation of biologically active metal homeostasis is a feature of 4 genetically distinct variants of neuronal ceroid lipofuscinoses, a group of fatal neurodegenerative disorders.
Design of coordination polymers with 4′-substituted functionalized terpyridyls in the backbone and pendent cyclopentadienyliron moieties
Authors: Abd-El-Aziz Alaa S. , Pilfold Jessica L. , Momeni Badri Z. , Proud Adam J. , Pearson Jason K.
Published: March 2014

Synthesis and characterization of coordination polymers containing 4′-substituted functionalized terpyridines and cyclopentadienyliron moieties.
Nucleation of decahedral Ag nanocrystals
Authors: Lan Yi-Kang , Su Chiu-Hun , Sun Wen-Hsien , Su An-Chung
Published: March 2014

Via MD simulation, we show that the transition barrier between icosahedral (Ih) and decahedral (Dh) silver clusters increases strongly with cluster size and thus effectively prohibits thermally induced transformation. It is further shown that coalescence of preformed Ih clusters may indeed serve as an effective path for the nucleation of Dh-like multiply twinned nanoparticles.
ESIPT or not ESIPT? Revisiting recent results on 2,1,3-benzothiadiazole under the TD-DFT light
Authors: Laurent Adèle D. , Houari Ymène , Carvalho Pedro H. P. R. , Neto Brenno A. D. , Jacquemin Denis
Published: March 2014

We provide a new interpretation of the spectroscopic signatures of an amino-substituted 2,1,3-benzothiadiazole.
PO43− polyanion-doping for stabilizing Li-rich layered oxides as cathode materials for advanced lithium-ion batteries
Authors: Zhang H. Z. , Qiao Q. Q. , Li G. R. , Gao X. P.
Published: March 2014

PO43− polyanion-doped Li-rich layered oxides offer excellent energy density retention during long cycling due to the stronger anion bonding of PO43− polyanions to transition metal cations.
Spatiotemporal model for Internet traffic anomalies
Authors: Bandara Vidarshana W. , Pezeshki Ali , Jayasumana Anura P.
Published: March 2014

Models for Internet traffic anomalies greatly benefit a range of applications including robust network design, network provisioning and performance studies. A novel approach to analyse and model network traffic anomalies is presented. The proposed approach individually characterises different aspects of anomalies, such as origin, termination, propagation and changes in duration and volume, with common random processes. These characteristics are then integrated into a single model that successfully captures the overall anomaly behaviours. Characterisation of each anomaly property requires only a few parameters, leading to a concise set of parameters for the entire model. Although the model is calibrated with local measurements made at nodes, it successfully represents the global behaviours of anomalies over the network. The proposed model is applicable both at nodal level and at subnet level. This enables hierarchically analysing large and sophisticated networks. Anomalies are analysed using a multi‐scale analysis framework based on which, a real‐time monitoring system that efficiently communicate ongoing anomaly information across the network is developed. The system is also used for learning regional model parameters distributively. Internet2 traffic data is analysed using the framework, and the corresponding model parameters are derived. These results provide insight on the nature of anomalies in networks.
A three‐phase four‐wire static synchronous compensator with reduced number of switches for unbalanced loads
Authors: Balikci Abdul , Akpinar Eyüp
Published: March 2014

In this paper, a three‐phase, Y‐connected, five‐level static synchronous compensator with reduced number of switches is proposed for single phase and unbalanced three‐phase loads. The level shifted carrier based sinusoidal pulse width modulation method is used for switching. The active and reactive powers demanded by the load are estimated for each phase independently to compensate the reactive power supplied from the power system. The simulation results obtained from Matlab are compared with the results of experimental work and dedicated model of the proposed system. The system is implemented in the laboratory by using DSP TMS320F28335.
Effect of size reduction on magnetic ordering in Bi0.2Sr0.8MnO3
Authors: Singh Geetanjali , Bhat S. V.
Published: March 2014

