bluuebunny/crossref_metadata_2025 huggingface dataset:
Superconductor Electronics: Status and Outlook
Authors: Braginski Alex I.
Published: November 2018

Superconductor electronics combines passive and active superconducting components and sometimes normal resistors into functional circuits and systems that also include room-temperature electronics for amplification, power sources, necessary controls, etc., usually computer operated. Furthermore, complete systems include magnetic and electromagnetic shielding, cryogenic enclosures, and increasingly a cryocooler in self-contained units. Components or devices of low or high critical temperature superconductors include inductances (coils), passive transmission lines, resonators, antennae, filters, as well as active elements: Josephson junctions, Josephson oscillators, and superconducting quantum interference devices. Of multiple demonstrated applications, mostly but not only in science and metrology, currently most successful are voltage standards, astronomy detectors and large telescope cameras, instruments for material characterization, and magnetometers for geomagnetic prospecting. Major current efforts concentrate on energy-efficient high-end computing and quantum computing. The outcomes of these efforts are likely to be known in the course of the following decade.
Speeding up non-Markovian first-passage percolation with a few extra edges
Authors: Medvedev Alexey , Pete Gábor
Published: November 2018

One model of real-life spreading processes is that of first-passage percolation (also called the SI model) on random graphs. Social interactions often follow bursty patterns, which are usually modelled with independent and identically distributed heavy-tailed passage times on edges. On the other hand, random graphs are often locally tree-like, and spreading on trees with leaves might be very slow due to bottleneck edges with huge passage times. Here we consider the SI model with passage times following a power-law distribution ℙ(ξ>t)∼t-α with infinite mean. For any finite connected graph G with a root s, we find the largest number of vertices κ(G,s) that are infected in finite expected time, and prove that for every k≤κ(G,s), the expected time to infect k vertices is at most O(k1/α). Then we show that adding a single edge from s to a random vertex in a random tree 𝒯 typically increases κ(𝒯,s) from a bounded variable to a fraction of the size of 𝒯, thus severely accelerating the process. We examine this acceleration effect on some natural models of random graphs: critical Galton--Watson trees conditioned to be large, uniform spanning trees of the complete graph, and on the largest cluster of near-critical Erdős‒Rényi graphs. In particular, at the upper end of the critical window, the process is already much faster than exactly at criticality.
Disparity of clustering coefficients in the Holme‒Kim network model
Authors: Oliveira R. I. , Ribeiro R. , Sanchis R.
Published: November 2018

The Holme‒Kim random graph process is a variant of the Barabási‒Álbert scale-free graph that was designed to exhibit clustering. In this paper we show that whether the model does indeed exhibit clustering depends on how we define the clustering coefficient. In fact, we find that the local clustering coefficient typically remains positive whereas global clustering tends to 0 at a slow rate. These and other results are proven via martingale techniques, such as Freedman's concentration inequality combined with a bootstrapping argument.
Large deviations for randomly connected neural networks: II. State-dependent interactions
Authors: Cabana Tanguy , Touboul Jonathan D.
Published: November 2018

We continue the analysis of large deviations for randomly connected neural networks used as models of the brain. The originality of the model relies on the fact that the directed impact of one particle onto another depends on the state of both particles, and they have random Gaussian amplitude with mean and variance scaling as the inverse of the network size. Similarly to the spatially extended case (see Cabana and Touboul (2018)), we show that under sufficient regularity assumptions, the empirical measure satisfies a large deviations principle with a good rate function achieving its minimum at a unique probability measure, implying, in particular, its convergence in both averaged and quenched cases, as well as a propagation of a chaos property (in the averaged case only). The class of model we consider notably includes a stochastic version of the Kuramoto model with random connections.
Spatiotemporal Patterns and Mechanisms of Chinese Tallowtree (Triadica sebifera) Spread along Edge Habitat in a Coastal Landscape, Mississippi, USA
Authors: Fan Zhaofei , Yang Shaoyang , Liu Xia
Published: November 2018

Chinese tallowtree [Triadica sebifera(L.) Small] has reached unprecedented prevalence in coastal landscapes in the Gulf of Mexico, especially along edge habitat with low competition and abundant resource (e.g., light) availability. This study investigated the spatiotemporal patterns and mechanisms ofT. sebiferaspread along roadways and fire lines.Triadica sebiferaindividuals and landscape and community features were surveyed in equally spaced, spatially mapped plots. AllT. sebiferaindividuals were felled to determine tree age and status (seed trees or non-seed bearing trees), andT. sebiferaseed and seedling (≤2 yr old) densities and community and landscape features (over- and understory conditions, distance to seed trees) were measured. A zero-inflated negative binomial model was used to evaluate factors affectingT. sebiferaseed dispersal and seedling recruitment contributing to the observed spatiotemporal patterns. Introduced into the Grand Bay National Wildlife Refuge around 30 yr ago,T. sebiferatrees distribute in clustered patterns along roadways and fire lines and exhibit an exponential growth in density. HighT. sebiferaseed and seedling densities mainly occurred in sites that are ≤250 m from seed trees or have sparse overstory and high understory grass/herb coverage. With respect to the avian seed dispersal mechanism, the spatiotemporal patterns ofT. sebiferaspread along roadways and fire lines could be simply characterized by using landscape and community features that influence avian behaviors, including distance to seed trees, overstory tree density, and ground grass/herb coverage.
VLADIMIR JABOTINSKY AND POPULATION TRANSFERS BETWEEN EASTERN EUROPE AND PALESTINE
Authors: RUBIN GIL S.
Published: November 2018

