bluuebunny/crossref_metadata_2025 huggingface dataset:
The Cd‐tolerant rice mutant cadH‐5 is a high Cd accumulator and shows enhanced antioxidant activity
Authors: Shen Guo‐Ming , Zhu Cheng , Shangguan Li‐Na. , Du Qi‐Zhen
Published: February 2012

To investigate the mechanism of cadmium (Cd) detoxification in rice (Oryza sativa L.), a Cd‐tolerant mutant cadH‐5, obtained by an Agrobacterium tumefaciens‐based gene‐delivery system, was used for a Cd‐tolerance and accumulation study. After 15 d of exposure to 0.75 mM CdCl2, significant phenotypic differences were observed between the wild type (WT) and cadH‐5. When exposed to 0.5 mM CdCl2, higher Cd levels were accumulated in cadH‐5 root cell wall, root cytosol, and membranes than those in WT. However, Cd concentrations in root tissues varied in both WT and cadH5. No significant difference of hydrogen peroxide (H2O2) concentrations was observed between WT and cadH‐5, while contents of cell‐wall polysaccharides and phytochelatins (PCs) in the mutant were higher compared to WT. The ratios of reduced glutathione to oxidized glutathione (GSH : GSSG) and ascorbate to dehydroascorbate (ASC : DHA) were lower in WT than in cadH‐5, while the NADPH : NADP+ ratio was different to the ratios of GSH : GSSG and ASC : DHA; the ascorbate peroxidase (APX, EC 1.11.1.11), glutathione peroxidase (GR, EC 1.6.4.2), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and monodehydroascorbate reductase (MDHAR, EC 1.6.5.4) activities were lower in WT compared to cadH‐5. Our results indicate that under long‐term Cd stress, cadH‐5 plants can accumulate more Cd with more PC. Also, the redox status of ASC‐GSH cycle was more inhibited in WT than in cadH‐5 plants, rendering WT less able to scavenge reactive oxygen species (ROS). The cadH‐5 mutant maintains relatively high ASC, GSH, and NADPH concentrations, ratios of ASC : DHA, GSH : GSSG, and NADPH : NADP+, as well as antioxidative enzymatic activities and PC concentrations. Thus, it is tolerant of relatively high Cd accumulation.
Plasmon lasers: coherent light source at molecular scales
Authors: Ma Ren‐Min , Oulton Rupert F. , Sorger Volker J. , Zhang Xiang
Published: February 2012

Plasmon lasers are a new class of coherent optical frequency electromagnetic wave amplifiers that deliver intense, coherent and directional surface plasmons well below the diffraction barrier. The strongly confined electric fields in plasmon lasers can enhance significantly light‐matter interactions and bring fundamentally new capabilities to bio‐sensing, data storage, photolithography and optical communications.
Short Chain Branches Distribution Characterization of Ethylene/1‐Hexene Copolymers by Using TREF + 13C‐NMR and TREF + SC Methods
Authors: Zhang Shiliang , Zhao Ning , Wu Yuxiang , Dong Qi , Wang Quntao , Tang Yan , Yu Yongling , Da Jianwen , He Xuelian , Cheng Ruihua , Liu Boping
Published: February 2012

Summary: Short chain branches distribution (SCBD) is the key factor for high density polyethylene (HDPE) pipe materials to achieve their excellent performance for long term (50 years) applications. However, the precise SCBD characterization of these HDPE materials with relatively low content of comonomer incorporation still remained as a challenge in this field. In this work, two characterization methods, namely temperature rising elution fractionation (TREF) cross step crystallization (SC) (TREF + SC) and TREF cross 13C‐NMR (TREF + 13C‐NMR), have been respectively used to qualitatively and quantitatively investigate the SCBD for two HDPE pipe materials (PE‐1 and PE‐2 with different long term performances) with small amount of 1‐hexene incorporation prepared from SiO2‐supported silyl chromate catalyst system (S‐2 catalyst) during UNIPOL gas phase polymerization. The comparison of SCBD between the two samples showed that: although short chain branches of PE‐2 with good performance were less than those of PE‐1 with bad performance, PE‐2 showed less comonomer incorporation on the low crystallinity and low molecular weight (MW) fractions keeping even higher comonomer incorporation on the high crystallinity and high MW parts compared with PE‐1. This difference on the SCBD for PE‐1 and PE‐2 was thought to be the key factor which is responsible for their great difference on environment slow crack resistance (ESCR). Moreover, TREF + SC method further reflected the intra‐ and inter‐molecular heterogeneities of each fraction from the two HDPE samples through the lamella thickness distribution compared with TREF + 13C‐NMR.
Microstructure and properties of polycaprolactone/calcium sulfate particle and whisker composites
Authors: Liu Jinyan , Ren Li , Wei Qiang , Wu J.L. , Liu Sa , Wang Yingjun , Li Guoyuan
Published: February 2012

