bluuebunny/crossref_metadata_2025 huggingface dataset:
In-situ temperature-controllable shear flow device for neutron scattering measurement—An example of aligned bicellar mixtures
Authors: Xia Yan , Li Ming , Kučerka Norbert , Li Shutao , Nieh Mu-Ping
Published: February 2015

We have designed and constructed a temperature-controllable shear flow cell for in-situ study on flow alignable systems. The device has been tested in the neutron diffraction and has the potential to be applied in the small angle neutron scattering configuration to characterize the nanostructures of the materials under flow. The required sample amount is as small as 1 ml. The shear rate on the sample is controlled by the flow rate produced by an external pump and can potentially vary from 0.11 to 3.8 × 105 s−1. Both unidirectional and oscillational flows are achievable by the setting of the pump. The instrument is validated by using a lipid bicellar mixture, which yields non-alignable nanodisc-like bicelles at low T and shear-alignable membranes at high T. Using the shear cell, the bicellar membranes can be aligned at 31 °C under the flow with a shear rate of 11.11 s−1. Multiple high-order Bragg peaks are observed and the full width at half maximum of the “rocking curve” around the Bragg’s condition is found to be 3.5°–4.1°. It is noteworthy that a portion of the membranes remains aligned even after the flow stops. Detailed and comprehensive intensity correction for the rocking curve has been derived based on the finite rectangular sample geometry and the absorption of the neutrons as a function of sample angle [See supplementary material at http://dx.doi.org/10.1063/1.4908165 for the detailed derivation of the absorption correction]. The device offers a new capability to study the conformational or orientational anisotropy of the solvated macromolecules or aggregates induced by the hydrodynamic interaction in a flow field.
From hydrogen bonding to metal coordination and back: Porphyrin-based networks on Ag(111)
Authors: Studener F. , Müller K. , Marets N. , Bulach V. , Hosseini M. W. , Stöhr M.
Published: February 2015

The self-assembly of a metal-free porphyrin bearing two pyridyl coordinating sites and two pentyl chains at trans meso positions was investigated under ultrahigh vacuum on a Ag(111) surface by scanning tunneling microscopy (STM). The STM measurements revealed a well-ordered close-packed structure with a rhombic unit cell for coverages ≤1 monolayer with their molecular plane parallel to the surface. The growth direction of the molecular islands is aligned along the step edges, which are restructured due to molecule-substrate interactions. The shorter unit cell vector of the molecular superstructure follows the 〈1-10〉 direction of the Ag(111) substrate. Hydrogen bonds between pyridyl and pyrrole groups of neighboring molecules as well as weak van der Waals forces between the pentyl chains stabilize the superstructure. Deposition of cobalt atoms onto the close-packed structure at room temperature leads to the formation of a hexagonal porous network stabilized by metal-ligand bonding between the pyridyl ligands and the cobalt atoms. Thermal annealing of the Co-coordination network at temperatures >450 K results in the transformation of the hexagonal network into a second close-packed structure. Changes in the molecule-substrate interactions due to metalation of the porphyrin core with Co as well as intermolecular interactions can explain the observed structural transformations.
Hydrogen-bonded clusters of 1, 1′-ferrocenedicarboxylic acid on Au(111) are initially formed in solution
Authors: Quardokus Rebecca C. , Wasio Natalie A. , Brown Ryan D. , Christie John A. , Henderson Kenneth W. , Forrest Ryan P. , Lent Craig S. , Corcelli Steven A. , Alex Kandel S.
Published: February 2015

Low-temperature scanning tunneling microscopy is used to observe self-assembled structures of ferrocenedicarboxylic acid (Fc(COOH)2) on the Au(111) surface. The surface is prepared by pulse-deposition of Fc(COOH)2 dissolved in methanol, and the solvent is evaporated before imaging. While the rows of hydrogen-bonded dimers that are common for carboxylic acid species are observed, the majority of adsorbed Fc(COOH)2 is instead found in six-molecule clusters with a well-defined and chiral geometry. The coverage and distribution of these clusters are consistent with a random sequential adsorption model, showing that solution-phase species are determinative of adsorbate distribution for this system under these reaction conditions.
H + H2 quantum dynamics using potential energy surfaces based on the XYG3 type of doubly hybrid density functionals: Validation of the density functionals
Authors: Su Neil Qiang , Chen Jun , Sun Zhigang , Zhang Dong H. , Xu Xin
Published: February 2015

The potential energy surfaces for the H + H2 exchange reaction are determined, using the standard Becke-3_parameter-Lee-Yang-Parr (B3LYP) hybrid exchange-correlation functional and the recently developed XYG3 type (xDH) doubly hybrid functionals. Quantum dynamical results calculated on these density functional theory surfaces revealed that the accuracy for the surfaces from the xDH functionals is quite satisfactory as compared to the benchmark Boothroyd-Keogh-Martin-Peterson-2 surface, whereas B3LYP is wholly inadequate in describing this simplest reaction despite the fact that it has been widely used to study reactions in complex systems. It is shown that further improvements can be achieved if the xDH functional parameters are fine-tuned to be reaction specific.
Collision-induced Raman scattering and the peculiar case of neon: Anisotropic spectrum, anisotropy, and the inverse scattering problem
Authors: Dixneuf Sophie , Rachet Florent , Chrysos Michael
Published: February 2015