Drawing on new archival findings, this article argues that shortly after the outbreak of the Second World War, Vladimir Jabotinsky, founder and leader of the right-wing Revisionist Zionist movement, had begun to advocate for the transfer of the Arab population from Palestine – an aspect of his thought previously unknown. Jabotinsky's support for population transfers runs counter to his lifelong political thought. Prior to the war, Jabotinsky was a staunch advocate of minority rights for Jews in Europe and for extensive autonomy for the Arab population in Palestine. This article argues that Jabotinsky's shift was a product of the war. Jabotinsky believed that millions of Jewish refugees would be prevented from returning to their pre-war homes in eastern Europe and would immigrateen masseto Palestine; to resettle these refugees, the Arab population, he argued, ‘would have to make room’. Attentively following debates on population transfers in Europe, Jabotinsky concluded that the era of minority rights had come to an end and envisioned an increasingly ethno-national Jewish state. By highlighting the eastern Europe context in Jabotinsky's thought, this article emphasizes the importance of studying the history of Zionism alongside the transformation of the nation-state in eastern Europe in the 1940s.
The Reinstatement Effect in Human Predictive Learning: Contextual Modulation and the Impact of Extinction Reminders
Authors: Gámez A. Matías , Bernal-Gamboa Rodolfo
Published: November 2018

One of the most relevant phenomena both from a theoretical and clinical perspective is extinction. In particular, several researchers are interested in the response recovery effects from extinction. Reinstatement is an effect that has been proposed as a laboratory model to study relapse from extinction-based therapeutic treatments. We designed two experiments with humans to evaluate the reinstatement effect in a predictive learning task. In both experiments, participants learned a specific relationship between two cues (X and Y) and two outcomes (O1 and O2) during the first phase. Throughout extinction, both cues were presented without outcomes. After an exposure to the original outcomes, reinstatement of the first-learned information was observed during testing in both experiments. However, we found that the reinstatement effect was contextual modulated (Experiment 1; ηp2= .78, 90% CI [.48, .86],p< .0001). Furthermore, in Experiment 2 we showed a reduction of reinstatement when an extinction reminder was used ηp2= .45, 90% CI [.07, .65],p =.012. Theoretical implications are discussed, and some potential uses are mentioned.
Response of Sweetpotato Cultivars to Linuron Rate and Application Time
Authors: Beam Shawn C. , Jennings Katherine M. , Chaudhari Sushila , Monks David W. , Schultheis Jonathan R. , Waldschmidt Mathew
Published: November 2018

Field studies were conducted in 2015 and 2016 in North Carolina to determine the response of ‘Covington’ and ‘Murasaki-29’ sweetpotato cultivars to four rates of linuron (420, 560, 840, and 1,120 g ai ha–1) alone or withS-metolachlor (803 g ai ha–1) applied 7 or 14 d after transplanting (DAP). Injury (chlorosis/necrosis and stunting) to both cultivars was greater when linuron was applied withS-metolachlor as compared to linuron applied alone. Herbicide application at 14 DAP caused greater injury (chlorosis/necrosis and stunting) to both cultivars than when applied at 7 DAP. At 4 wk after treatment (WAT), stunting of Covington and Murasaki-29 (hereafter Murasaki) from linuron at 420 to 1,120 g ha–1increased from 27% to 50% and 25% to 53%, respectively. At 7 or 8 WAT, crop stunting of 8% or less and 0% was observed in Covington and Murasaki, respectively, regardless of application rate and timing. Murasaki root yields were similar in the linuron alone or withS-metolachlor treatments, and were lower than the nontreated check. In 2016, no. 1 and marketable sweetpotato yields of Covington were similar for the nontreated check, linuron alone, or linuron plusS-metolachlor treatments, but not in 2015. Decreases in no. 1 and marketable root yields were observed when herbicides were applied 14 DAP compared to 7 DAP for Covington in 2015 and for Murasaki in both years. No. 1 and marketable yields of Covington were similar for 420 to 1,120 g ha–1linuron and nontreated check except marketable root yields in 2015. No. 1 and marketable sweetpotato yields of Murasaki decreased as application rates increased.
Developmental changes of cortical white–gray contrast as predictors of autism diagnosis and severity
Authors: Bezgin Gleb , Lewis John D. , Evans Alan C.
Published: November 2018

Recent studies suggest that both cortical gray and white-matter microstructural characteristics are distinct for subjects with autism. There is a lack of evidence regarding how these characteristics change in a developmental context. We analysed a longitudinal/cross-sectional dataset of 402 magnetic resonance imaging (MRI) scans (171 subjects with autism and 231 with typical development) from the Autism Brain Imaging Data Exchange, cohorts I–II (ABIDE-I-II). In the longitudinal sample, we computed the rate of change in the white–gray contrast, a measure which has been related to age and cognitive performance, at the boundary of the cerebral cortex. Then, we devised an analogous metric for the cross-sectional sample of the ABIDE dataset to measure age-related differences in cortical contrast. Further, we developed a probabilistic model to predict the diagnostic group in the longitudinal sample of the cortical contrast change data, using results obtained from the cross-sectional sample. In both subsets, we observed a similar overall pattern of greater decrease within the autistic population in intensity contrast for most cortical regions (81%), with occasional increases, mostly in primary sensory regions. This pattern correlated well with raw and calibrated behavioural scores. The prediction results show 76% accuracy for the whole-cortex diagnostic prediction and 86% accuracy in prediction using the motor system alone. Our results support a contrast change analysis strategy that appears sensitive in predicting diagnostic outcome and symptom severity in autism spectrum disorder, and is readily extensible to other MRI-based studies of neurodevelopmental cohorts.
NMT1 inhibition modulates breast cancer progression through stress-triggered JNK pathway
Authors: Deng Lu , Gao Xinlei , Liu Bingjie , He Xueyan , Xu Jiahui , Qiang Jiankun , Wu Qingfa , Liu Suling
Published: November 2018

