bluuebunny/crossref_metadata_2025_split huggingface dataset:
Independent evolution of tetraloop in enterovirus oriL replicative element and its putative binding partners in virus protein 3C
Authors: Prostova Maria A. , Deviatkin Andrei A. , Tcelykh Irina O. , Lukashev Alexander N. , Gmyl Anatoly P. 
Published: October 2017

BackgroundEnteroviruses are small non-enveloped viruses with a (+) ssRNA genome with one open reading frame. Enterovirus protein 3C (or 3CD for some species) binds the replicative element oriL to initiate replication. The replication of enteroviruses features a low-fidelity process, which allows the virus to adapt to the changing environment on the one hand, and requires additional mechanisms to maintain the genome stability on the other. Structural disturbances in the apical region of oriL domain d can be compensated by amino acid substitutions in positions 154 or 156 of 3C (amino acid numeration corresponds to poliovirus 3C), thus suggesting the co-evolution of these interacting sequences in nature. The aim of this work was to understand co-evolution patterns of two interacting replication machinery elements in enteroviruses, the apical region of oriL domain d and its putative binding partners in the 3C protein.MethodsTo evaluate the variability of the domain d loop sequence we retrieved all available full enterovirus sequences (>6, 400 nucleotides), which were present in the NCBI database on February 2017 and analysed the variety and abundance of sequences in domain d of the replicative element oriL and in the protein 3C.ResultsA total of 2,842 full genome sequences was analysed. The majority of domain d apical loops were tetraloops, which belonged to consensus YNHG (Y = U/C, N = any nucleotide, H = A/C/U). The putative RNA-binding tripeptide 154–156 (Enterovirus C3C protein numeration) was less diverse than the apical domain d loop region and, in contrast to it, was species-specific.DiscussionDespite the suggestion that the RNA-binding tripeptide interacts with the apical region of domain d, they evolve independently in nature. Together, our data indicate the plastic evolution of both interplayers of 3C-oriL recognition.
Characterization of Convective Plumes Associated With Oceanic Deep Convection in the Northwestern Mediterranean From High‐Resolution In Situ Data Collected by Gliders
Authors: Margirier Félix , Bosse Anthony , Testor Pierre , L'Hévéder Blandine , Mortier Laurent , Smeed David 
Published: October 2017

AbstractNumerous gliders have been deployed in the Gulf of Lions (northwestern Mediterranean Sea) and in particular during episodes of open‐ocean deep convection in the winter 2012–2013. The data collected represents an unprecedented density of in situ observations providing a first in situ statistical and 3‐D characterization of the important mixing agents of the deep convection phenomenon, the so‐called plumes. A methodology based on a glider‐static flight model was applied to infer the oceanic vertical velocity signal from the glider navigation data. We demonstrate that during the active phase of mixing, the gliders underwent significant oceanic vertical velocities up to 18 cm s−1. Focusing on the data collected by two gliders during the 2012–2013 winter, 120 small‐scale convective downward plumes were detected with a mean radius of 350 m and separated by about 2 km. We estimate that the plumes cover 27% of the convection area. Gliders detected downward velocities with a magnitude larger than that of the upward ones (−6 versus +2 cm s−1 on average). Along‐track recordings of temperature and salinity as well as biogeochemical properties (dissolved oxygen, fluorescence, and turbidity) allow a statistical characterization of the water masses' properties in the plumes' core with respect to the “background”: the average downward signal is of colder (−1.8 × 10−3 °C), slightly saltier (+4.9 × 10−4 psu) and thus denser waters (+7.5 × 10−4 kg m−3). The plunging waters are also on average more fluorescent (+2.3 × 10−2 μg L−1). The plumes are associated with a vertical diffusion coefficient of 7.0 m2 s−1 and their vertical velocity variance scales with the ratio of the buoyancy loss over the Coriolis parameter to the power 0.86.
Quasi‐Additivity of the Radiative Effects of Marine Cloud Brightening and Stratospheric Sulfate Aerosol Injection
Authors: Boucher Olivier , Kleinschmitt Christoph , Myhre Gunnar 
Published: October 2017

