bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurocognitive Functions in 3- to 15-Year-Old Children: An International Comparison
Authors: Rosenqvist Johanna , Lahti-Nuuttila Pekka , Urgesi Cosimo , Holdnack James , Kemp Sally L. , Laasonen Marja
Published: February 2017

Objectives:Performance on neurocognitive tasks develops with age, but it is still unknown whether this performance differs between children from different cultures. We compared cross-sectionally the development of neurocognitive functions in 3- to 15-year-old children from three countries: Finland, Italy, and the United States (N=2745).Methods:Language, face memory, emotion recognition, theory of mind, and visuospatial processing subtests from the NEPSY-II standardizations in Finland, Italy, and the United States were used to evaluate if children and adolescents from different linguistic and cultural backgrounds differ in performance on these measures.Results:We found significant differences in performance on the tasks between the countries. Generally, the differences were more pronounced in the younger age groups. Some subtests showed greater country effects than others, performance on these subtests being higher, in general, in one country over the others, or showed different patterns of age associated changes in test performance.Conclusions:Significant differences in neurocognitive performance between children from Finland, Italy, and the United States were found. These findings may be due to cultural or educational differences that impact test performance, or due to factors associated with the adaptation of measures from one culture to another. The finding of performance differences across countries on similar tasks indicate that cross-cultural and background variables impact performance on neuropsychological measures. Therefore, clinicians need to consider a child’s cultural background when evaluating performance on neuropsychological assessments. The results also indicate that future cross-cultural studies are needed to further examine the underlying cultural factors that influence neurocognitive performance. (JINS, 2017,23, 367–380)
Ethological principles predict the neuropeptides co-opted to influence parenting
Authors: Cunningham Christopher B. , Badgett Majors J. , Meagher Richard B. , Orlando Ron , Moore Allen J.
Published: February 2017

Ethologists predicted that parental care evolves by modifying behavioural precursors in the asocial ancestor. As a corollary, we predict that the evolved mechanistic changes reside in genetic pathways underlying these traits. Here we test our hypothesis in female burying beetles, Nicrophorus vespilloides, an insect where caring adults regurgitate food to begging, dependent offspring. We quantify neuropeptide abundance in brains collected from three behavioural states: solitary virgins, individuals actively parenting or post-parenting solitary adults and quantify 133 peptides belonging to 18 neuropeptides. Eight neuropeptides differ in abundance in one or more states, with increased abundance during parenting in seven. None of these eight neuropeptides have been associated with parental care previously, but all have roles in predicted behavioural precursors for parenting. Our study supports the hypothesis that predictable traits and pathways are targets of selection during the evolution of parenting and suggests additional candidate neuropeptides to study in the context of parenting.
A Global Approach for Quantitative Super Resolution and Electron Microscopy on Cryo and Epoxy Sections Using Self-labeling Protein Tags
Authors: Müller Andreas , Neukam Martin , Ivanova Anna , Sönmez Anke , Münster Carla , Kretschmar Susanne , Kalaidzidis Yannis , Kurth Thomas , Verbavatz Jean-Marc , Solimena Michele
Published: February 2017

Correlative light and electron microscopy (CLEM) is a powerful approach to investigate the molecular ultrastructure of labeled cell compartments. However, quantitative CLEM studies are rare, mainly due to small sample sizes and the sensitivity of fluorescent proteins to strong fixatives and contrasting reagents for EM. Here, we show that fusion of a self-labeling protein to insulin allows for the quantification of age-distinct insulin granule pools in pancreatic beta cells by a combination of super resolution and transmission electron microscopy on Tokuyasu cryosections. In contrast to fluorescent proteins like GFP organic dyes covalently bound to self-labeling proteins retain their fluorescence also in epoxy resin following high pressure freezing and freeze substitution, or remarkably even after strong chemical fixation. This enables for the assessment of age-defined granule morphology and degradation. Finally, we demonstrate that this CLEM protocol is highly versatile, being suitable for single and dual fluorescent labeling and detection of different proteins with optimal ultrastructure preservation and contrast.
Synergistic effects of metformin with liraglutide against endothelial dysfunction through GLP-1 receptor and PKA signalling pathway
Authors: Ke Jing , Liu Ye , Yang Jin , Lu Ran , Tian Qing , Hou Wenfang , Wang Guang , Wei Rui , Hong Tianpei
Published: February 2017

Metformin or glucagon-like peptide-1 (GLP-1) analogue liraglutide has cardiovascular benefits. However, it is not clear whether their combined treatment have additive or synergistic effects on the vasculature. In this study, human umbilical vein endothelial cells (HUVECs), exposed to palmitic acid (PA) to induce endothelial dysfunction, were incubated with metformin, liraglutide or their combination. High fat diet (HFD)-fed ApoE−/− mice were randomized into control, metformin, liraglutide, and combination treatment groups. Results showed that in PA-treated HUVECs and HFD-fed ApoE−/− mice, combination of metformin and liraglutide at lower dose significantly improved endothelial dysfunction compared with the single treatment. Metformin upregulated GLP-1 receptor (GLP-1R) level and protein kinase A (PKA) phosphorylation. However, PKA inhibition but not GLP-1R blockade eliminated the protective effects of metformin on endothelial function. Furthermore, AMPK inhibitor compound C abolished the metformin-mediated upregulation of GLP-1R level and PKA phosphorylation. In conclusion, combination of metformin and liraglutide has synergistic protective effects on endothelial function. Moreover, metformin stimulates GLP-1R and PKA signalling via AMPK-dependent pathway, which may account for its synergistic protective effects with liraglutide. Our findings provide new insights on the interaction between metformin and GLP-1, and provide important information for designing new GLP-1-based therapy strategies in treating type 2 diabetes.
Tuning the allosteric regulation of artificial muscarinic and dopaminergic ligand-gated potassium channels by protein engineering of G protein-coupled receptors
Authors: Moreau Christophe J. , Revilloud Jean , Caro Lydia N. , Dupuis Julien P. , Trouchet Amandine , Estrada-Mondragón Argel , Nieścierowicz Katarzyna , Sapay Nicolas , Crouzy Serge , Vivaudou Michel
Published: February 2017