Polycaprolactone (PCL)/calcium sulfate (CS) particle and whisker composites were prepared by coprecipitation method and studied by evaluating their microstructure, crystallization, and mechanical properties. Results show that both of the CS whisker and particle dispersed in PCL can reduce the spherulite size of PCL and improve the regularity of the spherulite. The nucleation effect of the CS whisker is stronger than that of the CS particle. Mechanical properties of PCL were obviously improved by both of the particle and whisker addition. The flexural modulus and impact strength of the whisker composites are higher than that of the particle composites, which could be explained by the interfacial debonding mechanism. On the basis of the crystallization and mechanical studies, it is found that the size of spherulites and the concentration of CS particles and whiskers have played an important role in the improvement in mechanical properties of the composite. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Narcissism, psychopathy and Five‐Factor Model in sexual assault perpetration
Authors: Mouilso Emily R. , Calhoun Karen S.
Published: February 2012

Perpetration of sexual aggression by college men has been well documented and results in a variety of negative outcomes for victims. Although most theory and research on sexual aggression among college students have focused on the role of attitudes and life experiences, recent research with college men suggests that personality traits play a larger role in perpetration in college samples than was once believed. A large (N = 235) sample of college men self‐reported levels of narcissism, psychopathy, Five‐Factor Model (FFM) and sexual assault perpetration. Both the Narcissistic Personality Inventory and the Structured Clinical Interview for DSM Disorders‐II Personality Questionnaire were used to assess narcissism. Men who scored highly on self‐report measures of psychopathic and narcissistic traits and low on self‐report measures of the FFM dimensions of Agreeableness and Conscientiousness were more likely to report perpetration and reported more frequent perpetration. All of the aforementioned variables distinguished between perpetrators and non‐perpetrators; however, FFM domains did not explain significant variance after controlling for narcissism and psychopathy. Copyright © 2012 John Wiley & Sons, Ltd.
A Role for English Language Teachers in Trauma Healing
Authors: Medley Michael
Published: February 2012

Because English language teachers should take into account the social‐psychological situation of the students they teach, they must be sensitive to the effects of traumatic stress among learners. Refugee and immigrant children are frequently survivors of trauma, along with their peers in crisis‐torn English as a foreign language settings around the world. Without experiencing some measure of healing from trauma, children will be frustrated in their language learning. This article explains how what we know about trauma can be aligned with effective language instructional practices. The author first provides information about the effects of trauma and then identifies teaching approaches that are sensitive to the needs of those affected by trauma. The author suggests ways that teachers can (a) include intelligences that may be neglected in traditional language classrooms as a way to address the needs of trauma‐affected youth in order to have multiple channels for self‐expression and language learning; (b) integrate language instruction with self‐expression and exploration of social relationships; and (c) incorporate content‐based language instruction that explains the trauma healing process. Although further investigations are needed, English language teachers can play a role in trauma healing for learners because artful acts of instruction are therapeutic, promoting both wholeness and effective instruction for all learners.
Sandwich problems on orientations
Authors: Durand de Gevigney Olivier , Klein Sulamita , Nguyen Viet-Hang , Szigeti Zoltán
Published: February 2012

The graph sandwich problem for property Π is defined as follows: Given two graphs G
1=(V,E
1) and G
2=(V,E
2) such that E
1⊆E
2, is there a graph G=(V,E) such that E
1⊆E⊆E
2 which satisfies property Π? We propose to study sandwich problems for properties Π concerning orientations, such as Eulerian orientation of a mixed graph and orientation with given in-degrees of a graph. We present a characterization and a polynomial-time algorithm for solving the m-orientation sandwich problem.
Perspectives on the automatic design of regulatory systems for synthetic biology
Authors: Rodrigo Guillermo , Carrera Javier , Landrain Thomas E. , Jaramillo Alfonso
Published: February 2012

Automatic design is based on computational modeling and optimization methods to provide prototype designs to targeted problems in an unsupervised manner. For biological circuits, we need to produce quantitative predictions of cell behavior for a given genotype as consequence of the different molecular interactions. Automatic design techniques aim at solving the inverse problem of finding the sequences of nucleotides that better fit a targeted behavior. In the post‐genomic era, our molecular knowledge and modeling capabilities have allowed to start using such methodologies with success. Herein, we describe how the emergence of this new type of tools could enable novel synthetic biology applications. We highlight the essential elements to develop automatic design procedures for synthetic biology pointing out their advantages and bottlenecks. We discuss in detail the experimental difficulties to overcome in the in vivo implementation of designed networks. The use of automatic design to engineer biological networks is starting to emerge as a new technique to perform synthetic biology, which should not be neglected in the future.
A ratchet trap for Leidenfrost drops
Authors: Cousins Thomas R. , Goldstein Raymond E. , Jaworski Justin W. , Pesci Adriana I.
Published: February 2012

The Leidenfrost effect occurs when a drop of liquid (or a sublimating solid) is levitated above a sufficiently hot surface through the action of an insulating vapour layer flowing from its bottom surface. When such a drop is levitated above a surface with parallel, asymmetric sawtooth-shaped ridges it is known to be propelled in a unique direction, or ratcheted, by the interaction of the vapour layer with the surface. Here we exploit this effect to construct a ‘ratchet trap’ for Leidenfrost drops: a surface with concentric circular ridges, each asymmetric in cross-section. A combination of experiment and theory is used to study the dynamics of drops in these traps, whose centre is a stable fixed point. Numerical analysis of the evaporating flows over a ratchet surface suggests new insights into the mechanism of motion rectification that are incorporated into the simplest equations of motion for ratchet-driven motion of a Leidenfrost body; these resemble a central force problem in celestial mechanics with mass loss and drag. A phase-plane analysis of experimental trajectories is used to extract more detailed information about the ratcheting phenomenon. Orbiting drops are found to exhibit substantial deformations; those with large internal angular momentum can even undergo binary fission. Such ratchet traps may thus prove useful in the controlled study of many properties of Leidenfrost drops.
Seasonality and farm/non-farm interactions in Western Kenya
Authors: Djurfeldt Agnes Andersson
Published: February 2012

