bluuebunny/crossref_metadata_2025 huggingface dataset:
Picture Naming and Verbal Fluency in Children With Cochlear Implants
Authors: Wechsler-Kashi Deena , Schwartz Richard G. , Cleary Miranda
Published: June 2014

Purpose

In the present study, the authors examined lexical naming in children with cochlear implants (CIs). The goal was to determine whether children with CIs have deficits in lexical access and organization as revealed through reaction time in picture-naming and verbal fluency (VF) experiments.

Method

Children with CIs (
n
= 20, ages 7–10) were compared with 20 children with normal hearing (NH) matched for age and nonverbal IQ. Lexical abilities were examined using two naming tasks: a timed picture-naming task and a phonological and semantic VF naming task. Picture naming taps into lexical access capabilities and the VF task elucidates lexical organization.

Results

No group differences were found between children with CIs and children with NH on the timed picture-naming task. Children with CIs generated significantly fewer words than the children with NH on the VF tasks. Larger group differences were found for the phonological VF task compared with the semantic VF task.

Conclusions

Limited early linguistic and auditory experiences may affect lexical representations and organization (lexical-semantic connections) in school-age children with hearing loss who use CIs. Further analyses and studies should continue to examine these underlying linguistic deficits. The present results suggest a need to emphasize not only increasing the size of children's vocabularies during therapy, but also expanding and increasing the semantic and phonological richness of their lexical representations.
Hybrid radio resource allocation and interference coordination for type 1a‐relayed long term evolution uplink
Authors: Ahmed Irfan , Mohamed Amr
Published: June 2014

Relay technology has been included in long term evolution (LTE) cellular system through 3GPP Release 10. Relay‐based LTE cellular system is one of the most promising technologies to enhance the throughput and coverage of access network. Deployment of relays in a cell opens many issues of frequency/time domain radio resource allocation and frequency planning. In this study, the authors consider the uplink of LTE relay‐assisted network and formulate the joint scheduling and intra‐cell interference mitigation as a non‐linear optimisation problem. They take into account the projection of the gradient of user's utility function over the user's rate vector based on Lagrangian method. They propose a novel transformation of scheduling problem into combinatorial Knapsack optimisation to convert the optimisation problem into binary integer non‐linear program. Finally, they present an alternate solution through a low complexity algorithm to allocate resources based on group of resource blocks, whereas considering the contiguity constraint. Simulation results show that the proposed scheme is near optimal with a much lower complexity order.
Analysis of significant current tracking error and suppression of over‐shoot current in grid‐connected voltage source converter with abc frame control
Authors: Zhao Guopeng , Han Minxiao
Published: June 2014

This study proposes an analysis and specification of current loop tracking error in the grid‐connected voltage source converter with direct current control. In practical applications, it is a common phenomenon that the current control loop sees a quite significant command‐tracking error while the actual output current of the converter is still satisfactory, for example, for static var generators or parallel active power filters, it is exactly the reactive current and/or the harmonic current that are needed to compensate the load current. In this study, a detailed analysis is presented to investigate this confusing issue. Based on the obtained current loop transfer function, analytical expressions of the current tracking error are derived. The reasons why a significant current tracking error exists together with satisfactory compensation result are revealed subsequently. The current tracking error has a relationship with the source voltage. An over‐shoot start current appears because of the current tracking error. Two new methods used to suppress the over‐shoot current are also presented. Finally, the hardware experimental results verify the analysis and the methods of suppressing the over‐shoot current.
Energy‐aware secondary user selection in cognitive sensor networks
Authors: Sepasi Zahmati Amir , Fernando Xavier , Grami Ali
Published: June 2014

In cognitive radio, accurate spectrum sensing is essential to optimally use the available spectrum opportunities. On the other hand, energy is a scarce resource especially in cognitive sensor networks. In this study, the authors combine both these conflicting requirements and propose an energy‐aware secondary user selection algorithm for cognitive sensor networks. First, an optimisation problem is solved to obtain the minimum required number of cognitive users, whereas satisfying the system requirements. Second, the most eligible cognitive users are identified through a probability‐based approach. They study two extreme cases by focusing on either energy or accuracy parameters. By numerical analysis, it is shown that the accuracy benchmark is increased by as much as 39% by only considering the sensing accuracy, and the energy benchmark is reduced by as low as 76% by only considering the remaining level of energy. In addition, they conduct computer simulation and compare the network's lifetime at several sensing accuracy thresholds. It is elaborated that greater sensing accuracy thresholds lead to longer network lifetime. Finally, the effects of several fusion rules on the proposed method are studied through simulation and numerical analyses. It is discussed that the Majority rule has the best performance among the examined rules.
Component Approach to the Temporomandibular Joint and Coronoid Process
Authors: Pfaff Miles J. , Clune James , Steinbacher Derek
Published: June 2014

