bluuebunny/crossref_metadata_2025 huggingface dataset:
A photometer array for atmospheric gravity wave measurements on the Lower Atmosphere Ionosphere Coupling Experiment (LAICE) mission
Authors: Philbrick C. P. , Westerhoff J. , Wang Z. , Hall S. , Swenson G. R.
Published: November 2018

The photometer payload of the lower atmosphere ionosphere coupling experiment CubeSat mission will observe and characterize atmospheric gravity wave (AGW) propagation through the mesosphere/lower thermosphere region of Earth’s atmosphere on a global scale. AGW characteristics will be measured via passive observation of airglow emission from atmospheric O2(b1Σg+) at 762.0 nm (O2A) and Herzberg I O2(A3Σu+−X3Σg−) at 277.0 nm (O2HI) under nighttime conditions. The photometer payload consists of a seven-element array of photomultiplier tubes grouped into four channels, which will measure O2A intensity at two emission wavelengths, O2HI band intensity at a single emission wavelength, and ambient background intensity at 770.0 nm. AGW horizontal wavelength will be measured from O2A band airglow perturbations related to rotational temperature and density, while vertical wavelength will be determined from the phase relationship between the O2HI and O2A bands. Wave number and wave amplitude will be used to determine the extent of energy and momentum flux associated with the wave. This is important in understanding the global distribution of high frequency waves which carry the bulk of the influence of wave energy and momentum flux from lower altitudes into the mesosphere. This can only be measured from space by nadir viewing. To our knowledge, nadir viewing of mesospheric airglow to quantify intrinsic properties of gravity waves from space has not been performed to date.
Time and frequency dependent mechanical properties of LaCoO3-based perovskites: Internal friction and negative creep
Authors: Lugovy Mykola , Orlovskaya Nina , Pathak Siddhartha , Radovic Miladin , Lara-Curzio Edgar , Verbylo Dmytro , Kuebler Jakob , Graule Thomas , Reece Michael J.
Published: November 2018

The internal friction and creep deformation behavior of La0.8Ca0.2CoO3 and pure LaCoO3 mixed ionic electronic conducting perovskite ceramics have been studied by Dynamic Mechanical Analysis and uniaxial compression under constant applied load, respectively. It was found that both the internal friction and creep strain were almost an order of magnitude higher for Ca2+ doped LaCoO3 as compared to pure undoped LaCoO3. The difference in Ca2+ doped LaCoO3 behavior was attributed to the much higher concentration of point defects (e.g., oxygen vacancies) in the structure and their interaction with other mobile defects, such as ferroelastic domain/twin walls, stacking faults, dislocations, etc. Such interactions of numerous point defects with domain walls produce energetic barriers and slow down the movement of ferroelastic domain walls under applied stress. At the same time, the defects' interactions increase the internal friction resulting in a much higher creep strain of La0.8Ca0.2CoO3 as compared to pure LaCoO3, as the creep strain is determined by the distance between the domain wall and its equilibrium position at the onset of the creep process. Therefore, the high friction will result in the larger distance the wall has to move to reach the equilibrium which in turn results in higher creep strain. The expansion of LaCoO3 under constant applied compressive stress, named here as negative creep, was also discovered to occur during room temperature creep experiments.
Time and frequency dependent mechanical properties of LaCoO3-based perovskites: Neutron diffraction and domain mobility
Authors: Lugovy Mykola , Aman Amjad , Orlovskaya Nina , Slyunyayev Viktor , Graule Thomas , Kuebler Jakob , Reece Michael J. , Chen Yan , Ma Dong , An Ke
Published: November 2018

The study of domain wall movement and texture formation in ferroelastic LaCoO3 perovskite under constant applied compressive stress has been performed using in situ neutron diffraction. It was established that under constant applied compressive stress the domain walls show mobility that may lead both to the shrinkage (creep strain) and to the expansion (negative creep strain) of LaCoO3 perovskite. The domain wall movement and texture formation can be explained by the availability, mobility, and interaction of twins, stacking faults, antiphase boundaries, dislocations, and point defects, such as oxygen vacancies and their complexes as well as impurity atoms. The equation of motion was used to describe the possible mechanisms of domain wall movement under applied stress, and it was determined that the available solutions of this equation allow both for the shrinkage (creep strain) and for the expansion (negative creep strain) of LaCoO3 perovskite to occur.
Fast real time and quantitative gas analysis method for the investigation of the CO2 reduction reaction mechanism
Authors: Mutschler Robin , Luo Wen , Moioli Emanuele , Züttel Andreas
Published: November 2018

We present a new fast real time and quantitative gas analysis method by means of mass spectrometry (MS), which has approximately an order of magnitude faster sampling rate in comparison with a traditional gas chromatography. The method is presented and discussed on the example of the CO2 reduction reaction. The advantages of the method are the possibility to analyze the reaction kinetics, where the kinetically determined reaction range is often only tens of degrees wide. Furthermore, due to the fast sampling rate, the experiments are much shorter and effects due to possible aging of the catalyst are significantly reduced. The quantification of the gas partial pressures is achieved by calibrating the Faraday detector in the quadrupole MS for the expected reactants and products. One major challenge to achieve a quantitative measurement with the MS is to correct for the pressure fluctuations over the probing capillary over the course of the experiment. This fluctuation is compensated in the analysis by normalizing the sum of all calculated partial pressures to the measured reaction pressure for every measured spectrum. With that, a precise, fast, and quantitative gas analysis is achieved. This is the fundament for, e.g., the kinetic reaction analysis where a high data point density is required. The method is discussed on the example of the CO2 hydrogenation reaction to CH4 on a commercial Ru/Al2O3 catalyst. Additionally, the key features of the gas controlling and analysis setup built for the CO2 hydrogenation reaction are described.
Generation of coherent phonons by coherent extreme ultraviolet radiation in a transient grating experiment
Authors: Maznev A. A. , Bencivenga F. , Cannizzo A. , Capotondi F. , Cucini R. , Duncan R. A. , Feurer T. , Frazer T. D. , Foglia L. , Frey H.-M. , Kapteyn H. , Knobloch J. , Knopp G. , Masciovecchio C. , Mincigrucci R. , Monaco G. , Murnane M. , Nikolov I. , Pedersoli E. , Simoncig A. , Vega-Flick A. , Nelson K. A.
Published: November 2018