This article considers the distributional consequences of seasonality by analysing the links between non-farm incomes, commercialisation within agriculture, and variations in consumption burdens and expenditures at the household level. The common focus in the literature on non-farm incomes as levellers of seasonality and sources of risk minimisation is complemented by perspectives which consider how seasonality affects and is handled by households depending on their broader livelihood situations. To this perspective is also added a consideration of in-kind transfers and transactions. The article uses a mixed methods approach, drawing on data from two villages in Western Kenya. The lack of non-farm sources of income and the variation over time in consumption burdens aggravate the seasonal aspects of the agricultural production cycle for poorer households. By contrast, the interaction between farm and non-farm sources of income enables wealthier households to profit from seasonality in relation to agricultural markets, while providing the basis for meeting both farm and non-farm expenditures.
High resolution electron beam measurements on the ALPHA-X laser–plasma wakefield accelerator
Authors: WELSH G. H. , WIGGINS S. M. , ISSAC R. C. , BRUNETTI E. , MANAHAN G. G. , ISLAM M. R. , CIPICCIA S. , ANICULAESEI C. , ERSFELD B. , JAROSZYNSKI D. A.
Published: February 2012

The Advanced Laser–Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme at the University of Strathclyde is developing laser–plasma accelerators for the production of ultra-short high quality electron bunches. Focussing such LWFA bunches into an undulator, for example, requires particular attention to be paid to the emittance, electron bunch duration and energy spread. On the ALPHA-X wakefield accelerator beam line, a high intensity ultra-short pulse from a 30 TW Ti:Sapphire laser is focussed into a helium gas jet to produce femtosecond duration electron bunches in the range of 90–220 MeV. Measurements of the electron energy spectrum, obtained using a high resolution magnetic dipole spectrometer, show electron bunch r.m.s. energy spreads down to 0.5%. A pepper-pot mask is used to obtain transverse emittance measurements of a 128 ± 3 MeV mono-energetic electron beam. An average normalized emittance of ϵrms,x,y = 2.2 ± 0.7, 2.3 ± 0.6 π-mm-mrad is measured, which is comparable to that of a conventional radio-frequency accelerator. The best measured emittance of ϵrms,x, = 1.1 ± 0.1 π-mm-mrad corresponds to the resolution limit of the detection system. 3D particle-in-cell simulations of the ALPHA-X accelerator partially replicate the generation of low emittance, low energy spread bunches with charge less than 4 pC and gas flow simulations indicate both long density ramps and shock formation in the gas jet nozzle.
Individualising care. The transformation of personal support in old age
Authors: FINE MICHAEL D.
Published: February 2012

This paper considers developments in long-term care that are increasingly focused around the individual. Recent decades have seen massive changes in the way that care is understood and provided. Yet in Australia, as in Europe, North America and Asia, we are still a long way from a stable state of agreed services and provisions. Emphasising the social theory behind the shift, it is argued that understanding the individualisation of care cannot be reduced to a simple dichotomy of good or bad. Individualised care promises much, but the concept is applied to a wide range of phenomena, often in ways that conceal rather than reveal the character of the transactions involved. For individualisation to become meaningful it must be developed as a condition of recognition that is equally applicable to those who provide and those who depend on care. It is also important to distinguish individualised care finance arrangements from real attainments in the practice of providing care. These distinctions are necessary if we are to distinguish its use as an ideological justification for welfare cutbacks and the restructuring of care provisions as markets from the liberating potential that the approach can present when care practices are more truly based around the recognition of the individuals concerned: those who receive and depend on assistance as well as those who provide it.
BETWEEN LOGIC AND MATHEMATICS: AL-KINDĪ'S APPROACH TO THE ARISTOTELIAN CATEGORIES
Authors: Ighbariah Ahmad
Published: February 2012

What is the function of logic in al-Kindī's corpus? What kind of relation does it have with mathematics? This article tackles these questions by examining al-Kindī's theory of categories as it was presented in his epistle On the Number of Aristotle's Books (Fī Kammiyyat kutub Arisṭū), from which we can learn about his special attitude towards Aristotle theory of categories and his interpretation, as well. Al-Kindī treats the Categories as a logical book, but in a manner different from that of the classical Aristotelian tradition. He ascribes a special status to the categories Quantity (kammiyya) and Quality (kayfiyya), whereas the rest of the categories are thought to be no more than different combinations of these two categories with the category Substance. The discussion will pay special attention to the function of the categories of Quantity and Quality as mediators between logic and mathematics.
Four-Year Longitudinal Performance of a Population-Based Sample of Healthy Children on a Neuropsychological Battery: The NIH MRI Study of Normal Brain Development
Authors: Waber Deborah P. , Forbes Peter W. , Almli C. Robert , Blood Emily A. ,   The Brain Development Cooperative Group
Published: February 2012

