bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does the Peak Response of the Ionospheric F2 Region Plasma Lag the Peak of 27‐Day Solar Flux Variation by Multiple Days?
Authors: Ren Dexin , Lei Jiuhou , Wang Wenbin , Burns Alan , Luan Xiaoli , Dou Xiankang 
Published: September 2018

AbstractIn this study, the in situ electron density measurements from the Challenging Minisatellite Payload (CHAMP) and solar extreme ultraviolet (EUV) radiation from the Solar Extreme Ultraviolet Experiment instrument on board the Thermosphere Ionosphere Mesosphere Energetic and Dynamics satellite, both with a time resolution of 1.5 hr, are used to explore the peak response of the ionospheric F2 region plasma to the peak of 27‐day solar EUV flux variation. The time delays of in situ electron density changes obtained from the CHAMP satellite in response to 27‐day solar EUV flux changes vary from 0 to about 3 days. Meanwhile, the Thermosphere Ionosphere Electrodynamics General Circulation Model simulations driven by the measured EUV flux and the actual geomagnetic activity show similar time delays as those observed in the CHAMP measurements. Further simulations reveal that the geomagnetic activity greatly affects the determination of the ionospheric time delay to the 27‐day solar EUV flux variations. Besides, the solar zenith angle change within the solar rotation interval can cause large latitudinal differences in the time delay. The ionospheric time delay to the pure 27‐day solar EUV flux variation is less than 1 day and slightly increases with latitude, when geomagnetic activity and seasonal variations are eliminated in the simulation. The simulation results further suggest that the ionospheric response time is associated with the photochemical, dynamic, and electrodynamic processes in the ionosphere‐thermosphere system.
Selective Attenuation of Lightning‐Generated Whistlers at Extralow Frequencies: DEMETER Spacecraft Observations
Authors: Záhlava J. , Němec F. , Santolík O. , Kolmašová I. , Parrot M. , Kouba D. 
Published: September 2018

AbstractFrequency‐time spectrograms measured by the Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) spacecraft (2004–2010, altitude about 700 km) at frequencies below 20 kHz sometimes contain lightning‐generated whistlers whose intensity is significantly reduced at specific frequencies. The frequencies of the reduced intensity vary smoothly over the event duration, forming apparent curves in frequency‐time spectrograms. Events at frequencies higher than the Earth‐ionosphere waveguide cutoff frequency were explained by the interference of the first few waveguide modes of lightning‐generated spherics propagating therein (Záhlava et al., 2015, https://doi.org/10.1002/2015JA021607. Here we present an analysis of events observed at frequencies lower than about 1 kHz. Altogether, we analyze 263 events identified at the times when DEMETER operated in the burst mode. The vast majority of the events (95%) took place during the nighttime, and they occurred more frequently during spring/autumn than during winter/summer. We present an overview of event properties. Moreover, measurements of all six electromagnetic field components performed by DEMETER allow us to perform a detailed wave analysis. It is shown that the emissions propagate with high wave normal angles inclined toward the Earth. We suggest that the events might be due to the wave propagation in the ionospheric waveguide formed around the refractive index maximum at the altitude of about 105 km.
Timing of Okhotsk Sea Plate Collision With Eurasia Plate: Zircon U‐Pb Age Constraints From the Sakhalin Island, Russian Far East
Authors: Zhao Pan , Alexandrov Igor , Jahn Bor‐ming , Ivin Vitaly 
Published: September 2018

AbstractThe Late Mesozoic to Cenozoic evolution of Northeast Asia involves successive subduction of the Pacific oceanic crust and amalgamation of the Eurasia, North American, and Okhotsk Sea Plates. The timing of plate collision is essential for understanding the tectonic evolution of Northeast Asia. In this study, we focus on the Okhotsk Sea Plate collision with the Eurasia Plate along the Sakhalin Island, Russian Far East, which is a highly controversial problem, especially about the timing of collision. In order to determine exact timing for this collision, we report zircon U‐Pb data from both the East Sakhalin accretionary complex and postcollisional granitic plutons in the Sakhalin Island. Detrital zircon data from four metasedimentary rocks show that the Sikhote‐Alin orogenic belt is the main provenance for the East Sakhalin accretionary complex. Meanwhile, the youngest detrital zircon age constrains the maximum depositional age of East Sakhalin accretionary complex later than 49 Ma. Both Langeri and Val'za plutons are made of peraluminous S‐type granite. Four granitic samples yielded consistent ages at 36–38 Ma, indicating that both plutons were emplaced at the middle Eocene. Their generation is considered to have been derived through crustal anatexis of accretionary wedge in the lower crust shortly after tectonic thickening caused by the Okhotsk Sea Plate collision with the Eurasia Plate. Consequently, our age data constrain that the Okhotsk Sea Plate and Eurasia Plate collision occurred in the middle Eocene between 49 and 38 Ma. This age range is consistent with late Eocene uncomformity identified in the Sakhalin Island and Okhotsk Sea.
On the Nature of Higher‐Order Ambient Seismic Field Correlations
Authors: Sheng Yixiao , Nakata Nori , Beroza Gregory C. 
Published: September 2018