Myristoylation is one of key post-translational modifications that involved in signal transduction, cellular transformation and tumorigenesis. Increasing evidence demonstrates that targeting myristoylation might provide a new strategy for eliminating cancers. However, the underlying mechanisms are still yielded unclear. In this study, we demonstrated that genetic inhibition of N-myristoyltransferase NMT1 suppressed initiation, proliferation and invasion of breast cancer cells either in vitro or in vivo. We identified ROS could negatively regulate NMT1 expression and NMT1 knockdown conversely promoted oxidative stress, which formed a feedback loop. Furthermore, inhibition of NMT1 caused degraded proteins increase and ER stress, which cross-talked with mitochondria to produce more ROS. And both of oxidative stress and ER stress could activate JNK pathway, leading to autophagy which abrogated breast cancer progression especially triple-negative breast cancer (TNBC). These studies provide a preclinical proof of concept for targeting NMT1 as a strategy to treat breast cancer.
Air quality co-benefits for human health and agriculture counterbalance costs to meet Paris Agreement pledges
Authors: Vandyck Toon , Keramidas Kimon , Kitous Alban , Spadaro Joseph V. , Van Dingenen Rita , Holland Mike , Saveyn Bert
Published: November 2018

Local air quality co-benefits can provide complementary support for ambitious climate action and can enable progress on related Sustainable Development Goals. Here we show that the transformation of the energy system implied by the emission reduction pledges brought forward in the context of the Paris Agreement on climate change (Nationally Determined Contributions or NDCs) substantially reduces local air pollution across the globe. The NDCs could avoid between 71 and 99 thousand premature deaths annually in 2030 compared to a reference case, depending on the stringency of direct air pollution controls. A more ambitious 2 °C-compatible pathway raises the number of avoided premature deaths from air pollution to 178–346 thousand annually in 2030, and up to 0.7–1.5 million in the year 2050. Air quality co-benefits on morbidity, mortality, and agriculture could globally offset the costs of climate policy. An integrated policy perspective is needed to maximise benefits for climate and health.
An oviduct-on-a-chip provides an enhanced in vitro environment for zygote genome reprogramming
Authors: Ferraz Marcia A. M. M. , Rho Hoon Suk , Hemerich Daiane , Henning Heiko H. W. , van Tol Helena T. A. , Hölker Michael , Besenfelder Urban , Mokry Michal , Vos Peter L. A. M. , Stout Tom A. E. , Le Gac Séverine , Gadella Bart M.
Published: November 2018

Worldwide over 5 million children have been conceived using assisted reproductive technology, and research has concentrated on increasing the likelihood of ongoing pregnancy. However, studies using animal models have indicated undesirable effects of in vitro embryo culture on offspring development and health. In vivo, the oviduct hosts a period in which the early embryo undergoes complete reprogramming of its (epi)genome in preparation for the reacquisition of (epi)genetic marks. We designed an oviduct-on-a-chip platform to better investigate the mechanisms related to (epi)genetic reprogramming and the degree to which they differ between in vitro and in vivo embryos. The device supports more physiological (in vivo-like) zygote genetic reprogramming than conventional IVF. This approach will be instrumental in identifying and investigating factors critical to fertilization and pre-implantation development, which could improve the quality and (epi)genetic integrity of IVF zygotes with likely relevance for early embryonic and later fetal development.
Encryption and steganography of synthetic gene circuits
Authors: Purcell Oliver , Wang Jerry , Siuti Piro , Lu Timothy K.
Published: November 2018

Synthetic biologists use artificial gene circuits to control and engineer living cells. As engineered cells become increasingly commercialized, it will be desirable to protect the intellectual property contained in these circuits. Here, we introduce strategies to hide the design of synthetic gene circuits, making it more difficult for an unauthorized third party to determine circuit structure and function. We present two different approaches: the first uses encryption by overlapping uni-directional recombinase sites to scramble circuit topology and the second uses steganography by adding genes and interconnections to obscure circuit topology. We also discuss a third approach: to use synthetic genetic codes to mask the function of synthetic circuits. For each approach, we discuss relative strengths, weaknesses, and practicality of implementation, with the goal to inspire further research into this important and emerging area.
Microwave emission from superconducting vortices in Mo/Si superlattices
Authors: Dobrovolskiy O. V. , Bevz V. M. , Mikhailov M. Yu. , Yuzephovich O. I. , Shklovskij V. A. , Vovk R. V. , Tsindlekht M. I. , Sachser R. , Huth M.
Published: November 2018