Owing in part to the p orbitals of its filled L shell, neon has repeatedly come on stage for its peculiar properties. In the context of collision-induced Raman spectroscopy, in particular, we have shown, in a brief report published a few years ago [M. Chrysos et al., Phys. Rev. A 80, 054701 (2009)], that the room-temperature anisotropic Raman lineshape of Ne–Ne exhibits, in the far wing of the spectrum, a peculiar structure with an aspect other than a smooth wing (on a logarithmic plot) which contrasts with any of the existing studies, and whose explanation lies in the distinct way in which overlap and exchange interactions interfere with the classical electrostatic ones in making the polarizability anisotropy, α∥ − α⊥. Here, we delve deeper into that study by reporting data for that spectrum up to 450 cm−1 and for even- and odd-order spectral moments up to M6, as well as quantum lineshapes, generated from SCF, CCSD, and CCSD(T) models for α∥ − α⊥, which are critically compared with the experiment. On account of the knowledge of the spectrum over the augmented frequency domain, we show how the inverse scattering problem can be tackled both effectively and economically, and we report an analytic function for the anisotropy whose quantum lineshape faithfully reproduces our observations.
On the modified active region design of interband cascade lasers
Authors: Motyka M. , Ryczko K. , Dyksik M. , Sęk G. , Misiewicz J. , Weih R. , Dallner M. , Höfling S. , Kamp M.
Published: February 2015

Type II InAs/GaInSb quantum wells (QWs) grown on GaSb or InAs substrates and designed to be integrated in the active region of interband cascade lasers (ICLs) emitting in the mid infrared have been investigated. Optical spectroscopy, combined with band structure calculations, has been used to probe their electronic properties. A design with multiple InAs QWs has been compared with the more common double W-shaped QW and it has been demonstrated that it allows red shifting the emission wavelength and enhancing the transition oscillator strength. This can be beneficial for the improvements of the ICLs performances, especially when considering their long-wavelength operation.
Nonlinear magnetohydrodynamics of edge localized mode precursors
Authors: Guo Z. B. , Wang Lu , Wang X. G.
Published: February 2015

A possible origin of edge-localized-mode (ELM) precursors based on nonlinear ideal peeling-ballooning mode is reported. Via nonlinear variational principle, a nonlinear evolution equation of the radial displacement is derived and solved, analytically. Besides an explosive growth in the initial nonlinear phase, it is found that the local displacement evolves into an oscillating state in the developed nonlinear phase. The nonlinear frequency of the ELM precursors scales as ωpre∼x1/3ξ̂ψ,in2/3n, with x position in radial direction, ξ̂ψ,in strength of initial perturbation, and n toroidal mode number.
Nanoscale wear and kinetic friction between atomically smooth surfaces sliding at high speeds
Authors: Rajauria Sukumar , Canchi Sripathi V. , Schreck Erhard , Marchon Bruno
Published: February 2015

The kinetic friction and wear at high sliding speeds is investigated using the head-disk interface of hard disk drives, wherein the head and the disk are less than 10 nm apart and move at sliding speeds of 5–10 m/s relative to each other. While the spacing between the sliding surfaces is of the same order of magnitude as various AFM based fundamental studies on friction, the sliding speed is nearly six orders of magnitude larger, allowing a unique set-up for a systematic study of nanoscale wear at high sliding speeds. In a hard disk drive, the physical contact between the head and the disk leads to friction, wear, and degradation of the head overcoat material (typically diamond like carbon). In this work, strain gauge based friction measurements are performed; the friction coefficient as well as the adhering shear strength at the head-disk interface is extracted; and an experimental set-up for studying friction between high speed sliding surfaces is exemplified.
Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode
Authors: Yuan Tao , Zhu Xiaoguang , Zhou Lingyu , Zhang Jian , Tu Guoli
Published: February 2015

Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PFEOSO3Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PFEOSO3Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC71BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC71BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a useful approach to improve the performance of inverted polymer solar cells.
Absorption enhancement through Fabry-Pérot resonant modes in a 430 nm thick InGaAs/GaAsP multiple quantum wells solar cell
Authors: Behaghel B. , Tamaki R. , Vandamme N. , Watanabe K. , Dupuis C. , Bardou N. , Sodabanlu H. , Cattoni A. , Okada Y. , Sugiyama M. , Collin S. , Guillemoles J.-F.
Published: February 2015

We study light management in a 430 nm-thick GaAs p-i-n single junction solar cell with 10 pairs of InGaAs/GaAsP multiple quantum wells (MQWs). The epitaxial layer transfer on a gold mirror improves light absorption and increases the external quantum efficiency below GaAs bandgap by a factor of four through the excitation of Fabry-Perot resonances. We show a good agreement with optical simulation and achieve around 10% conversion efficiency. We demonstrate numerically that this promising result can be further improved by anti-reflection layers. This study paves the way to very thin MQWs solar cells.
Controllable vortex chirality switching on spherical shells
Authors: Yershov Kostiantyn V. , Kravchuk Volodymyr P. , Sheka Denis D. , Gaididei Yuri
Published: February 2015