Ligand-gated ion channels enable intercellular transmission of action potential through synapses by transducing biochemical messengers into electrical signal. We designed artificial ligand-gated ion channels by coupling G protein-coupled receptors to the Kir6.2 potassium channel. These artificial channels called ion channel-coupled receptors offer complementary properties to natural channels by extending the repertoire of ligands to those recognized by the fused receptors, by generating more sustained signals and by conferring potassium selectivity. The first artificial channels based on the muscarinic M2 and the dopaminergic D2L receptors were opened and closed by acetylcholine and dopamine, respectively. We find here that this opposite regulation of the gating is linked to the length of the receptor C-termini, and that C-terminus engineering can precisely control the extent and direction of ligand gating. These findings establish the design rules to produce customized ligand-gated channels for synthetic biology applications.
Programmability of Co-antidot lattices of optimized geometry
Authors: Schneider Tobias , Langer Manuel , Alekhina Julia , Kowalska Ewa , Oelschlägel Antje , Semisalova Anna , Neudert Andreas , Lenz Kilian , Potzger Kay , Kostylev Mikhail P. , Fassbender Jürgen , Adeyeye Adekunle O. , Lindner Jürgen , Bali Rantej
Published: February 2017

Programmability of stable magnetization configurations in a magnetic device is a highly desirable feature for a variety of applications, such as in magneto-transport and spin-wave logic. Periodic systems such as antidot lattices may exhibit programmability; however, to achieve multiple stable magnetization configurations the lattice geometry must be optimized. We consider the magnetization states in Co-antidot lattices of ≈50 nm thickness and ≈150 nm inter-antidot distance. Micromagnetic simulations were applied to investigate the magnetization states around individual antidots during the reversal process. The reversal processes predicted by micromagnetics were confirmed by experimental observations. Magnetization reversal in these antidots occurs via field driven transition between 3 elementary magnetization states – termed G, C and Q. These magnetization states can be described by vectors, and the reversal process proceeds via step-wise linear operations on these vector states. Rules governing the co-existence of the three magnetization states were empirically observed. It is shown that in an n × n antidot lattice, a variety of field switchable combinations of G, C and Q can occur, indicating programmability of the antidot lattices.
Photoacoustic Sounds from Meteors
Authors: Spalding Richard , Tencer John , Sweatt William , Conley Benjamin , Hogan Roy , Boslough Mark , Gonzales GiGi , Spurný Pavel
Published: February 2017

Concurrent sound associated with very bright meteors manifests as popping, hissing, and faint rustling sounds occurring simultaneously with the arrival of light from meteors. Numerous instances have been documented with −11 to −13 brightness. These sounds cannot be attributed to direct acoustic propagation from the upper atmosphere for which travel time would be several minutes. Concurrent sounds must be associated with some form of electromagnetic energy generated by the meteor, propagated to the vicinity of the observer, and transduced into acoustic waves. Previously, energy propagated from meteors was assumed to be RF emissions. This has not been well validated experimentally. Herein we describe experimental results and numerical models in support of photoacoustic coupling as the mechanism. Recent photometric measurements of fireballs reveal strong millisecond flares and significant brightness oscillations at frequencies ≥40 Hz. Strongly modulated light at these frequencies with sufficient intensity can create concurrent sounds through radiative heating of common dielectric materials like hair, clothing, and leaves. This heating produces small pressure oscillations in the air contacting the absorbers. Calculations show that −12 brightness meteors can generate audible sound at ~25 dB SPL. The photoacoustic hypothesis provides an alternative explanation for this longstanding mystery about generation of concurrent sounds by fireballs.
Topological Characteristics of the Hong Kong Stock Market: A Test-based P-threshold Approach to Understanding Network Complexity
Authors: Xu Ronghua , Wong Wing-Keung , Chen Guanrong , Huang Shuo
Published: February 2017

In this paper, we analyze the relationship among stock networks by focusing on the statistically reliable connectivity between financial time series, which accurately reflects the underlying pure stock structure. To do so, we firstly filter out the effect of market index on the correlations between paired stocks, and then take a t-test based P-threshold approach to lessening the complexity of the stock network based on the P values. We demonstrate the superiority of its performance in understanding network complexity by examining the Hong Kong stock market. By comparing with other filtering methods, we find that the P-threshold approach extracts purely and significantly correlated stock pairs, which reflect the well-defined hierarchical structure of the market. In analyzing the dynamic stock networks with fixed-size moving windows, our results show that three global financial crises, covered by the long-range time series, can be distinguishingly indicated from the network topological and evolutionary perspectives. In addition, we find that the assortativity coefficient can manifest the financial crises and therefore can serve as a good indicator of the financial market development.
Altered expression of miR-181a and miR-146a does not change the expression of surface NCRs in human NK cells
Authors: Rady Mona , Watzl Carsten , Claus Maren , Khorshid Ola , Mahran Laila , Abou-Aisha Khaled
Published: February 2017