Most of superconductors in a magnetic field are penetrated by a lattice of quantized flux vortices. In the presence of a transport current causing the vortices to cross sample edges, emission of electromagnetic waves is expected due to the continuity of tangential components of the fields at the surface. Yet, such a radiation has not been observed so far due to low radiated power levels and lacking coherence in the vortex motion. Here, we clearly evidence the emission of electromagnetic waves from vortices crossing the layers of a superconductor/insulator Mo/Si superlattice. The emission spectra consist of narrow harmonically related peaks which can be finely tuned in the GHz range by the dc bias current and, coarsely, by the in-plane magnetic field value. Our findings show that superconductor/insulator superlattices can act as dc-tunable microwave generators bridging the frequency gap between conventional radiofrequency oscillators and (sub-)terahertz generators relying upon the Josephson effect.
Coral-associated bacteria demonstrate phylosymbiosis and cophylogeny
Authors: Pollock F. Joseph , McMinds Ryan , Smith Styles , Bourne David G. , Willis Bette L. , Medina Mónica , Thurber Rebecca Vega , Zaneveld Jesse R.
Published: November 2018

Scleractinian corals’ microbial symbionts influence host health, yet how coral microbiomes assembled over evolution is not well understood. We survey bacterial and archaeal communities in phylogenetically diverse Australian corals representing more than 425 million years of diversification. We show that coral microbiomes are anatomically compartmentalized in both modern microbial ecology and evolutionary assembly. Coral mucus, tissue, and skeleton microbiomes differ in microbial community composition, richness, and response to host vs. environmental drivers. We also find evidence of coral-microbe phylosymbiosis, in which coral microbiome composition and richness reflect coral phylogeny. Surprisingly, the coral skeleton represents the most biodiverse coral microbiome, and also shows the strongest evidence of phylosymbiosis. Interactions between bacterial and coral phylogeny significantly influence the abundance of four groups of bacteria–including Endozoicomonas-like bacteria, which divide into host-generalist and host-specific subclades. Together these results trace microbial symbiosis across anatomy during the evolution of a basal animal lineage.
Deep-subwavelength control of acoustic waves in an ultra-compact metasurface lens
Authors: Chen Jian , Xiao Jing , Lisevych Danylo , Shakouri Amir , Fan Zheng
Published: November 2018

Space-coiling acoustic metasurfaces have been largely exploited and shown their outstanding wave manipulation capacity. However, they are complex in realization and cannot directly manipulate acoustic near-fields by controlling the effective path length. Here, we propose a comprehensive paradigm for acoustic metasurfaces to extend the wave manipulations to both far- and near-fields and markedly reduce the implementation complexity with a simple structure, which consists of an array of deep-subwavelength-spaced slits perforated in a thin plate. A semi-analytical approach for such a design is established using a microscopic coupled-wave model, which reveals that the acoustic diffractive pattern at every slit exit is the sum of the initial transmission and the secondary scatterings of the coupled fields from other slits. For proof-of-concept, we examine two metasurface lenses for sound focusing within and beyond the diffraction limit. This work provides a feasible strategy for creating ultra-compact acoustic components with versatile potentials.
Author Correction: Expression-based drug screening of neural progenitor cells from individuals with schizophrenia
Authors: Readhead Benjamin , Hartley Brigham J. , Eastwood Brian J. , Collier David A. , Evans David , Farias Richard , He Ching , Hoffman Gabriel , Sklar Pamela , Dudley Joel T. , Schadt Eric E. , Savić Radoslav , Brennand Kristen J.
Published: November 2018

In the originally published version of this Article, the affiliation details for Eric E. Schadt and Radoslav Savic incorrectly omitted ‘Sema4, a Mount Sinai venture, Stamford, Connecticut, USA’. This has been corrected in both the PDF and HTML versions of the Article.
Visible light-promoted CO2 fixation with imines to synthesize diaryl α-amino acids
Authors: Fan Xinyuan , Gong Xu , Ma Mengyue , Wang Rui , Walsh Patrick J.
Published: November 2018

Light-mediated transformations with CO2 have recently attracted great attention, with the focus on CO2 incorporation into C–C double and triple bonds, organohalides and amines. Herein is demonstrated visible light -mediated umpolung imine reactivity capable of engaging CO2 to afford α-amino acid derivatives. By employing benzophenone ketimine derivatives, CO2 fixation by hydrocarboxylation of C=N double bonds is achieved. Good to excellent yields of a broad range of α,α–disubstituted α-amino acid derivatives are obtained under mild conditions (rt, atmospheric pressure of CO2, visible light). A procedure that avoids tedious chromatographic purification and uses sustainable sunlight is developed to highlight the simplicity of this method.
Machine learning analysis of extreme events in optical fibre modulation instability
Authors: Närhi Mikko , Salmela Lauri , Toivonen Juha , Billet Cyril , Dudley John M. , Genty Goëry
Published: November 2018

A central research area in nonlinear science is the study of instabilities that drive extreme events. Unfortunately, techniques for measuring such phenomena often provide only partial characterisation. For example, real-time studies of instabilities in nonlinear optics frequently use only spectral data, limiting knowledge of associated temporal properties. Here, we show how machine learning can overcome this restriction to study time-domain properties of optical fibre modulation instability based only on spectral intensity measurements. Specifically, a supervised neural network is trained to correlate the spectral and temporal properties of modulation instability using simulations, and then applied to analyse high dynamic range experimental spectra to yield the probability distribution for the highest temporal peaks in the instability field. We also use unsupervised learning to classify noisy modulation instability spectra into subsets associated with distinct temporal dynamic structures. These results open novel perspectives in all systems exhibiting instability where direct time-domain observations are difficult.
Frequency-dependent decoupling of domain-wall motion and lattice strain in bismuth ferrite
Authors: Liu Lisha , Rojac Tadej , Damjanovic Dragan , Di Michiel Marco , Daniels John
Published: November 2018