We present a comparative study of the temperature dependent magnetic properties and electron paramagnetic resonance parameters of nano and bulk samples of Bi0.2Sr0.8MnO3 (BSMO). Bulk BSMO is known to have a high TN ∼ 260 K and robust charge ordering (TCO ∼ 360 K). We confirm that the bulk sample shows an antiferromagnetic transition around ∼260 K and a spin-glass transition ∼40 K. For the nano sample, we see a clear ferromagnetic transition at around ∼120 K. We conclude that spin glass state, which is present due to the co-existence of antiferromagnetic and ferromagnetic states in the bulk sample, is suppressed in the nano sample and ferromagnetism is induced instead.
A Fokker-Planck-Landau collision equation solver on two-dimensional velocity grid and its application to particle-in-cell simulation
Authors: Yoon E. S. , Chang C. S.
Published: March 2014

An approximate two-dimensional solver of the nonlinear Fokker-Planck-Landau collision operator has been developed using the assumption that the particle probability distribution function is independent of gyroangle in the limit of strong magnetic field. The isotropic one-dimensional scheme developed for nonlinear Fokker-Planck-Landau equation by Buet and Cordier [J. Comput. Phys. 179, 43 (2002)] and for linear Fokker-Planck-Landau equation by Chang and Cooper [J. Comput. Phys. 6, 1 (1970)] have been modified and extended to two-dimensional nonlinear equation. In addition, a method is suggested to apply the new velocity-grid based collision solver to Lagrangian particle-in-cell simulation by adjusting the weights of marker particles and is applied to a five dimensional particle-in-cell code to calculate the neoclassical ion thermal conductivity in a tokamak plasma. Error verifications show practical aspects of the present scheme for both grid-based and particle-based kinetic codes.
Weakly relativistic quantum kinetic theory for electrostatic wave modes in magnetized plasmas
Authors: Hussain Azhar , Stefan Martin , Brodin Gert
Published: March 2014

We have derived the electrostatic dispersion relation in a magnetized plasma using a recently developed quantum kinetic model based on the Dirac equation. The model contains weakly relativistic spin effects such as Thomas precession, the polarization currents associated with the spin and the spin-orbit coupling. It turns out that for strictly electrostatic perturbations the non-relativistic spin effects vanish, and the modification of the classical dispersion relation is solely associated with the relativistic terms. Several new wave modes appear due the electron spin effects, and an example for astrophysical plasmas are given.
Effect of interface configurations on the dynamic scaling behavior of Pb(Zr0.53Ti0.47)O3 thin films
Authors: Li Kui , Sama Nossikpendou , Li Tao , Rémiens Denis , Du Gang , Dong Xianlin , Wang Genshui
Published: March 2014

The ferroelectric hysteresis and the scaling relations of hysteresis area ⟨A⟩ against field amplitude E and frequency f in Pb(Zr0.53Ti0.47)O3 thin films using platinum and LaNiO3 (LNO) as both bottom and top electrodes were systematically investigated. Interestingly, it was found that the influence of top electrodes is dominant in affecting the scaling behavior of the dynamic hysteresis, which may be the result of the asymmetric interface structure deriving from the differences in conductivity and crystallization of the top and bottom LNO electrodes. The bottom electrodes affect the scaling behavior slightly via influencing the micro-structural and level of space charge.
Investigation on visible quantum cutting of Tb3+ in oxide hosts
Authors: Zhang Jia , Wang Yuhua , Chen Guibin , Huang Yan
Published: March 2014

Visible quantum cutting (QC) through downconversion was observed upon 4f8-4f75d1 excitation of Tb3+ in both BaGdB9O16 and Ca8MgGd(PO4)7 compounds. The QC involves a cross relaxation process between two neighboring Tb3+. Modified and new QC models are proposed based on the QC mechanisms in Gd3+-Tb3+ system. Two calculation equations for the cross relaxation efficiency are suggested according to the energy transfer theory and spectral results. By studying the spectral characteristics of Tb3+ in hosts from fluoride to oxide, it indicates that the visible QC in Gd3+-Tb3+ system may occur mainly depending on the structural features of phosphors, rather than the phonon energies of matrixes. All of the above conclusions have meaning of guidance for investigating other phosphors with QC phenomenon.
Components of strong magnetoresistance in Mn implanted Ge
Authors: Simons A. , Gerber A. , Korenblit I. Ya. , Suslov A. , Raquet B. , Passacantando M. , Ottaviano L. , Impellizzeri G. , Aronzon B.
Published: March 2014