MicroRNAs (miRNAs) play an important role in regulating gene expression and immune responses. Of interest, miR-181a and miR-146a are key players in regulating immune responses and are among the most abundant miRNAs expressed in NK cells. Bioinformatically, we predicted miR-181a to regulate the expression of the natural cytotoxicity receptor NCR2 by seeded interaction with the 3′-untranslated region (3′-UTR). Whereas, miR-146a expression was not significantly different (P = 0.7361), miR-181a expression was, on average 10-fold lower in NK cells from breast cancer patients compared to normal subjects; P < 0.0001. Surface expression of NCR2 was detected in NK cells from breast cancer patients (P = 0.0384). While cytokine receptor-induced NK cell activation triggered overexpression of miR-146a when stimulated with IL-2 (P = 0.0039), IL-15 (P = 0.0078), and IL-12/IL-18 (P = 0.0072), expression of miR-181a was not affected. Overexpression or knockdown of miR-181a or miR-146a in primary cultured human NK cells did not affect the level of expression of any of the three NCRs; NCR1, NCR2 or NCR3 or NK cell cytotoxicity. Expression of miR-181a and miR-146a did not correlate to the expression of the NCRs in NK cells from breast cancer patients or cytokine-stimulated NK cells from healthy subjects.
Comparative genomics of Vibrio campbellii strains and core species of the Vibrio Harveyi clade
Authors: Ke Huei-Mien , Prachumwat Anuphap , Yu Chun-Ping , Yang Yi-Ting , Promsri Sutitcha , Liu Kuan-Fu , Lo Chu-Fang , Lu Mei-Yeh Jade , Lai Mei-Chin , Tsai Isheng J. , Li Wen-Hsiung
Published: February 2017

The core of the Vibrio Harveyi clade contains V. harveyi, V. campbellii, V. owensii, V. jasicida, and V. rotiferianus. They are well recognized aquatic animal pathogens, but misclassification has been common due to similarities in their rDNA sequences and phenotypes. To better understand their evolutionary relationships and functional features, we sequenced a shrimp pathogen strain V. harveyi 1114GL, reclassified it as V. campbellii and compared this and 47 other sequenced Vibrio genomes in the Harveryi clade. A phylogeny based on 1,775 genes revealed that both V. owensii and V. jasicida were closer to V. campbellii than to V. harveyi and that V. campbellii strains can be divided into two distinct groups. Species-specific genes such as intimin and iron acquisition genes were identified in V. campbellii. In particular, the 1114GL strain contains two bacterial immunoglobulin-like genes for cell adhesion with 22 Big_2 domains that have been extensively reshuffled and are by far the most expanded among all species surveyed in this study. The 1114GL strain differed from ATCC BAA-1116 by ~9% at the synonymous sites, indicating high diversity within V. campbellii. Our study revealed the characteristics of V. campbellii in the Harveyi clade and the genetic basis for their wide-spread pathogenicity.
Asymmetric response of ferroelectric/metal oxide heterojunctions for catalysis arising from interfacial chemistry
Authors: Iyer Ashwathi A. , Ertekin Elif
Published: February 2017

The free energy profile of the oxygen evolution reaction on TiO2/BaTiO3 composites exhibits an asymmetric response to positive and negative polarizations, a result of the influence of interface chemistry.
Interfacial defects induced electronic property transformation at perovskite SrVO3/SrTiO3 and LaCrO3/SrTiO3 heterointerfaces
Authors: Li Junjie , Yin Deqiang , Li Qiang , Sun Rong , Huang Sumei , Meng Fanzhi
Published: February 2017

Unravelling the atomic structure and chemical species of interfacial defects is critical to understanding the origin of interfacial properties in many heterojunctions.
Effect of protonation on the solvation structure of solute N-butylamine in an aprotic ionic liquid
Authors: Hashimoto Kei , Fujii Kenta , Ohara Koji , Shibayama Mitsuhiro
Published: February 2017

Significant change in the solvation structure by protonation reaction in the ionic liquid [C2mIm][TFSA].
Synthesis of highly functionalised plasma polymer films from protonated precursor ions via the plasma α–γ transition
Authors: Saboohi Solmaz , Coad Bryan R. , Griesser Hans J. , Michelmore Andrew , Short Robert D.
Published: February 2017

Functional group retention in plasma polymers is maximised by tuning the pressure/power to the α to γ transition.
Rats’ urinary metabolomes reveal the potential roles of functional foods and exercise in obesity management
Authors: Farag Mohamed A. , Ammar N. M. , Kholeif T. E. , Metwally N. S. , El-Sheikh N. M. , Wessjohann Ludger A. , Abdel-Hamid A. Z.
Published: February 2017

A GC-MS based metabolomics approach targeting urine metabolism has been applied to assess the potential roles of functional foods and exercise in obesity management in rats.
Stabilization of peptides against proteolysis through disulfide-bridged conjugation with synthetic aromatics
Authors: Chen Yaqi , Li Tao , Li Jianguo , Cheng Shiyan , Wang Jinghui , Verma Chandra , Zhao Yibing , Wu Chuanliu
Published: February 2017