The National Institutes of Health (NIH) Magnetic Resonance Imaging (MRI) Study of Normal Brain Development is a landmark study in which structural and metabolic brain development and behavior are followed longitudinally from birth to young adulthood in a population-based sample of healthy children. Cross-sectional findings from the neuropsychological test battery have been previously described (Waber et al., 2007). The present report details 4-year longitudinal neuropsychological outcomes for those children who were aged 6 to 18 years at baseline (N = 383), of whom 219 (57.2%) completed all 3 visits. Primary observations were (1) individual children displayed considerable variation in scores across visits on the same measures; (2) income-related differences were more prominent in the longitudinal than in the cross-sectional data; (3) no association between cognitive and behavioral measures and body mass index; and (4) several measures showed practice effects, despite the 2-year interval between visits. These data offer an unparalleled opportunity to observe normative performance and change over time on a set of standard and commonly used neuropsychological measures in a population-based sample of healthy children. They thus provide important background for the use and interpretation of these instruments in both research settings and clinical practice. (JINS, 2012, 18, 179–190)
Decision making by pension fund trustees in the face of demographic and economic shocks: a vignette study
Authors: VAN DALEN HENDRIK P. , HENKENS KÈNE , KOEDIJK KEES , SLAGER ALFRED
Published: February 2012

How do pension fund trustees deal with demographic and economic shocks? We examine this issue by using a vignette study among pension fund trustees in the Netherlands. Trustees show asymmetric reactions to shocks in the level of reserves of pension funds. Pension premiums are upwardly flexible but trustees are reluctant to decrease premiums. Asymmetries are also revealed by choices regarding the inflation indexation of benefits and changing real (defined) benefits. Asymmetry is not visible in the policy responses to demographic shocks: increases in life expectancy are reflected by taking structural measures for a defined benefit contract: raising pension premiums and the pension age. Furthermore, trustees allow their choices to be affected by the forces of social comparison: the reserve position of their fund compared to the position of other funds has a significant influence in choosing pension fund policy instruments.
Cassini observation of Jovian anomalous continuum radiation
Authors: Ye Sheng‐Yi , Gurnett D. A. , Menietti J. D. , Kurth W. S. , Fischer G. , Schippers P. , Hospodarsky G. B.
Published: February 2012

Jovian anomalous continuum is a narrowband electromagnetic radiation near 10 kHz that can escape from Jupiter's magnetosphere to interplanetary space. One possible source mechanism is the magnetosheath re‐radiation of the Jovian low frequency radio emissions such as the quasiperiodic (QP) radio emissions, broadband kilometric radiation (bKOM) and non‐thermal continuum. Jovian anomalous continuum was consistently observed by the Cassini Radio and Plasma Wave Science instrument from 2000 to 2004, right before the Saturn orbit insertion, which means the radiation can be detected as far as 8 AU away from Jupiter. An analysis of intensity versus radial distance shows that the Jovian anomalous continuum has a line source rather than a point source, consistent with the theory that the emission is radiated by the whole length of the magnetotail. The emissions are modulated at the system III period of Jupiter and are unpolarized. Since the lower cutoff frequency of the anomalous continuum is related to the plasma frequency in the magnetosheath of Jupiter, which is a function of solar wind density, the recurrent variations of the lower cutoff frequency can be used as a remote diagnostic of the solar wind condition at Jupiter. We propose that the frequency dispersion, a unique characteristic of the anomalous continuum, is likely a comprehensive effect of both the slow group velocity near the local plasma frequency and the refraction/scattering of the waves by density structures as they propagate in the magnetosheath.
Coastal upwelling in summer 2000 in the northeastern South China Sea
Authors: Wang Dongxiao , Zhuang Wei , Xie Shang‐Ping , Hu Jianyu , Shu Yeqiang , Wu Risheng
Published: February 2012

Using a combination of hydrographic, tide‐gauge, near‐bottom mooring, and satellite observations; and a numerical circulation model, we investigate the coastal upwelling in the northeastern South China Sea (NSCS) off the coast of Fujian and Guangdong Provinces, China, in the summer of 2000. Subsurface upwelling phenomenon exists mainly near the bottom boundary in the whole region investigated. It is closely related to the coastal sea level fluctuations, which are evidently modulated by both the local wind‐forcing and the large‐scale circulation. The northeastward interior flow following the bathymetry is accelerated by the drop of coastal sea level and leads to onshore transport and subsequent cooling in the bottom boundary layer (BBL) over the shelf west of Shantou. To the east of Shantou, the near‐bottom flow veers more eastward, parallel to the coastline, and transports the nearshore cold water mass farther to the southern Fujian coast. The cross‐shelf advected cold water does not always penetrate through the stratification and reach the surface. The local wind exhibits considerable synoptic variability. The decrease in sea surface temperature (SST) is mostly significant near Dongshan‐Shantou, intermittent in time and intensifies preferably during weather events that bring southwesterly alongshore wind. To the west a freshwater tongue originating from the Pearl River forms a barrier layer, which results in high surface temperature in the freshwater plume. The observational evidences and modeled results shown in this study provide important information for further understanding the ecological effects associated with the upwelling processes in the NSCS.
Exploratory functional flood frequency analysis and outlier detection
Authors: Chebana Fateh , Dabo‐Niang Sophie , Ouarda Taha B. M. J.
Published: February 2012