AbstractStratospheric sulfate aerosol injection (SAI) and marine cloud brightening (MCB) are the two most studied solar radiation management techniques. For the first time we combine them in a climate model to investigate their complementarity in terms of both instantaneous and effective radiative forcings. The effective radiative forcing induced by SAI is significantly stronger than its instantaneous counterpart evaluated at the top of atmosphere. Radiative kernel calculations indicate that this occurs because of a significant stratospheric warming and despite a large increase in stratospheric water vapor that strengthens the greenhouse effect. There is also a large decrease in high‐level cloudiness induced by a stratification of the upper tropopause. Our model experiments also show that the radiative effects of SAI and MCB are quasi‐additive and have fairly complementary patterns in the Tropics. This results in less spatial and temporal variability in the radiative forcing for combined SAI and MCB as compared to MCB alone.
The Magnetospheric Source Region of the Bright Proton Aurora
Authors: Spanswick E. , Donovan E. , Kepko L. , Angelopoulos V. 
Published: October 2017

AbstractThe bright proton aurora is generally understood to be the projection of the Central Plasma Sheet where there is sufficient particle energy to cause auroral luminosity and strong pitch angle scattering (presumably due to field line curvature). This region is often interpreted as the transition region between dipolar and tail‐like magnetic topologies. The location of auroral features relative to the peak in the proton aurora has been used, for example, to argue that the substorm onset arc lies on field lines that thread this transition region. In this paper, we present statistics of proton aurora luminosity computed from Time History of Events and Macroscale Interactions in Substorms electrostatic analyzer measurements for various radial distances in the magnetotail. These results are compared to ground observations of proton auroral luminosity and used to derive a statistical source region of the bright proton aurora.
A twentieth century perspective on summer Antarctic pressure change and variability and contributions from tropical SSTs and ozone depletion
Authors: Fogt Ryan L. , Goergens Chad A. , Jones Julie M. , Schneider David P. , Nicolas Julien P. , Bromwich David H. , Dusselier Hallie E. 
Published: October 2017

AbstractDuring the late twentieth century, the Antarctic atmospheric circulation has changed and significantly influenced the overall Antarctic climate, through processes including a poleward shift of the circumpolar westerlies. However, little is known about the full spatial pattern of atmospheric pressure over the Antarctic continent prior to 1979. Here we investigate surface pressure changes across the entire Antarctic continent back to 1905 by developing a new summer pressure reconstruction poleward of 60°S. We find that only across East Antarctica are the recent pressures significantly lower than pressures in the early twentieth century; we also discern periods of significant positive pressure trends in the early twentieth century across the coastal South Atlantic sector of Antarctica. Climate model simulations reveal that both tropical sea surface temperature variability and other radiative forcing mechanisms, in addition to ozone depletion, have played an important role in forcing the recent observed negative trends.
Effect of Topography Degradation on Crater Size‐Frequency Distributions: Implications for Populations of Small Craters and Age Dating
Authors: Xie Minggang , Zhu Meng‐Hua , Xiao Zhiyong , Wu Yunzhao , Xu Aoao 
Published: October 2017

AbstractWhether or not background secondary craters dominate populations of small impact craters on terrestrial bodies is a half‐century controversy. It has been suggested that small craters on some planetary bodies are dominated by background secondary craters based partly on the steepened slope of crater size‐frequency distribution (CSFD) toward small diameters, such as the less than ~1 km diameter crater population on the lunar mare. Here we show that topography degradation enlarges craters and increases CSFD slopes with time. When topography degradation is taken into account, for various‐aged crater populations, the observed steep CSFD at small diameters is uniformly consistent with an originally shallower CSFD, whose slope is undifferentiated from the CSFD slope estimated from near‐Earth objects and terrestrial bolides. The results show that the effect of topography degradation on CSFD is important in dating planetary surfaces, and the steepening of CSFD slopes is not necessarily caused by secondary cratering, but rather a natural consequence of topography degradation.
Thermal Conductivity of the Multicomponent Neutral Atmosphere
Authors: Pavlov A. V. 
Published: October 2017

AbstractApproximate expressions for the thermal conductivity coefficient of the multicomponent neutral atmosphere consisting of N2, O2, O, He, and H are analyzed and evaluated for the atmospheric conditions by comparing them with that given by the rigorous hydrodynamic theory. The new approximations of the thermal conductivity coefficients of simple gases N2, O2, O, He, and H are derived and used. It is proved that the modified Mason and Saxena approximation of the atmospheric thermal conductivity coefficient is more accurate in reproducing the atmospheric values of the rigorous hydrodynamic thermal conductivity coefficient in comparison with those that are generally accepted in atmospheric studies. This approximation of the thermal conductivity coefficient is recommended to use in calculations of the neutral temperature of the atmosphere.
Turbulence and Mixing in a Shallow Shelf Sea From Underwater Gliders
Authors: Schultze Larissa K. P. , Merckelbach Lucas M. , Carpenter Jeffrey R. 
Published: October 2017