We investigate the excitation of coherent acoustic and optical phonons by ultrashort extreme ultraviolet (EUV) pulses produced by a free electron laser. Two crossed femtosecond EUV (wavelength 12.7 nm) pulses are used to excite coherent phonons at a wavelength of 280 nm, which are detected via diffraction of an optical probe beam. Longitudinal and surface acoustic waves are measured in BK-7 glass, diamond, and Bi4Ge3O12; in the latter material, the excitation of a coherent optical phonon mode is also observed. We discuss probing different acoustic modes in reflection and transmission geometries and frequency mixing of surface and bulk acoustic waves in the signal. The use of extreme ultraviolet radiation will allow the creation of tunable GHz to THz acoustic sources in any material without the need to fabricate transducer structures.
Length-dependent instability of shear electroconvective flow: From electroconvective instability to Rayleigh-Bénard instability
Authors: Shi Pengpeng , Liu Wei
Published: November 2018

Ion and water transport by electroconvection continually finds new applications, arousing considerable research interest. This paper is devoted to the important issue of the effects caused by shear flow, as this flow always occurs in various electrochemical applications, such as electrodeposition, electroplating, and electrodialysis. In this paper, the dimensionless Poiseuille-Navier-Stokes and Poisson-Nernst-Planck model is proposed, which contains the buoyancy force induced by ion concentration polarization. The numerical results show that in the existing literature, the Rayleigh-Bénard convection is neglected and the Debye layer effect is overestimated, leading to a large difference between the simulation results and the experimental data. In addition, the chaotic phenomenon of shear flow is discussed in detail based on the proposed model. The main contributions are as follows: (i) There are two distinct instability phenomena, namely, electroconvective instability, caused by the electric force, and Rayleigh-Bénard instability, caused by the buoyancy force. (ii) For electroconvective instability, the fully overlapping vortex structures in the microchannel are obtained numerically for the first time. In addition, the shear sheltering effect is verified numerically. (iii) The effects of the characteristic length and electrohydrodynamic coupling constant on the Rayleigh-Bénard instability are studied. (iv) The transition condition from electroconvective instability to Rayleigh-Bénard instability is investigated. The analysis shows that choosing a characteristic length consistent with the actual structure is a necessary condition for achieving high-precision analysis of fluid behaviors such as the flow pattern. This conclusion provides important guidance for the design and optimization of the concentration microfluidic chip.
Electric-field-controllable nonvolatile multilevel resistance switching of Bi0.93Sb0.07/PMN-0.29PT(111) heterostructures
Authors: Xu Zhi-Xue , Yan Jian-Min , Xu Meng , Guo Lei , Chen Ting-Wei , Gao Guan-Yin , Wang Yu , Li Xiao-Guang , Luo Hao-Su , Zheng Ren-Kui
Published: November 2018

Electric-field switchable multilevel nonvolatile resistance states are achieved at room temperature in Bi0.93Sb0.07/0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3(111) (PMN-0.29PT) heterostructures. During the initial poling of the PMN-0.29PT, the variation of the resistance of the Bi0.93Sb0.07 film with the electric field tracks the variation of the electric-field-induced in-plane strain of the PMN-0.29PT effectively, revealing that the resistance switching is dominated by the ferroelectric-domain-switching-induced lattice strain but not the domain-switching-induced polarization charges. A relative resistance change ΔR/R ∼ 7% at 300 K and up to ∼10% at 180 K were achieved near the coercive field EC of the PMN-0.29PT(111) substrate. At least five stable resistance states with good endurance properties could be obtained at room temperature by precisely controlling the electric-field pulse sequence as a result of the nonvolatile remnant strain transferring from the PMN-0.29PT to the film, providing a simple and energy efficient way to construct multistate resistive memory.
Dynamics of a shock wave with time dependent energy release generated by an exploding wire in air
Authors: Rodríguez Prieto Gonzalo , Bilbao Luis , Milanese Maria Magdalena
Published: November 2018

When there is a fast release of energy in any suitable fluid, a shock wave is produced. One of the ways to create shock waves in a laboratory environment is the use of an exploding wire system; a metallic wire transformed into plasma due to the action of a strong, above kiloamperes, and fast, under tens of microseconds, electrical current. Therefore, it has been used in many experiments to study shock waves with an energy release that can be considered instantaneous with respect to the shock wave evolution time. On the contrary, this work presents experimental results for the dynamics of a shock wave created by an exploding wire with an energy release dependent on time.
Growth of SiGe epitaxial quantum dots on patterned Si (001) surfaces by in situ annealing of initially conformal layers
Authors: Amatya J. M. , Heinrich H. , Tersoff J. , Floro J. A.
Published: November 2018