We developed an efficient strategy for the stabilization of peptides against proteolysis, which involves noncovalent π–π interactions between aromatic amino acid residues in peptides and synthetic electron-deficient aromatics.
Rational design of a biomimetic glue with tunable strength and ductility
Authors: Payra Debabrata , Fujii Yoshihisa , Das Sandip , Takaishi Junko , Naito Masanobu
Published: February 2017

A biomimetic design has been explored to achieve high-performance polymer glue with tuneable strength and ductility, which is suitable for a wide-range of substrates under both similar and dissimilar bonding.
Sr1.7Zn0.3CeO4F0.2:Eu3+: novel dual-emission temperature sensors for remote, noncontact thermometric application
Authors: Li Haifeng , Pang Ran , Sun Wenzhi , Li Huimin , Ma Tengfei , Jia Yonglei , Li Da , Jiang Lihong , Zhang Su , Li Chengyu
Published: February 2017

A novel dual-emitting temperature sensor Sr1.7Zn0.3CeO4F0.2:Eu3+ was synthesized. The intensity ratio shows superior linearity as a function of the temperature, indicating the potential application in the thermometry field.
N2O-emission-free exhaust remediation by Rh-NbOx nanocomposites developed from Rh3Nb alloy precursor
Authors: Imai Tsubasa , Ueda Shigenori , Nagao Satoshi , Hirata Hirohito , Deepthi Koolath Ramakrishnan , Abe Hideki
Published: February 2017

Metal-oxide nanocomposites comprising rhodium (Rh) nanoparticles (<50 nm) and oxygen-deficient niobium oxides (NbOx: x < 5/2) were developed from Rh3Nb alloy precursors.
Detection of Janus-activated kinase-1 and its interacting proteins by the method of luminescent oxygen channeling
Authors: Guo Xin-Xin , Wu Han-Tao , Zhuang Si-Hui , Chen Zhen-Hua , Liang Rong-Liang , Chen Yao , Wu Ying-Song , Liu Tian-Cai
Published: February 2017

Janus-activated kinase-1 (JAK1) plays an important role in many signaling pathways, including the JAK–STAT and SOCS pathways.
Mass spectrometry captures structural intermediates in protein fiber self-assembly
Authors: Landreh Michael , Andersson Marlene , Marklund Erik G. , Jia Qiupin , Meng Qing , Johansson Jan , Robinson Carol V. , Rising Anna
Published: February 2017

Integrating ion mobility mass spectrometry and molecular dynamics simulations provides insights into intermediates in spider silk formation. The resulting structural models reveal how soluble spidroin proteins use their terminal domains to assemble into silk fibers.
Proton conductivity of imidazole entrapped in microporous molecular sieves
Authors: Jankowska A. , Zalewska A. , Skalska A. , Ostrowski A. , Kowalak S.
Published: February 2017

Novel zeolite–imidazole composites as efficient and steady proton conductors.
Virus-like particles composed of sphere-forming polystyrene-block-poly(t-butyl acrylate) (PS-b-PtBA) and control of surface morphology by homopolymer blending
Authors: Hirai Yutaro , Wakiya Takeshi , Yabu Hiroshi
Published: February 2017

Submicron-sized virus-like particles comprising asymmetric PS-b-PtBA diblock copolymer particles having dot patterns on their surface were successfully prepared by a simple solvent evaporation process.
Effect of samarium and vanadium co-doping on structure, ferroelectric and photocatalytic properties of bismuth titanate
Authors: Ramana E. Venkata , Prasad N. V. , Tobaldi David Maria , Zavašnik Janez , Singh M. K. , Hortigüela María Jésus , Seabra M. P. , Prasad G. , Valente M. A.
Published: February 2017

A systematic analysis of the structure, ferroelectricity and photocatalytic activity (PCA) of Sm and V modified Bi4Ti3O12was performed. Highly reproducible gas–solid phase PCA of NOxabatement and improved ferroelectricity were achieved.
Evidence of a forward energy cascade and Kolmogorov self-similarity in submesoscale ocean surface drifter observations
Authors: Poje Andrew C. , Özgökmen Tamay M. , Bogucki Darek J. , Kirwan A. D.
Published: February 2017

Using two-point velocity and position data from the near-simultaneous release of O(100) GPS-tracked surface drifters in the northern Gulf of Mexico, we examine the applicability of classical turbulent scaling laws to upper ocean velocity fields. The dataset allows direct estimates of both velocity structure functions and the temporal evolution of the distribution of particle pair separations. On 100 m-10 km spatial scales, and time scales of order 1-10 days, all metrics of the observed surface fluctuations are consistent with standard Kolmogorov turbulence theory in an energy cascade inertial-range regime. The sign of the third-order structure function is negative and proportional to the separation distance for scales ≲10 km where local, fluctuating Rossby numbers are found to be larger than 0.1. The scale-independent energy dissipation rate, or downscale spectral flux, estimated from Kolmogorov’s 4/5th law in this regime closely matches nearby microscale dissipation measurements in the near-surface. In contrast, similar statistics derived from a like-sized set of synthetic drifters advected by purely geostrophic altimetric AVISO data agree well with Kolmogorov-Kraichnan scaling for 2D turbulence in the forward enstrophy cascade range.
A simplified digital lock-in amplifier for the scanning grating spectrometer
Authors: Wang Jingru , Wang Zhihong , Ji Xufei , Liu Jie , Liu Guangda
Published: February 2017