A simple mechanism of controllable switching of magnetic vortex chirality is proposed. We consider curvilinear magnetic nanoshells of spherical geometry whose ground state is a vortex magnetization distribution. Chirality of this magnetic vortex can be switched in controllable way by applying a Gaussian pulse of spatially uniform magnetic field along the symmetry axis of the shell. The chirality switching process is explored in detail numerically for various parameters of magnetic pulse: the corresponding switching diagram is build. The role of the curvature is ascertained by studying the switching diagram evolution under the continuous transition from hemispherical shell to the disk shaped sample with the volume and thickness kept constant.
Optical phase conjugation by four-wave mixing in Nd:YAG laser oscillator for optical energy transfer to a remote target
Authors: Kawakami K. , Okamura H. , Komurasaki K.
Published: February 2015

A self-starting phase conjugator was designed for optical energy transfer to a remote target. Saturable-gain four-wave mixing in a laser resonator was achieved using a flash-lamp pumped Nd:YAG crystal and phase-conjugate light (PCL) generation were verified. Wavefront correction experimentation revealed that beam wander caused by air turbulence is compensated. Tracking capability was demonstrated in the range of 9 mrad with tracking accuracy of ±0.04 mrad. The maximum field of view was measured to be 4.7°. Dependence of phase-conjugate light energy on reference light energy was investigated. The maximum output of 320 mJ was obtained. The temporal behavior of PCL is discussed based on the four-wave mixing mechanism. Unlike a conventional loop resonator type phase conjugator, this system is applicable for wireless energy transfer to a remote target.
Enhancement of electrical conductivity of a liquid crystal-gold nanoparticle composite by a gel network of aerosil particles
Authors: Kamaliya B. , Vijay Kumar M. , Yelamaggad C. V. , Krishna Prasad S.
Published: February 2015

We report electrical conductivity measurements on a pure nematic liquid crystal (LC) and its composites comprising Gold nanoparticles (GNPs) as well as aerosil particles. The inclusion of aerosil particles creating a gel network, albeit being non-conducting, surprisingly enhances the already high conductivity of the LC-GNP material. The presence of aerosil also makes the frequency dependence of the conductivity compatible with the universal phenomenon expected for disordered solids despite the LC confined in the network is still a liquid. The nature of the aerosil corona (hydrophobic/hydrophilic) also controls the behavior. We argue that these features are caused by the amelioration of the percolation network of GNPs through the primary gel network of the hydrogen bonding aerosil particles. The concept can be generalized for a variety of systems wherein metal nanoparticles are embedded in an insulating matrix.
Morphological changes in polycrystalline Fe after compression and release
Authors: Gunkelmann Nina , Tramontina Diego R. , Bringa Eduardo M. , Urbassek Herbert M.
Published: February 2015

Despite a number of large-scale molecular dynamics simulations of shock compressed iron, the morphological properties of simulated recovered samples are still unexplored. Key questions remain open in this area, including the role of dislocation motion and deformation twinning in shear stress release. In this study, we present simulations of homogeneous uniaxial compression and recovery of large polycrystalline iron samples. Our results reveal significant recovery of the body-centered cubic grains with some deformation twinning driven by shear stress, in agreement with experimental results by Wang et al. [Sci. Rep. 3, 1086 (2013)]. The twin fraction agrees reasonably well with a semi-analytical model which assumes a critical shear stress for twinning. On reloading, twins disappear and the material reaches a very low strength value.
70 °C synthesis of high-Sn content (25%) GeSn on insulator by Sn-induced crystallization of amorphous Ge
Authors: Toko K. , Oya N. , Saitoh N. , Yoshizawa N. , Suemasu T.
Published: February 2015

Polycrystalline GeSn thin films are fabricated on insulating substrates at low temperatures by using Sn-induced crystallization of amorphous Ge (a-Ge). The Sn layer stacked on the a-Ge layer (100-nm thickness each) had two roles: lowering the crystallization temperature of a-Ge and composing GeSn. Slow annealing at an extremely low temperature of 70 °C allowed for a large-grained (350 nm) GeSn layer with a lattice constant of 0.590 nm, corresponding to a Sn composition exceeding 25%. The present investigation paves the way for advanced electronic optical devices integrated on a flexible plastic substrate as well as on a Si platform.
Thermal modeling and coefficient identification of shape memory polymer nanocomposites structure
Authors: Shen He , Mark August , Thompson Kenneth , Xu Yunjun , Liang Fei , Gou Jihua , Mabbott Bob
Published: February 2015

An increasing amount of research has been conducted on developing new shape memory polymer nanocomposite structures. Estimating thermal properties of these types of structures is a crucial step towards their successful application. In this paper, a finite element based thermal model is proposed, of which the coefficients are identified using a nonlinear programming method in a nested loop. The model and identification results are validated in three material samples.
Effect of OFF-state stress induced electric field on trapping in AlGaN/GaN high electron mobility transistors on Si (111)
Authors: Anand M. J. , Ng G. I. , Arulkumaran S. , Manoj Kumar C. M. , Ranjan K. , Vicknesh S. , Foo S. C. , Syamal B. , Zhou X.
Published: February 2015