The prevention of flood risks and the effective planning and management of water resources require river flows to be continuously measured and analyzed at a number of stations. For a given station, a hydrograph can be obtained as a graphical representation of the temporal variation of flow over a period of time. The information provided by the hydrograph is essential to determine the severity of extreme events and their frequencies. A flood hydrograph is commonly characterized by its peak, volume, and duration. Traditional hydrological frequency analysis (FA) approaches focused separately on each of these features in a univariate context. Recent multivariate approaches considered these features jointly in order to take into account their dependence structure. However, all these approaches are based on the analysis of a number of characteristics and do not make use of the full information content of the hydrograph. The objective of the present work is to propose a new framework for FA using the hydrographs as curves: functional data. In this context, the whole hydrograph is considered as one infinite‐dimensional observation. This context allows us to provide more effective and efficient estimates of the risk associated with extreme events. The proposed approach contributes to addressing the problem of lack of data commonly encountered in hydrology by fully employing all the information contained in the hydrographs. A number of functional data analysis tools are introduced and adapted to flood FA with a focus on exploratory analysis as a first stage toward a complete functional flood FA. These methods, including data visualization, location and scale measures, principal component analysis, and outlier detection, are illustrated in a real‐world flood analysis case study from the province of Quebec, Canada.
Non-linear Effects in Asymmetric Catalysis: Whys and Wherefores
Authors: Chandrasekhar Sosale
Published: February 2012

It is argued that the titled non-linear effects (NLE) may arise whenever the order of the reaction in the chiral catalyst in greater than 1. In a fundamental departure from previous approaches, this is mathematically elaborated for the second order case. (NLE may also be observed if the chiral catalyst forms non-reacting dimers in a competing equilibrium; practically, however, this implies the in situ resolution of the catalyst.) The amplification of enantiomeric excess by NLE implies a relative (although modest) reduction in the entropy of mixing. The consequent increase in free energy apparently indicates a non-equilibrium process. It is suggested, based on arguments involving the chemical potential, that kinetically-controlled reactions lead to a state of “quasi-equilibrium”: in this, although overall equilibrium is attained, the product-spread is far from equilibrium. Thus, both the linear and NLE cases of chiral catalysis represent departures from equilibrium (which requires that the product e.e. = 0). Interesting similarities exist with models of non-equilibrium systems, the NLE cases apparently being analogs of open systems just after the bifurcation point has been crossed.
Effect of thickness of MgO, Co-Fe-B, and Ta layers on perpendicular magnetic anisotropy of [Ta/Co60Fe20B20/MgO]5 multilayered films
Authors: Yuan Fu-Te , Lin Yi-Hung , Mei J. K. , Hsu Jen-Hwa , Kuo P. C.
Published: February 2012

This study elucidates the magnetic properties of [Ta/Co60Fe20B20/MgO]5 as functions of thickness of each layer. Its perpendicular magnetic anisotropy (PMA) is found to depend strongly on the thickness of the MgO (tMgO) and Co-Fe-B (tCoFeB) layers. The Ta/CoFeB interface is critical to inducing PMA. A maximum room-temperature (RT) anisotropic energy (KuRT) of about 1 × 106 erg/cm3 and an anisotropic field (HkRT) of 4.7 kOe are obtained in the RT-prepared multilayered sample with tMgO = 1.0, tCoFeB = 1.3, and thickness of layer tTa = 10 nm. These values are comparable to the published values for Co60Fe20B20 after optimized field annealing. In this investigation, post-annealing has a more complicated effect on PMA in a multilayered structure than in a single or a double Co-Fe-B layer, both of which structure have been examined elsewhere. This result may be explained by the competing effects of the thermal process, which is an improvement of the crystallinity of Co-Fe-B and roughening of the interface.
Electrical determination of spin mixing conductance at metal/insulator interface using inverse spin Hall effect
Authors: Takahashi R. , Iguchi R. , Ando K. , Nakayama H. , Yoshino T. , Saitoh E.
Published: February 2012

The spin mixing conductance at Au/BiY2Fe5O12 and Pt/BiY2Fe5O12 interfaces was electrically determined using the inverse spin Hall effect (ISHE) and the spin pumping. By measuring the electromotive force due to the ISHE and the ferromagnetic resonance spectra, we evaluated the magnitude of the generated spin currents and the magnetization-precession trajectory. The spin mixing conductance was estimated as 1.82 × 1018 m−2 for the Pt/BiY2Fe5O12 film, and as 2.21 × 1018 m−2 for the Au/BiY2Fe5O12 film, demonstrating efficient spin exchange at these metal/insulator interfaces.
Permalloy and Co50Pd50 as ferromagnetic contacts for magnetoresistance measurements in carbon nanotube-based transport structures
Authors: Morgan Caitlin , Schneider Claus M. , Meyer Carola
Published: February 2012

