bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: Phase, amplitude, and clustering effects
Authors: Minati Ludovico
Published: October 2014

In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes and in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.
Phase behaviour of polarizable colloidal hard rods in an external electric field: A simulation study
Authors: Troppenz Thomas , Filion Laura , van Roij René , Dijkstra Marjolein
Published: October 2014

We present a double-charge model for the interaction between parallel polarizable hard spherocylinders subject to an external electric field. Using Monte Carlo simulations and free-energy calculations, we predict the phase behaviour for this model as a function of the density and electric field strength, at a fixed length-to-diameter ratio L/D = 5. The resulting phase diagram contains, in addition to the well-known nematic, smectic A, ABC crystal, and columnar phases, a smectic C phase, and a low temperature crystal X phase. We also find a string fluid at low densities and field strengths, resembling results found for dipolar spheres.
An improved simple polarisable water model for use in biomolecular simulation
Authors: Bachmann Stephan J. , van Gunsteren Wilfred F.
Published: October 2014

The accuracy of biomolecular simulations depends to some degree on the accuracy of the water model used to solvate the biomolecules. Because many biomolecules such as proteins are electrostatically rather inhomogeneous, containing apolar, polar, and charged moieties or side chains, a water model should be able to represent the polarisation response to a local electrostatic field, while being compatible with the force field used to model the biomolecules or protein. The two polarisable water models, COS/G2 and COS/D, that are compatible with the GROMOS biomolecular force fields leave room for improvement. The COS/G2 model has a slightly too large dielectric permittivity and the COS/D model displays a much too slow dynamics. The proposed COS/D2 model has four interaction sites: only one Lennard-Jones interaction site, the oxygen atom, and three permanent charge sites, the two hydrogens, and one massless off-atom site that also serves as charge-on-spring (COS) polarisable site with a damped or sub-linear dependence of the induced dipole on the electric field strength for large values of the latter. These properties make it a cheap and yet realistic water model for biomolecular solvation.
Relaxation of a steep density gradient in a simple fluid: Comparison between atomistic and continuum modeling
Authors: Pourali Meisam , Meloni Simone , Magaletti Francesco , Maghari Ali , Casciola Carlo Massimo , Ciccotti Giovanni
Published: October 2014

We compare dynamical nonequilibrium molecular dynamics and continuum simulations of the dynamics of relaxation of a fluid system characterized by a non-uniform density profile. Results match quite well as long as the lengthscale of density nonuniformities are greater than the molecular scale (∼10 times the molecular size). In presence of molecular scale features some of the continuum fields (e.g., density and momentum) are in good agreement with atomistic counterparts, but are smoother. On the contrary, other fields, such as the temperature field, present very large difference with respect to reference (atomistic) ones. This is due to the limited accuracy of some of the empirical relations used in continuum models, the equation of state of the fluid in the present example.
A chirped-pulse Fourier-transform microwave/pulsed uniform flow spectrometer. I. The low-temperature flow system
Authors: Oldham James M. , Abeysekera Chamara , Joalland Baptiste , Zack Lindsay N. , Prozument Kirill , Sims Ian R. , Park G. Barratt , Field Robert W. , Suits Arthur G.
Published: October 2014

We report the development of a new instrument that combines chirped-pulse microwave spectroscopy with a pulsed uniform supersonic flow. This combination promises a nearly universal detection method that can deliver isomer and conformer specific, quantitative detection and spectroscopic characterization of unstable reaction products and intermediates, product vibrational distributions, and molecular excited states. This first paper in a series of two presents a new pulsed-flow design, at the heart of which is a fast, high-throughput pulsed valve driven by a piezoelectric stack actuator. Uniform flows at temperatures as low as 20 K were readily achieved with only modest pumping requirements, as demonstrated by impact pressure measurements and pure rotational spectroscopy. The proposed technique will be suitable for application in diverse fields including fundamental studies in spectroscopy, kinetics, and reaction dynamics.
A fast tomographic method for searching the minimum free energy path
Authors: Chen Changjun , Huang Yanzhao , Jiang Xuewei , Xiao Yi
Published: October 2014

Minimum Free Energy Path (MFEP) provides a lot of important information about the chemical reactions, like the free energy barrier, the location of the transition state, and the relative stability between reactant and product. With MFEP, one can study the mechanisms of the reaction in an efficient way. Due to a large number of degrees of freedom, searching the MFEP is a very time-consuming process. Here, we present a fast tomographic method to perform the search. Our approach first calculates the free energy surfaces in a sequence of hyperplanes perpendicular to a transition path. Based on an objective function and the free energy gradient, the transition path is optimized in the collective variable space iteratively. Applications of the present method to model systems show that our method is practical. It can be an alternative approach for finding the state-to-state MFEP.
Broadband gain in poly(3-hexylthiophene):phenyl-C61-butyric-acid-methyl-ester photodetectors enabled by a semicontinuous gold interlayer
Authors: Melancon Justin M. , Živanović Sandra R.
Published: October 2014