AbstractThe seasonal thermocline in shallow shelf seas acts as a natural barrier for boundary‐generated turbulence, damping scalar transport to the upper regions of the water column and controlling primary production to a certain extent. To better understand turbulence and mixing conditions within the thermocline, two unique 12 and 17 day data sets with continuous measurements of the dissipation rate of turbulent kinetic energy (ɛ) collected by autonomous underwater gliders under stratified to well‐mixed conditions are presented. A highly intermittent ɛ signal was observed in the stratified thermocline region, which was mainly characterized by quiescent flow (turbulent activity index below 7). The rate of diapycnal mixing remained relatively constant for the majority of the time with peaks of higher fluxes that were responsible for much of the increase in bottom mixed layer temperature. The water column stayed predominantly strongly stratified, with a bulk Richardson number across the thermocline well above 2. A positive relationship between the intensity of turbulence, shear, and stratification was found. The trend between turbulence levels and the bulk Richardson number was relatively weak but suggests that ɛ increases as the bulk Richardson number approaches 1. The results also highlight the interpretation difficulties in both quantifying turbulent thermocline fluxes as well as the responsible mechanisms.
Physical Mechanisms Routing Nutrients in the Central Red Sea
Authors: Zarokanellos Nikolaos D. , Kürten Benjamin , Churchill James H. , Roder Cornelia , Voolstra Christian R. , Abualnaja Yasser , Jones Burton H. 
Published: October 2017

AbstractMesoscale eddies and boundary currents play a key role in the upper layer circulation of the Red Sea. This study assesses the physical and biochemical characteristics of an eastern boundary current (EBC) and recurrent eddies in the central Red Sea (CRS) using a combination of in situ and satellite observations. Hydrographic surveys in November 2013 (autumn) and in April 2014 (spring) in the CRS (22.15°N–24.1°N) included a total of 39 and 27 CTD stations, respectively. In addition, high‐resolution hydrographic data were acquired in spring 2014 with a towed undulating vehicle (ScanFish). In situ measurements of salinity, temperature, chlorophyll fluorescence, colored dissolved organic matter (CDOM), and dissolved nitrate: phosphorous ratios reveal distinct water mass characteristics for the two periods. An EBC, observed in the upper 150 m of the water column during autumn, transported low‐salinity and warm water from the south toward the CRS. Patches of the low‐salinity water of southern origin tended to contain relatively high concentrations of chlorophyll and CDOM. The prominent dynamic feature observed in spring was a cyclonic/anticyclonic eddy pair. The cyclonic eddy was responsible for an upward nutrient flux into the euphotic zone. Higher chlorophyll and CDOM concentrations, and concomitant lower nitrate:phosphorous ratios indicate the influence of the EBC in the CRS at the end of the stratified summer period.
Assessment of radiopharmaceutical retention for vascular access ports using positron emission tomography imaging
Authors: Gossman Michael S. , Zheng Huaiyu , Evans John G. , Li Junling , Ng Chin K. 
Published: October 2017

AbstractPurposeThe purpose of this study was to resolve the issue of whether various generations of CR Bard peripheral vascular access ports and catheters are prone to retain PET radiopharmaceuticals. The study evaluates the residual radioactivity remaining following injection for two PET radiopharmaceuticals currently used extensively in the clinic, FDG and Na18F.MethodsFDG was purchased from a local cyclotron facility and Na18F was prepared in‐house. Three generations of currently marketed vascular access ports were tested. A total of five (n = 5) of each model was tested. Radiopharmaceutical of 2–3 mCi of each was injected into each port and flushed with 10, 30, 60, and 120 ml of saline. MicroPET scans were performed after each flush to detect the residual radioactivity on each port. A dose calibrator was used to detect the retention of radioactivity after each flush.ResultsRadioactivity retention for all vascular port models measured by microPET imaging was similar for both FDG and Na18F, with less than 1% residual activity following a 10 ml saline flush. Based on the microPET images, all the subsequent flushes of 30, 60, and 120 ml were also considered. Dose calibrator activity measurements validated microPET measurements as negligible for all the ports, even with the first 10 ml flush.ConclusionsMicroPET imaging was more sensitive than the dose calibrator in determining the radioactivity retention of the vascular access ports from CR Bard. These ports may be used for the injection of FDG and Na18F to track glucose metabolism and bone uptake with PET imaging. It is recommended to apply at least a 10 ml flush after radiopharmaceutical administration, to reduce residual activity to baseline levels.
Thermoreversible Self‐Assembly of Perfluorinated Core‐Coronas Cellulose‐Nanoparticles in Dry State
Authors: Wang Yonggui , Groszewicz Pedro B. , Rosenfeldt Sabine , Schmidt Hendrik , Volkert Cynthia A. , Vana Philipp , Gutmann Torsten , Buntkowsky Gerd , Zhang Kai 
Published: October 2017