Dynamics of domain walls are among the main features that control strain mechanisms in ferroic materials. Here, we demonstrate that the domain-wall-controlled piezoelectric behaviour in multiferroic BiFeO3 is distinct from that reported in classical ferroelectrics. In situ X-ray diffraction was used to separate the electric-field-induced lattice strain and strain due to displacements of non-180° domain walls in polycrystalline BiFeO3 over a wide frequency range. These piezoelectric strain mechanisms have opposing trends as a function of frequency. The lattice strain increases with increasing frequency, showing negative piezoelectric phase angle (i.e., strain leads the electric field), an unusual feature so far demonstrated only in the total macroscopic piezoelectric response. Domain-wall motion exhibits the opposite behaviour, it decreases in magnitude with increasing frequency, showing more common positive piezoelectric phase angle (i.e., strain lags behind the electric field). Charge redistribution at conducting domain walls, oriented differently in different grain families, is demonstrated to be the cause.
Tunneling time probed by quantum shot noise
Authors: Février Pierre , Gabelli Julien
Published: November 2018

In typical metallic tunnel junctions, the tunneling events occur on a femtosecond timescale. An estimation of this time requires current measurements at optical frequencies and remains challenging. However, it has been known for more than 40 years that as soon as the bias voltage exceeds one volt, the junction emits infrared radiation as an electrically driven optical antenna. We demonstrate here that the photon emission results from the fluctuations of the current inside the tunneling barrier. Photon detection is then equivalent to a measurement of the current fluctuations at optical frequencies, allowing to probe the tunneling time. Based on this idea, we perform optical spectroscopy and electronic current fluctuation measurements in the far from equilibrium regime. Our experimental data are in very good agreement with theoretical predictions based on the Landauer Büttiker scattering formalism. By combining the optics and the electronics, we directly estimate the so-called traversal time.
Author Correction: Variants in exons 5 and 6 of ACTB cause syndromic thrombocytopenia
Authors: Latham Sharissa L. , Ehmke Nadja , Reinke Patrick Y. A. , Taft Manuel H. , Eicke Dorothee , Reindl Theresia , Stenzel Werner , Lyons Michael J. , Friez Michael J. , Lee Jennifer A. , Hecker Ramona , Frühwald Michael C. , Becker Kerstin , Neuhann Teresa M. , Horn Denise , Schrock Evelin , Niehaus Indra , Sarnow Katharina , Grützmann Konrad , Gawehn Luzie , Klink Barbara , Rump Andreas , Chaponnier Christine , Figueiredo Constanca , Knöfler Ralf , Manstein Dietmar J. , Di Donato Nataliya
Published: November 2018

The original version of this Article contained an error in Figure 4. In panel i, the lower CYA and α-SMA images were inadvertently inverted. This has been corrected in both the PDF and HTML versions of the Article.
Interconvertible vanadium-seamed hexameric pyrogallol[4]arene nanocapsules
Authors: Su Kongzhao , Wu Mingyan , Yuan Daqiang , Hong Maochun
Published: November 2018

Research into stimuli-responsive controlled self-assembly and reversible transformation of molecular architectures has received much attention recently, because it is important to understand and reproduce this natural self-assembly behavior. Here, we report two coordination nanocapsules with variable cavities: a contracted octahedral V24 capsule and an expanded ball-shaped V24 capsule, both of which are constructed from the same number of subcomponents. The assemblies of these two V24 capsules are solvent-controlled, and capable of reversible conversion between contracted and expanded forms via control of the geometries of the metal centers by association and dissociation with axial water molecules. Following such structural interconversions, the magnetic properties are significantly changed. This work not only provides a strategy for the design and preparation of coordination nanocapsules with adaptable cavities, but also a unique example with which to understand the transformation process and their structure-property relationships.
Independence of topological surface state and bulk conductance in three-dimensional topological insulators
Authors: Cai Shu , Guo Jing , Sidorov Vladimir A. , Zhou Yazhou , Wang Honghong , Lin Gongchang , Li Xiaodong , Li Yanchuan , Yang Ke , Li Aiguo , Wu Qi , Hu Jiangping , Kushwaha Satya. K. , Cava Robert J. , Sun Liling
Published: November 2018

The archetypical 3D topological insulators Bi2Se3, Bi2Te3, and Sb2Te3 commonly exhibit high bulk conductivities, hindering the characterization of the surface state charge transport. The optimally doped topological insulators Bi2Te2Se and Bi2−xSbxTe2S, however, allow for such characterizations to be made. Here we report an experimental comparison of the conductance for the topological surface and bulk states in Bi2Te2Se and Bi1.1Sb0.9Te2S, based on temperature-dependent high-pressure measurements. We find that the surface state conductance at low temperature remains constant in the face of orders of magnitude increase in the bulk state conductance, revealing in a straightforward way that the topological surface states and bulk states are decoupled at low temperatures, consistent with theoretical models, and confirming topological insulators to be an excellent venue for studying charge transport in 2D Dirac electron systems.
North-South Asymmetry in the Geographic Location of Auroral Substorms correlated with Ionospheric Effects
Authors: Liou Kan , Sotirelis Thomas , Mitchell Elizabeth J.
Published: November 2018