Ordered arrays of semiconductor quantum dots may provide new electronic, optical, or thermoelectric functionalities. In this work, we create ordered two-dimensional arrays of Si-Ge quantum dots by heteroepitaxial growth on Si (001) with pre-patterned pits. Instead of growing the dots directly at elevated temperatures, we first grow conformal alloy layers and then use post-growth annealing to promote directed self-assembly. Annealing provides monodisperse size distributions with excellent control over the quantum dot (QD) mean size and shape. Similar to QD formation during growth, intermixing with substrate Si occurs, despite the conformal layer, due to the presence of the pattern topography itself.
Toward reproducible metal-insulator transition characteristics in V2O3 thin films sputter-deposited on glass
Authors: Rúa Armando , Echeverría Karla , Ayala Brian , Goenaga Gabriel A. , Lysenko Sergiy , Fernández Félix E.
Published: November 2018

Vanadium sesquioxide (V2O3) exhibits remarkable property changes through its metal-insulator transition near 150 K and is a very promising candidate for device applications. Thin V2O3 films were deposited on SiO2 glass by reactive DC magnetron sputtering. While resistivity changes over four orders of magnitude were demonstrated, films deposited under nominally identical conditions exhibited significant differences in electrical characteristics, which would hinder reproducibility under deposition techniques appropriate for industrial scale production with standard control features. These differences were attributed to small deviations from exact stoichiometry. A post-deposition thermal treatment consistent with equilibrium temperature and oxygen pressure conditions for V2O3 applied to the samples succeeded in nearly equalizing their characteristics within a relatively short time and without negatively impacting the glass substrate or film continuity. Analysis of film structure, morphology, and resistivity measured from room temperature through the metal-insulator transitions, both before and after the thermal process, revealed information about the interplay between non-stoichiometry, residual stress, and electrical characteristics of the films. The approach employed can lead to reproducible results for V2O3 films and is applicable to similar materials which exhibit metal-insulator transitions.
Translation-orientation coupling and Cox-Merz rule of liquid hexane
Authors: Yamaguchi Tsuyoshi , Matsuoka Tatsuro
Published: November 2018

Equilibrium and non-equilibrium molecular dynamics simulations are performed on liquid hexane in order to clarify the origin of the Cox-Merz rule of liquids composed of chain-like molecules. The relation between the frequency-dependent complex shear viscosity and the shear-rate dependent nonlinear viscosity follows the Cox-Merz rule as expected. The slowest viscoelastic relaxation mode is explained by the translation-orientation coupling mechanism, and the saturation of the shear-induced orientational order is observed in the non-equilibrium simulation at the onset of the shear thinning. The origin of the Cox-Merz rule is discussed in terms of the translation-orientation coupling.
Electron attachment to hexafluoropropylene oxide (HFPO)
Authors: Zawadzki M. , Chachereau A. , Kočišek J. , Franck C. M. , Fedor J.
Published: November 2018

We probe the electron attachment in hexafluoropropylene oxide (HFPO), C3F6O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10−4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20–100 mbar. In the latter method, the cross sections are unfolded from the electron attachment rate coefficients. The cross sections derived independently by the two methods are in very good agreement. We additionally discuss the dissociative electron attachment fragmentation patterns and their role in the radical production in industrial HFPO plasmas.
Tenfold increase in the photostability of an azobenzene guest in vapor-deposited glass mixtures
Authors: Qiu Yue , Antony Lucas W. , Torkelson John M. , de Pablo Juan J. , Ediger M. D.
Published: November 2018

Improvements to the photostability of organic glasses for use in electronic applications have generally relied on the modification of the chemical structure. We show here that the photostability of a guest molecule can also be significantly improved—without chemical modification—by using physical vapor deposition to pack molecules more densely. Photoisomerization of the substituted azobenzene, 4,4′-diphenyl azobenzene, was studied in a vapor-deposited glass matrix of celecoxib. We directly measure photoisomerization of trans- to cis-states via Ultraviolet-visible (UV-Vis) spectroscopy and show that the rate of photoisomerization depends upon the substrate temperature used during co-deposition of the glass. Photostability correlates reasonably with the density of the glass, where the optimum glass is about tenfold more photostable than the liquid-cooled glass. Molecular simulations, which mimic photoisomerization, also demonstrate that photoreaction of a guest molecule can be suppressed in vapor-deposited glasses. From the simulations, we estimate that the region that is disrupted by a single photoisomerization event encompasses approximately 5 molecules.
Room temperature spin injection into SiC via Schottky barrier
Authors: Huang L. , Wu H. , Liu P. , Zhang X. M. , Tao B. S. , Wan C. H. , Yan Y. , Han X. F.
Published: November 2018

Electrical spin injection into and spin extraction from a wide-bandgap semiconductor SiC at room temperature were demonstrated via Schottky junctions. The spin relaxation time of SiC could reach 300 ps, overwhelming that of Si with similar carrier density due to the smaller atomic number. We also found that there existed two channels in SiC/CoFeB Schottky junctions for spin relaxation, one from bulk SiC and the other from interfacial defect states within the barrier whose spin relaxation times were about 1 ns. The bias condition controlled transport channels via bulk or defect states within the barrier and then affected the effective spin relaxation process. Realization of spin injection into SiC shed light on spintronics of wide-bandgap semiconductors such as spin-resolved blue light emitting diodes and high power/temperature spintronics.
Polarization controllable and wide-angle frequency tunable metamaterial absorber
Authors: Thummaluru Sreenath Reddy , Chaudhary Raghvendra Kumar
Published: November 2018