The influence of electric field (EF) on the dynamic ON-resistance (dyn-RDS[ON]) and threshold-voltage shift (ΔVth) of AlGaN/GaN high electron mobility transistors on Si has been investigated using pulsed current-voltage (IDS-VDS) and drain current (ID) transients. Different EF was realized with devices of different gate-drain spacing (Lgd) under the same OFF-state stress. Under high-EF (Lgd = 2 μm), the devices exhibited higher dyn-RDS[ON] degradation but a small ΔVth (∼120 mV). However, at low-EF (Lgd = 5 μm), smaller dyn-RDS[ON] degradation but a larger ΔVth (∼380 mV) was observed. Our analysis shows that under OFF-state stress, the gate electrons are injected and trapped in the AlGaN barrier by tunnelling-assisted Poole-Frenkel conduction mechanism. Under high-EF, trapping spreads towards the gate-drain access region of the AlGaN barrier causing dyn-RDS[ON] degradation, whereas under low-EF, trapping is mostly confined under the gate causing ΔVth. A trap with activation energy 0.33 eV was identified in the AlGaN barrier by ID-transient measurements. The influence of EF on trapping was also verified by Silvaco TCAD simulations.
Sb surfactant mediated growth of InAs/AlAs0.56Sb0.44 strained quantum well for intersubband absorption at 1.55 μm
Authors: Zhao Yu , Nicolaï Julien , Bertru Nicolas , Folliot Hervé , Perrin Mathieu , Gatel Christophe , Warot-Fonrose B. , Ponchet Anne
Published: February 2015

Surfactant mediated growth of strained InAs/AlAs0.56Sb0.44 quantum wells on InP (001) substrate is investigated. X ray diffraction and transmission electron microscopy analysis reveal that the supply of antimony on InAs surface delays the 2D to 3D growth transition and allows the growth of thick InAs/AlAsSb quantum wells. Quantum well as thick as 7 ML, without defect was achieved by Sb surfactant mediated growth. Further high resolution transmission electron microscopy measurement and geometric phase analysis show that InAs/AlAsSb interfaces are not abrupt. At InAs on AlAsSb interface, the formation of a layer presenting lattice parameter lower than InP leads to a tensile stress. From energetic consideration, the formation of As rich AlAsSb layer at interface is deduced. At AlAsSb on InAs interface, a compressive layer is formed. The impact on optical properties and the chemical composition of this layer are discussed from microscopic analysis and photoluminescence experiments.
Distinct populations of neurons respond to emotional valence and arousal in the human subthalamic nucleus
Authors: Sieger Tomáš , Serranová Tereza , Růžička Filip , Vostatek Pavel , Wild Jiří , Šťastná Daniela , Bonnet Cecilia , Novák Daniel , Růžička Evžen , Urgošík Dušan , Jech Robert
Published: February 2015

Significance

The involvement of the subthalamic nucleus (STN) in affective processing has been suggested with the appearance of neuropsychiatric side effects of deep brain stimulation in Parkinson’s disease (PD), but direct evidence has been lacking. In our study, we recorded single-neuron activity from the STN during affective picture presentation to PD patients intraoperatively. We discovered two spatially distinct populations of “affective” neurons responding to the emotional dimensions of the stimuli: valence (pleasantness-unpleasantness) and arousal (intensity). As previously believed, neural circuits underlying these two affective dimensions are functionally segregated. Here we observed separated emotional processing even at the single neuron level. These results extend our knowledge regarding the emotional role of the STN and the neural basis of emotions.
Decorrelation of retinal response to natural scenes by fixational eye movements
Authors: Segal Irina Yonit , Giladi Chen , Gedalin Michael , Rucci Michele , Ben-Tov Mor , Kushinsky Yam , Mokeichev Alik , Segev Ronen
Published: February 2015

Significance

Our observation provides the first direct experimental confirmation, to our knowledge, of the prediction that fixational eye movements act to reduce the correlations in retinal response. Reduction of correlation was suggested as a design principle in the visual system a long time ago. It was argued that efficient representation of sensory information requires reducing the amount of redundancy in the neural response. Although these works are considered to be cornerstones of our understanding of visual processing, they still do not consider the actual input to the retina. Our result contributes to these classic works by showing that the amount of correlation in the retinal output can be reduced by the patterns of eye movements prior to any neural processing.
Climate-driven introduction of the Black Death and successive plague reintroductions into Europe
Authors: Schmid Boris V. , Büntgen Ulf , Easterday W. Ryan , Ginzler Christian , Walløe Lars , Bramanti Barbara , Stenseth Nils Chr.
Published: February 2015

Significance

The second plague pandemic in medieval Europe started with the Black Death epidemic of 1347–1353 and killed millions of people over a time span of four centuries. It is commonly thought that after its initial introduction from Asia, the disease persisted in Europe in rodent reservoirs until it eventually disappeared. Here, we show that climate-driven outbreaks ofYersinia pestisin Asian rodent plague reservoirs are significantly associated with new waves of plague arriving into Europe through its maritime trade network with Asia. This association strongly suggests that the bacterium was continuously reimported into Europe during the second plague pandemic, and offers an alternative explanation to putative European rodent reservoirs for how the disease could have persisted in Europe for so long.
Model-guided quantitative analysis of microRNA-mediated regulation on competing endogenous RNAs using a synthetic gene circuit
Authors: Yuan Ye , Liu Bing , Xie Peng , Zhang Michael Q. , Li Yanda , Xie Zhen , Wang Xiaowo
Published: February 2015