Substantial broadband photoconductive gain has been realized for organic, thin-film photodetectors with a poly(3-hexylthiophene):phenyl-C61-butyric-acid-methyl-ester (P3HT:PCBM) active layer at low bias voltages. External quantum efficiencies upwards of 1500% were achieved when a semicontinuous gold layer was introduced at the anode interface. Significant gain was also observed in the sub-band gap, near infrared region where the external quantum efficiency approached 100% despite the lack of a sensitizer. The gain response was highly dependent on the thickness of the active layer of the photodetector with the best results achieved with the thinnest devices. The gain is the result of the injection of secondary electrons due to hole charge trapping at the semicontinuous gold layer.
Nonlinear scaling analysis approach of agent-based Potts financial dynamical model
Authors: Hong Weijia , Wang Jun
Published: October 2014

A financial agent-based price model is developed and investigated by one of statistical physics dynamic systems—the Potts model. Potts model, a generalization of the Ising model to more than two components, is a model of interacting spins on a crystalline lattice which describes the interaction strength among the agents. In this work, we investigate and analyze the correlation behavior of normalized returns of the proposed financial model by the power law classification scheme analysis and the empirical mode decomposition analysis. Moreover, the daily returns of Shanghai Composite Index and Shenzhen Component Index are considered, and the comparison nonlinear analysis of statistical behaviors of returns between the actual data and the simulation data is exhibited.
Graphene induced remote surface scattering in graphene/AlGaN/GaN heterostructures
Authors: Liu Xiwen , Li Dan , Wang Bobo , Liu Bin , Chen Famin , Jin Guangri , Lu Yanwu
Published: October 2014

The mobilities of single-layer graphene combined with AlGaN/GaN heterostructures on two-dimensional electron gases in graphene/AlGaN/GaN double heterojunction are calculated. The impact of electron density in single-layer graphene is also studied. Remote surface roughness (RSR) and remote interfacial charge (RIC) scatterings are introduced into this heterostructure. The mobilities limited by RSR and RIC are an order of magnitude higher than that of interface roughness and misfit dislocation. This study contributes to designing structures for generation of higher electron mobility in graphene/AlGaN/GaN double heterojunction.
Detachment energies of spheroidal particles from fluid-fluid interfaces
Authors: Davies Gary B. , Krüger Timm , Coveney Peter V. , Harting Jens
Published: October 2014

The energy required to detach a single particle from a fluid-fluid interface is an important parameter for designing certain soft materials, for example, emulsions stabilised by colloidal particles, colloidosomes designed for targeted drug delivery, and bio-sensors composed of magnetic particles adsorbed at interfaces. For a fixed particle volume, prolate and oblate spheroids attach more strongly to interfaces because they have larger particle-interface areas. Calculating the detachment energy of spheroids necessitates the difficult measurement of particle-liquid surface tensions, in contrast with spheres, where the contact angle suffices. We develop a simplified detachment energy model for spheroids which depends only on the particle aspect ratio and the height of the particle centre of mass above the fluid-fluid interface. We use lattice Boltzmann simulations to validate the model and provide quantitative evidence that the approach can be applied to simulate particle-stabilized emulsions, and highlight the experimental implications of this validation.
Transport behavior of water molecules through two-dimensional nanopores
Authors: Zhu Chongqin , Li Hui , Meng Sheng
Published: October 2014

Water transport through a two-dimensional nanoporous membrane has attracted increasing attention in recent years thanks to great demands in water purification and desalination applications. However, few studies have been reported on the microscopic mechanisms of water transport through structured nanopores, especially at the atomistic scale. Here we investigate the microstructure of water flow through two-dimensional model graphene membrane containing a variety of nanopores of different size by using molecular dynamics simulations. Our results clearly indicate that the continuum flow transits to discrete molecular flow patterns with decreasing pore sizes. While for pores with a diameter ≥15 Å water flux exhibits a linear dependence on the pore area, a nonlinear relationship between water flux and pore area has been identified for smaller pores. We attribute this deviation from linear behavior to the presence of discrete water flow, which is strongly influenced by the water-membrane interaction and hydrogen bonding between water molecules.
Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing
Authors: Ling Xue , Wang Yusheng , Li Xide
Published: October 2014

An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li–Etsion–Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.
The confluent supersymmetry algorithm for Dirac equations with pseudoscalar potentials
Authors: Contreras-Astorga Alonso , Schulze-Halberg Axel
Published: October 2014

We introduce the confluent version of the quantum-mechanical supersymmetry formalism for the Dirac equation with a pseudoscalar potential. Application of the formalism to spectral problems is discussed, regularity conditions for the transformed potentials are derived, and normalizability of the transformed solutions is established. Our findings extend and complement former results [L. M. Nieto, A. A. Pecheritsin, and B. F. Samsonov, “Intertwining technique for the one-dimensional stationary Dirac equation,” Ann. Phys. 305, 151–189 (2003)].
Synchronizing spatio-temporal chaos with imperfect models: A stochastic surface growth picture
Authors: Pazó Diego , López Juan M. , Gallego Rafael , Rodríguez Miguel A.
Published: October 2014