For the common measurement and control system of a scanning grating spectrometer, the use of an analog lock-in amplifier requires complex circuitry and sophisticated debugging, whereas the use of a digital lock-in amplifier places a high demand on the calculation capability and storage space. In this paper, a simplified digital lock-in amplifier based on averaging the absolute values within a complete period is presented and applied to a scanning grating spectrometer. The simplified digital lock-in amplifier was implemented on a low-cost microcontroller without multipliers, and got rid of the reference signal and specific configuration of the sampling frequency. Two positive zero-crossing detections were used to lock the phase of the measured signal. However, measurement method errors were introduced by the following factors: frequency fluctuation, sampling interval, and integer restriction of the sampling number. The theoretical calculation and experimental results of the signal-to-noise ratio of the proposed measurement method were 2055 and 2403, respectively.
Geminate electron-hole recombination in organic photovoltaic cells. A semi-empirical theory
Authors: Wojcik Mariusz , Nowak Artur , Seki Kazuhiko
Published: February 2017

We propose a semi-empirical theory which describes the geminate electron-hole separation probability in both homogeneous systems and donor-acceptor heterojunction systems applicable in organic photovoltaics. The theory is based on the results of extensive simulation calculations, which were carried out using various lattice models of the medium and different charge-carrier hopping mechanisms, over the parameter ranges typical for organic solar cells. It is found that the electron-hole separation probability can be conveniently described in terms of measurable parameters by a formula whose functional form is derived from the existing recombination theories, and which contains only one empirical parameter. For homogeneous systems, this parameter is determined by the structure of the medium and only weakly depends on the charge-carrier hopping mechanism. In the case of donor-acceptor heterojunction systems, this empirical parameter shows a simple power-law dependence on the product of the dielectric constant and inter-molecular contact distance. We also study the effect of heterojunction structure on the electron-hole separation probability and show that this probability decreases with increasing roughness of the heterojunction. By analyzing the simulation results obtained for systems under the influence of an external electric field, we find that the field effect on the electron-hole separation probability in donor-acceptor heterojunction systems is weaker than in homogeneous systems. We also describe this field effect by a convenient empirical formula.
A tunable electronic beam splitter realized with crossed graphene nanoribbons
Authors: Brandimarte Pedro , Engelund Mads , Papior Nick , Garcia-Lekue Aran , Frederiksen Thomas , Sánchez-Portal Daniel
Published: February 2017

Graphene nanoribbons (GNRs) are promising components in future nanoelectronics due to the large mobility of graphene electrons and their tunable electronic band gap in combination with recent experimental developments of on-surface chemistry strategies for their growth. Here, we explore a prototype 4-terminal semiconducting device formed by two crossed armchair GNRs (AGNRs) using state-of-the-art first-principles transport methods. We analyze in detail the roles of intersection angle, stacking order, inter-GNR separation, GNR width, and finite voltages on the transport characteristics. Interestingly, when the AGNRs intersect at θ=60°, electrons injected from one terminal can be split into two outgoing waves with a tunable ratio around 50% and with almost negligible back-reflection. The split electron wave is found to propagate partly straight across the intersection region in one ribbon and partly in one direction of the other ribbon, i.e., in analogy with an optical beam splitter. Our simulations further identify realistic conditions for which this semiconducting device can act as a mechanically controllable electronic beam splitter with possible applications in carbon-based quantum electronic circuits and electron optics. We rationalize our findings with a simple model suggesting that electronic beam splitters can generally be realized with crossed GNRs.
Effective NOx remediation from a surrogate flue gas using the US NRL Electra electron beam facility
Authors: Petrova Tz. B. , Petrov G. M. , Wolford M. F. , Giuliani J. L. , Ladouceur H. D. , Hegeler F. , Myers M. C. , Sethian J. D.
Published: February 2017

Nitric oxide (NOx) emission is under restrictive federal regulations because of its negative impact on atmosphere, biosphere, and human health. Therefore, its removal has been a subject of extensive research to develop new efficient and cost effective techniques that can be applied on an industrial scale. In this work, we study both experimentally and theoretically an effective removal of NOx pollutants from a surrogate flue gas (SFG) using high power electron beam (e-beam) pulses. SFG is a simulant for exhaust from coal combustion power plants (82% N2, 6% O2, 12% CO2, and ∼100 ppm of NOx). The pulsed electron beam is generated using the United States Naval Research Laboratory Electra facility, which delivers e-beams with energies of ∼500 keV and a power pulse duration of ∼140 ns. During the e-beam irradiation, the energetic electrons generate a non-equilibrium plasma containing chemically active species, which then react with NOx to form harmless substances. A non-equilibrium time-dependent model is developed to describe NOx remediation from SFG. The model combines e-beam deposition rates obtained by solving the electron Boltzmann equation and extensive plasma chemistry modeling, which follows the species on a time scale from sub-nanoseconds to a few seconds. NOx decomposition as a function of electron beam parameters is studied. It is demonstrated experimentally that short (ns) pulses are the most efficient for NOx removal. A sharp reduction of NOx was measured with e-beam power deposition increasing, following the trend predicted by the model, achieving a 20 fold reduction to ∼5 ppm at energy deposition ∼20 J/l.
Dimension from covariance matrices
Authors: Carroll T. L. , Byers J. M.
Published: February 2017