In this paper, the design, fabrication, and measurement of a high-performance metamaterial absorber (MMA) have been presented. The three major concerns of MMA's are narrow bandwidth, angle sensitivity, and uncontrollable polarization. By smartly controlling the proposed design, the solutions to these three concerns of MMA are given in this paper. By integrating the design with varactor diodes, we make the MMA tunable to wide frequency ranges. Frequency tunability ranges from 4.2 to 7 GHz. By using circular sectors in the resonator, wide incident angle insensitivity has been achieved. The presented MMA exhibits more than 80% absorptivity up to 70° incident angles. With the proposed design, it is possible to control either TM or TE polarization resonant frequency by fixing the resonant frequency of other polarization. Also, a biasing technique which is simple and effective to control both TM and TE resonant frequencies simultaneously is given in this paper. Moreover, all these advantages have been achieved by using a single layer low cost FR4 material having thickness 0.6 mm as a substrate. By using a standard parameter retrieval technique, the real and imaginary parts of both permittivity and permeability of the presented MMA are calculated. It is expected that the presented work improves the state-of-the-art in the smart metamaterial absorber domain.
Infrared spectra of the 1,1-dimethylallyl and 1,2-dimethylallyl radicals isolated in solid para-hydrogen
Authors: Amicangelo Jay C. , Lee Yuan-Pern
Published: November 2018

The reaction of hydrogen atoms (H) with isoprene (C5H8) in solid para-hydrogen (p-H2) matrices at 3.2 K has been studied using infrared (IR) spectroscopy. Mixtures of C5H8 and Cl2 were co-deposited in p-H2 at 3.2 K, followed by irradiation with ultraviolet light at 365 nm to produce Cl atoms from the Cl2, and subsequent irradiation with IR light to produce H atoms from the reaction of the Cl atoms with p-H2. The H atoms then react with the C5H8 to form H atom addition radicals (C5H9•). Upon 365-nm/IR photolysis, a multitude of new lines appeared in the IR spectrum and, based on the secondary photolysis behavior, it was determined that the majority of the new lines belong to two distinct chemical species, denoted as set X (an intense line at 776.0 cm−1 and 12 other weaker lines) and set Y (an intense line at 766.7 cm−1 and 12 other weaker lines). Quantum-chemical calculations were performed at the B3PW91/6-311++G(2d,2p) level to determine the relative energetics and predict the IR spectra for the four possible isomers of C5H9• that can be produced from the addition of the H atom to the four distinct carbon atoms in C5H8. The newly observed lines of set X and Y are assigned to the 1,2-dimethylallyl (addition to carbon 4) and the 1,1-dimethylallyl (addition to carbon 1) radicals according to comparison with the predicted IR spectra of the possible products. The 1,2-dimethylallyl radical and the 1,1-dimethylallyl radical were predicted to be the most stable isomers, with the latter ∼8 kJ mol−1 lower in energy than the former and to have significantly lower barriers than the addition pathways for the two central carbons. The ratio of the 1,1-dimethylallyl to the 1,2-dimethylallyl radicals is estimated to be (1.0 ± 0.5):1.0, indicating that the two radicals are produced in similar amounts, which is consistent with the theoretical predictions that the barrier heights are very similar for the H atom addition to the two terminal carbon atoms.
High thermal conductivity of nanoparticles not necessarily contributing more to nanofluids
Authors: Song Dongxing , Jing Dengwei , Ma Weigang , Zhang Xing
Published: November 2018

Nanofluids with high thermal conductivity represent a promising means of enhancing heat transfer. It is generally believed that nanoparticles with higher thermal conductivity offer greater improvements in the thermal conductivity of the associated nanofluid. However, some experimental results are inconsistent with this opinion, which seems surprising. In this letter, an effective medium model based on phonon theory is used to show that the phonon frequencies of the liquid and the nanoparticles play a key role. Nanoparticles with higher thermal conductivity that match the phonon frequency of the liquid can be more effective at very small sizes.
A phase-stabilized superradiant Ka-band oscillator driven by nanosecond voltage pulses with amplitude variations and reduced rise rates
Authors: Sharypov K. A. , Rostov V. V. , Sadykova A. G. , Shpak V. G. , Shunailov S. A. , Yalandin M. I.
Published: November 2018

This paper presents the results of experiments and a numerical simulation of the conditions for phase stabilization (standard deviation < 0.5 rad) of a subgigawatt relativistic superradiant Ka-band backward wave oscillator with the accelerating voltage amplitude varying within 15%. It is shown that phase stabilization can be achieved for the voltage rise rate (dU/dt)max ∼ 2 MV/ns by using our recently developed approach. Particular emphasis is given to the cases of substantially lower voltage rise rates at which stabilization of the microwave oscillation phase is also possible. The mode with (dU/dt)max ≪ 1 MV/ns is considered for specific voltage waveforms that ensure efficient kinematic peaking of the beam current. In this case, stabilization of the microwave oscillation phase can be achieved by initiating a voltage prepulse, provided that the accelerating pulse leading edge has a segment of stable rise rate and stable shape.
1.5 μm quantum-dot diode lasers directly grown on CMOS-standard (001) silicon
Authors: Zhu Si , Shi Bei , Li Qiang , Lau Kei May
Published: November 2018