In this paper, magnetoresistance (MR) measurements on carbon nanotube (CNT) 2-terminal spin-valve devices are presented. Results from samples with both permalloy (Py) and CoPd contacts show repeatable MR switching. In performing gate-dependent MR measurements on the Py-contacted CNTs, two distinct transport regimes are identified, and their transport behavior is discussed with respect to optimizing MR. Results from the first CoPd-contacted CNTs indicate a stable magnetic response with a higher magnitude than that of a Py-contacted nanotube in the same transport regime.
Vortex bursting and tracer transport of a counter-rotating vortex pair
Authors: Misaka T. , Holzäpfel F. , Hennemann I. , Gerz T. , Manhart M. , Schwertfirm F.
Published: February 2012

Large-eddy simulations of a coherent counter-rotating vortex pair in different environments are performed. The environmental background is characterized by varying turbulence intensities and stable temperature stratifications. Turbulent exchange processes between the vortices, the vortex oval, and the environment, as well as the material redistribution processes along the vortex tubes are investigated employing passive tracers that are superimposed to the initial vortex flow field. It is revealed that the vortex bursting phenomenon, known from photos of aircraft contrails or smoke visualization, is caused by collisions of secondary vortical structures traveling along the vortex tube which expel material from the vortex but do not result in a sudden decay of circulation or an abrupt change of vortex core structure. In neutrally stratified and weakly turbulent conditions, vortex reconnection triggers traveling helical vorticity structures which is followed by their collision. A long-lived vortex ring links once again establishing stable double rings. Key phenomena observed in the simulations are supported by photographs of contrails. The vertical and lateral extents of the detrained passive tracer strongly depend on environmental conditions where the sensitivity of detrainment rates on initial tracer distributions appears to be low.
Dynamic transitions for quasilinear systems and Cahn-Hilliard equation with Onsager mobility
Authors: Liu Honghu , Sengul Taylan , Wang Shouhong
Published: February 2012

The main objectives of this article are two-fold. First, we study the effect of the nonlinear Onsager mobility on the phase transition and on the well-posedness of the Cahn-Hilliard equation modeling a binary system. It is shown in particular that the dynamic transition is essentially independent of the nonlinearity of the Onsager mobility. However, the nonlinearity of the mobility does cause substantial technical difficulty for the well-posedness and for carrying out the dynamic transition analysis. For this reason, as a second objective, we introduce a systematic approach to deal with phase transition problems modeled by quasilinear partial differential equations, following the ideas of the dynamic transition theory developed in Ma and Wang [Phase Transition Dynamics in Nonlinear Sciences (Springer) (to be published); Bifurcation Theory and Applications, World Scientific Series on Nonlinear Science. Series A: Monographs and Treatises Vol. 53 (World Scientific, Hackensack, NJ, 2005)].
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/MoO3 composite layer for efficient and stable hole injection in organic semiconductors
Authors: Zhao Yongbiao , Chen Jiangshan , Chen Wei , Ma Dongge
Published: February 2012

We report a composite hole injection layer (HIL) composed of an ultrathin film of MoO3on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) for efficient and stable hole injection in organic semiconductors. The optimized thickness of MoO3 layer was determined to be about 0.5 nm, which was enough to increase the work function of the underlying films substantially. The composite HIL can inject holes efficiently into a variety of hole transport layers (HTLs), even that with very deep highest occupied molecular orbital (HOMO) levels. Moreover, the utilization of PEDOT:PSS/MoO3 composite HIL greatly improved the stability of hole injection in organic devices, as compared to those based on pure PEDOT:PSS or MoO3 HILs, beneficial to practical applications.
ZnO/anthracene based inorganic/organic nanowire heterostructure: Photoresponse and photoluminescence studies
Authors: Dhara Soumen , Giri P. K.
Published: February 2012

The effects of surface modification of vertically aligned ZnO nanowires (NWs) with anthracene for the improved photocurrent, photoresponse, and UV photoluminescence have been investigated in this work. The formation of ZnO/anthracene based inorganic/organic NWs heterostructure by surface capping with anthracene solution was confirmed from the high resolution transmission electron microscopy and Fourier transport infrared spectroscopy analyses. After the anthracene capping of ZnO NWs, despite an increase in dark current, we obtained a significant improvement in the photocurrent and photoresponsivity. A sixfold improvement in the UV photocurrent-to-dark current ratio is obtained with capping. Compared to the uncapped NWs, the photoresponse is significantly faster for the ZnO/anthracene system with response and reset times of 1.5 and 1.6 s, respectively. The room temperature photoluminescence spectra show threefold enhanced UV emission with large enhancement in the ratio of UV to green emission intensities. The faster photoresponse and enhanced photocurrent from the ZnO/anthracene heterostructure are explained on the basis of modification of surface defects and interfacial charge transfer process.
CdS nanofilms: Synthesis and the role of annealing on structural and optical properties
Authors: Kumar Suresh , Sharma Pankaj , Sharma Vineet
Published: February 2012

Cadmium sulfide (CdS) nanofilms have been deposited on the glass substrate using the chemical bath technique. Cadmium chloride and thiourea have been used as Cd2+ and S2− ion sources with ammonia as a complexing agent in the presence of a nonionic surfactant. The deposited films have been annealed in air at 373 K, 473 K, 573 K, and 673 K ± 5 K temperature. The effect of the annealing on the structure, morphology, and optical properties of CdS nanofilms has been studied. CdS films have been characterized by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, and UV-Vis-NIR spectrophotometer. The CdS films have been found to be nanocrystalline in nature with the zinc blende structure. The direct bandgap has been determined. Various parameters, viz. the grain size, inter-planer spacing, lattice constant, dislocation density, microstrain, surface morphology, absorption coefficient, and optical bandgap has been calculated and found to vary with annealing. The results have been explained on the basis of structural, surface, and optical changes.
Thermal transport in crystalline Si/Ge nano-composites: Atomistic simulations and microscopic models
Authors: Hao Feng , Fang Daining , Xu Zhiping
Published: February 2012