Reconstruction of the temporomandibular joint (TMJ) region is challenging. The conventional direct preauricular incision permits only limited access to the TMJ and surrounding structures, therefore risking injury to the facial nerve during retraction. The ideal approach allows sufficient exposure, preservation of underlying neurovascular structures, and achieves an optimal aesthetic outcome. We describe a preauricular posttragal incision with a superficial musculoaponeurotic system flap to allow wide exposure of the zygomatic arch, TMJ, condyle, and coronoid process. We postulate that this approach improves access, lessens the amount of retraction required, and creates a more inconspicuous scar.
Electronic structure and magnetic properties of graphite intercalated with 3d-metals
Authors: Grechnev G. E. , Lyogenkaya A. A. , Kolesnichenko Yu. A. , Prylutskyy Yu. I. , Hayn Roland
Published: June 2014

Electronic structure and magnetic properties of graphite-based systems with intercalated 3d-transition metal atoms (V, Cr, Mn, Fe, Co, Ni) were calculated ab initio using the density functional theory. The presence of different magnetic states depending on the type of inserted M atoms is revealed for hexagonal P6/mmm and P63/mmc crystall structures. The values of magnetic moments appeared to be governed by the p–d hybridization, and by variations of exchange interactions with intercalation. The results of calculations clearly indicate itinerancy of the 3d-electrons of inserted M atoms.
Dynamic and static properties of rigidly fixed ultrathin ferromagnetic films with S = 1 and competing anisotropies
Authors: Gorelikov G. A. , Meleshko A. G. , Fridman Yu. A.
Published: June 2014

The mean field approximation is used to study the phase states and phase transitions in ultrathin ferromagnetic films with S = 1 and a combination of easy-plane and tilted anisotropies and mechanical boundary conditions. Depending on the relationship among the material parameters, the system can exist in an angular ferromagnetic phase, a quadrupole phase, or a spatially inhomogeneous state. The spectra of elementary excitations and the stability curves are determined for these phases. An analysis of the stability curves makes it possible to construct a phase diagram for the system.
Magnetoelastic properties of Nd0.9Dy0.1Fe3(BO3)4 ferroborate
Authors: Zvyagina G. A.
Published: June 2014

The low-temperature elastic characteristics of single-crystal Nd0.9Dy0.1Fe3(BO3)4 are studied. A transition of the magnetic system into an antiferromagnetic ordered state and a spontaneous spin-reorientation phase transition are observed in the temperature behavior of the speed and absorption of acoustic modes. Two anomalies in the speed and absorption of transverse acoustic modes are discovered at the lowest experimental temperature of 1.7 K in an external magnetic field directed along the trigonal axis of the crystal. These features are associated with two reorientation phase transitions that follow one another.
On the dynamics of non-spherical magnetic microbubbles
Authors: Lind Steven J.
Published: June 2014

Magnetic microbubbles are a relatively recent development with the potential to greatly improve the efficacy of the minimally invasive drug-delivery procedure sonoporation. However, very little is known about the dynamics of magnetic microbubbles, in general. In this paper, a novel mathematical model and numerical method are developed to simulate the dynamics of non-spherical magnetic microbubbles in vitro. The ambient fluid is assumed to be inviscid and the flow irrotational, enabling a generalized Bernoulli equation to be derived that includes surface tension effects and the effect of the applied magnetic field. The governing equations are solved using the boundary element method in which both the bubble surface and the velocity potential are represented by cubic splines. Results show that magnetic microbubble dynamics are highly dependent on the magnetic susceptibility difference, Δχ, between the bubble and the ambient fluid, with the sign and magnitude of Δχ dictating the direction and velocity of any formed liquid jets. Importantly, it is shown that the magnetic field can provide an additional means of flow control to the experimental investigator: in the presence of surface tension, weak magnetic fields do not generate jets. However, increasing the magnitude of the magnetic field can instigate jet formation, and increase the maximum and time-averaged jet velocities. Experimentally relevant parameter values are also considered, and results suggest that a combined application of magnetic and ultrasound fields is required to generate the high-speed bubble collapse events most likely to maximise cell poration and drug delivery.
Mixed confinement regimes during equilibrium confinement spectroscopy of DNA
Authors: Gupta Damini , Sheats Julian , Muralidhar Abhiram , Miller Jeremy J. , Huang Derek E. , Mahshid Sara , Dorfman Kevin D. , Reisner Walter
Published: June 2014

We have used a combination of fluorescence microscopy experiments and Pruned Enriched Rosenbluth Method simulations of a discrete wormlike chain model to measure the mean extension and the variance in the mean extension of λ-DNA in 100 nm deep nanochannels with widths ranging from 100 nm to 1000 nm in discrete 100 nm steps. The mean extension is only weakly affected by the channel aspect ratio. In contrast, the fluctuations of the chain extension qualitatively differ between rectangular channels and square channels with the same cross-sectional area, owing to the “mixing” of different confinement regimes in the rectangular channels. The agreement between experiment and simulation is very good, using the extension due to intercalation as the only adjustable parameter.
Molecular dynamics simulation of electrokinetic flow of an aqueous electrolyte solution in nanochannels
Authors: Yoshida Hiroaki , Mizuno Hideyuki , Kinjo Tomoyuki , Washizu Hitoshi , Barrat Jean-Louis
Published: June 2014