AbstractWe find that higher‐order ambient seismic field correlations, specifically C3 (correlation of the coda of correlations) of long‐duration data sets from Southern California are symmetric despite the fact that the background wavefield is strongly directional. We demonstrate that this symmetry arises primarily from the structure of the C3 time series analysis rather than the diffuse character of the coda. For that reason, the resulting ambient‐field Green's function symmetry may not be diagnostic of correlation quality. We propose an alternative prestack processing scheme that constructs C3 correlations from each C1 (cross correlation) coda time window, but stacks the results only at the final step of processing. Prestack C3 leads to faster convergence and extracts arrivals at higher frequencies than standard poststack processing.
Characteristics of Optically Thin Coastal Florida Cumuli Derived From Surface‐Based Lidar Measurements
Authors: Delgadillo Rodrigo , Voss Kenneth J. , Zuidema Paquita 
Published: September 2018

AbstractThe optical depths and sizes of optically thin passive shallow cumuli are characterized with a micropulse lidar. The measurements are from a coastal south Florida location spanning a 10‐week synoptically suppressed winter time period with almost no upper‐level clouds present. Clouds are distinguished from aerosol through visual comparison to zenith‐viewing time‐lapse camera images, establishing an instrument‐specific particle backscatter coefficient threshold. Sun photometers provide a continuous independent aerosol optical depth estimate applied within the lidar retrieval of cloud optical depth. The focus is on clouds that do not attenuate the lidar signal. Clouds with optical depths less than one constitute more than 13% of the sampled data set, with decreasing optical depths occurring more frequently. Most of the clouds are less than 60 m thick and are located below 1 km. The optically thin regions occur most frequently in individual 15‐s samples, corresponding to a horizontal width of less than 100 m, with occasional stratiform segments extending up to 2 km. Many segments border optically thicker regions, but some are self‐contained, reflecting small‐scale humidity variations near‐saturation. To our knowledge, this study is the first to apply micropulse lidar data toward characterizing these low, shallow, broken clouds, too small for robust characterization from space but whose ubiquitiousness renders them radiatively important.
Wireless whispering-gallery-mode sensor for thermal sensing and aerial mapping
Authors: Xu Xiangyi , Chen Weijian , Zhao Guangming , Li Yihang , Lu Chenyang , Yang Lan 
Published: September 2018

AbstractThe Internet of Things (IoT)1,2 employs a large number of spatially distributed wireless sensors to monitor physical environments, e.g., temperature, humidity, and air pressure, and has many applications, including environmental monitoring3, health care monitoring4, smart cities5, and precision agriculture. A wireless sensor can collect, analyze, and transmit measurements of its environment1,2. Currently, wireless sensors used in the IoT are predominately based on electronic devices that may suffer from electromagnetic interference in many circumstances. Being immune to the electromagnetic interference, optical sensors provide a significant advantage in harsh environments6. Furthermore, by introducing optical resonance to enhance light–matter interactions, optical sensors based on resonators exhibit small footprints, extreme sensitivity, and versatile functionalities7,8, which can significantly enhance the capability and flexibility of wireless sensors. Here we provide the first demonstration of a wireless photonic sensor node based on a whispering-gallery-mode (WGM) optical resonator, in which light propagates along the circular rim of such a structure like a sphere, a disk, or a toroid by continuous total internal reflection. The sensor node is controlled via a customized iOS app. Its performance was studied in two practical scenarios: (1) real-time measurement of the air temperature over 12 h and (2) aerial mapping of the temperature distribution using a sensor node mounted on an unmanned drone. Our work demonstrates the capability of WGM optical sensors in practical applications and may pave the way for the large-scale deployment of WGM sensors in the IoT.
Evolution of the quantum Hall bulk spectrum into chiral edge states
Authors: Patlatiuk T. , Scheller C. P. , Hill D. , Tserkovnyak Y. , Barak G. , Yacoby A. , Pfeiffer L. N. , West K. W. , Zumbühl D. M. 
Published: September 2018