We study the synchronization of two spatially extended dynamical systems where the models have imperfections. We show that the synchronization error across space can be visualized as a rough surface governed by the Kardar-Parisi-Zhang equation with both upper and lower bounding walls corresponding to nonlinearities and model discrepancies, respectively. Two types of model imperfections are considered: parameter mismatch and unresolved fast scales, finding in both cases the same qualitative results. The consistency between different setups and systems indicates that the results are generic for a wide family of spatially extended systems.
Localized surface plasmon assisted contrast microscopy for ultrathin transparent specimens
Authors: Wei Feifei , Lu Dylan , Aguinaldo Ryan , Ma Yicong , Sinha Sunil K. , Liu Zhaowei
Published: October 2014

We demonstrate a high contrast imaging technique, termed localized surface plasmon assisted contrast microscopy, by combining localized surface plasmon resonances (LSPR) and dark-field microscopy technique. Due to the sensitive response of LSPR to the refractive index of the surrounding media, this technique is capable of converting a small refractive index difference to a change in scattering intensity, resulting in a high-contrast, diffraction limited image of a thin unstained specimen with small, gradual refractive-index variation.
Pseudopotential calculations of strained-GeSn/SiGeSn hetero-structures
Authors: Sant Saurabh , Schenk Andreas
Published: October 2014

We have obtained empirical pseudopotential parameters for α-Sn and employed the pseudopotential method along with the virtual crystal approximation to model GeSn and SiGeSn alloys. The calculated direct and indirect band gaps of GeSn and SiGeSn show good agreement with experimental data at 300 K available till date. The derived pseudopotential parameter set was used to extract various band structure quantities required to model band-to-band tunneling in simulating GeSn/SiGeSn hetero-junction Tunnel Field Effect Transistors (TFET). All the required band structure quantities have been extracted as a function of biaxial strain, Si content, and Sn content and have been fitted to a quadratic expression. An attempt to simulate Si0.5Ge0.5/Si hetero-junction TFETs based on the extracted band structure quantities yields ID − VG plots that are in good agreement with the experimental ones—an indication for the reliability of the extracted band structure quantities. Thus, the calculated pseudopotential and extracted band structure parameters provide a complete data base for the modeling of GeSn/SiGeSn hetero-junction TFETs.
Ferromagnetic-nonmagnetic and metal-insulator phase transitions at the interfaces of KTaO3 and PbTiO3
Authors: Yang Yi , Lin Chen-Sheng , Chen Jin-Feng , Hu Lei , Cheng Wen-Dan
Published: October 2014

We studied the electronic and magnetic properties of hole doped KTaO3/PbTiO3 interface using density functional theory methods. Ferromagnetic-nonmagnetic phase transition and metal-insulator phase transition occur simultaneously at the interface with ferroelectric polarization reversal. Furthermore, these two transitions are coupled with each other because hole doping with large concentration of holes gives rise to ferromagnetism. The interfacial magnetization, which is proportional to hole concentration at the interface, can be tuned by ferroelectric polarization, leading to strong intrinsic magnetoelectric effect at the interface of originally nonmagnetic KTaO3 and PbTiO3.
Controllable film densification and interface flatness for high-performance amorphous indium oxide based thin film transistors
Authors: Ou-Yang Wei , Mitoma Nobuhiko , Kizu Takio , Gao Xu , Lin Meng-Fang , Nabatame Toshihide , Tsukagoshi Kazuhito
Published: October 2014

To avoid the problem of air sensitive and wet-etched Zn and/or Ga contained amorphous oxide transistors, we propose an alternative amorphous semiconductor of indium silicon tungsten oxide as the channel material for thin film transistors. In this study, we employ the material to reveal the relation between the active thin film and the transistor performance with aid of x-ray reflectivity study. By adjusting the pre-annealing temperature, we find that the film densification and interface flatness between the film and gate insulator are crucial for achieving controllable high-performance transistors. The material and findings in the study are believed helpful for realizing controllable high-performance stable transistors.
Super-Planckian far-zone thermal emission from asymmetric hyperbolic metamaterials
Authors: Nefedov Igor S. , Melnikov Leonid A.
Published: October 2014

We demonstrate the production of strong directive thermal emissions in the far-field zone of asymmetric hyperbolic metamaterials (AHMs), exceeding that predicted by Planck's limit. Asymmetry is inherent to the uniaxial medium, where the optical axis is tilted with respect to medium interfaces. The use of AHMs is shown to enhance the free-space coupling efficiency of thermally radiated waves, resulting in Super-Planckian far-field thermal emission in certain directions. This effect is impossible in usual hyperbolic materials because emission of high density of states (DOS) photons into vacuum with smaller DOS is preserved by the total internal reflection. Different plasmonic metamaterials are proposed for realizing AHM media; the thermal emission from a AHM, based on a grapheme multilayer structure, is presented, as an example.
Coherent kilo-electron-volt backscattering from plasma-wave boosted relativistic electron mirrors
Authors: Li F. Y. , Sheng Z. M. , Chen M. , Wu H. C. , Liu Y. , Meyer-ter-Vehn J. , Mori W. B. , Zhang J.
Published: October 2014