Electrokinetic flows of an aqueous NaCl solution in nanochannels with negatively charged surfaces are studied using molecular dynamics simulations. The four transport coefficients that characterize the response to weak electric and pressure fields, namely, the coefficients for the electrical current in response to the electric field (Mjj) and the pressure field (Mjm), and those for the mass flow in response to the same fields (Mmj and Mmm), are obtained in the linear regime using a Green–Kubo approach. Nonequilibrium simulations with explicit external fields are also carried out, and the current and mass flows are directly obtained. The two methods exhibit good agreement even for large external field strengths, and Onsager's reciprocal relation (Mjm = Mmj) is numerically confirmed in both approaches. The influence of the surface charge density on the flow is also considered. The values of the transport coefficients are found to be smaller for larger surface charge density, because the counter-ions strongly bound near the channel surface interfere with the charge and mass flows. A reversal of the streaming current and of the reciprocal electro-osmotic flow, with a change of sign of Mmj due to the excess co-ions, takes places for very high surface charge density.
Reaction dynamics of Al + O2 → AlO + O studied by a crossed-beam velocity map imaging technique: Vib-rotational state selected angular-kinetic energy distribution
Authors: Honma Kenji , Miyashita Kazuki , Matsumoto Yoshiteru
Published: June 2014

Oxidation reaction of a gas-phase aluminum atom by a molecular oxygen was studied by a crossed-beam condition at 12.4 kJ/mol of collision energy. A (1+1) resonance-enhanced multiphoton ionization (REMPI) via the D2Σ+-X2Σ+ transition of AlO was applied to ionize the product. The REMPI spectrum was analyzed to determine rotational state distributions for v = 0-2 of AlO. For several vib-rotational states of AlO, state selected angular and kinetic energy distributions were determined by a time-sliced ion imaging technique for the first time. Kinetic energy distributions were well represented by that taken into account initial energy spreads of collision energy and the population of the spin-orbit levels of the counter product O(3PJ) determined previously. All angular distributions showed forward and backward peaks, and the forward peaks were more pronounced than the backward one for the states of low internal energy. The backward peak intensity became comparable to the forward one for the states of high internal energy. These results and the rotational state distributions suggested that the reaction proceeds via an intermediate which has a lifetime comparable to or shorter than its rotational period.
Experimental characterization of plasma formation and shockwave propagation induced by high power pulsed underwater electrical discharge
Authors: Claverie A. , Deroy J. , Boustie M. , Avrillaud G. , Chuvatin A. , Mazanchenko E. , Demol G. , Dramane B.
Published: June 2014

High power pulsed electrical discharges into liquids are investigated for new industrial applications based on the efficiency of controlled shock waves. We present here new experimental data obtained by combination of detailed high speed imaging equipments. It allows the visualization of the very first instants of plasma discharge formation, and then the pulsations of the gaseous bubble with an accurate timing of events. The time history of the expansion/compression of this bubble leads to an estimation of the energy effectively transferred to water during the discharge. Finally, the consecutive shock generation driven by this pulsating bubble is optically monitored by shadowgraphs and schlieren setup. These data provide essential information about the geometrical pattern and chronometry associated with the shock wave generation and propagation.
Direct measurement system of nitrogen dioxide in the atmosphere using a blue light-emitting diode induced fluorescence technique
Authors: Sadanaga Yasuhiro , Suzuki Kazunari , Yoshimoto Takatoshi , Bandow Hiroshi
Published: June 2014

An instrument for measuring atmospheric nitrogen dioxide has been developed by a light-emitting diode induced fluorescence (LED-IF) technique. Air was introduced into a fluorescence detection cell. A pulsed blue light LED with a peak wavelength of 430 nm was irradiated to excite NO2 molecules in this cell. Fluorescence emitted from excited NO2 molecules was detected by a dynode-gated photomultiplier tube. The current detection limit of the LED-IF instrument was estimated to be 7.0 and 0.91 ppbv (parts per billion by volume) at 1-min and 1-h integration times, respectively, with a signal to noise ratio of 2. This result indicates that this LED-IF instrument can measure sufficiently precise 1-h values of NO2 concentrations in the urban atmosphere. An NO2 test observation and an intercomparison of the LED-IF instrument with an NO2 measurement system based on a photolytic converter/NO-O3 chemiluminescence method were performed in the urban atmosphere. Concentration differences between the two methods were within ±25% for about 90% of the data. It has been demonstrated by these observations that NO2 concentrations can be observed in the urban areas using the LED-IF instrument.
MagnetoSperm: A microrobot that navigates using weak magnetic fields
Authors: Khalil Islam S. M. , Dijkslag Herman C. , Abelmann Leon , Misra Sarthak
Published: June 2014

In this work, a propulsion system similar in motion to a sperm-cell is investigated. This system consists of a structure resembling a sperm-cell with a magnetic head and a flexible tail of 42 μm and 280 μm in length, respectively. The thickness, length, and width of this structure are 5.2 μm, 322 μm, and 42 μm, respectively. The magnetic head includes a 200 nm-thick cobalt-nickel layer. The cobalt-nickel layer provides a dipole moment and allows the flexible structure to align along oscillating weak (less than 5 mT) magnetic field lines, and hence generates a propulsion thrust force that overcomes the drag force. The frequency response of this system shows that the propulsion mechanism allows for swimming at an average speed of 158 ± 32 μm/s at alternating weak magnetic field of 45 Hz. In addition, we experimentally demonstrate controlled steering of the flexible structure towards reference positions.
The Euclidean algebra in rank 2 classical Lie algebras
Authors: Douglas Andrew , Repka Joe , Joseph Wainwright
Published: June 2014