Energetic particles of magnetospheric origin constantly strike the Earth’s upper atmosphere in the polar regions, producing optical emissions known as the aurora. The most spectacular auroral displays are associated with recurrent events called magnetospheric substorms (aka auroral substorms). Substorms are initiated in the nightside magnetosphere on closed magnetic field lines. As a consequence, it is generally thought that auroral substorms should occur in both hemispheres on the same field line (i.e., magnetically conjugated). However, such a hypothesis has not been verified statistically. Here, by analyzing 2659 auroral substorms acquired by the Ultraviolet Imager on board the NASA satellite “Polar”, we have discovered surprising evidence that the averaged location for substorm onsets is not conjugate but shows a geographic preference that cannot be easily explained by current substorm theories. In the Northern Hemisphere (NH) the auroral substorms occur most frequently in Churchill, Canada (~90°W) and Khatanga, Siberia (~100°E), up to three times as often as in Iceland (~22°W). In the Southern Hemisphere (SH), substorms occur more frequently over a location in the Antarctic ocean (~120°E), up to ~4 times more than over the Antarctic Continent. Such a large difference in the longitudinal distribution of north and south onset defies the common belief that substorms in the NH and SH should be magnetically conjugated. A further analysis indicates that these substorm events occurred more frequently when more of the ionosphere was dark. These geographic areas also coincide with regions where the Earth’s magnetic field is largest. These facts suggest that auroral substorms occur more frequently, and perhaps more intensely, when the ionospheric conductivity is lower. With much of the magnetotail energy coming from the solar wind through merging of the interplanetary and Earth’s magnetic field, it is generally thought that the occurrence of substorms is externally controlled by the solar wind and plasma instability in the magnetotail. The present study results provide a strong argument that the ionosphere plays a more active role in the occurrence of substorms.
A link between plasma membrane calcium ATPase 2 (PMCA2), estrogen and estrogen receptor α signaling in mechanical pain
Authors: Khariv Veronika , Acioglu Cigdem , Ni Li , Ratnayake Ayomi , Li Lun , Tao Yuan-Xiang , Heary Robert F. , Elkabes Stella
Published: November 2018

Earlier studies on genetically modified mice indicated that plasma membrane calcium ATPase 2 (PMCA2), a calcium extrusion pump, plays a novel and sex-dependent role in mechanical pain responses: female, but not male, PMCA2+/− mice manifest increased mechanical pain compared to female PMCA2+/+ mice. The goal of the present studies was to determine the contribution of ovarian steroids to the genotype- and sex-dependent manifestation of mechanical pain in PMCA2+/+ versus PMCA2+/− mice. Ovariectomy increased mechanical pain sensitivity and 17β-estradiol (E2) replacement restored it to basal levels in PMCA2+/+ mice, but not in PMCA2+/− littermates. Intrathecal administration of an estrogen receptor alpha (ERα) agonist induced ERα signaling in the dorsal horn (DH) of female PMCA2+/+ mice, but was ineffective in PMCA2+/− mice. In male PMCA2+/+ and PMCA2+/− mice, E2 treatment following orchidectomy did not recapitulate the genotype-dependent differential pain responses observed in females and the agonist did not elicit ERα signaling. These findings establish a novel, female-specific link between PMCA2, ERα and mechanical pain. It is postulated that PMCA2 is essential for adequate ERα signaling in the female DH and that impaired ERα signaling in the female PMCA2+/− mice hinders the analgesic effects of E2 leading to increased sensitivity to mechanical stimuli.
Wavelength-optimized Two-Photon Polymerization Using Initiators Based on Multipolar Aminostyryl-1,3,5-triazines
Authors: Tromayer Maximilian , Gruber Peter , Rosspeintner Arnulf , Ajami Aliasghar , Husinsky Wolfgang , Plasser Felix , González Leticia , Vauthey Eric , Ovsianikov Aleksandr , Liska Robert
Published: November 2018

Two-photon induced polymerization (2PP) based 3D printing is a powerful microfabrication tool. Specialized two-photon initiators (2PIs) are critical components of the employed photosensitive polymerizable formulations. This work investigates the cooperative enhancement of two-photon absorption cross sections (σ2PA) in a series of 1,3,5-triazine-derivatives bearing 1-3 aminostyryl-donor arms, creating dipolar, quadrupolar and octupolar push-pull systems. The multipolar 2PIs were successfully prepared and characterized, σ2PA were determined using z-scan at 800 nm as well as spectrally resolved two-photon excited fluorescence measurements, and the results were compared to high-level ab initio computations. Modern tunable femtosecond lasers allow 2PP-processing at optimum wavelengths tailored to the absorption behavior of the 2PI. 2PP structuring tests revealed that while performance at 800 nm is similar, at their respective σ2PA-maxima the octupolar triazine-derivative outperforms a well-established ketone-based quadrupolar reference 2PI, with significantly lower fabrication threshold at exceedingly high writing speeds up to 200 mm/s and a broader window for ideal processing parameters.
Pivotal role of bZIPs in amylose biosynthesis by genome survey and transcriptome analysis in wheat (Triticum aestivum L.) mutants
Authors: Kumar Pankaj , Mishra Ankita , Sharma Himanshu , Sharma Dixit , Rahim Mohammed Saba , Sharma Monica , Parveen Afsana , Jain Prateek , Verma Shailender Kumar , Rishi Vikas , Roy Joy
Published: November 2018