Electrically pumped on-chip C-band lasers provide additional flexibility for silicon photonics in the design of optoelectronic circuits. III–V quantum dots, benefiting from their superior optical properties and enhanced tolerance to defects, have become the active medium of choice for practical light sources monolithically grown on Si. To fully explore the potentials of integrated lasers for silicon photonics in telecommunications and datacenters, we report the realization of 1.5 μm room-temperature electrically pumped III–V quantum dot lasers epitaxially grown on complementary metal-oxide-semiconductor (CMOS)-standard (001) Si substrates without offcut. A threshold current density of 1.6 kA/cm2, a total output power exceeding 110 mW, and operation up to 80 °C under pulsed current injection have been achieved. These results arose from applying our well-developed InAs/InAlGaAs/InP QDs on low-defect-density InP-on-Si templates utilizing nano-patterned V-grooved (001) Si and InGaAs/InP dislocation filters. This demonstration marks a major advancement for future monolithic photonic integration on a large-area and cost-effective Si platform.
Intensity-modulated LED achieved through integrating p-GaN/n-ZnO heterojunction with multilevel RRAM
Authors: Qi Meng , Zhang Xue , Yang Liu , Wang Zhongqiang , Xu Haiyang , Liu Weizhen , Zhao Xiaoning , Liu Yichun
Published: November 2018

We developed an intensity-modulated light-emitting device (LED) by integrating a p-GaN/n-ZnO heterojunction with multilevel resistive random access memory (RRAM). In this device, the luminous intensity of LED can be adjusted through regulating the injection current according to the variable resistance state of RRAM. As one critical foundation of device fabrication, uniform operation of multilevel RRAM was achieved by inserting carbon quantum dots into HfO2−x RRAM as a local-electric-field regulator. Eventually, the reversible regulation of electroluminescence intensity was demonstrated by tuning the compliance current in the modulated LED. Thanks to the simple structure and nanoscale switching region, this modulated LED may offer a feasible method to replace traditional thin film transistors or CMOSs with complicated structures and techniques, enabling the potential application of low-cost and high-density LED displays.
Creation of aspheric interfaces on an electrowetting liquid lens using surface oscillations
Authors: Strauch Matthias , Somers Peter A. A. M. , Bociort Florian , Urbach H. Paul
Published: November 2018

A technique to create aspheric surface shapes on commercially available electrowetting liquid lenses is demonstrated. Based on a previously published surface oscillation model a technique using a Hankel transform is proposed and tested experimentally. An alternating actuation voltage is applied to the liquid lens to stimulate surface oscillations, that temporarily add up to the desired surface shape. The voltage signal can be repeated at video rate. The measurements were taken with a Mach-Zehnder interferometer and confirm the previous results. The capabilities and limitations of the proposed method are demonstrated using the examples of a Bessel surface, spherical aberration, an axicon, and a top hat structure.
Roadkill mitigation: trialing virtual fence devices on the west coast of Tasmania
Authors: Fox Samantha , Potts Joanne M. , Pemberton David , Crosswell Dale
Published: November 2018

Wildlife roadkill is a worldwide issue being tackled using several mitigation methods that have variable efficacy. Tasmania has a significant roadkill issue, and several endemic species that are vulnerable to roadkill. Virtual fence devices are manufactured in Austria and were originally designed to mitigate against the impact of vehicles hitting large game species such as deer and boar. Here, we trial the devices over three years at a single site in Tasmania to determine whether they are effective in reducing roadkill of Tasmanian mammal species. While there was no spatial replication in this trial, a reduction in total roadkill rate, and in the most commonly affected species, by 50% suggests that these devices have enormous potential to substantially reduce roadkill rates. Many unique mammal species no longer found in the wild on mainland Australia are still found in Tasmania, making mitigating roadkill hotspots an important conservation tool to help maintain presence of these species in their last remaining stronghold. Road managers, including councils, in other Australian States that suffer from high rates of wildlife roadkill may benefit from the knowledge of the results of this trial.
Short-term impact of PM
2.5
on contemporaneous asthma medication use: Behavior and the value of pollution reductions
Authors: Williams Austin M. , Phaneuf Daniel J. , Barrett Meredith A. , Su Jason G.
Published: November 2018

Asthma ranks among the most costly of chronic diseases, accounting for over $50 billion annually in direct medical expenditures in the United States. At the same time, evidence has accumulated that fine particulate matter pollution can exacerbate asthma symptoms and generate substantial economic costs. To measure these costs, we use a unique nationwide panel dataset tracking asthmatic individuals’ use of rescue medication and their exposure to PM
2.5
(particulate matter with an aerodynamic diameter of <2.5 μm) concentration between 2012 and 2017, to estimate the causal relationship between pollution and inhaler use. Our sample consists of individuals using an asthma digital health platform, which relies on a wireless sensor to track the place and time of inhaler use events, as well as regular nonevent location and time indicators. These data provide an accurate measurement of inhaler use and allow spatially and temporally resolute assignment of pollution exposure. Using a high-frequency research design and individual fixed effects, we find that a 1 μg/m
3
(12%) increase in weekly exposure to PM
2.5
increases weekly inhaler use by 0.82%. We also show that there is seasonal, regional, and income-based heterogeneity in this response. Using our response prediction, and an estimate from the literature on the willingness to pay to avoid asthma symptoms, we show that a nationwide 1 μg/m
3
reduction in particulate matter concentration would generate nearly $350 million annually in economic benefits.
Evaluating science communication
Authors: Fischhoff Baruch
Published: November 2018