We classify the embeddings of the Euclidean algebra \documentclass[12pt]{minimal}\begin{document}$\mathfrak {e}(2)$\end{document}e(2) into the rank 2 semisimple, classical Lie algebras. The classifications are up to inner automorphism. We also examine the finite-dimensional, irreducible representations of the rank 2 semisimple, classical Lie algebras restricted to \documentclass[12pt]{minimal}\begin{document}$\mathfrak {e}(2)$\end{document}e(2) with respect to various embeddings. All Lie algebras and representations are over the complex numbers.
Optical separation of ellipsoidal particles in a uniform flow
Authors: Chang Cheong Bong , Huang Wei-Xi , Lee Kyung Heon , Sung Hyung Jin
Published: June 2014

The behavior of an ellipsoidal particle subjected to a vertical optical force by a loosely focused laser beam in a uniform flow was studied numerically. The fluid flow and the particle motion were separately solved and coupled using the penalty immersed boundary method, and the optical force was calculated using the dynamic ray tracing method. The optical force and optically induced torque on the ellipsoidal particle varied according to the aspect ratio and initial inclination angle. The ellipsoidal particle, whose major axis was initially aligned with the laser beam axis, was more migrated as the aspect ratio increased. The migration distance also depended on the initial inclination angle, even for a given ellipsoidal particle shape. As the laser beam power increased and the flow velocity decreased, the effect of the initial inclination angle increased. The ellipsoidal particles with different aspect ratios could be effectively separated if the rotation along the spanwise direction was suppressed. Moreover, the migration distance could be predicted analytically by introducing a new dimensionless number Sc to represent the ratio of the optical force to the viscous force for the ellipsoidal particles.
Tunable broadband transmission and phase modulation of light through graphene multilayers
Authors: Wang Bing , Zhang Xiang , Ping Loh Kian , Teng Jinghua
Published: June 2014

In this work, we study the light transmission through multilayer graphene sheets that are spatially separated. By adopting the transfer matrix method modified for two-dimensional material, we find that the graphene multilayers manifest a broad passband in the transmission spectrum. The two edges of the passband are determined by the interband threshold of electron transition in graphene and the cutoff wavelength of Bloch mode in the multilayer structure. By varying the interlayer space of the graphene multilayers, the structure can be used to increase the phase velocity of normally incident light or to make the phase at rest like epsilon-near-zero material. The study shows that the graphene multilayers may find great applications in optical switches, filters, and phase modulators.
Photo-guided sampling for rapid detection and imaging of traces of explosives by a compact Raman spectrometer
Authors: Malka Itamar , Rosenwaks Salman , Bar Ilana
Published: June 2014

Rapid acquisition of Raman spectra and Raman spectral maps of traces of compounds at proximal distances by a compact Raman system is demonstrated. The performance of the system was further improved by photographing the target, prior to data acquisition, allowing selective monitoring of spatially resolved particles and thus mapping at reduced sampling times, compared to raster-scanning. This spectrometer and its photo-guided sampling make it a potential candidate for detection of other partially covered substrates.
Electro-optical, UV absorbance, and UV photoluminescence analysis of Se95In5 chalcogenide glass microparticle doped ferroelectric liquid crystal
Authors: Pratap Singh Dharmendra , Kumar Gupta Swadesh , Pandey Shivani , Singh Kedar , Manohar Rajiv
Published: June 2014

The dandelion like Se95In5 chalcogenide glass microparticle (CGMPs) doped ferroelectric liquid crystal (FLC) has been investigated. The electro-optical parameters of the pure and doped FLC were carried out as a function of applied voltage. The experimental response time and polarization curves for the Se95In5 CGMPs doped FLC have also been theoretically fitted. The presence of Se95In5 CGMPs affects the molecular dynamics of the FLC molecules, which was proved by the Fourier transformed infrared spectroscopy. The UV absorbance of the pure FLC material has been enhanced in the presence of CGMPs, which is analogous to the coupling between phonons of CGMPs and radiation field. The photoluminescence (PL) of the pure FLC has also been enhanced and blue shifted with the addition of Se95In5 CGMPs. The enhanced PL is attributed to the constructive interaction between low energy phonons of the CGMPs and incident photons of the monochromatic light in the LC medium. The blue shifting of PL emission is due to the enhanced optical band gap of the Se95In5 CGMPs doped FLC. The enhancement in the optical band gap of the CGMPs doped FLC was explained by the model of density states in the composite. Ultra-violet lasing, UV filtering, and optical band gap engineering are the possible applications of the investigated Se95In5 CGMPs doped FLC material.
Bulk heterojunction PCPDTBT:PC71BM organic solar cells deposited by emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation
Authors: Ge Wangyao , McCormick Ryan D. , Nyikayaramba Gift , Stiff-Roberts Adrienne D.
Published: June 2014