Starch makes up 70% of the wheat grain, and is an important source of calories for humans, however, the overconsumption of wheat starch may contribute to nutrition-associated health problems. The challenge is to develop resistant starch including high amylose wheat varieties with health benefits. Adapting advance genomic approaches in EMS-induced mutant lines differing in amylose content, basic leucine zipper (bZIP) regulatory factors that may play role in controlling amylose biosynthesis were identified in wheat. bZIP transcription factors are key regulators of starch biosynthesis genes in rice and maize, but their role in regulating these genes in wheat is poorly understood. A genome-wide survey identified 370 wheat bZIPs, clustered in 11 groups, showing variations in amino acids composition and predicted physicochemical properties. Three approaches namely, whole transcriptome sequencing, qRT-PCR, and correlation analysis in contrasting high and low amylose mutants and their parent line identified 24 candidate bZIP (positive and negative regulators), suggesting bZIPs role in high amylose biosynthesis. bZIPs positive role in high amylose biosynthesis is not known. In silico interactome studies of candidate wheat bZIP homologs in Arabidopsis and rice identified their putative functional role. The identified bZIPs are involved in stress-related pathways, flower and seed development, and starch biosynthesis. An in-depth analysis of molecular mechanism of novel candidate bZIPs may help in raising and improving high amylose wheat varieties.
Air trapping in usual interstitial pneumonia pattern at CT: prevalence and prognosis
Authors: Hochhegger Bruno , Sanches Felipe Duenhas , Altmayer Stephan Philip Leonhardt , Pacini Gabriel Sartori , Zanon Matheus , Guedes Álvaro da Costa Batista , Watte Guilherme , Meirelles Gustavo , Barros Marcelo Cardoso , Marchiori Edson , Rubin Adalberto Sperb
Published: November 2018

This study was conducted to evaluate the presence of air trapping in patients with idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases (ILDs) (non-IPF), showing the radiological pattern of usual interstitial pneumonia (UIP). Retrospectively, we included 69 consecutive patients showing the typical UIP pattern on computed tomography (CT), and 15 final diagnosis of IPF with CT pattern “inconsistent with UIP” due to extensive air trapping. Air trapping at CT was assessed qualitatively by visual analysis and quantitatively by automated-software. In the quantitative analysis, significant air trapping was defined as >6% of voxels with attenuation between −950 to −856 HU on expiratory CT (expiratory air trapping index [ATIexp]) or an expiratory to inspiratory (E/I) ratio of mean lung density >0.87. The sample comprised 51 (60.7%) cases of IPF and 33 (39.3%) cases of non-IPF ILD. Most patients did not have air trapping (E/I ratio ≤0.87, n = 53, [63.1%]; ATIexp ≤6%, n = 45, [53.6%]). Air trapping in the upper lobes was the only variable distinguishing IPF from non-IPF ILD (prevalence, 3.9% vs 33.3%, p < 0.001). In conclusion, air trapping is common in patients with ILDs showing a UIP pattern on CT, as determined by qualitative and quantitative evaluation, and should not be considered to be inconsistent with UIP. On subjective visual assessment, air trapping in the upper lobes was associated with a non-IPF diagnoses.
Changes in short term river flow regulation and hydropeaking in Nordic rivers
Authors: Ashraf Faisal Bin , Haghighi Ali Torabi , Riml Joakim , Alfredsen Knut , Koskela Jarkko J. , Kløve Bjørn , Marttila Hannu
Published: November 2018

Quantifying short-term changes in river flow is important in understanding the environmental impacts of hydropower generation. Energy markets can change rapidly and energy demand fluctuates at sub-daily scales, which may cause corresponding changes in regulated river flow (hydropeaking). Due to increasing use of renewable energy, in future hydropower will play a greater role as a load balancing power source. This may increase current hydropeaking levels in Nordic river systems, creating challenges in maintaining a healthy ecological status. This study examined driving forces for hydropeaking in Nordic rivers using extensive datasets from 150 sites with hourly time step river discharge data. It also investigated the influence of increased wind power production on hydropeaking. The data revealed that hydropeaking is at high levels in the Nordic rivers and have seen an increase over the last decade and especially over the past few years. These results indicate that increased building for renewable energy may increase hydropeaking in Nordic rivers.
Effects of Low Intensity Focused Ultrasound on Liposomes Containing Channel proteins
Authors: Babakhanian Meghedi , Yang Limin , Nowroozi Bryan , Saddik George , Boodaghians Lilian , Blount Paul , Grundfest Warren
Published: November 2018

The ability to reversibly and non-invasively modulate region-specific brain activity in vivo suggests Low Intensity Focused Ultrasound (LIFU) as potential therapeutics for neurological dysfunctions such as epilepsy and Parkinson’s disease. While in vivo studies provide evidence of the bioeffects of LIFU on neuronal activity, they merely hint at potential mechanisms but do not fully explain how this technology achieves these effects. One potential hypothesis is that LIFU produces local membrane depolarization by mechanically perturbing the neuronal cell membrane, or activating channels or other proteins embedded in the membrane. Proteins that sense mechanical perturbations of the membrane, such as those gated by membrane tension, are prime candidates for activating in response to LIFU and thus leading to the neurological responses that have been measured. Here we use the bacterial mechanosensitive channel MscL, which has been purified and reconstituted in liposomes, to determine how LIFU may affect the activation of this membrane-tension gated channel. Two bacterial voltage-gated channels, KvAP and NaK2K F92A channels were also studied. Surprisingly, the results suggest that ultrasound modulation and membrane perturbation does not induce channel gating, but rather induces pore formation at the membrane protein-lipid interface. However, in vesicles with high MscL mechanosensitive channel concentrations, apparent decreases in pore formation are observed, suggesting that this membrane-tension-sensitive protein may serve to increase the elasticity of the membrane, presumably because of expansion of the channel in the plane of the membrane independent of channel gating.
Engineering the hinge region of human IgG1 Fc-fused bispecific antibodies to improve fragmentation resistance
Authors: Suzuki Saori , Annaka Hiroaki , Konno Shota , Kumagai Izumi , Asano Ryutaro
Published: November 2018