A different parameter regime of laser wakefield acceleration driven by sub-petawatt femtosecond lasers is proposed, which enables the generation of relativistic electron mirrors further accelerated by the plasma wave. Integrated particle-in-cell simulation, including both the mirror formation and Thomson scattering, demonstrates that efficient coherent backscattering up to keV photon energy can be obtained with moderate driving laser intensities and high density gas targets.
Visible-light-induced instability in amorphous metal-oxide based TFTs for transparent electronics
Authors: Ha Tae-Jun
Published: October 2014

We investigate the origin of visible-light-induced instability in amorphous metal-oxide based thin film transistors (oxide-TFTs) for transparent electronics by exploring the shift in threshold voltage (Vth). A large hysteresis window in amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs possessing large optical band-gap (≈3 eV) was observed in a visible-light illuminated condition whereas no hysteresis window was shown in a dark measuring condition. We also report the instability caused by photo irradiation and prolonged gate bias stress in oxide-TFTs. Larger Vth shift was observed after photo-induced stress combined with a negative gate bias than the sum of that after only illumination stress and only negative gate bias stress. Such results can be explained by trapped charges at the interface of semiconductor/dielectric and/or in the gate dielectric which play a role in a screen effect on the electric field applied by gate voltage, for which we propose that the localized-states-assisted transitions by visible-light absorption can be responsible.
Supersymmetric dark matter in the harsh light of the Large Hadron Collider
Authors: Peskin Michael E.
Published: October 2014

I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC).
Transplantation of prokaryotic two-component signaling pathways into mammalian cells
Authors: Hansen Jonathan , Mailand Erik , Swaminathan Krishna Kumar , Schreiber Joerg , Angelici Bartolomeo , Benenson Yaakov
Published: October 2014

Significance

Synthetic biology and genetic engineering would greatly benefit from engineered genetic elements that are orthogonal to the host in which they operate. Two-component signaling pathways are the prevalent signal processing modality in prokaryotes that is also found in low eukaryotes and plants but absent from vertebrate cells. Here we investigate whether the elements of prokaryotic two-component pathways are operational in mammalian cells. We find that the core biochemical processes are maintained, whereas the capacity to sense chemical ligands is diminished or obscured. We use the pathways for multiinput gene regulation and show that they can serve as a rich source of orthogonal building blocks for gene expression control in mammalian cells. Our findings open new avenues in synthetic circuit design.
Dopamine release from transplanted neural stem cells in Parkinsonian rat striatum in vivo
Authors: Kang Xinjiang , Xu Huadong , Teng Sasa , Zhang Xiaoyu , Deng Zijun , Zhou Li , Zuo Panli , Liu Bing , Liu Bin , Wu Qihui , Wang Li , Hu Meiqin , Dou Haiqiang , Liu Wei , Zhu Feipeng , Li Qing , Guo Shu , Gu Jingli , Lei Qian , Lü Jing , Mu Yu , Jin Mu , Wang Shirong , Jiang Wei , Liu Kun , Wang Changhe , Li Wenlin , Zhang Kang , Zhou Zhuan
Published: October 2014

Significance

With a combination of HPLC and carbon fiber electrodes, we demonstrate that grafted neural stem cells directly release dopamine in the damaged striatum in vivo and partially rescue a Parkinson’s disease (PD) model. (
i
) Primitive neural stem cell–dopamine-like neuron (pNSC–DAn) retained tyrosine hydroxylase expression and reduced the PD-like asymmetric rotation; (
ii
) depolarization-evoked dopamine release and reuptake were significantly rescued in striatum in vitro (brain slices) and in vivo, as determined jointly by microdialysis-based HPLC and electrochemical micro-carbon fiber electrodes; and (
iii
) the rescued dopamine was released directly from the grafted pNSC–DAn (not from the injured original cells). Thus, pNSC–DAn grafts release and reuptake dopamine in the striatum in vivo and alleviate PD symptoms in rats, providing proof-of-concept for human clinical translation.
WWOX, the common fragile site FRA16D gene product, regulates ATM activation and the DNA damage response
Authors: Abu-Odeh Mohammad , Salah Zaidoun , Herbel Christoph , Hofmann Thomas G. , Aqeilan Rami I.
Published: October 2014