Organic solar cells based on poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) were fabricated by emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE). Two different deposition modes, namely simultaneous deposition and sequential deposition, were investigated for fabricating bulk-heterojunction organic solar cells. This work demonstrates that the RIR-MAPLE sequential deposition mode provides precise ratio control for the fabrication of bulk-heterojunction organic solar cells.
Electric double layer transistors with ferroelectric BaTiO3 channels
Authors: Ito M. , Matsubara Y. , Kozuka Y. , Takahashi K. S. , Kagawa F. , Ye J. T. , Iwasa Y. , Ueno K. , Tokura Y. , Kawasaki M.
Published: June 2014

We report the surface conduction of a BaTiO3 thin film using electric double layer transistor (EDLT) structure. A transistor operation was observed at 220 K with an on/off ratio exceeding 105, demonstrating that ionic liquid gating is effective to induce carriers at the surface of ferroelectric materials. Temperature dependence of channel resistance exhibited a metallic behavior down to 150 K. EDLT structure is also fabricated using a commercial BaTiO3 bulk single crystal for comparison, which shows abrupt resistance increase across the orthorhombic to rhombohedral transition temperature at 183 K. This result indicates that the epitaxial strain is effective to maintain low resistance in this material with keeping the single domain structure.
Imprinted labyrinths and percolation in Nd-Co/Nb magnetic/superconducting hybrids
Authors: Ruiz-Valdepeñas L. , Velez M. , Valdés-Bango F. , Alvarez-Prado L. M. , Garcia-Alonso F. J. , Martin J. I. , Navarro E. , Alameda J. M. , Vicent J. L.
Published: June 2014

Magnetization reversal processes have been studied in hybrid magnetic/superconducting Nd-Co/Nb bilayers by the comparison of out-of-plane magnetic hysteresis loops and superconducting phase diagrams as a function of magnetic layer thickness and of disorder in the magnetic layer induced by a nanostructured copolymer template. A good correlation is found between the regimes corresponding to percolation effects in the superconductor and to the transition from extended to confined superconductivity with the characteristic fields for reverse domain nucleation and fast domain expansion in the magnetic layer, indicating that superconductivity nucleates on the disordered network imprinted on the superconducting layer by the labyrinth domain structure of the magnetic layer. As disorder increases in the magnetic layer, percolation effects disappear from the superconducting transitions in agreement with a more homogeneous magnetization reversal process.
Evolution and interaction of twins, dislocations and stacking faults in rolled α-brass during nanostructuring at sub-zero temperature
Authors: Roy Barna , Kumar Nand Kishor , Nambissan Padinharu Madathil Gopalakrishnan , Das Jayanta
Published: June 2014

The effect of cryorolling (CR) strain at 153 K on the evolution of structural defects and their interaction in α−brass (Cu–30 wt.% Zn) during nanostructuring has been evaluated. Even though the lattice strain increases up to 2.1 × 10−3 at CR strain of 0.6 initially, but it remains constant upon further rolling. Whereas, the twin density (β) increases to a maximum value of 5.9 × 10−3 at a CR strain of 0.7 and reduces to 1.1 × 10−5 at 0.95. Accumulation of stacking faults (SFs) and lattice disorder at the twin boundaries causes dynamic recrystallization, promotes grain refinement and decreases the twin density by forming subgrains. Detailed investigations on the formation and interaction of defects have been done through resistivity, positron lifetime and Doppler broadening measurements in order to understand the micro-mechanism of nanostructuring at sub-zero temperatures.
Synchrotron radiation spectra and synchrotron radiation spot shape of runaway electrons in Experimental Advanced Superconducting Tokamak
Authors: Zhou R. J. , Pankratov I. M. , Hu L. Q. , Xu M. , Yang J. H.
Published: June 2014

A detailed analysis of the spectra of synchrotron radiation emitted by runaway electrons, and an analysis of synchrotron radiation spot shapes are presented for EAST runaway cases. Conditions required for the asymptotic expressions of synchrotron radiation spectra to be valid are studied for these EAST parameters. We provide the correct synchrotron radiation spectra in typical EAST discharges, and we show results of calculations of the shape of the synchrotron radiation spots emitted by runaway electrons. These shapes are detected by a visible light camera in EAST. Safety factor q(r), the horizontal displacement of electron drift surfaces with respect to the magnetic surfaces δe, pitch angle θp, and the position of the camera were taken into account. Our results indicate that the θp and q profiles can significantly affect the synchrotron radiation spot shape; it is simpler to record all synchrotron radiation if the camera is placed far from the plasma. An asymmetrical synchrotron radiation spot shape can be deduced when the effect of the drift orbit shift is taken into account. Our results can explain the asymmetrical ring-like synchrotron radiation spot shape from runaway electron beams in EAST experiments.
Negotiating the farmland dilemmas: ‘barefoot planners’ in China’s urban periphery
Authors: Wang Yiming
Published: June 2014