Thermal transport in Si/Ge nano-composites, consisting of crystalline silicon as matrix and aligned germanium nanowires as inclusions, is investigated here through non-equilibrium and equilibrium molecular dynamics (MD) simulations. Our results show increasing of temperature gradient at the interface between silicon and germanium, which is limited in an interfacial phase of few lattices. A thermal boundary phase is included explicitly in our three-phase model, in companion with the modified effective medium theory, to be compared with MD simulation results with various nanowire concentrations. The results suggest that the presence of nanowires leads to a dramatic decrease of κ for heat transfer across nanowires arising from interfacial phase, while along the interfaces, the reduction of phonon mean free path due to interfacial scattering lowers κ of silicon matrix and germanium nanowires.
Axially Aligned Confinement of 1,4-Bis(triethylammoniomethyl)benzene by Two p-Sulfonatocalix[4]arenes
Authors: Ling Irene , Alias Yatimah , Rahim Munirah Sufiyah Abdul , Skelton Brian W. , Byrne Lindsay T. , Raston Colin L.
Published: February 2012

A multiple component bi-layer complex containing 1,4-bis(triethylammoniomethyl)benzene and mono-phosphonium cations, and p-sulfonatocalix[4]arene involves preferential binding of the ammonium cation in the cavities of two geometrically opposed calixarenes with the mono-phosphonium cation embedded within a bilayer of calixarenes. The complex has channels between bilayers ~14 Å in diameter which are lined with both polar sulfonate groups and the hydrophobic surface of the central part of the ammonium cation. 1H NMR and 1D-ROESY experiments establish the formation of supermolecules of the bis-triethylammonium cation and two calixarenes in solution.
Which Mix — code-switching or a mixed language? — Gurindji Kriol
Authors: Meakins Felicity
Published: February 2012

Gurindji Kriol is a contact variety spoken in northern Australia which has been identified as a mixed language. Yet its status as an autonomous language system must be questioned for three reasons — (i) it continues to be spoken alongside its source languages, Gurindji and Kriol, (ii) it has a close diachronic and synchronic relationship to code-switching between Gurindji and Kriol, and (iii) its structure bears a strong resemblance to patterns found in this code-switching. Nonetheless in this paper I present criteria which support the claim of ‘language-hood’ for Gurindji Kriol. I demonstrate that Gurindji Kriol (i) is a stable language variety (it has child language learners and a high degree of inter-speaker consistency), (ii) has developed independent forms and structural subsystems which have not been adopted back into the source languages, and (iii) contains structural features from both languages which is rare in other language contact varieties including Kriol/Gurindji code-switching. I also present a number of structural indicators which can be used to distinguish Gurindji Kriol mixed language clauses from code-switched clauses.
Symbolic power in the heritage language classroom
Authors: Showstack Rachel Elizabeth
Published: February 2012

This study examined classroom discourse in two Spanish language courses for Spanish-English bilingual students at a large university in central Texas, in order to investigate the ways that participants used language to construct their linguistic and cultural identities. The study found that students’ identities as bilinguals are linked to socially constructed discourses on the value of different language varieties and cultural experiences that draw from an oversimplification of the reality of the sociolinguistic world. Participants constructed essentialized categories of different kinds of U.S. Hispanics, often assuming an essential connection between language and identity. Students constructed their identities by positioning themselves and others within these categories and by constructing their language skills and cultural backgrounds as either a value or a deficit. Results suggest the need to further develop methodologies for raising heritage language learners’ consciousness about the heteroglossic nature of the social world.
Multistability in perception: binding sensory modalities, an overview
Authors: Schwartz Jean-Luc , Grimault Nicolas , Hupé Jean-Michel , Moore Brian C. J. , Pressnitzer Daniel
Published: February 2012

This special issue presents research concerning multistable perception in different sensory modalities. Multistability occurs when a single physical stimulus produces alternations between different subjective percepts. Multistability was first described for vision, where it occurs, for example, when different stimuli are presented to the two eyes or for certain ambiguous figures. It has since been described for other sensory modalities, including audition, touch and olfaction. The key features of multistability are: (i) stimuli have more than one plausible perceptual organization; (ii) these organizations are not compatible with each other. We argue here that most if not all cases of multistability are based on competition in selecting and binding stimulus information. Binding refers to the process whereby the different attributes of objects in the environment, as represented in the sensory array, are bound together within our perceptual systems, to provide a coherent interpretation of the world around us. We argue that multistability can be used as a method for studying binding processes within and across sensory modalities. We emphasize this theme while presenting an outline of the papers in this issue. We end with some thoughts about open directions and avenues for further research.
Non‐replication of genome‐wide‐based associations of efficient food conversion in dairy cows
Authors: Littlejohn Mathew , Grala Talia , Sanders Kathryn , Walker Caroline , Waghorn Garry , Macdonald Kevin , Spelman Richard , Davis Steve , Snell Russell
Published: February 2012