Significance

Genomic instability is a hallmark of human cancers. Common fragile sites (CFSs) pose nonrandom, preferential targets of genomic instability, such as chromosome breaks, in response to replicative stress. The tumor suppressor WW domain-containing oxidoreductase (WWOX) spans the CFS FRA16D and has been implicated in carcinogenesis by a currently unknown mechanism. In this study, we identify a direct role of WWOX in DNA damage response, which is a major antagonist of genomic instability. We show that WWOX maintains genomic stability and regulates DNA repair by modulating the activity of the DNA damage checkpoint kinase ataxia telangiectasia-mutated (ATM). Our findings provide evidence that a fragile gene product is directly involved in the response to DNA damage, suggesting a rationale for its preferential loss during carcinogenesis.
Proteolytic control of neurite outgrowth inhibitor NOGO-A by the cAMP/PKA pathway
Authors: Sepe Maria , Lignitto Luca , Porpora Monia , Delle Donne Rossella , Rinaldi Laura , Belgianni Giuseppe , Colucci Gianna , Cuomo Ornella , Viggiano Davide , Scorziello Antonella , Garbi Corrado , Annunziato Lucio , Feliciello Antonio
Published: October 2014

Significance

Damage of the central nervous system (CNS) and neurodegenerative disorders represent the principal cause of morbidity and mortality among adults. An injured CNS is unable to regenerate dendritic or neurite connections because they spontaneously occur in the peripheral nervous system. Inhibitory influences of the glial cells and of myelin-associated inhibitors oppose the spontaneous regeneration of CNS neurons. Here, we identify a positive mechanism of neuronal differentiation, which acts in response to activation of intracellular pathway(s) to remove an inhibitory constraint of neurite outgrowth. Unveiling the molecular events regulating the regenerative capacity of neurons will impact on therapeutic initiatives to stem the course of brain damage or neurodegeneration.
Compartmentalization of the protein repair machinery in photosynthetic membranes
Authors: Puthiyaveetil Sujith , Tsabari Onie , Lowry Troy , Lenhert Steven , Lewis Robert R. , Reich Ziv , Kirchhoff Helmut
Published: October 2014

Significance

The fitness and robustness of plants crucially depend on the molecular repair of the vulnerable photosystem II (PS II) supercomplex, embedded in photosynthetic thylakoid membranes. To maintain photosynthetic performance, plants evolved an efficient multistep PS II repair cycle. The PS II repair cycle relies on a well-defined order of reactions and partial separation of individual repair steps. By combining biochemical, spectroscopic, and ultrastructural techniques, we discover that plants establish reaction order and separation by confinement of the enzymes that catalyze the individual steps to spatially separated thylakoid subcompartments—grana, grana margins, and stroma lamellae—formed by the stacked membranes. Structural flexibility of the thylakoid architecture allows controlled access of the damaged PS II by the repair machinery.
Kinetic evidence against partitioning of the ubiquinone pool and the catalytic relevance of respiratory-chain supercomplexes
Authors: Blaza James N. , Serreli Riccardo , Jones Andrew J. Y. , Mohammed Khairunnisa , Hirst Judy
Published: October 2014

Significance

Mitochondria produce ATP by using respiration to drive ATP synthase. Respiration is catalyzed by several membrane-bound complexes that are structurally organized into supercomplex assemblies. Supercomplexes have been proposed to confer a catalytic advantage by channeling of substrates between enzymes in the assemblies. Here, we test three simple predictions of the behavior of the mammalian respiratory chain that depend on whether channeling in supercomplexes is kinetically important and show that it is not. We reinterpret previous data taken to support substrate channeling and reveal an alternative explanation for these data. Finally, we discuss alternative proposals for why the respiratory-chain complexes have evolved to form supercomplex structures.
Cog5–Cog7 crystal structure reveals interactions essential for the function of a multisubunit tethering complex
Authors: Ha Jun Yong , Pokrovskaya Irina D. , Climer Leslie K. , Shimamura Gregory R. , Kudlyk Tetyana , Jeffrey Philip D. , Lupashin Vladimir V. , Hughson Frederick M.
Published: October 2014

Significance

In all eukaryotes, the docking and fusion of the vesicles that mediate intracellular trafficking requires multisubunit tethering complexes (MTCs). MTCs are thought to mediate the initial interaction between the vesicle and its target membrane and to orchestrate the assembly of the protein fusion machinery. The largest family of MTCs—of which the conserved oligomeric Golgi (COG) complex is a well-studied member—has been recalcitrant to structural characterization, presumably owing to the size and intrinsic flexibility of the complexes and their constituent subunits. Here we report the initial characterization of subunit interactions within the COG complex by X-ray crystallography. Mutations in the conserved intersubunit interface may be responsible for human congenital glycosylation disorders.
A rice ABC transporter, OsABCC1, reduces arsenic accumulation in the grain
Authors: Song Won-Yong , Yamaki Tomohiro , Yamaji Naoki , Ko Donghwi , Jung Ki-Hong , Fujii-Kashino Miho , An Gynheung , Martinoia Enrico , Lee Youngsook , Ma Jian Feng
Published: October 2014