We describe a method to estimate embedding dimension from a time series. This method includes an estimate of the probability that the dimension estimate is valid. Such validity estimates are not common in algorithms for calculating the properties of dynamical systems. The algorithm described here compares the eigenvalues of covariance matrices created from an embedded signal to the eigenvalues for a covariance matrix of a Gaussian random process with the same dimension and number of points. A statistical test gives the probability that the eigenvalues for the embedded signal did not come from the Gaussian random process.
Conservation laws for collisional and turbulent transport processes in toroidal plasmas with large mean flows
Authors: Sugama H. , Nunami M. , Nakata M. , Watanabe T.-H.
Published: February 2017

A novel gyrokinetic formulation is presented by including collisional effects into the Lagrangian variational principle to yield the governing equations for background and turbulent electromagnetic fields and gyrocenter distribution functions, which can simultaneously describe classical, neoclassical, and turbulent transport processes in toroidal plasmas with large toroidal flows on the order of the ion thermal velocity. Noether's theorem modified for collisional systems and the collision operator given in terms of Poisson brackets are applied to derivation of the particle, energy, and toroidal momentum balance equations in the conservative forms, which are desirable properties for long-time global transport simulation.
Breaking of dynamical adiabaticity in direct laser acceleration of electrons
Authors: Robinson A. P. L. , Arefiev A. V.
Published: February 2017

The interaction of an electron oscillating in an ion channel and irradiated by a plane electromagnetic wave is considered. It is shown that the interaction qualitatively changes with the increase of electron energy, as the oscillations across the channel become relativistic. The “square-wave-like” profile of the transverse velocity in the relativistic case enables breaking of the adiabaticity that precludes electron energy retention in the non-relativistic case. For an electron with a relativistic factor γ0, the adiabaticity breaks if ωL/ωp0≪γ0. Under these conditions, the kinetic energy acquired by the electron is retained once the interaction with the laser field ceases. This mechanism notably enables electron heating in regimes that do not require a resonant interaction between the initially oscillating electron and the laser electric field.
Generation of trains of ultrashort microwave pulses by two coupled helical gyro-TWTs operating in regimes of amplification and nonlinear absorption
Authors: Ginzburg N. S. , Denisov G. G. , Vilkov M. N. , Sergeev A. S. , Zotova I. V. , Samsonov S. V. , Mishakin S. V.
Published: February 2017

Based on a time-domain model, we demonstrate that a periodic train of powerful ultrashort microwave pulses can be generated in an electron oscillator consisting of two coupled helically corrugated gyrotron travelling wave tubes (gyro-TWTs) operating in regimes of amplification and saturable absorption, respectively. The mechanism of pulse formation in such an oscillator is based on the effect of passive mode-locking widely used in laser physics. Saturable absorption can be implemented in a gyro-TWT in the Kompfner dip regime by a proper matching of the guiding magnetic field. According to simulations with the parameters of an experimentally realized Ka-band gyro-TWT, the peak power of generated pulses with a duration of 200 ps can achieve 400 kW.
Fractal characterization and wettability of ion treated silicon surfaces
Authors: Yadav R. P. , Kumar Tanuj , Baranwal V. , Vandana  , Kumar Manvendra , Priya P. K. , Pandey S. N. , Mittal A. K.
Published: February 2017

Fractal characterization of surface morphology can be useful as a tool for tailoring the wetting properties of solid surfaces. In this work, rippled surfaces of Si (100) are grown using 200 keV Ar+ ion beam irradiation at different ion doses. Relationship between fractal and wetting properties of these surfaces are explored. The height-height correlation function extracted from atomic force microscopic images, demonstrates an increase in roughness exponent with an increase in ion doses. A steep variation in contact angle values is found for low fractal dimensions. Roughness exponent and fractal dimensions are found correlated with the static water contact angle measurement. It is observed that after a crossover of the roughness exponent, the surface morphology has a rippled structure. Larger values of interface width indicate the larger ripples on the surface. The contact angle of water drops on such surfaces is observed to be lowest. Autocorrelation function is used for the measurement of ripple wavelength.
Relativistic surface plasmon enhanced harmonic generation from gratings
Authors: Fedeli L. , Sgattoni A. , Cantono G. , Macchi A.
Published: February 2017

The role of relativistic surface plasmons (SPs) in high order harmonic emission from laser-irradiated grating targets has been investigated by means of particle-in-cell simulations. SP excitation drives a strong enhancement of the intensity of harmonics, particularly in the direction close to the surface tangent. The SP-driven enhancement overlaps with the angular separation of harmonics generated by the grating, which is beneficial for applications requiring monochromatic extreme ultraviolet (XUV) pulses.
Experimental study of relationship between interfacial electroadhesive force and applied voltage for different substrate materials
Authors: Guo J. , Bamber T. , Petzing J. , Justham L. , Jackson M.
Published: February 2017

An experimental investigation into the relationship between the interfacial electroadhesive force and applied voltage up to 20 kV has been presented. Normal electroadhesive forces have been obtained between a double-electrode electroadhesive pad and three optically flat and different substrate materials: glass, acrylic, and polycarbonate. The results have shown that not all substrate materials are good for the generation of electroadhesive forces. Only 15.7 Pa has been obtained between the pad and the polycarbonate substrate under 20 kV, whereas 46.3 Pa and 123.4 Pa have been obtained on the acrylic and glass substrate, respectively. Based on the experimental data, empirical models, with an adjusted R-square value above 0.995 in all cases, have been obtained for the three substrates. However, it has not been possible to develop a general empirical model which is suitable for all substrates. This further indicates the need for a large quantity of experimental data to obtain robust empirical models for different substrate materials in order to reliably use electroadhesive technologies for material handling applications.
Current-driven skyrmion motion along disordered magnetic tracks
Authors: Raposo Victor , Luis Martinez Ricardo Francisco , Martinez Eduardo
Published: February 2017