China is confronted with three intrinsic dilemmas related to farmland conversion: (1) conserving farmland for national food security versus converting farmland to boost local government income; (2) protecting farmland to ensure the basic living conditions of vulnerable farmers versus developing farmland to encourage farmers’ transition toward urban livelihoods; (3) preserving farmland by exercising national regulatory controls versus managing farmland through localised negotiations among the concerned stakeholders. This paper analyses three cases based on interview data collected from Shanghai, Guizhou, and Henan between 2009 and 2012. Each case consists of an informal local resolution to one of the three farmland dilemmas, and involves a variety of actors—local entrepreneurs, ethnic minority farmers, and village committee members—who act as ‘barefoot planners’. On the basis of these findings, this paper makes a series of policy recommendations and calls for more flexible, spontaneous, and place-based farmland planning in China through social learning.
Continuous Connectivity, Handheld Computers, and Mobile Spatial Knowledge
Authors: Wilson Matthew W
Published: June 2014

As geospatial information seemingly moves from users' personal computers to ‘the cloud’, the use of the phrase ‘geographic technologies’ has increasingly indicated things beyond desktop GIS. With these shifts in the distribution of geospatial data and practices, and the rise of the geoweb as a site of inquiry, new concepts are needed to better understand the conditions of geographic technologies. In this paper I conceptualize one such element of interactivity: Connection. Here, I argue that a logic of continuous connectivity underlies the development of digital spatial media and influences the contemporary production of spatial knowledge. For those lives lived that are presumed to be ‘always connected’, interactions are figured by these connections to digital media. Many of these digital devices (especially mobile ones) become functional only through a series of connections to data and communication networks. For instance, mobile phones are in continuous communication regardless of direct use, ‘listening’ to cellular towers and analyzing proximity to deliver the best possible connection. From these system-level codes that maintain device connectivity to software-level codes that push and pull data to and from ‘the cloud’, being always connected is part of a cultural milieu that has diverse implications not only for attention but also for the development of collective, spatial knowledge. Here, I situate the emergence of continuous connectivity in the marketing of handheld computers in the late 1990s, to historicize the importance of connection for understanding geospatial practices.
Local versus basin-scale limitation of marine nitrogen fixation
Authors: Weber Thomas , Deutsch Curtis
Published: June 2014

Significance

This paper addresses a longstanding debate regarding the factors that limit nitrogen fixation by diazotrophic plankton—the primary source of an essential nutrient to the ocean. Multiple lines of evidence show that diazotroph growth can be locally limited by the atmospheric iron supply, but large-scale rates of N
2
fixation are ultimately controlled by N deficits generated within the ocean. These findings can reconcile the conflicting observations of biologists and geochemists, while implying a new sensitivity of the marine N cycle to anthropogenic climate warming.
Processing multiple visual objects is limited by overlap in neural channels
Authors: Cohen Michael A. , Konkle Talia , Rhee Juliana Y. , Nakayama Ken , Alvarez George A.
Published: June 2014

Significance

Human cognition is inherently limited: only a finite amount of visual information can be processed at a given instant. What determines those limits? Here, we show that more objects can be processed when they are from different stimulus categories than when they are from the same category. This behavioral benefit maps directly onto the functional organization of the ventral visual pathway. These results suggest that our ability to process multiple items at once is limited by the extent to which those items compete with one another for neural representation. Broadly, these results provide strong evidence that the capacities and limitations of human behavior can be inferred from our functional neural architecture.
Deep mantle structure as a reference frame for movements in and on the Earth
Authors: Torsvik Trond H. , van der Voo Rob , Doubrovine Pavel V. , Burke Kevin , Steinberger Bernhard , Ashwal Lewis D. , Trønnes Reidar G. , Webb Susan J. , Bull Abigail L.
Published: June 2014

Significance

Since the Pangea supercontinent formed about 320 million years ago, plumes that sourced large igneous provinces and kimberlites have been derived from the edges of two stable thermochemical reservoirs at the core–mantle boundary. We test whether it is possible to maintain this remarkable surface-to-deep Earth correlation before Pangea through the development of a new plate reconstruction method and find that our reconstructions for the past 540 million years comply with known geological and tectonic constraints (opening and closure of oceans, mountain building, and more). These results have important implications for Earth history, including the style of mantle convection in the deep past and the long-term stability of mantle reservoirs.
Metformin promotes lifespan through mitohormesis via the peroxiredoxin PRDX-2
Authors: De Haes Wouter , Frooninckx Lotte , Van Assche Roel , Smolders Arne , Depuydt Geert , Billen Johan , Braeckman Bart P. , Schoofs Liliane , Temmerman Liesbet
Published: June 2014

Significance

Recently it has been suggested that metformin, the most commonly used antidiabetic drug, might also possess general health-promoting properties. Elucidating metformin’s mode of action will vastly increase its application range and will contribute to healthy aging. We reveal a signaling cascade in which metformin is able to extend lifespan by increasing the production of reactive oxygen species (ROS). This allowed us to further work at the crossroads of human disease and aging research, identifying a key molecule that is able to translate the ROS signal into a prolongevity cue: an antioxidant peroxiredoxin is also able to activate a lifespan-promoting signaling cascade, here described in detail. Continued research efforts in this field lead toward a targeted improvement of aging-related complications.
Reconstitution of the mitochondrial calcium uniporter in yeast
Authors: Kovács-Bogdán Erika , Sancak Yasemin , Kamer Kimberli J. , Plovanich Molly , Jambhekar Ashwini , Huber Robert J. , Myre Michael A. , Blower Michael D. , Mootha Vamsi K.
Published: June 2014