Significance

We established a minimum competing endogenous RNA (ceRNA) model to quantitatively analyze the behavior of the ceRNA regulation and implemented multifluorescent synthetic gene circuits in cultured human cells to validate our predictions. Our results suggested that the ceRNA effect is affected by the abundance of microRNA (miRNA) and ceRNAs, the number and affinity of binding sites, and the mRNA degradation pathway determined by the degree of miRNA–mRNA complementarity. Furthermore, we found that a nonreciprocal competing effect between partial and perfect complementary targets is mainly due to different miRNA loss rates in these two types of repressions, which sheds light on utilizing such a competing model for rational design of effective siRNA.
Histone titration against the genome sets the DNA-to-cytoplasm threshold for the
Xenopus
midblastula transition
Authors: Amodeo Amanda A. , Jukam David , Straight Aaron F. , Skotheim Jan M.
Published: February 2015

Significance

Embryos depend on maternally deposited RNA until zygotic transcription activates. In many species, genome activation coincides with cell cycle lengthening and cellular motility, which collectively comprise the midblastula transition (MBT). A long-standing model is that MBT onset is controlled by titration of a maternally loaded inhibitor against exponentially increasing DNA. To identify MBT inhibitors, we developed an assay using
Xenopus
egg extract that recapitulates transcriptional activation only above a DNA-to-cytoplasm ratio similar to MBT embryos and identified histones H3 and H4 as inhibitors. Changing histone levels quantitatively shifts the DNA concentration required for transcription in vitro and alters the onset of both zygotic transcription and cell cycle lengthening in vivo. Our work strongly supports histones as a titrated MBT inhibitor.
Thiopeptide antibiotics stimulate biofilm formation in
Bacillus subtilis
Authors: Bleich Rachel , Watrous Jeramie D. , Dorrestein Pieter C. , Bowers Albert A. , Shank Elizabeth A.
Published: February 2015

Significance

Thiazolyl peptides are known antibiotics produced by diverse bacterial taxa. It has been believed that antibiotics are deployed by bacteria as weapons, providing them with an evolutionary advantage over other microbes. We show here that these weapons can also act as chemical tools that elicit biofilm production in the model bacterium
Bacillus subtilis
. Importantly, the biofilm-inducing (and therefore signaling) properties of these compounds are independent of their killing activity. We go on to use this biofilm-inducing activity to identify and confirm the presence of thiazolyl peptide gene clusters in other bacteria. These results indicate that thiazolyl peptides, and potentially other antibiotics, have the ability to alter bacterial behavior in ways important both to the environment and to human health.
Predator diversity, intraguild predation, and indirect effects drive parasite transmission
Authors: Rohr Jason R. , Civitello David J. , Crumrine Patrick W. , Halstead Neal T. , Miller Andrew D. , Schotthoefer Anna M. , Stenoien Carl , Johnson Lucinda B. , Beasley Val R.
Published: February 2015

Significance

Humans are altering biodiversity globally and infectious diseases are on the rise; thus, there is considerable interest in understanding how changes to biodiversity affect disease risk. We show that the diversity of predators that consume parasites was the best negative predictor of infections in frogs, suggesting that predation on parasites can be an important mechanism of disease reduction. Follow-up experiments, field data, and mathematical models revealed that intraguild predators, predators that consume both hosts and parasites, decrease macroparasite infections per host less than predators that only consume parasites, representing a general trait of predators that predicts their ability to reduce disease. Consequently, managing assemblages of non-intraguild and intraguild predators is an underutilized tool to minimize human and wildlife diseases.
Oxytocin prevents ethanol actions at δ subunit-containing GABA
A
receptors and attenuates ethanol-induced motor impairment in rats
Authors: Bowen Michael T. , Peters Sebastian T. , Absalom Nathan , Chebib Mary , Neumann Inga D. , McGregor Iain S.
Published: February 2015

Significance

Even moderate doses of alcohol can cause considerable motor impairment. This effect has been linked to ethanol-induced potentiation of GABA actions at δ subunit-containing GABA
A
receptors (δ-GABA
A
Rs). Here, we demonstrate that the neuropeptide oxytocin selectively attenuates ethanol-induced motor impairment in rats as well as ethanol-induced potentiation of GABAergic activity at δ-GABA
A
Rs. This effect of oxytocin is shown to be independent of the oxytocin receptor (OTR) and involves a direct action at δ-GABA
A
Rs. To our knowledge, this study provides the first evidence of oxytocin having a direct, non-OTR–mediated effect on GABA–ethanol interactions. Recent preclinical and clinical studies indicate that oxytocin may also attenuate alcohol consumption, craving, and withdrawal, and the present study shows a previously unidentified mechanism through which some of these effects may occur.
Kelvin–Helmholtz instability in an ultrathin air film causes drop splashing on smooth surfaces
Authors: Liu Yuan , Tan Peng , Xu Lei
Published: February 2015