The motion of skyrmions along ferromagnetic strips driven by current pulses is theoretically analyzed by means of micromagnetic simulations. Analytical expressions describing the skyrmion dynamics during and after the current pulse are obtained from an extended rigid skyrmion model, and its predictions are compared with full micromagnetic simulations for perfect samples with a remarkable agreement. The dynamics along realistic samples with random disorder is also studied by both models. Our analysis describes the relevant ingredients behind the current-driven skyrmion dynamics, and it is expected to be useful to understand recent and future experimental.
Dehydrogenation of goethite in Earth’s deep lower mantle
Authors: Hu Qingyang , Kim Duck Young , Liu Jin , Meng Yue , Yang Liuxiang , Zhang Dongzhou , Mao Wendy L. , Mao Ho-kwang
Published: February 2017

Significance

We found at high pressure–temperature (
P-T
) that the goethite FeO
2
H transforms to P-phase FeO
2
via a two-step dehydrogenation process. First it releases some hydrogen to form P-phase FeO
2
H
x
, and then it continuously releases the remaining hydrogen through prolonged heating. This work provides an important example that the dehydration reaction changes to dehydrogenation of FeO
2
H at the lower mantle conditions and the cycles of hydrogen and water become separated.
Blockade to pathological remodeling of infarcted heart tissue using a porcupine antagonist
Authors: Moon Jesung , Zhou Huanyu , Zhang Li-shu , Tan Wei , Liu Ying , Zhang Shanrong , Morlock Lorraine K. , Bao Xiaoping , Palecek Sean P. , Feng Jian Q. , Williams Noelle S. , Amatruda James F. , Olson Eric N. , Bassel-Duby Rhonda , Lum Lawrence
Published: February 2017

Significance

A significant factor influencing longevity and quality of life in heart attack survivors is the extent of adverse tissue remodeling in injured heart tissue, which impedes mechanical function and accelerates the progression of heart failure. Despite the general consensus that mitigating fibrotic responses would delay the onset of heart failure and improve heart function after a heart attack, there currently are no agents that directly target this pathological process available for heart disease management. Here we demonstrate that chemical inhibition of the Wnt acyltransferase Porcupine results in improvements in heart function following myocardial infarction in mice. Our findings advocate for the development of Porcupine inhibitors as proregenerative agents in the heart and other tissues.
EBI3 regulates the NK cell response to mouse cytomegalovirus infection
Authors: Jensen Helle , Chen Shih-Yu , Folkersen Lasse , Nolan Garry P. , Lanier Lewis L.
Published: February 2017

Significance

Natural killer (NK) cells play a key role in early viral control of CMV replication and in shaping the adaptive immune response. Despite an early control, CMV persists by exploiting host immune inhibitory pathways. Here, we describe a previously unidentified pathway wherein the cytokine Epstein–Barr virus-induced 3 (EBI3) affects the establishment of mouse cytomegalovirus (MCMV) latency. We also show that both human and mouse NK cells express EBI3 and the EBI3 receptor, gp130, after stimulation. MCMV-infected EBI3-deficient mice showed decreased IL-10 production by NK cells, increased dendritic cell maturation and activation of CD8+T cells, and significantly diminished viral loads in the salivary glands and oral lavage. Together, our results provide insight into how CMV establishes latent infection.
Identification of the active protein in rice bran protein having an inhibitory activity of cholesterol micellar solubility
Authors: Wang Jilite , Shimada Masaya , Nagaoka Satoshi
Published: February 2017

In our previous study, rice bran protein (RBP) inhibited cholesterol micellar solubility in vitro and decreased serum cholesterol level in rats. In the present study, RBP was separated and purified by size-exclusion chromatography and reversed-phase chromatography. The active protein of RBP related to cholesterol micellar solubility was identified as lectin and non-specific lipid-transfer protein 1 using MALDI-TOF mass spectrometry analysis.
Optical Readout Method for Solid State Dosemeters
Authors: McDonald J.C. , Eichner F.N. , Stahl K.A. , Miller S.D.
Published: February 2017

The readout of solid state dosemeters is usually accomplished by heating to produce thermoluminescence. This technique has several disadvantages including stressing the dosemeter crystals, melting Teflon enclosures, and destroying the thin dosemeters designed for beta particle measurements. An optical readout method is being developed to avoid these difficulties. Standard dosemeters were irradiated to a dose of approximately 0.02 Sv with 137Cs gamma rays. The dosemeters were then irradiated with light produced by a high intensity xenon lamp. Various wavelength bands, from the ultraviolet through the visible and to the near infrared, were used. The degree of trap emptying was found to be proportional to the total optical power incident. With the intensities used in the preliminary experiments, over 90% trap emptying was achieved. This new technique will prove useful for dosemeters that are encased in plastic for automatic processing. The details of this optical readout method, along with some possible applications in neutron and beta dosimetry are described.
Natural Radioactivity in the Principal Constituents of French River Ecosystems
Authors: Descamps B. , Foulquier L.
Published: February 2017