AbstractSelf‐assembly of nanoparticles (NPs) forming unique structures has been investigated extensively over the past few years. However, many self‐assembled structures by NPs are irreversible, because they are generally constructed using their suspensions. It is still challenging for NPs to reversibly self‐assemble in dry state, let alone of polymeric NPs with general sizes of hundreds of nm. Herein, this study reports a new reversible self‐assembly phenomenon of NPs in dry state, forming thermoreversible strip‐like supermolecular structures. These novel NPs of around 150 nm are perfluorinated surface‐undecenoated cellulose nanoparticles (FSU‐CNPs) with a core‐coronas structure. The thermoreversible self‐assembled structure is formed after drying in the air at the interface between FSU‐CNP films and Teflon substrates. Remarkably, the formation and dissociation of this assembled structure are accompanied by a reversible conversion of the surface hydrophobicity, film transparency, and anisotropic properties. These findings show novel feasibility of reversible self‐assembly of NPs in dry state, and thereby expand our knowledge of self‐assembly phenomenon.
Giant Room‐Temperature Magnetodielectric Response in a MOF at 0.1 Tesla
Authors: Chen Li‐Hong , Guo Jiang‐Bin , Wang Xuan , Dong Xin‐Wei , Zhao Hai‐Xia , Long La‐Sheng , Zheng Lan‐Sun 
Published: October 2017

AbstractA giant room‐temperature magnetodielectric (MD) response upon the application of a small magnetic field is of fundamental importance for the practical application of a new generation of devices. Here, the giant room‐temperature magnetodielectric response is demonstrated in the metal–organic framework (MOF) of [NH2(CH3)2]n[FeIIIFeII(1−x)NiIIx(HCOO)6]n (x ≈ 0.63–0.69) (1) with its MD coefficient remaining between −20% and −24% in the 300–410 K temperature range, even at 0.1 T. Because a room‐temperature magnetodielectric response has never been observed in MOFs, the present work not only provides a new type of magnetodielectric material but also takes a solid step toward the practical application of MOFs in a new generation of devices.
Lithiation Mechanism of Tunnel‐Structured MnO2 Electrode Investigated by In Situ Transmission Electron Microscopy
Authors: Lee Seung‐Yong , Wu Lijun , Poyraz Altug S. , Huang Jianping , Marschilok Amy C. , Takeuchi Kenneth J. , Takeuchi Esther S. , Kim Miyoung , Zhu Yimei 
Published: October 2017

AbstractManganese oxide (α‐MnO2) has been considered a promising energy material, including as a lithium‐based battery electrode candidate, due to its environmental friendliness. Thanks to its unique 1D [2 × 2] tunnel structure, α‐MnO2 can be applied to a cathode by insertion reaction and to an anode by conversion reaction in corresponding voltage ranges, in a lithium‐based battery. Numerous reports have attributed its remarkable performance to its unique tunnel structure; however, the precise electrochemical reaction mechanism remains unknown. In this study, finding of the lithiation mechanism of α‐MnO2 nanowire by in situ transmission electron microscopy (TEM) is reported. By elaborately modifying the existing in situ TEM experimental technique, rapid lithium‐ion diffusion through the tunnels is verified. Furthermore, by tracing the full lithiation procedure, the evolution of the MnO intermediate phase and the development of the MnO and Li2O phases with preferred orientations is demonstrated, which explains how the conversion reaction occurs in α‐MnO2 material. This study provides a comprehensive understanding of the electrochemical lithiation process and mechanism of α‐MnO2 material, in addition to the introduction of an improved in situ TEM biasing technique.
Electrochemical Tantalum Oxide for Resistive Switching Memories
Authors: Zaffora Andrea , Cho Deok‐Yong , Lee Kug‐Seung , Di Quarto Francesco , Waser Rainer , Santamaria Monica , Valov Ilia 
Published: October 2017