Strong magnetoresistance reaching thousands of percent and non-monotonic field dependent Hall effect were measured in Mn implanted Ge samples in fields up to 60 T and analyzed in the framework of a two carriers model. The measured Hall effect and temperature dependent zero field resistance can be consistently described by parallel conductance along thick p-type Ge substrate with low concentration of highly mobile carriers and along thin Mn doped Ge layer with low mobility carriers. However, the same model is not sufficient to explain experimentally observed suppression of quadratic field dependence of magnetoresistance at low fields and absence of its saturation at high fields. Two additional mechanisms were identified: a strong quasi-linear magnetoresistance of Ge substrate that dominates the low field range and a non-saturating “3/2” power law magnetoresistance of the Mn doped Ge layer dominating the high field range.
Experimental investigation of spin-orbit coupling in n-type PbTe quantum wells
Authors: Peres M. L. , Monteiro H. S. , Chitta V. A. , de Castro S. , Mengui U. A. , Rappl P. H. O. , Oliveira N. F. , Abramof E. , Maude D. K.
Published: March 2014

The spin-orbit coupling is studied experimentally in two PbTe quantum wells by means of weak antilocalization effect. Using the Hikami-Larkin-Nagaoka model through a computational global optimization procedure, we extracted the spin-orbit and inelastic scattering times and estimated the strength of the zero field spin-splitting energy Δso. The values of Δso are linearly dependent on the Fermi wave vector (kF) confirming theoretical predictions of the existence of large spin-orbit coupling in IV-VI quantum wells originated from pure Rashba effect.
Canonicalization and symplectic simulation of the gyrocenter dynamics in time-independent magnetic fields
Authors: Zhang Ruili , Liu Jian , Tang Yifa , Qin Hong , Xiao Jianyuan , Zhu Beibei
Published: March 2014

The gyrocenter dynamics of charged particles in time-independent magnetic fields is a non-canonical Hamiltonian system. The canonical description of the gyrocenter has both theoretical and practical importance. We provide a general procedure of the gyrocenter canonicalization, which is expressed by the series of a small variable ϵ depending only on the parallel velocity u and can be expressed in a recursive manner. We prove that the truncation of the series to any given order generates a set of exact canonical coordinates for a system, whose Lagrangian approximates to that of the original gyrocenter system in the same order. If flux surfaces exist for the magnetic field, the series stops simply at the second order and an exact canonical form of the gyrocenter system is obtained. With the canonicalization schemes, the canonical symplectic simulation of gyrocenter dynamics is realized for the first time. The canonical symplectic algorithm has the advantage of good conservation properties and long-term numerical accuracy, while avoiding numerical instability. It is worth mentioning that explicitly expressing the canonical Hamiltonian in new coordinates is usually difficult and impractical. We give an iteration procedure that is easy to implement in the original coordinates associated with the coordinate transformation. This is crucial for modern large-scale simulation studies in plasma physics. The dynamics of gyrocenters in the dipole magnetic field and in the toroidal geometry are simulated using the canonical symplectic algorithm by comparison with the higher-order non symplectic Runge-Kutta scheme. The overwhelming superiorities of the symplectic method for the gyrocenter system are evidently exhibited.
Positron annihilation characteristics in mesostructural silica films with various porosities
Authors: Xiong Bangyun , Mao Wenfeng , Tang Xiuqin , He Chunqing
Published: March 2014