Effective science communication requires assembling scientists with knowledge relevant to decision makers, translating that knowledge into useful terms, establishing trusted two-way communication channels, evaluating the process, and refining it as needed.
Communicating Science Effectively: A Research Agenda
[National Research Council (2017)] surveys the scientific foundations for accomplishing these tasks, the research agenda for improving them, and the essential collaborative relations with decision makers and communication professionals. Recognizing the complexity of the science, the decisions, and the communication processes, the report calls for a systems approach. This perspective offers an approach to creating such systems by adapting scientific methods to the practical constraints of science communication. It considers staffing (are the right people involved?), internal collaboration (are they talking to one another?), and external collaboration (are they talking to other stakeholders?). It focuses on contexts where the goal of science communication is helping people to make autonomous choices rather than promoting specific behaviors (e.g., voter turnout, vaccination rates, energy consumption). The approach is illustrated with research in two domains: decisions about preventing sexual assault and responding to pandemic disease.
Dual functions for OVAAL in initiation of RAF/MEK/ERK prosurvival signals and evasion of p27-mediated cellular senescence
Authors: Sang Ben , Zhang Yuan Yuan , Guo Su Tang , Kong Ling Fei , Cheng Qiong , Liu Guang Zhi , Thorne Rick F. , Zhang Xu Dong , Jin Lei , Wu Mian
Published: November 2018

Significance

Here, we report that the long noncoding RNA (lncRNA) ovarian adenocarcinoma-amplified lncRNA (OVAAL) is a mediator of cancer cell resistance, counteracting the effects of apoptosis-inducing agents acting through both the extrinsic and intrinsic pathways. Building upon previous reports associating OVAAL amplification with ovarian and endometrial cancers, we now show that OVAAL overexpression occurs during the pathogenesis of colorectal cancer and melanoma. Mechanistically, our findings also establish that OVAAL expression more generally contributes a prosurvival role to cancer cells under steady-state conditions. OVAAL accomplishes these actions utilizing distinct functional modalities: one promoting activation of RAF/MEK/ERK signaling and the other blocking cell entry into senescence. Our study demonstrates that expression of a single OVAAL in cancer cells drives two distinct but coordinated actions contributing to cancer pathology.
Strong impact of wildfires on the abundance and aging of black carbon in the lowermost stratosphere
Authors: Ditas Jeannine , Ma Nan , Zhang Yuxuan , Assmann Denise , Neumaier Marco , Riede Hella , Karu Einar , Williams Jonathan , Scharffe Dieter , Wang Qiaoqiao , Saturno Jorge , Schwarz Joshua P. , Katich Joseph M. , McMeeking Gavin R. , Zahn Andreas , Hermann Markus , Brenninkmeijer Carl A. M. , Andreae Meinrat O. , Pöschl Ulrich , Su Hang , Cheng Yafang
Published: November 2018

Wildfires inject large amounts of black carbon (BC) particles into the atmosphere, which can reach the lowermost stratosphere (LMS) and cause strong radiative forcing. During a 14-month period of observations on board a passenger aircraft flying between Europe and North America, we found frequent and widespread biomass burning (BB) plumes, influencing 16 of 160 flight hours in the LMS. The average BC mass concentrations in these plumes (∼140 ng·m
−3
, standard temperature and pressure) were over 20 times higher than the background concentration (∼6 ng·m
−3
) with more than 100-fold enhanced peak values (up to ∼720 ng·m
−3
). In the LMS, nearly all BC particles were covered with a thick coating. The average mass equivalent diameter of the BC particle cores was ∼120 nm with a mean coating thickness of ∼150 nm in the BB plume and ∼90 nm with a coating of ∼125 nm in the background. In a BB plume that was encountered twice, we also found a high diameter growth rate of ∼1 nm·h
−1
due to the BC particle coatings. The observed high concentrations and thick coatings of BC particles demonstrate that wildfires can induce strong local heating in the LMS and may have a significant influence on the regional radiative forcing of climate.
TOR and RPS6 transmit light signals to enhance protein translation in deetiolating
Arabidopsis
seedlings
Authors: Chen Guan-Hong , Liu Ming-Jung , Xiong Yan , Sheen Jen , Wu Shu-Hsing
Published: November 2018

Significance

Light enhances the translation efficiency of thousands of mRNAs during photomorphogenic development in
Arabidopsis
, but the underlying molecular mechanism remains elusive. Here we show that light activates the auxin-target of rapamycin (TOR)-ribosome protein S6 (RPS6) pathway to enhance translation in deetiolating
Arabidopsis
. We discovered that CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) represses TOR activity in dark-grown seedlings. The perception of far-red and blue light by photoreceptors inactivates COP1, which leads to the derepression of the auxin-TOR-RPS6 pathway and enhanced de novo protein synthesis. Our study revealed a light-triggered signaling pathway for translational regulation. This sophisticated regulation also functions to ensure that young seedlings have strict skotomorphogenic development in the dark and a timely switch to photomorphogenic development.
Biparental Inheritance of Mitochondrial DNA in Humans
Authors: Luo Shiyu , Valencia C. Alexander , Zhang Jinglan , Lee Ni-Chung , Slone Jesse , Gui Baoheng , Wang Xinjian , Li Zhuo , Dell Sarah , Brown Jenice , Chen Stella Maris , Chien Yin-Hsiu , Hwu Wuh-Liang , Fan Pi-Chuan , Wong Lee-Jun , Atwal Paldeep S. , Huang Taosheng
Published: November 2018