AbstractOne of the most intriguing and fundamental properties of topological systems is the correspondence between the conducting edge states and the gapped bulk spectrum. Here, we use a GaAs cleaved edge quantum wire to perform momentum-resolved spectroscopy of the quantum Hall edge states in a tunnel-coupled 2D electron gas. This reveals the momentum and position of the edge states with unprecedented precision and shows the evolution from very low magnetic fields all the way to high fields where depopulation occurs. We present consistent analytical and numerical models, inferring the edge states from the well-known bulk spectrum, finding excellent agreement with the experiment—thus providing direct evidence for the bulk to edge correspondence. In addition, we observe various features beyond the single-particle picture, such as Fermi level pinning, exchange-enhanced spin splitting and signatures of edge-state reconstruction.
Patterns of posterior ocular complications in myopic eyes of Indian population
Authors: Dhakal Rohit , Goud Abhilash , Narayanan Raja , Verkicharla Pavan K. 
Published: September 2018

AbstractThis is a retrospective study aimed to investigate the patterns of myopic fundus complications in Indian children and young adults. Electronic medical records of 29,592 patients, aged 10–40 years, who visited L V Prasad Eye Institute between 1st January to 31st December 2016 were analysed in the study. Data such as age, gender, refractive error and various pathologic lesions of posterior globe were considered for analysis. Among all the patients with different types of refractive errors, myopia was found in 47.4%, high myopia in 6.8% and pathologic myopia in 2.2%. There was no trend of the increased prevalence of pathologic myopia with increasing age, except for a significant difference between the children aged 10–15 years (2.7%) and those aged more than 15 years (>4%). . Although, the overall pattern of pathologic lesions was similar across different grades of myopia (2.5% in low myopes vs. 2.2% in severe myopes), lesions like staphyloma and retinal detachment increased with increasing degree of myopia. The proportion of pathologic lesions across different grades of myopia suggests the necessity for careful peripheral fundus examinations irrespective of the degree of myopia for better management and prognostic purposes.
A Cambrian unarmoured lobopodian, †Lenisambulatrix humboldti gen. et sp. nov., compared with new material of †Diania cactiformis
Authors: Ou Qiang , Mayer Georg 
Published: September 2018

AbstractCambrian marine lobopodians are generally considered as predecessors of modern panarthropods (onychophorans, tardigrades, and arthropods). Hence, further study of their morphological diversity and early radiation may enhance our understanding of the ground pattern and evolutionary history of panarthropods. Here, we report a rare lobopodian species, †Lenisambulatrix humboldtigen. et sp. nov. (“Humboldt lobopodian”), from the early Cambrian Chengjiang Lagerstätte and describe new morphological features of †Diania cactiformis, a coeval armoured lobopodian nicknamed “walking cactus”. Both lobopodian species were similar in possessing rather thick, elongate lobopods without terminal claws. However, in contrast to †Diania cactiformis, the body of which was heavily armored with spines, the trunk and limbs of the Humboldt lobopodian were entirely unarmored. Our study augments the morphological diversity of Cambrian lobopodians and presents two evolutionary extremes of cuticular ornamentation: one represented by the Humboldt lobopodian, which was most likely entirely “naked”, the other epitomized by †D. cactiformis, which was highly “armoured”.
Mercury and arsenic attenuate canonical and non-canonical NLRP3 inflammasome activation
Authors: Ahn Huijeong , Kim Jeongeun , Kang Seung Goo , Yoon Sung-il , Ko Hyun-Jeong , Kim Pyeung-Hyeun , Hong Eui-Ju , An Beum-Soo , Lee Eunsong , Lee Geun-Shik 
Published: September 2018