Porous silica films with various porosities were prepared via a sol-gel method using a nonionic amphiphilic triblock copolymer F127 as the structure-directing agent. Doppler broadening of positron annihilation radiation (DBAR) spectra were collected for the prepared films using a variable energy slow positron beam. Different linear relationships between positron annihilation line shape parameters S and W are found for the as-deposited films and calcined ones, indicative of the decomposition of the copolymer porogen in the as-deposited films upon calcination. This also reveals the variation of positron annihilation sites as a function of F127 loading or porosity. Strong correlations between positronium 3γ annihilation fraction, S parameter and porosity of the mesoporous silica films with isolated pores are obtained, which may provide a complementary method to determine closed porosities of mesoporous silica films by DBAR.
Tunable enhancement of exciton emission from MgZnO by hybridized quadrupole plasmons in Ag nanoparticle aggregation
Authors: Chen Hong-Yu , Liu Ke-Wei , Jiang Ming-Ming , Zhang Zhen-Zhong , Xie Xiu-Hua , Wang Deng-Kui , Liu Lei , Li Bing-Hui , Zhao Dong-Xu , Shan Chong-Xin , Shen De-Zhen
Published: March 2014

Mg0.2Zn0.8O/metal nanoparticle systems have been fabricated and investigated. The photoluminescence results indicate that Al and Au nanoparticles could slightly enhance the near-band-edge (NBE) emission from Mg0.2Zn0.8O. In contrast, a giant and tunable NBE emission enhancement could be induced by Ag nanoparticles based on the coupling interaction between the hybridized quadrupole plasmon in Ag nanoparticle aggregation and the excitons of Mg0.2Zn0.8O. Interestingly, the intensity and position of the narrow quadrupole resonance could be controlled by tuning the interspace gap and size of Ag nanoparticles, which was clearly demonstrated both experimentally and theoretically. Our findings may pave the way for further development of high-efficiency UV light-emitting devices.
Giant dielectric constant in TiO2/Al2O3 nanolaminates grown on doped silicon substrate by pulsed laser deposition
Authors: Walke P. , Bouregba R. , Lefevre A. , Parat G. , Lallemand F. , Voiron F. , Mercey B. , Lüders U.
Published: March 2014

High quality amorphous nanolaminates by means of alternate Al2O3 and TiO2 oxide sublayers were grown with atomic scale thickness control by pulsed laser deposition. A giant dielectric constant (>10 000), strongly enhanced compared to the value of either Al2O3 or TiO2 or their solid solution, was observed. The dependence of the dielectric constant and the dielectric loss on the individual layer thickness of each of the constituting materials was investigated between 0.3 nm and 1 nm, in order to understand the prevailing mechanisms and allow for an optimization of the performances. An impedance study confirmed as the key source of the giant dielectric constant a Maxwell–Wagner type dielectric relaxation, caused by space charge polarization in the nanolaminate structure. The current work provides better insight of nanolaminates and their sublayer thickness engineering for potential applications.
Tunneling spectroscopy of superconducting MoN and NbTiN grown by atomic layer deposition
Authors: Groll Nickolas R. , Klug Jeffrey A. , Cao Chaoyue , Altin Serdar , Claus Helmut , Becker Nicholas G. , Zasadzinski John F. , Pellin Michael J. , Proslier Thomas
Published: March 2014

A tunneling spectroscopy study is presented of superconducting MoN and Nb0.8Ti0.2N thin films grown by atomic layer deposition (ALD). The films exhibited a superconducting gap of 2 meV and 2.4 meV, respectively, with a corresponding critical temperature of 11.5 K and 13.4 K, among the highest reported Tc values achieved by the ALD technique. Tunnel junctions were obtained using a mechanical contact method with a Au tip. While the native oxides of these films provided poor tunnel barriers, high quality tunnel junctions with low zero bias conductance (below ∼10%) were obtained using an artificial tunnel barrier of Al2O3 on the film's surface grown ex situ by ALD. We find a large critical current density on the order of 4 × 106 A/cm2 at T = 0.8Tc for a 60 nm MoN film and demonstrate conformal coating capabilities of ALD onto high aspect ratio geometries. These results suggest that the ALD technique offers significant promise for thin film superconducting device applications.
Post-fire recovery of an endemic Canarian pine forest
Authors: Arévalo J. R. , Fernández-Lugo S. , Naranjo-Cigala A. , Salas M. , Ruíz R. , Ramos R. , Moreno M.
Published: March 2014