Significance

The energy-producing organelle mitochondrion contains its own compact genome, which is separate from the nuclear genome. In nearly all mammals, this mitochondrial genome is inherited exclusively from the mother, and transmission of paternal mitochondria or mitochondrial DNA (mtDNA) has not been convincingly demonstrated in humans. In this paper, we have uncovered multiple instances of biparental inheritance of mtDNA spanning three unrelated multiple generation families, a result confirmed by independent sequencing across multiple unrelated laboratories with different methodologies. Surprisingly, this pattern of inheritance appears to be determined in an autosomal dominantlike manner. This paper profoundly alters a widespread belief about mitochondrial inheritance and potentially opens a novel field in mitochondrial medicine.
Contact mechanics between the human finger and a touchscreen under electroadhesion
Authors: Ayyildiz Mehmet , Scaraggi Michele , Sirin Omer , Basdogan Cagatay , Persson Bo N. J.
Published: November 2018

Significance

The technology for generating tactile feedback on a touchscreen via electroadhesion is already available—and straightforward to implement—but the knowledge on human skin contact mechanics is limited. To better understand the contact mechanism between the finger pad and touchscreen under electroadhesion, we investigated the sliding friction as a function of normal force and voltage using (
i
) a mean field theory based on multiscale contact mechanics, (
ii
) a full-scale computational contact mechanics study, and (
iii
) experiments performed on a custom-made tribometer. We show that the real contact area and the electroadhesion force depend strongly on the skin surface roughness and on the nature of the touchscreen coating. Thus, by reducing the effective thickness of the latter, the human tactile sensing can be drastically enhanced.
Eurasian river spring flood observations support net Arctic Ocean mercury export to the atmosphere and Atlantic Ocean
Authors: Sonke Jeroen E. , Teisserenc Roman , Heimbürger-Boavida Lars-Eric , Petrova Mariia V. , Marusczak Nicolas , Le Dantec Theo , Chupakov Artem V. , Li Chuxian , Thackray Colin P. , Sunderland Elsie M. , Tananaev Nikita , Pokrovsky Oleg S.
Published: November 2018

Significance

Elevated levels of mercury in Arctic marine wildlife have been linked to midlatitude anthropogenic mercury emissions which are transported to the Arctic Ocean by air. Modeling studies, however, suggest that Arctic rivers contribute equal amounts of mercury to the Arctic Ocean. In this study, we provide comprehensive mercury data on large Eurasian rivers. We find that the spring flood mercury flux from Eurasian rivers is indeed large, which confirms a new Arctic mercury cycling paradigm: Mid-latitude anthropogenic emissions reach the terrestrial Arctic by air, whereby vegetation uptake transfers atmospheric mercury to tundra and boreal peat soils. Springtime snowmelt subsequently mobilizes peat soil mercury to the Arctic Ocean, where photochemistry drives net export of mercury back to the atmosphere.
Integrative approach using
Yersinia pestis
genomes to revisit the historical landscape of plague during the Medieval Period
Authors: Namouchi Amine , Guellil Meriam , Kersten Oliver , Hänsch Stephanie , Ottoni Claudio , Schmid Boris V. , Pacciani Elsa , Quaglia Luisa , Vermunt Marco , Bauer Egil L. , Derrick Michael , Jensen Anne Ø. , Kacki Sacha , Cohn Samuel K. , Stenseth Nils C. , Bramanti Barbara
Published: November 2018

Over the last few years, genomic studies on
Yersinia pestis
, the causative agent of all known plague epidemics, have considerably increased in numbers, spanning a period of about 5,000 y. Nonetheless, questions concerning historical reservoirs and routes of transmission remain open. Here, we present and describe five genomes from the second half of the 14th century and reconstruct the evolutionary history of
Y. pestis
by reanalyzing previously published genomes and by building a comprehensive phylogeny focused on strains attributed to the Second Plague Pandemic (14th to 18th century). Corroborated by historical and ecological evidence, the presented phylogeny, which includes our
Y. pestis
genomes, could support the hypothesis of an entry of plague into Western European ports through distinct waves of introduction during the Medieval Period, possibly by means of fur trade routes, as well as the recirculation of plague within the human population via trade routes and human movement.
Citrate-based materials fuel human stem cells by metabonegenic regulation
Authors: Ma Chuying , Tian Xinggui , Kim Jimin P. , Xie Denghui , Ao Xiang , Shan Dingying , Lin Qiaoling , Hudock Maria R. , Bai Xiaochun , Yang Jian
Published: November 2018

Significance

Differentiation of mesenchymal stem cells (MSCs) to bone-forming cells is central to bone regeneration, the extent of which is largely regulated by microenvironment factors. Here, we find that citrate as a metabolic factor that is abundant in bone can be consumed by MSCs to fuel osteogenesis by regulating metabolic pathways. We explored the mechanism of citrate benefit and designed a biomimetic citrate-based material that could provide a citrate- and phosphoserine-rich environment during degradation based on the previously unexplored concerted action between the two bioactive factors in accelerating bone regeneration. Together, these studies open up avenues for the study of stem cell biology and design of bone biomaterials to treat critically sized defects and bone disorders of metabolic origin.
Hinge region of
Arabidopsis
phyA plays an important role in regulating phyA function
Authors: Zhou Yangyang , Yang Li , Duan Jie , Cheng Jinkui , Shen Yunping , Wang Xiaoji , Han Run , Li Hong , Li Zhen , Wang Lihong , Terzaghi William , Zhu Danmeng , Chen Haodong , Deng Xing Wang , Li Jigang
Published: November 2018