AbstractExposure to heavy metals can cause several diseases associated with the immune system. Although the effects of heavy metals on production of inflammatory cytokines have been previously studied, the role of heavy metals in inflammasome activation remains poorly studied. The inflammasome is an intracellular multi-protein complex that detects intracellular danger signals, resulting in inflammatory responses such as cytokine maturation and pyroptosis. In this study, we elucidated the effects of four heavy metals, including cadmium (Cd), mercury (Hg), arsenic (As), and lead (Pb), on the activation of NLRP3, NLRC4, and AIM2 inflammasomes. In our results, mercury and arsenic inhibited interleukin (IL)-1β and IL-18 secretion resulting from canonical and non-canonical NLRP3 inflammasome activation in macrophages and attenuated elevation of serum IL-1β in response to LPS treatment in mice. In the mechanical studies, mercury interrupted production of mitochondrial reactive oxygen species, release of mitochondrial DNA, and activity of recombinant caspase-1, whereas arsenic down-regulated expression of promyelocytic leukemia protein. Both mercury and arsenic inhibited Asc pyroptosome formation and gasdermin D cleavage. Thus, we suggest that exposure to mercury and/or arsenic could disrupt inflammasome-mediated inflammatory responses, which might cause unexpected side effects.
Novel digital signatures of tissue phenotypes for predicting distant metastasis in colorectal cancer
Authors: Sirinukunwattana Korsuk , Snead David , Epstein David , Aftab Zia , Mujeeb Imaad , Tsang Yee Wah , Cree Ian , Rajpoot Nasir 
Published: September 2018

AbstractDistant metastasis is the major cause of death in colorectal cancer (CRC). Patients at high risk of developing distant metastasis could benefit from appropriate adjuvant and follow-up treatments if stratified accurately at an early stage of the disease. Studies have increasingly recognized the role of diverse cellular components within the tumor microenvironment in the development and progression of CRC tumors. In this paper, we show that automated analysis of digitized images from locally advanced colorectal cancer tissue slides can provide estimate of risk of distant metastasis on the basis of novel tissue phenotypic signatures of the tumor microenvironment. Specifically, we determine what cell types are found in the vicinity of other cell types, and in what numbers, rather than concentrating exclusively on the cancerous cells. We then extract novel tissue phenotypic signatures using statistical measurements about tissue composition. Such signatures can underpin clinical decisions about the advisability of various types of adjuvant therapy.
Chimeric O1K foot-and-mouth disease virus with SAT2 outer capsid as an FMD vaccine candidate
Authors: Kotecha Abhay , Perez-Martin Eva , Harvey Yongjie , Zhang Fuquan , Ilca Serban L , Fry Elizabeth E. , Jackson Ben , Maree Francois , Scott Katherine , Hecksel Corey W. , Harmsen Michiel M. , Mioulet Valérie , Wood Britta , Juleff Nick , Stuart David I. , Charleston Bryan , Seago Julian 
Published: September 2018

AbstractFoot-and-mouth disease virus (FMDV) is highly contagious and infects cloven-hoofed domestic livestock leading to foot-and-mouth disease (FMD). FMD outbreaks have severe economic impact due to production losses and associated control measures. FMDV is found as seven distinct serotypes, but there are numerous subtypes within each serotype, and effective vaccines must match the subtypes circulating in the field. In addition, the O and Southern African Territories (SAT) serotypes, are relatively more thermolabile and their viral capsids readily dissociate into non-immunogenic pentameric subunits, which can compromise the effectiveness of FMD vaccines. Here we report the construction of a chimeric clone between the SAT2 and O serotypes, designed to have SAT2 antigenicity. Characterisation of the chimeric virus showed growth kinetics equal to that of the wild type SAT2 virus with better thermostability, attributable to changes in the VP4 structural protein. Sequence and structural analyses confirmed that no changes from SAT2 were present elsewhere in the capsid as a consequence of the VP4 changes. Following exposure to an elevated temperature the thermostable SAT2-O1K chimera induced higher neutralizing-antibody titres in comparison to wild type SAT2 virus.
Improved fragment-based protein structure prediction by redesign of search heuristics
Authors: Kandathil Shaun M. , Garza-Fabre Mario , Handl Julia , Lovell Simon C. 
Published: September 2018