In this study, we analysed the effect of a wildfire that occurred in 2007 in a well-preserved Canarian pine forest located in the ‘Integral Natural Reserve of Inagua’. This reserve has the highest level of protection of the Canarian Network of Natural Protected Areas. In 2009, we established in an area that was affected by fire in the central part of the reserve a grid of quadrats of 500×500m in size. Following the corners of the quadrats, we set up a network of 28 permanent square plots of 25×25m. Ten more plots were randomly located in a surrounding area unaffected by the fire, with similar vegetation and environmental conditions. We monitored the effect of fire on pine regeneration, species composition, soil nutrient composition and forest structure. Results indicate that, 4 years following the fire, the effect on soil nutrients is still evident, with a higher level of organic matter in the burned plots. However, fire effect on species richness and composition was not long lasting, with no significant differences between the burned and control plots. Regarding regeneration, the density of saplings older than 2 years was significantly higher in burned plots. Based on the results, we suggest that fire should not be considered disastrous from an ecological point of view in this plant community. Moreover, the current fire suppression policy and the highly effective work of forest fire fighters can exacerbate the well known ‘fire paradox’.
Molecular adaptations of striatal spiny projection neurons during levodopa-induced dyskinesia
Authors: Heiman Myriam , Heilbut Adrian , Francardo Veronica , Kulicke Ruth , Fenster Robert J. , Kolaczyk Eric D. , Mesirov Jill P. , Surmeier Dalton J. , Cenci M. Angela , Greengard Paul
Published: March 2014

Significance

Parkinson's disease is characterized by a set of motor features that depend on a loss of dopamine-producing cells in the midbrain. The most common pharmacotherapy for Parkinson's disease is dopamine replacement with levodopa administration. The majority of patients receiving this treatment develop debilitating abnormal involuntary movements, termed “levodopa-induced dyskinesia.” It is known that striatal projection neurons (SPNs) are involved in the genesis of levodopa-induced dyskinesia, but the genes involved in this process are not fully understood. We reveal the gene-expression profiles of different classes of SPNs during chronic levodopa administration. We correlate gene expression to mouse behavior, predicting which genes are most likely involved in the emergence of levodopa-induced dyskinesia, and which are thus potential targets for new antidyskinetic treatments.
Ethylene-orchestrated circuitry coordinates a seedling’s response to soil cover and etiolated growth
Authors: Zhong Shangwei , Shi Hui , Xue Chang , Wei Ning , Guo Hongwei , Deng Xing Wang
Published: March 2014

Significance

Seedlings’ ability to both adapt to their soil environment and acquire photoautotrophic capacity under various buried conditions is a life-or-death issue for terrestrial flowering plants. By designing and utilizing a standardized real-soil assay, we identify the key features of germinating seedlings’ soil response and deduce that the gaseous phytohormone ethylene acts as the primary regulator of soil-induced plant morphogenetic changes. Moreover, our study illustrates that an EIN3/EIL1-conducted PIF3–ERF1 molecular circuitry enables seedlings to synchronize the rate of protochlorophyllide biosynthesis with upward growth, a mechanism critical to the prevention of photooxidative damage during seedlings’ initial transition from dark to light in natural conditions.
An aims‐based curriculum illustrated by the teaching of science in schools
Authors: Reiss Michael J. , White John
Published: March 2014

We begin by arguing that curriculum development should start with aims rather than, as is typically the case, with subjects. We, therefore, ask what might be the fundamental aims of school education. We conclude that they are twofold, namely, to enable each learner to lead a life that is personally flourishing and to help others to do so too. These high level aims can be translated into more specific ones by considering how human flourishing requires, for most people, such things as the acquisition of a broad background understanding, moral education, a life of imagination and reflection, and preparation for work. To illustrate our argument more specifically we then turn to the teaching of science. We show how our position relates to and simplifies present writing about the aims of science education and conclude that our proposals would result in a school science education that had similarities with much current school education, which is desirable as it suggests that our proposals are not completely unrealistic, but some non‐trivial differences too, which is encouraging as it suggests that our approach has practical worth rather than simply replicating existing approaches.