Significance

The plant phytochrome molecule consists of an N-terminal photosensory domain and a C-terminal dimerization domain, connected by a flexible hinge region. It was previously shown that a serine residue in the hinge region of oat phytochrome A (phyA) could be phosphorylated in vivo and plays an important role in regulating phyA function. However, little is known regarding the function of the hinge region of
Arabidopsis
phyA. Here, we show that three residues in the hinge region of
Arabidopsis
phyA are essential in regulating phyA phosphorylation and function. Our study thus provides new insights into the regulatory role of the phytochrome hinge region, suggesting that phosphorylation and function of the hinge region may differ between oat and
Arabidopsis
phyA photoreceptors.
PYL8 mediates ABA perception in the root through non-cell-autonomous and ligand-stabilization–based mechanisms
Authors: Belda-Palazon Borja , Gonzalez-Garcia Mary-Paz , Lozano-Juste Jorge , Coego Alberto , Antoni Regina , Julian Jose , Peirats-Llobet Marta , Rodriguez Lesia , Berbel Ana , Dietrich Daniela , Fernandez Maria A. , Madueño Francisco , Bennett Malcolm J. , Rodriguez Pedro L.
Published: November 2018

Significance

The phytohormone abscisic acid (ABA) controls root responses to environmental signals such as abiotic stress. ABA signaling in roots depends on the nonredundant role of the PYL8 receptor. This study reveals special features of this ABA receptor. ABA binding triggers hormone-dependent stabilization of PYL8 through reduced ubiquitination and induces nuclear localization of the receptor. ABA-induced stabilization also allows movement of the PYL8 receptor from the root epidermis and stele to adjacent tissues. Hence, like mobile transcription factors that regulate plant development, the PYL8 protein can move between cells. In summary, our study reports a novel non-cell-autonomous mechanism to regulate hormone perception and root growth.
Molecular mechanism of fusion pore formation driven by the neuronal SNARE complex
Authors: Sharma Satyan , Lindau Manfred
Published: November 2018

Significance

SNARE proteins facilitate the synaptic vesicle fusion with the plasma membrane. The structure of the fusion pore and the mechanism of its formation are not clearly understood. Using coarse-grained molecular dynamics simulations of a nanodisc bridged by four SNARE proteins to a bilayer, we identify the importance of the C termini of synaptobrevin 2 and syntaxin 1 in facilitating fusion pore formation. The conductances of the simulated fusion pores agree with experimental values, and SNARE mutants that inhibit fusion experimentally fail to form fusion pores in the simulations. Confinement of SNARE complexes is essential for rapid fusion pore formation, but release of the SNARE complexes from this confinement is required for fusion pore expansion.
Mechanically activated ion channel PIEZO1 is required for lymphatic valve formation
Authors: Nonomura Keiko , Lukacs Viktor , Sweet Daniel T. , Goddard Lauren M. , Kanie Akemi , Whitwam Tess , Ranade Sanjeev S. , Fujimori Toshihiko , Kahn Mark L. , Patapoutian Ardem
Published: November 2018

Significance

PIEZOs are mechanically activated cation channels. Recently, loss-of-function mutations of human
PIEZO1
were found among patients with familial lymphedema, suggesting a requirement of PIEZO1 in the lymphatic system. In this paper, utilizing mouse models lacking PIEZO1 in endothelial cells, we show that this ion channel is required for the formation of lymphatic valves, a key structure for proper circulation of lymph in the body. The requirement of PIEZO1 in valve formation provides mechanistic insight on how
PIEZO1
variants cause lymphatic dysfunction in patients. This study also extends the relevance of PIEZOs beyond acute signaling molecules (e.g., touch sensation) and highlights the importance of these ion channels in controlling morphological/structural specification during development.
A contrastive (English, Czech English, Czech) study of rhetorical functions of citations in Linguistics research
articles
Authors: Dontcheva-Navrátilová Olga
Published: November 2018

This study explores variation in the use of citations in a specialised corpus of Linguistics research articles
comprising Czech-medium and English-medium texts by Czech linguists and English-medium texts by Anglophone authors.
Drawing on the typologies suggested by Thompson and Tribble (2001), Petrić (2007) and Dontcheva-Navratilova
(2016), the investigation aims at identifying the frequency and rhetorical functions of citations across
the generic moves of RAs and exploring how they contribute to academic persuasion. The findings of the contrastive
analysis indicate that the existing divergences in citation practices of Czech writers writing in Czech and English
and Anglophone authors are related to the intended readership and the linguacultural context in which they strive to
convince readers to accept their claims and views.
How to internationalise and empower academic research?
Authors: Ruzaitė Jūratė , Petrauskaitė Rūta
Published: November 2018

The current chapter accounts for the trends of internationalisation in research papers in Linguistics with a primary
focus on academic conventions in articles published in a national journal in various languages (including Lithuanian
and English) as compared to those published in a well-established international journal (solely in English). The
trends of internationalisation are assessed with regard to the overall journal structure, publication languages, the
degree of transnational cooperation, and the rhetorical structure of the papers. Based on the results, it is argued
that in the field of Linguistics it is not so much the language that predetermines differences in the two journals,
but the academic conventions that differ across cultures and publishing houses.