Significance

Contamination of water and foods with arsenic (As) poses a threat to millions of people worldwide. Because the rice grain is the major source of As intake, reducing the transfer of As from soil to the grain is a pressing public health issue. We found that a member of the
Oryza sativa
C-type ATP-binding cassette transporter (OsABCC) family, OsABCC1, detoxifies As and reduces the amount of As in the rice grain. OsABCC1 in the upper nodes of rice plants restricts the distribution of As to the grain by sequestering it in the vacuoles of the phloem companion cells of diffuse vascular bundles directly connected to the grain. Our work suggests a strategy for limiting As accumulation in rice grains and thereby reducing human As exposure.
Individual differences in the peripheral immune system promote resilience versus susceptibility to social stress
Authors: Hodes Georgia E. , Pfau Madeline L. , Leboeuf Marylene , Golden Sam A. , Christoffel Daniel J. , Bregman Dana , Rebusi Nicole , Heshmati Mitra , Aleyasin Hossein , Warren Brandon L. , Labonté Benoit , Horn Sarah , Lapidus Kyle A. , Stelzhammer Viktoria , Wong Erik H. F. , Bahn Sabine , Krishnan Vaishnav , Bolaños-Guzman Carlos A. , Murrough James W. , Merad Miriam , Russo Scott J.
Published: October 2014

Significance

Depression and anxiety have been linked to increased inflammation. However, we do not know if inflammatory status predates onset of disease or whether it contributes to depression symptomatology. We report preexisting individual differences in the peripheral immune system that predict and promote stress susceptibility. Replacing a stress-naive animal’s peripheral immune system with that of a stressed animal increases susceptibility to social stress including repeated social defeat stress (RSDS) and witness defeat (a purely emotional form of social stress). Depleting the cytokine IL-6 from the whole body or just from leukocytes promotes resilience, as does sequestering IL-6 outside of the brain. These studies demonstrate that the emotional response to stress can be generated or blocked in the periphery, and offer a potential new form of treatment for stress disorders.
Switching dynamics of the bacterial flagellar motor near zero load
Authors: Wang Fangbin , Yuan Junhua , Berg Howard C.
Published: October 2014

Significance

The behavior of the flagellar rotary motor was monitored by following the rotation of small gold particles attached to flagellar hooks, nanometer-sized components found at the ends of motor drive shafts, providing an accurate readout of motor function. Some measurements were made in the past with large markers on flagellar filaments that suggested the presence of hidden steps preceding switching events. These steps were probably filament polymorphic transformations. Our data argue for a simple two-state system with transitions between clockwise and counterclockwise states that occur at random times.
Another Attempt to Put Sleeping Beauty to Rest
Authors: Stalnaker Robert
Published: October 2014

Sleeping Beauty has become like Newcomb's problem used to be: a puzzle where both intuitions and arguments cluster around two competing responses. In both cases, the real interest is in the frameworks that are constructed to treat the problem: causal vs. evidential decision theory in the case of Newcomb's problem, and different accounts of essentially indexical or self-locating belief in the case of Sleeping Beauty. Many of the arguments about Sleeping Beauty have been carried out in a common framework for representing self-locating belief, with alternative responses agreeing about the presuppositions of that framework. I want to question some of these presuppositions and to set the problem up in a way that is only subtly different from the standard formulation, but different in a way that I think is important.
Active Belief
Authors: Boyle Matthew
Published: October 2014

The man who changes his mind, in response to evidence of the truth of a proposition, does not act upon himself; nor does he bring about an effect.- Hampshire (1965, 100)

A point of persistent controversy in recent philosophical discussions of belief concerns whether we can exercise some sort of agential control over what we believe. On the one hand, the idea that we have some kind of discretion over what we believe has appealed to philosophers working in several areas. This idea has been invoked, for instance, to characterize the basic difference between rational and non-rational cognition, to account for our epistemic responsibility for what we believe, and to explain how we are able, normally, to say what we presently believe without relying on self-observation or inference. On the other hand, most contemporary philosophers agree that, in one significant sense, what we believe isnotup to us: we cannot simply believe “at will,” and, although what we wish were so can influence what we believe to be so, this influence hardly amounts to a form of control or agency.
Identification of genes encoding photoconvertible (Class I) water-soluble chlorophyll-binding proteins from Chenopodium ficifolium
Authors: Takahashi Shigekazu , Abe Eriko , Nakayama Katsumi , Satoh Hiroyuki
Published: October 2014