Significance

Liquid drops always splash when they impact smooth surfaces with high enough speeds. This common phenomenon is crucial in many important fields such as agriculture, printing, surface coating, and spray cooling. However, despite extensive studies over one century, the origin of splashing remains a big mystery. Combining experiment with model, we show that the air trapped under the liquid drop forms a special flow within a nanoscale gap. This airflow produces a stress 10 times stronger than the common airflow and generates small Kelvin–Helmholtz instabilities that trigger splash. Our model agrees quantitatively with the experimental verifications and brings a fundamental understanding to the general phenomenon of drop splashing on smooth surfaces.
Quantitative relations between cooperative motion, emergent elasticity, and free volume in model glass-forming polymer materials
Authors: Pazmiño Betancourt Beatriz A. , Hanakata Paul Z. , Starr Francis W. , Douglas Jack F.
Published: February 2015

Significance

Diverse viewpoints have been developed to understand the scientifically fascinating and universal dynamics of glass-forming fluids. Currently, there are several prevailing models in the scientific literature based on seemingly different physical conceptions of glass formation, a fact that limits both theoretical and technological development in many scientific fields. We address this fundamental problem by simulating polymer glass-forming materials having a wide variation in the temperature dependence of structural relaxation (“fragility”), and we show by direct comparison that existing models equally describe our data, revealing deep relations between them. In this way, we achieve a greater theoretical unity of understanding glass-forming materials that should aid many applications in materials development and biology, the preservation and aesthetic properties of food, and medical science.
Spatiotemporally dynamic, cell-type–dependent premeiotic and meiotic phasiRNAs in maize anthers
Authors: Zhai Jixian , Zhang Han , Arikit Siwaret , Huang Kun , Nan Guo-Ling , Walbot Virginia , Meyers Blake C.
Published: February 2015

Significance

By RNA profiling of 10 stages of maize anthers plus mature pollen, we found two distinct classes of phased small-interfering RNAs (phasiRNAs): 21-nt premeiotic phasiRNAs, after germinal and somatic cell specification, and 24-nt meiotic phasiRNAs coordinately accumulated during meiosis and persist into pollen. Sequencing of RNA from five male-sterile, anther developmental mutants—ocl4,mac1,ms23,msca1, andameiotic1—demonstrated the involvement of specific somatic layers. Premeiotic phasiRNAs require a functional epidermis, whereas meiotic phasiRNAs require a normal tapetum. Mammalian germ cells express “prepachytene” or “pachytene” PIWI-interacting RNAs (piRNAs). Whereas differences in biogenesis indicate independent origins, grass phasiRNAs and mammalian piRNAs share developmental timing, a lack of obvious targets, and an impact on male fertility, suggesting a possible evolutionary convergence.
Multicolor CRISPR labeling of chromosomal loci in human cells
Authors: Ma Hanhui , Naseri Ardalan , Reyes-Gutierrez Pablo , Wolfe Scot A. , Zhang Shaojie , Pederson Thoru
Published: February 2015

Significance

The detection of specific genes in fixed cells was first accomplished in 1969 by Gall and Pardue. The development of analogous methods applicable to living cells is now at hand. At the forefront of this advance (2013–2014), we and other investigators have used transcription activator-like effectors (TALEs) conjugated with fluorescent proteins to tag genomic loci in live cells. More recently, the CRISPR/Cas9 system has provided a more flexible approach to targeting specific loci. In this paper, we describe the labeling of human genomic loci in live cells with three orthogonal CRISPR/Cas9 components, allowing multicolor detection of genomic loci with high spatial resolution, which provides an avenue for barcoding elements of the human genome in the living state.
Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function
Authors: Lakhal-Littleton Samira , Wolna Magda , Carr Carolyn A. , Miller Jack J. J. , Christian Helen C. , Ball Vicky , Santos Ana , Diaz Rebeca , Biggs Daniel , Stillion Richard , Holdship Philip , Larner Fiona , Tyler Damian J. , Clarke Kieran , Davies Benjamin , Robbins Peter A.
Published: February 2015

Significance

The iron-exporting protein ferroportin is recognized as central to systemic iron regulation, but its role in tissues other than those involved in iron handling is unknown. This study shows that ferroportin expression in cardiomyocytes is essential to intracellular iron homeostasis and to normal cardiac function. It also demonstrates that the site of iron accumulation in the iron-overloaded heart depends on whether ferroportin is expressed in the cardiomyocytes. It further shows that the functional significance of cardiac iron overload is highly dependent upon the site of iron accumulation. These findings change our understanding of intracellular iron homeostasis and have significant implications for the clinical management of cardiac dysfunction associated with iron imbalance.
Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
Authors: Zhang Fan , Blasiak Leah C. , Karolin Jan O. , Powell Ryan J. , Geddes Chris D. , Hill Russell T.
Published: February 2015