Fc domain fusion can improve the therapeutic effects of relatively small biological molecules such as peptides, cytokines, and antibody fragments. Fc fusion proteins can also be used to enhance the cytotoxic effects of small bispecific antibodies (bsAbs). However, fragmentation of Fc fusion proteins, which mainly occurs around the hinge regions during production, storage, and circulation in the blood, is a major issue. In this study, we first investigated the mechanisms of fragmentation around the hinge region during storage using Fc-fused bsAbs with specificity for epidermal growth factor receptor and CD3 as a model. The fragmentation peaks generated by gel filtration analysis indicated that both contaminating proteases and dissolved active oxygen should be considered causes of fragmentation. We designed and constructed variants by introducing a point mutation into the upper hinge region, which reduced the cleavage caused by dissolved active oxygen, and shortened the hinge region to restrict access of proteases. These hinge modifications improved fragmentation resistance and did not affect the biological activity of the bsAbs in vitro. We confirmed the versatility of the hinge modifications using another Fc-fused bsAb. Our results show that hinge modifications to the Fc fusion protein, especially the introduction of a point mutation into the upper hinge region, can reduce fragmentation substantially, and these modifications can be used to improve the fragmentation resistance of other recombinant Fc fusion proteins.
Guided-mode resonant narrowband terahertz filtering by periodic metallic stripe and patch arrays on cyclo-olefin substrates
Authors: Ferraro Antonio , Zografopoulos Dimitrios C. , Caputo Roberto , Beccherelli Romeo
Published: November 2018

We experimentally and theoretically demonstrate a class of narrowband transmissive filters in the terahertz spectrum. Their operation is based on the excitation of guided-mode resonances in thin films of the low-loss cyclo-olefin polymer Zeonor, upon which aluminum stripe and patch arrays are patterned via standard photolithography. The filters are engineered to operate in low atmospheric loss THz spectral windows, they exhibit very high transmittance and quality factors, compact thickness, and mechanical stability. The dependence of their filtering properties on the geometrical parameters, the substrate thickness and the angle of incidence is investigated, discussing the physical limitations in their performance. This class of filters provides a cost-effective solution for broadband source or channel filtering in view of emerging terahertz wireless communication systems.
Arabidopsis thaliana DGAT3 is a [2Fe-2S] protein involved in TAG biosynthesis
Authors: Aymé Laure , Arragain Simon , Canonge Michel , Baud Sébastien , Touati Nadia , Bimai Ornella , Jagic Franjo , Louis-Mondésir Christelle , Briozzo Pierre , Fontecave Marc , Chardot Thierry
Published: November 2018

Acyl-CoA:diacylglycerol acyltransferases 3 (DGAT3) are described as plant cytosolic enzymes synthesizing triacylglycerol. Their protein sequences exhibit a thioredoxin-like ferredoxin domain typical of a class of ferredoxins harboring a [2Fe-2S] cluster. The Arabidopsis thaliana DGAT3 (AtDGAT3; At1g48300) protein is detected in germinating seeds. The recombinant purified protein produced from Escherichia coli, although very unstable, exhibits DGAT activity in vitro. A shorter protein version devoid of its N-terminal putative chloroplast transit peptide, Δ46AtDGAT3, was more stable in vitro, allowing biochemical and spectroscopic characterization. The results obtained demonstrate the presence of a [2Fe-2S] cluster in the protein. To date, AtDGAT3 is the first metalloprotein described as a DGAT.
Development of whole brain versus targeted dentate gyrus irradiation model to explain low to moderate doses of exposure effects in mice
Authors: Dos Santos M. , Kereselidze D. , Gloaguen C. , Benadjaoud M. A. , Tack K. , Lestaevel P. , Durand C.
Published: November 2018

Evaluation of the consequences of low to moderate doses of ionizing radiation (IR) remains a societal challenge, especially for children exposed to CT scans. Appropriate experimental models are needed to improve scientific understanding of how exposure of the postnatal brain to IR affects behavioral functions and their related pathophysiological mechanisms, considering brain complex functional organization. In the brain, the dorsal and ventral hippocampal dentate gyrus can be involved in distinct major behavioral functions. To study the long term behavioral effects of brain exposure at low to moderate doses of IR (doses range 0.25–1 Gy), we developed three new experimental models in 10-day-old mice: a model of brain irradiation and two targeted irradiation models of the dorsal and ventral dentate gyrus. We used the technological properties of the SARRP coupled with MR imaging. Our irradiation strategy has been twofold endorsed. The millimetric ballistic specificity of our models was first validated by measuring gamma-H2AX increase after irradiation. We then demonstrated higher anxiety/depressive-like behavior, preferentially mediate by the ventral part of the dentate gyrus, in mice after brain and ventral dentate gyrus IR exposure. This work provides new tools to enhance scientific understanding of how to protect children exposed to IR.