Photoconvertible water-soluble chlorophyll-binding proteins, called Class I WSCPs, have been detected in Chenopodiaceae, Amaranthaceae and Polygonaceae plant species. To date, Chenopodium album WSCP (CaWSCP) is the only cloned gene encoding a Class I WSCP. In this study, we identified two cDNAs encoding Chenopodium ficifolium Class I WSCPs, CfWSCP1, and CfWSCP2. Sequence analyses revealed that the open reading frames of CfWSCP1 and CfWSCP2 were 585 and 588 bp, respectively. Furthermore, both CfWSCPs contain cystein2 and cystein30, which are essential for the chlorophyll-binding ability of CaWSCP. Recombinant CfWSCP1 and CfWSCP2, expressed in Escherichia coli as hexa-histidine fusion proteins (CfWSCP1-His and CfWSCP2-His), formed inclusion bodies; however, we were able to solubilize these using a buffer containing 8 M urea and then refold them by dialysis. The refolded CfWSCP1-His and CfWSCP2-His could bind chlorophylls and exhibited photoconvertibility, confirming that the cloned CfWSCPs are further examples of Class I WSCPs.
The influence of different footwear on 3‐D kinematics and muscle activation during the barbell back squat in males
Authors: Sinclair Jonathan , McCarthy Derek , Bentley Ian , Hurst Howard Thomas , Atkins Stephen
Published: October 2014

The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot‐inspired footwear. This study aimed to determine how these footwear influence 3‐D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3‐D kinematics from the torso, hip, knee and ankle were measured using an eight‐camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated‐measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi‐squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi‐squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot‐inspired footwear although no biomechanical evidence was found to support this notion.
Neuronal BC RNAs cooperate with eIF4B to mediate activity-dependent translational control
Authors: Eom Taesun , Muslimov Ilham A. , Tsokas Panayiotis , Berardi Valerio , Zhong Jun , Sacktor Todd C. , Tiedge Henri
Published: October 2014

In neurons, translational regulation of gene expression has been implicated in the activity-dependent management of synapto-dendritic protein repertoires. However, the fundamentals of stimulus-modulated translational control in neurons remain poorly understood. Here we describe a mechanism in which regulatory brain cytoplasmic (BC) RNAs cooperate with eukaryotic initiation factor 4B (eIF4B) to control translation in a manner that is responsive to neuronal activity. eIF4B is required for the translation of mRNAs with structured 5′ untranslated regions (UTRs), exemplified here by neuronal protein kinase Mζ (PKMζ) mRNA. Upon neuronal stimulation, synapto-dendritic eIF4B is dephosphorylated at serine 406 in a rapid process that is mediated by protein phosphatase 2A. Such dephosphorylation causes a significant decrease in the binding affinity between eIF4B and BC RNA translational repressors, enabling the factor to engage the 40S small ribosomal subunit for translation initiation. BC RNA translational control, mediated via eIF4B phosphorylation status, couples neuronal activity to translational output, and thus provides a mechanistic basis for long-term plastic changes in nerve cells.
Dyskerin, tRNA genes, and condensin tether pericentric chromatin to the spindle axis in mitosis
Authors: Snider Chloe E. , Stephens Andrew D. , Kirkland Jacob G. , Hamdani Omar , Kamakaka Rohinton T. , Bloom Kerry
Published: October 2014

Condensin is enriched in the pericentromere of budding yeast chromosomes where it is constrained to the spindle axis in metaphase. Pericentric condensin contributes to chromatin compaction, resistance to microtubule-based spindle forces, and spindle length and variance regulation. Condensin is clustered along the spindle axis in a heterogeneous fashion. We demonstrate that pericentric enrichment of condensin is mediated by interactions with transfer ribonucleic acid (tRNA) genes and their regulatory factors. This recruitment is important for generating axial tension on the pericentromere and coordinating movement between pericentromeres from different chromosomes. The interaction between condensin and tRNA genes in the pericentromere reveals a feature of yeast centromeres that has profound implications for the function and evolution of mitotic segregation mechanisms.
Sex steroid blockade enhances thymopoiesis by modulating Notch signaling
Authors: Velardi Enrico , Tsai Jennifer J. , Holland Amanda M. , Wertheimer Tobias , Yu Vionnie W.C. , Zakrzewski Johannes L. , Tuckett Andrea Z. , Singer Natalie V. , West Mallory L. , Smith Odette M. , Young Lauren F. , Kreines Fabiana M. , Levy Emily R. , Boyd Richard L. , Scadden David T. , Dudakov Jarrod A. , van den Brink Marcel R.M.
Published: October 2014

Paradoxical to its importance for generating a diverse T cell repertoire, thymic function progressively declines throughout life. This process has been at least partially attributed to the effects of sex steroids, and their removal promotes enhanced thymopoiesis and recovery from immune injury. We show that one mechanism by which sex steroids influence thymopoiesis is through direct inhibition in cortical thymic epithelial cells (cTECs) of Delta-like 4 (Dll4), a Notch ligand crucial for the commitment and differentiation of T cell progenitors in a dose-dependent manner. Consistent with this, sex steroid ablation (SSA) led to increased expression of Dll4 and its downstream targets. Importantly, SSA induced by luteinizing hormone-releasing hormone (LHRH) receptor antagonism bypassed the surge in sex steroids caused by LHRH agonists, the gold standard for clinical ablation of sex steroids, thereby facilitating increased Dll4 expression and more rapid promotion of thymopoiesis. Collectively, these findings not only reveal a novel mechanism underlying improved thymic regeneration upon SSA but also offer an improved clinical strategy for successfully boosting immune function.
Do Peer Effects Improve Hand Hygiene Adherence among Healthcare Workers?
Authors: Monsalve Mauricio N. , Pemmaraju Sriram V. , Thomas Geb W. , Herman Ted , Segre Alberto M. , Polgreen Philip M.
Published: October 2014

Objective.