Significance

The mitochondrial uniporter is a highly selective calcium channel found in many diverse eukaryotes, but absent in the yeast
Saccharomyces cerevisiae
. Although the uniporter’s existence was recognized more than 50 y ago, its molecular components have been identified only recently. Here we use yeast as a facile reconstitution system to identify the minimal components sufficient for in vivo uniporter activity. We describe the simplified calcium uniporter of slime mold, consisting of one transmembrane component, DdMCU, which alone is sufficient for robust calcium uptake in yeast mitochondria. Intriguingly, the human uniporter requires two proteins, MCU and the animal-specific protein EMRE, that together are sufficient for uniporter activity. Our work provides a powerful reconstitution system for studying the evolution and function of this channel.
NAD
+
and SIRT3 control microtubule dynamics and reduce susceptibility to antimicrotubule agents
Authors: Harkcom William T. , Ghosh Ananda K. , Sung Matthew S. , Matov Alexandre , Brown Kevin D. , Giannakakou Paraskevi , Jaffrey Samie R.
Published: June 2014

Significance

Nicotinamide adenine dinucleotide (NAD
+
) is an endogenous small molecule that has effects on diverse processes, including obesity, lifespan, and cancer. A major goal is to identify the NAD
+
-regulated cellular pathways that may mediate these effects. In this study, we demonstrate that NAD
+
regulates the microtubule cytoskeleton. We find that these effects are mediated by the mitochondrial sirtuin-3. Our findings have implications for many clinically used chemotherapeutics that target microtubules, as we demonstrate that high NAD
+
levels can reduce sensitivity to these drugs. These results are also significant because they demonstrate for the first time that NAD
+
, a molecule regulated by age, diet, and disease state, can influence basic microtubule functions.
In situ selectivity profiling and crystal structure of SML-8-73-1, an active site inhibitor of oncogenic K-Ras G12C
Authors: Hunter John C. , Gurbani Deepak , Ficarro Scott B. , Carrasco Martin A. , Lim Sang Min , Choi Hwan Geun , Xie Ting , Marto Jarrod A. , Chen Zhe , Gray Nathanael S. , Westover Kenneth D.
Published: June 2014

Significance

SML-8-73-1 (SML) is the first example, to our knowledge, of a GTP-competitive inhibitor of V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras). A high-resolution structure of K-Ras G12C bound to SML shows K-Ras in an inactive conformation. In situ proteomic-based chemical profiling of SML demonstrates that SML is highly selective for K-Ras G12C over other small GTPases. A novel chemosensor-based assay allows measurement of covalent reaction rates between K-Ras G12C and SML and enables characterization of this reaction in the context of millimolar concentrations of GTP and GDP, well in exccss of what is found in living cells. These results demonstrate that even in the presence of high concentrations of GTP and GDP, SML is able to exchange into the GN site.
Transcription is initiated on silent variant surface glycoprotein expression sites despite monoallelic expression in
Trypanosoma brucei
Authors: Kassem Ali , Pays Etienne , Vanhamme Luc
Published: June 2014

Significance

African trypanosomes are a major plague in sub-Saharan Africa. They cause sleeping sickness in humans and nagana in cattle, preventing extensive cattle raising. They escape the immune system of their host through frequent changes in their major surface antigen, the variant surface glycoprotein (VSG). The control of VSG expression is poorly understood, and the level at which it takes place has been a matter of debate for the last 25 y. A better understanding of the mechanism by which it works would facilitate the identification of the proteins involved and would provide putative targets for drug design. We report data indicating an unusual control level, namely after transcription initiation, suggesting transcription elongation or RNA processing as a control step.
Pressure-enabled phonon engineering in metals
Authors: Lanzillo Nicholas A. , Thomas Jay B. , Watson Bruce , Washington Morris , Nayak Saroj K.
Published: June 2014

Significance

Understanding the pressure response of the electrical properties of metals provides a fundamental way of manipulating material properties for potential device applications. In particular, the electrical resistivity of a metal, which is an intrinsic property determined primarily by the interaction strength between electrons and collective lattice vibrations (phonons), can be reduced when the metal is pressurized. In this article, we show that first-principles calculations of the resistivity, as well as experimental measurements using a solid media piston–cylinder apparatus, predict a significant reduction in the electrical resistivity of aluminum and copper when subject to high pressure due primarily to the reduction in the electron–phonon interaction strength. This study suggests innovative ways of controlling transport phenomena in metals.
How Secular is European Secularism?
Authors: Bhargava Rajeev
Published: June 2014