AbstractRedox‐based resistive switching memories (ReRAMs) are strongest candidates for the next‐generation nonvolatile memories fulfilling the criteria for fast, energy efficient, and scalable green IT. These types of devices can also be used for selector elements, alternative logic circuits and computing, and memristive and neuromorphic operations. ReRAMs are composed of metal/solid electrolyte/metal junctions in which the solid electrolyte is typically a metal oxide or multilayer oxides structures. Here, this study offers an effective and cheap electrochemical approach to fabricate Ta/Ta2O5‐based devices by anodizing. This method allows to grow high‐quality and dense oxide thin films onto a metallic substrates with precise control over morphology and thickness. Electrochemical‐oxide‐based devices demonstrate superior properties, i.e., endurance of at least 106 pulse cycles and/or 103I–V sweeps maintaining a good memory window with a low dispersion in ROFF and RON values, nanosecond fast switching, and data retention of at least 104 s. Multilevel programing capability is presented with both I–V sweeps and pulse measurements. Thus, it is shown that anodizing has a great prospective as a method for preparation of dense oxide films for resistive switching memories.
Supramolecular Synthesis of Multifunctional Holey Carbon Nitride Nanosheet with High‐Efficiency Photocatalytic Performance
Authors: Wan Shipeng , Ou Man , Zhong Qin , Zhang Shule , Cai Wei 
Published: October 2017

AbstractNovel carbon nitride (CN) nanosheets are for the first time fabricated by facial supramolecular approach using cyanuric acid, melamine, and 2,4‐diamino‐6‐methyl‐1,3,5‐triazine as starting materials. This is also the first report where the third monomer is used in such synthetic route. With the unique structural advantages for efficient separation of photoinduced charge–hole pairs, light absorption, and the richly available restive sites, the as‐synthesized porous CN nanosheets exhibit a superior photocatalytic hydrogen evolution activity whether they are under simulated solar light or under visible light (λ > 420 nm) irradiation. The hydrogen evolution rate can reach 11 946.1 µmol h−1g−1under visible light irradiation, to the best of our knowledge, the highest of all the metal‐free CN semiconductor photocatalysts. Also, the synthetic holey CN nanosheets exhibit excellent photocatalytic oxidation performance of high concentration nitric oxide (NO, ≈400 ppm) and outstanding photocatalytic degradation of rhodamine B under visible light. The supramolecular synthesis of multifunctional CN nanosheets using suitable monomers as raw materials may provide a possible pathway for alleviating energy issues and environmental pollution problems.
Association of common genetic variants with human skin color variation in Indian populations
Authors: Sarkar Anujit , Nandineni Madhusudan R. 
Published: October 2017

AbstractObjectivesHuman skin color is one of the most conspicuously variable physical traits that has attracted the attention of physical anthropologists, social scientists and human geneticists. Although several studies have established the underlying genes and their variants affecting human skin color, they were mostly confined to Europeans and Africans and similar studies in Indian populations have been scanty. Studying the association between candidate genetic variants and skin color will help to validate previous findings and to better understand the molecular mechanism of skin color variation.MethodsIn this study, 22 candidate SNPs from 12 genes were tested for association with skin color in 299 unrelated samples sourced from nine geographical locations in India.ResultsOur study establishes the association of 9 SNPs with the phenotype in Indian populations and could explain ∼31% of the variance in skin color. Haplotype analysis of chromosome 15 revealed a significant association of alleles G, A and C of SNPs rs1426654, rs11070627, and rs12913316, respectively, to the phenotype, and accounted for 17% of the variance. Latitude of the sampling location was also a significant factor, contributing to ∼19% of the variation observed in the samples.ConclusionsThese observations support the findings that rs1426654 and rs4775730 located in SLC24A5, and rs11070627 and rs12913316 located in MYEF2 and CTXN2 genes respectively, are major contributors toward skin pigmentation and would aid in further unraveling the genotype‐phenotype association in Indian populations. These findings can be utilized in forensic DNA applications for criminal investigations.