AbstractDifficulty in sampling large and complex conformational spaces remains a key limitation in fragment-based de novo prediction of protein structure. Our previous work has shown that even for small-to-medium-sized proteins, some current methods inadequately sample alternative structures. We have developed two new conformational sampling techniques, one employing a bilevel optimisation framework and the other employing iterated local search. We combine strategies of forced structural perturbation (where some fragment insertions are accepted regardless of their impact on scores) and greedy local optimisation, allowing greater exploration of the available conformational space. Comparisons against the Rosetta Abinitio method indicate that our protocols more frequently generate native-like predictions for many targets, even following the low-resolution phase, using a given set of fragment libraries. By contrasting results across two different fragment sets, we show that our methods are able to better take advantage of high-quality fragments. These improvements can also translate into more reliable identification of near-native structures in a simple clustering-based model selection procedure. We show that when fragment libraries are sufficiently well-constructed, improved breadth of exploration within runs improves prediction accuracy. Our results also suggest that in benchmarking scenarios, a total exclusion of fragments drawn from homologous templates can make performance differences between methods appear less pronounced.
Thermoresponsive gels containing gold nanoparticles as smart antibacterial and wound healing agents
Authors: Arafa Mona G. , El-Kased Reham F. , Elmazar M. M. 
Published: September 2018

AbstractThermoresponsive gels containing gold nanoparticles (AuNPs) were prepared using Pluronic®127 alone (F1) and with hydroxypropyl methylcellulose (F2) at ratios of 15% w/w and 15:1% w/w, respectively. AuNPs were evaluated for particle size, zeta-potential, polydispersity index (PDI), morphology and XRD pattern. AuNP-containing thermoresponsive gels were investigated for their gelation temperature, gel strength, bio-adhesive force, viscosity, drug content, in vitro release and ex-vivo permeation, in addition to in vitro antibacterial activity against bacteria found in burn infections, Staphylococcus aureus. In vivo burn healing and antibacterial activities were also investigated and compared with those of a commercial product using burn-induced infected wounds in mice. Spherical AuNPs sized 28.9–37.65 nm displayed a surface plasmon resonance band at 522 nm, a PDI of 0.461, and a zeta potential of 34.8 mV with a negative surface charge. F1 and F2 showed gelation temperatures of 37.2 °C and 32.3 °C, bio-adhesive forces of 2.45 ± 0.52 and 4.76 ± 0.84 dyne/cm2, viscosities of 10,165 ± 1.54 and 14,213 ± 2.31 cP, and gel strengths between 7.4 and 10.3 sec, respectively. The in vitro release values of F1 and F2 were 100% and 98.03% after 6 h, with permeation flux values of (J1) 0.2974 ± 2.85 and (J2) 0.2649 ± 1.43 (µg/cm2·h), respectively. The formulations showed antibacterial activity with the highest values for wound healing properties, as shown in vivo and by histopathological studies. This study demonstrates that a smart AuNPs thermoresponsive gel was successful as an antibacterial and wound healing transdermal drug delivery system.
Redox control and autoxidation of class 1, 2 and 3 phytoglobins from Arabidopsis thaliana
Authors: Mot Augustin C. , Puscas Cristina , Miclea Patricia , Naumova-Letia Galaba , Dorneanu Sorin , Podar Dorina , Dissmeyer Nico , Silaghi-Dumitrescu Radu 
Published: September 2018

AbstractDespite a recent increase in interest towards phytoglobins and their importance in plants, much is still unknown regarding their biochemical/biophysical properties and physiological roles. The present study presents data on three recombinant Arabidopsis phytoglobins in terms of their UV-vis and Raman spectroscopic characteristics, redox state control, redox potentials and autoxidation rates. The latter are strongly influenced by pH for all three hemoglobins – (with a fundamental involvement of the distal histidine), as well as by added anion concentrations – suggesting either a process dominated by nucleophilic displacement of superoxide for AtHb2 or an inhibitory effect for AtHb1 and AtHb3. Reducing agents, such as ascorbate and glutathione, are found to either enhance– (presumably via direct electron transfer or via allosteric regulation) or prevent autoxidation. HbFe3+ reduction was possible in the presence of high (presumably not physiologically relevant) concentrations of NADH, glutathione and ascorbate, with differing behaviors for the three globins. The iron coordination sphere is found to affect the autoxidation, redox state interconversion and redox potentials in these three phytoglobins.