European Secularism, one of the many versions of secularism available in the world, was developed in the context predominantly of single-religion societies, after a great deal of religious homogenization had already taken place. It was and remains a modest secularism. However, with the migration of workers from former colonies and the intensification of globalization, pre-Christian (Hindu, Buddhist, and Jain) and post-Christian faiths (Islam and Sikhism) have been thrown together for the first time in modern Europe creating an unprecedented diversity the like of which has not been witnessed in Europe under conditions of modernity. This has destabilized European secular states and the conception of secularism that underpins them. European Secularism is in crisis for as it now turns out it is not quite secular enough.
Cyclotomic Carter-Payne homomorphisms
Authors: Lyle Sinéad , Mathas Andrew
Published: June 2014

We construct a new family of homomorphisms between (graded) Specht modules of the quiver Hecke algebras of type 

A
A

. These maps have many similarities with the homomorphisms constructed by Carter and Payne in the special case of the symmetric groups, although the maps that we obtain are both more and less general than these.
Peer‐Effects in Obesity among Public Elementary School Children: A Grade‐Level Analysis
Authors: Asirvatham Jebaraj , Nayga Rodolfo M. , Thomsen Michael R.
Published: June 2014

Using a panel dataset at the grade level from Arkansas public schools, this study finds that changes in the obesity prevalence at the oldest grade are associated with changes in obesity prevalence at younger grades. Furthermore, analysis across different school types shows that the peer effects are statistically significant but the magnitude of the effect is greater in kindergarten to fourth‐grade schools than in kindergarten to sixth‐grade schools. We also use tests on spatial and temporal dimensions, as well as by weight status grouping, to provide evidence that these peer effects are more than just a statistical correlation.
as Experimental Theater
Authors: Savran David
Published: June 2014

Stephen Sondheim and his critics usually ascribe the failure ofAnyone Can Whistle, Sondheim’s most revered flop, to the volatile social and political context in the United States, claiming that it was ahead of its time. This chapter argues, in contrast, that it is very much of its time and that no other musical of the period epitomizes the social and cultural contradictions of the mid-1960s as vividly asWhistle. Attempting to bring the kind of theatrical and political provocation that was flourishing Off-Off-Broadway to Broadway audiences unfamiliar with experimental idioms,Whistlerepresents a determined hybrid: part satire, part romance, part musical comedy, part Broadway razzle-dazzle, part political polemic. It is also symptomatic of the contradictions inherent in the dominant political philosophy of the 1960s, liberal individualism, in its opposition to standardization and conformism and its inclination toward an arrogant egocentrism. ThatWhistlehad to wait decades to find an audience is a tribute less to Sondheim’s prescience than to his ascendency since the 1970s as his generation’s preeminent architect of experimental music theatre.
Biosemiotic Criticism
Authors: Maran Timo
Published: June 2014

This article examines the concept of biosemiotic criticism. It contrasts biosemiotics with the semiology of Ferdinand de Saussure and provides an overview of biosemiotics as a synthetic biological discipline. It describes how the emergence of biosemiotics widened the sphere of semiotic processes to embrace all living organisms on Earth and offers a perspective of what biosemiotic criticism might be. The article also considers attempts to develop models that would bridge biosemiotics (or semiotic thinking more generally) and cultural or literary criticism.
Media Moralia
Authors: McMurry Andrew
Published: June 2014

This article gives ecocritical consideration to digital media. It discusses Elizabeth Kolbert’s work which highlights how a technological society is destroying itself. It suggests that while humans have the power to modify their surroundings to suit their needs, they do not have the wisdom to suit their needs to their surroundings. The chapter considers the possibility that digital media have less environmental impact than their analogue predecessors, and that, conversely, such media dangerously insulate us from contact with nonhuman nature.
Talking About Climate Change
Authors: Kluwick Ursula
Published: June 2014

This article examines the issue of climate change in the context of ecocriticism. It analyzes some of the narrative forms employed in the mediation of climate change science, focusing on those used by mediators who are not themselves scientists in the transmission of scientific information to a nonspecialist readership or audience. It reviews four relevant works that combine the communication of scientific theories and facts with pedagogical and motivational impulses. These include Davis Guggenheim’s documentary film An Inconvenient Truth, Fred Pearce’s book The Last Generation: How Nature Will Take Her Revenge for Climate Change and the climate change manuals The Live Earth Global Warming Survival Handbook and How to Save the Climate.
Nontraditional Employment: The Careers of Temporary Workers
Authors: De Cuyper Nele , Fontinha Rita , De Witte Hans
Published: June 2014

This chapter focuses upon the careers of temporary workers. Temporary employment for many workers presents a route to permanent employment. Other workers, however, get trapped into temporary employment or cycle between unstable jobs and spells of unemployment. Predictors of such transitions are multiple. We selected two broad categories, namely perceived employability from the area of career research and health and well-being from the area of occupational health and well-being research. The overall conclusion is that the association between temporary employment and both perceived employability and health and well-being is inconclusive. This suggests that there are boundary conditions that may make some temporary workers successful and others not. Risk factors include dynamics related to the dual labor market, including lower job quality, lower investments on the part of employers, and negative stereotyping of temporary workers as second-class citizens. On the positive side, many temporary workers have learned to manage their careers in the sense that they invest in training and in continuous job search.