The study is based on data covering the water, sediments, plants and fish sampled over a 20-year period at 15 stations along French rivers. Three geographic zones were investigated: one containing a uranium mining complex (Zone 1), another including five major rivers along which nuclear power plants are sited (Zone II) and a third unaffected by nuclear activities (Zone III). Natural radioactivity basically involves 238U, 226Ra and 210Pb in the uranium series, 232Th from the thorium series, 40K and 7Be. The natural radioactivity in Zone II is not different from Zone III, and is thus unaffected by waste discharges from nuclear power plants. The most abundant radionuclide is 40K, while the other nuclides are often found in trace amounts near the detection threshold of the analysis method used (Ge gamma spectrometry with a 15-hour counting period). The 226Ra and 238U concentrations observed in Zone I are at least an order of magnitude higher than in the other two zones due to authorised waste discharges from the Lodève mining complex, but only a small stream is affected. The measured 226Ra concentrations would result in an annual whole body committed dose equivalent attributable to a 200 g weekly fish consumption from this stream of 4.4 x 10-5 Sv.y-1, or 0.86% of the maximum permissible dose (5 mSv).
Microscopic Spatial Inhomogeneity of Radiopharmaceutical Deposition in Mammalian Tissues: Dosimetry at the Cellular Level and Comparison with Conventional Dosimetry
Authors: Makrigiorgos G.M. , Baranowska-Kortylewicz J. , Van den Abbeele A.D. , Ito S. , Vinter D.W. , Adelstein S.J. , Kassis A.I.
Published: February 2017

An experimental and a theoretical examination of the validity of the dosimetric assumptions of conventional internal dosimetry at the cellular level has been performed. Conventional dosimetry assumes a homogeneous distribution of radioactivity over the organ of interest. Experiments were carried out to derive in a quantitative manner the distribution of intravenously injected 99Tcm-labelled albumin colloid (Microlite) in mouse spleen and lung. Using tritium autoradiography, Microlite was found to concentrate highly and nearly exclusively in the macrophages of the reticloendothelial system in the organs examined. These cells comprise about 1 to 2% of the spleen volume and about 0.1 to 1% of the lung volume. The intracellular-to-extracellular radionuclide concentration was measured using a quantitative videodensitometer, and the fraction of the mouse organ volume occupied by the radiolabelled macrophages was derived from enlarged autoradiographs. The data were supplied as input to a recently developed model of dosimetry for individual cells in a multicellular cluster (representing an 'organ') which was assumed to contain 99Tcm-labelled Microlite. The program accounts for differences in intracellular and extracellular concentration of radioactivity and for selective uptake of the radionuclide by specific cells in the cluster (in the present case, macrophages): finally it compares the dose estimates for the labelled cells to the ones predicted assuming a homogeneous deposition of 99Tcm-labelled Microlite over the whole cellular cluster volume (conventional approach). It is demonstrated that conventional dosimetry under-estimates the dose received by the 99Tcm-Microlite labelled cells by factors of 10 to 50 and 15 to 60 for human spleen and lung, respectively. The implications for both the diagnostic and the therapeutic use of radiopharmaceuticals is discussed.
Kinetic Analysis of Al2O3:Mg,Y Glow Curves
Authors: Peto Á.
Published: February 2017

The thermoluminescence of differently doped Al2O3:Mg, Y phosphors was measured in the 6.5 Gy - 6.5 kGy dose range. The glow curves were deconvoluted using a computerised least squares fitting method. The results show at least four different peaks, contributing to the thermoluminescence of Al2O3:Mg,Y in the 300-800 K temperature region. Most of the peaks are second order, indicating strong retrapping of the thermally untrapped charge carriers. Trap parameters for the deconvoluted glow peaks are given.
The Optical Dating of Sediments Using Quartz
Authors: Smith B.W. , Rhodes E.J. , Stokes S. , Spooner N.A.
Published: February 2017

The technique of optical dating has been applied to quartz extracts from geological and archaeological sediments. The method involves measurement of the luminescence emitted when the quartz is optically stimulated, and yields the time which has elapsed since the sediments were last deposited. The luminescence originates from charge in traps associated with the 325 oC TL peak, and the kinetics of charge movement have been carefully considered in the formulation of the dating procedure. A cross-comparison of the optical dates with alternative dating evidence is presented, giving strong indication that the technique is reliable and can be applied to both wind- and water-borne sediments in the age range one thousand to one hundred thousand years. In some circumstances younger dates can be obtained.
Dose Algorithms for Personal Thermoluminescence Dosimetry
Authors: Moscovitch (INVITED) M.
Published: February 2017

Dose algorithms are used in thermoluminescence personnel dosimetry for the interpretation of the dosemeter response in terms of a risk related quantity, i.e. dose equivalent. Significant advances have been made in recent years to improve calibration methodology and dose calculation algorithms. This process was accelerated in the United States by the need to meet mandatory accreditation requirements. A family of empirical algorithms was recently developed, which are based on parametrisation of the response of the dosemeter to various pure and mixed fields. The empirical algorithms are especially effective in mixed low energy photon and beta fields and are capable of identifying the radiation field types and applying appropriate energy correction factors. These algorithms have been in routine use for several years in large scale personnel dosimetry programmes. The accuracy of the dose estimation has been demonstrated in several independent official blind tests and has been shown to meet the requirements of the US Department of Energy Laboratory Accreditation Programme. Experience gained and lessons learned during this period of testing and practical use are discussed.