Animal growth relative to food energy input is of key importance to agricultural production. Several recent studies highlighted genetic markers associated with food conversion efficiency in beef cattle, and there is now a requirement to validate these associations in additional populations and to assess their potential utility for selecting animals with enhanced food‐use efficiency. The current analysis tested a population of dairy cattle using 138DNAmarkers previously associated with food intake and growth in a whole‐genome association analysis of beef animals. Although seven markers showed point‐wise significance atP < 0.05, none of the single‐nucleotide polymorphisms tested were significantly associated with food conversion efficiency after correction for multiple testing. These data do not support the involvement of this subset of previously implicated markers in the food conversion efficiency of the physiologically distinctNewZealandHolstein‐Friesian dairy breed.
Variation in the XKR4 gene was significantly associated with subcutaneous rump fat thickness in indicine and composite cattle
Authors: Porto Neto L. R. , Bunch R. J. , Harrison B. E. , Barendse W.
Published: February 2012

Variation in the XK, Kell blood group complex subunit–related family, member 4 (XKR4) gene on BTA14 was associated with rump fat thickness in a recent genome‐wide association study. This region is also of interest because it is known to show evidence of a signature of population genetic selection. In this study, additional variation in this gene was genotyped in a sample of a total of 1283 animals of the Belmont Red (BEL) and Santa Gertrudis (SGT) breeds. The SNP rs41724387 was significantly (P < 0.001) associated with rump fat thickness and explained 5.9% of the genetic variance for the trait in this sample. Using the 4466 genotypes for the SNP rs42646708 from several data sets to estimate effects in seven breeds, this relatively large quantitative trait locus effect appears to be a result of the variation in indicine and taurine–indicine composite cattle. However, the only DNA variant found in Brahman cattle that altered the predicted amino acid sequence of XKR4 was not associated with rump fat thickness. This suggests that causative mutations lie outside the coding sequence of this gene.
Can acoustic shadows identify fish species? A novel application of imaging sonar data
Authors: LANGKAU M. C. , BALK H. , SCHMIDT M. B. , BORCHERDING J.
Published: February 2012

Abstract  This study addresses a fish species discrimination method based on normalised elliptic Fourier descriptors applied to acoustic shadows derived by Dual‐frequency Identification Sonar (DIDSON). Acoustic shadows of templates (20, 30, 40 and 50 cm) and live fish of four species [bream, Abramis brama (L.); barbel, Barbus barbus (L.); chub, Leuciscus cephalus (L.); and trout, Salmo trutta (L.)] were projected on a plate in an experimental set‐up and tested on suitability for species discrimination. Twenty‐centimetre templates were correctly classified in 97.5% of the cases, indicating a size threshold. The larger templates reached values of 100% correct classification based on cross‐validated discriminant function analysis. It was also possible to classify moving fish based on screenshots of their acoustic shadows with a certainty of 83.9%. Extended field tests are required to evaluate the method for use in practical monitoring applications in multispecies river environments.
A pilot randomized controlled trial of dual‐plasmid HBV DNA vaccine mediated by in vivo electroporation in chronic hepatitis B patients under lamivudine chemotherapy
Authors: Yang F.‐Q. , Yu Y.‐Y. , Wang G.‐Q. , Chen J. , Li J.‐H. , Li Y.‐Q. , Rao G.‐R. , Mo G.‐Y. , Luo X.‐R. , Chen G.‐M.
Published: February 2012

Summary.  A DNA vaccine against the hepatitis B virus (HBV), enhanced by IL‐2/IFN‐γ fusion protein expression from a plasmid construct and mediated by in vivo electroporation, was evaluated in a total of 39 HBeAg‐positive patients with chronic hepatitis B (CHB). The six of 39 patients with a serum alanine aminotransferase (ALT) value of 1–2 times upper limit of normal (ULN) were assigned to the open‐label arm (Group01) receiving vaccine monotherapy; the remaining 33 patients with an ALT of more than two times ULN were enroled to the randomized and controlled arm (Group02) receiving lamivudine (LAM) monotherapy (LAM+placebo) or combined therapy (LAM+DNA vaccine) in 1:2 ratio. In Group01, a significant elevation of HBV‐specific IFN‐γ‐secreting T‐cell counts in comparison with baseline was observed. In Group02, the proportion of patients with HBV DNA suppression was higher with LAM+DNA vaccine than with LAM monotherapy at each visit time point after the final injection of DNA vaccine at week 36, revealing a significant difference between the two groups (P = 0.03) at week 60. The incidence of dual‐site mutations of rtM204/I/S+rtL180M was significantly lower (P = 0.03) with an identified lower virological breakthrough (VBT) rate (P = 0.03) in patients receiving LAM+DNA vaccine than LAM monotherapy, accompanied with a significant higher positive T‐cell response rate in patients receiving LAM+DNA vaccine (P = 0.03). In conclusion, this study provides evidence that HBV DNA vaccination is safe and immunologically effective, and that the HBV‐specific T‐cell responses induced by DNA vaccination under LAM chemotherapy showed a correlation with the suppression of viral replication in patients with CHB.