Significance

Coral reefs are highly productive ecosystems that raise a conundrum called “Darwin’s paradox”: How can high production flourish in low-nutrient conditions? We show here that in three abundant Caribbean sponges, the granules that have been commonly observed in sponge tissue for decades are polyphosphate granules. These granules can account for up to 40% of the total phosphorus (P) in sponge tissue. This finding has important implications for understanding P sequestration and recycling in the reef environment. We provide evidence that these granules are of bacterial origin and propose a P sequestration pathway by microbial symbionts and the sponge hosts. Considering the ancient origin of both partners, this process may have had an impact on the P cycle in Earth’s early history.
Mutations in early follicular lymphoma progenitors are associated with suppressed antigen presentation
Authors: Green Michael R. , Kihira Shingo , Liu Chih Long , Nair Ramesh V. , Salari Raheleh , Gentles Andrew J. , Irish Jonathan , Stehr Henning , Vicente-Dueñas Carolina , Romero-Camarero Isabel , Sanchez-Garcia Isidro , Plevritis Sylvia K. , Arber Daniel A. , Batzoglou Serafim , Levy Ronald , Alizadeh Ash A.
Published: February 2015

Significance

Follicular lymphoma (FL) is a disease characterized by multiple relapses that are linked by a common progenitor bearing only a subset of the mutations found within the tumor that presents clinically. Inability to cure this disease may therefore be linked to the failure of current therapies to clear these early tumor-propagating clones. Here we further define the genetic hallmarks of this disease and model the steps in evolution through phylogenetic analysis of serial tumor biopsies. This identified
CREBBP
mutations as early events in genome evolution that are enriched within tumor cell progenitors and provided evidence that these mutations act by allowing immune evasion. This highlights
CREBBP
mutations as an attractive therapeutic target in FL and provides insight into their pathogenic mechanism.
Comparison of airway management techniques for different access in a simulated motor vehicle entrapment scenario
Authors: Steinmann Daniel , Ahne Thomas , Heringhaus Christian , Goebel Ulrich
Published: February 2015

Background

Emergency airway management can be particularly challenging in patients entrapped in crashed cars because of limited access. The aim of this study was to analyse the feasibility of four different airway devices in various standardized settings utilized by paramedics and emergency physicians.

Methods

Twenty-five paramedics and 25 emergency physicians were asked to perform advanced airway management in a manikin entrapped in a car’s left front seat, with access to the patient through the opened driver’s door or access from the back seat. Available airway devices included Macintosh and Airtraq laryngoscopes, as well as laryngeal mask airway (LMA) Supreme and the Laryngeal Tube. The primary endpoints were successful placement, along with attempts needed to do so, and time for successful placement. The secondary endpoints included Cormack–Lehane grades and rating of the difficulty of the technique with the different devices.

Results

The overall intubation and placement success rates were equal for the Macintosh and Airtraq laryngoscopes as well as the LMA Supreme and Laryngeal Tube, with access from the back seat being superior in terms of placement time and ease of use. Supraglottic airway devices required half of the placement time and were easier to use compared with endotracheal tubes (with placement times almost >30 s). Paramedics and emergency physicians achieved equal overall successful placement rates for all devices.

Conclusion

Both scenarios of securing the airway seem suitable in this manikin study, with access from the back seat being superior. Although all airway devices were applicable by both groups, paramedics and emergency physicians, supraglottic device placement was faster and always possible at the first attempt. Therefore, the LMA Supreme and the Laryngeal Tube are attractive alternatives for airway management in this context if endotracheal tube placement fails. Furthermore, supraglottic device placement, while the patient is still in the vehicle, followed by a definitive airway once the patient is extricated would be a worthwhile alternative course of action.
Gendered variations in the experience of ageing at work in Switzerland
Authors: Le Feuvre Nicky , Kuehni Morgane , Rosende Magdalena , Schoeni Céline
Published: February 2015

Purpose

– The purpose of this paper is to examine the gendered processes of ageing at work in Switzerland, a country already characterised by particularly high employment rates for seniors of both sexes, and where the notion of “active ageing” has recently appeared on the policy agenda. The study illustrates the mechanisms through which men and women accumulate dis-/advantage across the life course, and the influence that critical events in different life domains have on the conditions under which they prepare the transition to retirement.

Design/methodology/approach

– The data used in the paper were collected with a mixed methods approach, including secondary statistical data analysis, expert interviews (with human resource and line managers), company case studies and 63-biographical interviews with male and female seniors employed in three different sectors (food distribution, health, transport) of the Swiss labour market. The interview guide covered issues relating directly to the employment histories and working conditions of the over 50s, but also enabled respondents to reflect on the influence of past or recent events in their private lives on their experiences of ageing at work (and vice versa).

Findings

– The study shows that, in the Swiss context, ageing at work is a social experience, that is profoundly marked by societal-level normative “gender scripts” and by the gendered nature of major life-course transitions. However, rather than producing a clear distinction between the experiences of men on the one hand and women on the other, studying the accumulation of dis-/advantages (Dannefer, 2009) enables us to elaborate a more nuanced typology, mapping the Swiss experience of ageing at work according to four alternative ideal-type models: confident, resentful, determined and distressed.

Social implications

– In a context characterised by prolonged life expectancy and restricted welfare budgets, a clearer understanding of the conditions under which men and women make decisions about the continuation, interruption or adaptation of their professional activities (and care commitments) in the second half of their adult lives has clear implications, both for patterns of “active ageing” and for gender equality.