To determine whether hand hygiene adherence is influenced by peer effects and, specifically, whether the presence and proximity of other healthcare workers has a positive effect on hand hygiene adherence

Design.

An observational study using a sensor network.

Setting.

A 20-bed medical intensive care unit at a large university hospital.

Participants.

Hospital staff assigned to the medical intensive care unit.

Methods.

We deployed a custom-built, automated, hand hygiene monitoring system that can (1) detect whether a healthcare worker has practiced hand hygiene on entering and exiting a patient’s room and (2) estimate the location of other healthcare workers with respect to each healthcare worker exiting or entering a room.

Results.

We identified a total of 47,694 in-room and out-of-room hand hygiene opportunities during the 10-day study period. When a worker was alone (no recent healthcare worker contacts), the observed adherence rate was 20.85% (95% confidence interval [CI], 19.78%–21.92%). In contrast, when other healthcare workers were present, observed adherence was 27.90% (95% CI, 27.48%–28.33%). This absolute increase was statistically significant (P < .01). We also found that adherence increased with the number of nearby healthcare workers but at a decreasing rate. These results were consistent at different times of day, for different measures of social context, and after controlling for possible confounding factors.

Conclusions.

The presence and proximity of other healthcare workers is associated with higher hand hygiene rates. Furthermore, our results also indicate that rates increase as the social environment becomes more crowded, but with diminishing marginal returns.

Infect Control Hosp Epidemiol 2014;35(10):1277–1285
Electronic Solutions to Enhance Tracking and Compliance with Mandatory Influenza Vaccination for All Hospital Staff
Authors: Quan Kathleen A. , Cousins Sarah M. , Hizon Denise A. , Heck Kristie K. , Samuelson Pamela , Garcia Froylan , Huang Susan S.
Published: October 2014

In implementing a hospital mandatory influenza vaccination policy, we developed an automated, real-time tracking and reminder system. Of 6,957 policy-covered individuals automatically identified, automated reminders left only 5 requiring counseling. This decreased Occupational Health workload in contacting noncompliant individuals and hosting vaccination events while simultaneously facilitating a 96% vaccination rate.

Infect Control Hosp Epidemiol 2014;35(11):1421–1424
Nodal solutions for (𝑝,2)-equations
Authors: Aizicovici Sergiu , Papageorgiou Nikolaos , Staicu Vasile
Published: October 2014

In this paper, we study a nonlinear elliptic equation driven by the sum of a

p
p

-Laplacian and a Laplacian (

(
p
,
2
)

\left ( p,2\right )

-equation), with a Carathéodory

(
p
−
1
)

\left ( p-1\right )

-(sub-)linear reaction. Using variational methods combined with Morse theory, we prove two multiplicity theorems providing precise sign information for all the solutions (constant sign and nodal solutions). In the process, we prove two auxiliary results of independent interest.
Reduced-intensity FOLFOXIRI in Treating Refractory Metastatic Colorectal Cancer
Authors: Chen Hung-Ming , Lin Jen-Kou , Chen Wei-Shone , Jiang Jeng-Kai , Yang Shung-Haur , Lan Yuan-Tzu , Lin Chun-Chi , Teng Hao-Wei
Published: October 2014

Objectives:

To report on the efficacy and safety of reduced-intensity FOLFOXIRI (RI-FOLFOXIRI) as salvage chemotherapy for patients with refractory metastatic colorectal cancer (mCRC).

Methods:

From October 2009 to March 2014, a total of 45 patients with refractory mCRC received RI-FOLFOXIRI as salvage chemotherapy. The initial dose of RI-FOLFOXIRI was 85% of the dose last used for each drug. All patients received a 2-hour infusion of folinate, followed by a bolus of 5-fluorouracil, and then 2400 to 3000 mg/m2 for 46 hours; in addition, patients were either administered irinotecan on day 1 followed by oxaliplatin on day 3 (group A), oxaliplatin on day 1 followed by irinotecan on day 3 (group B), or irinotecan and oxaliplatin on day 1 (group C).

Results:

Seven patients (15.6%) showed a partial response, and 15 patients (33.3%) had stable disease. The median progression-free and overall survival durations were 3.9 and 7.6 months, respectively. Patients who had wild-type K-RAS showed a longer overall survival duration (8.5 vs. 7.0 mo; P=0.04) but no difference in progression-free survival durations (4.4 vs. 3.4 mo; P=0.20) compared with patients with mutant K-RAS. The most common adverse events were neutropenia (28.9%) and diarrhea (26.7%).

Conclusions:

RI-FOLFOXIRI as salvage chemotherapy is effective and enables management of patients with refractory mCRC.