Originality/value

– The paper sheds new light on the gendered variations in the experience of ageing at work in the Swiss context; it examines the implications of the dis-/advantages accumulated by different categories of men and women during various transitions in the employment and family spheres on their autonomy, well-being and satisfaction during this critical period of their adult lives.
Parenthood and employment: the impact of policies and culture on gender inequality in Switzerland
Authors: Epple Ruedi , Gasser Martin , Kersten Sarah , Nollert Michael , Schief Sebastian
Published: February 2015

Purpose

– The purpose of this paper is to analyse the effect of cantonal social policies and cultural settings (in Switzerland) on women’s and men’s employment behaviour. Special consideration is given to the transition to parenthood.

Design/methodology/approach

– Based on data from the Swiss Labour Force Survey (SLFS) this paper conducts multilevel analyses to test individual and cantonal effects on the probability of employment and on working hours. To analyse the effect of parenthood, models for women and men with children under three are contrasted with models for women and men without children or with older children.

Findings

– The paper documents the persistence of gender inequality in employment linked to parenthood. How the reconciliation of work and family life can be realised for women and men strongly depends on a set of policies and cultural conditions. Moreover, individual characteristics such as education or marriage are important predictors.

Research limitations/implications

– A shortcoming of this study is the focus on the individual employment use and not on household-level division of labour. This disadvantage is due to the design of the SLFS, which is (at present) the only available survey to allow regionalisation at the cantonal level. However, the paper adds important results to the debate about gender inequality and parenthood in Switzerland as previous research has focused only little on cantonal diversity.

Originality/value

– The paper connects to previous cantonal comparative studies of female employment but extends their analyses in three important ways. By analysing cantonal differences in policies and culture this paper takes the diversity of framework conditions in Switzerland into account. Furthermore it simultaneously analyses male and female employment behaviour to get a better understanding of gender inequality and parenthood.
Determination of distance ease of pants using 3D scanning data
Authors: Su Junqiang , Gu Bingfei , Liu Guolian , Xu Bugao
Published: February 2015

Purpose

– The purpose of this paper is to focus on the determination of distance ease of pants from the 3D scanning data of a clothed and unclothed body.

Design/methodology/approach

– A human model whose body size conformed to the Chinese dummy standard and four pairs of suit pants were chosen for the study. The scanned surfaces of both the body and the pant were superimposed based on the preset markers. The circumferences at four important positions – abdomen, hip, thigh and knee – were selected for pant ease determination. At one position (e.g. hip), the two cross-sections were divided into several characteristic sections and the distance ease, i.e. the space between the cross-sections at each section was measured. The regression equations between the distance ease and ease allowance were then derived so that the distance ease can be estimated.

Findings

– The relationship was found between the distance ease and the ease allowance. Meanwhile, a mathematic model was established to convert the distance ease into the increments of a pant pattern, which helps to develop an individual pant pattern automatically.

Social implications

– The paper provided the concept and the method to customize a pant by using the 3D scanning data of body. It created a link between the 3D distance ease and the 2D ease allowance, and the model to calculate the distance ease increments which warrant proper ease distributions. The method helps to develop an individualized garment pattern automatically from a basic and tight pant pattern.

Originality/value

– Understanding the relationship between the distance ease and the ease allowance and increments of pattern could help develop an individual apparel pattern from 3D measurements. This paper showed a way to solve the problem of distribution of the apparel ease in a virtual environment and convert body measurements from a 3D scanner into personalized apparel patterns.
LIBOR, base rate spreads and the UK housing market
Authors: Hinch Martin , Berry Jim , McGreal William , Grissom Terry
Published: February 2015

Purpose

– The purpose of this paper is to analyse how London Interbank Offered Rate Index (LIBOR) and the spread between LIBOR and the base rate of interest as set by the Bank of England (BoE) influences the variation in house prices in the UK.

Design/methodology/approach

– This paper uses monthly data over a long time series, since 1986, to investigate the relationships between house price and LIBOR. Data are drawn from several different sources to include housing, financial and macro-economic variables. The time series is sub-divided into a series of splines based on stages in the economic and property market cycle. Both value-based and percentage change models are developed.

Findings

– The results show that BoE base/LIBOR margin variable has a strong positive and significant effect on house price; however, the percentage change model infers a weaker and inverse relationship. The spline analysis re-emphasised the significance of the BoE base/LIBOR margin variable. Where variation between base rates and LIBOR is reduced, a significant positive effect can be observed in the average house price; however, where significant variation exists, the BoE base/LIBOR margin has little effect and LIBOR itself becomes a significant driver.

Research limitations/implications

– The results highlight that the predictive qualities of the BoE base/LIBOR margin, as the contribution of this margin to the explanation of house price, exceeds both the base rate and LIBOR variables individually. Also highlighted is the contribution of unemployment to the explanation of house price. In both the value and percentage change models, unemployment is shown as a negative and highly significant contributor.

Originality/value

– Previous papers have demonstrated the important linkage between house price and interest rates, the originality in this paper lies in examining the impact of LIBOR and the spreads between LIBOR and base rate as key variables influencing variation in UK house prices.