bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatiotemporal Variability in Lake‐Atmosphere Net CO2 Exchange in the Littoral Zone of an Oligotrophic Lake
Authors: Spafford Lynsay , Risk David 
Published: March 2018

AbstractLakes may function as either sinks or sources of CO2. Their response to climate change is uncertain, as we lack continuous data of lake CO2 efflux and its drivers. This is especially true in the littoral zone of lakes, which can be very dynamic from the continuous injection and remobilization of terrestrial nutrients. This study used high‐frequency measurements of CO2 exchange during the ice‐free season by prototype low‐power floating forced diffusion autochambers. We quantified the net surface flux of CO2 across a transect of the littoral zone of a small deep oligotrophic lake in eastern Nova Scotia, Canada, and examined potential drivers. The littoral zone was a net source for CO2, on average emitting 0.171 ± 0.023 μmol CO2 · m−2 · s−1, but we did observe significant temporal variation across diel and seasonal periods, as well as with distance from shore. While no pelagic environmental driver appeared to explain this variability in CO2 exchange, our study suggests that factors that vary on a fine spatial scale within the littoral zone may effectively regulate CO2 exchange. If environmental drivers of pelagic CO2 exchange are unrelated to CO2 exchange in the littoral zone, this may have large implications for current mechanistic understandings of lake carbon dynamics and for upscalings of fluxes. This work shows the spatial and temporal variability of littoral CO2 efflux, as well as the utility of low‐power forced diffusion automated chambers for observing lake‐atmosphere net CO2 exchange.
Experimental Demonstration of In‐Place Calibration for Time Domain Microwave Imaging System
Authors: Kwon S. , Son S. , Lee K. 
Published: March 2018

AbstractIn this study, the experimental demonstration of in‐place calibration was conducted using the developed time domain measurement system. Experiments were conducted using three calibration methods—in‐place calibration and two existing calibrations, that is, array rotation and differential calibration. The in‐place calibration uses dual receivers located at an equal distance from the transmitter. The received signals at the dual receivers contain similar unwanted signals, that is, the directly received signal and antenna coupling. In contrast to the simulations, the antennas are not perfectly matched and there might be unexpected environmental errors. Thus, we experimented with the developed experimental system to demonstrate the proposed method. The possible problems with low signal‐to‐noise ratio and clock jitter, which may exist in time domain systems, were rectified by averaging repeatedly measured signals. The tumor was successfully detected using the three calibration methods according to the experimental results. The cross correlation was calculated using the reconstructed image of the ideal differential calibration for a quantitative comparison between the existing rotation calibration and the proposed in‐place calibration. The mean value of cross correlation between the in‐place calibration and ideal differential calibration was 0.80, and the mean value of cross correlation of the rotation calibration was 0.55. Furthermore, the results of simulation were compared with the experimental results to verify the in‐place calibration method. A quantitative analysis was also performed, and the experimental results show a tendency similar to the simulation.
Wireless Sensor Network for Radiometric Detection and Assessment of Partial Discharge in High‐Voltage Equipment
Authors: Upton D. W. , Saeed B. I. , Mather P. J. , Lazaridis P. I. , Vieira M. F. Q. , Atkinson R. C. , Tachtatzis C. , Garcia M. S. , Judd M. D. , Glover I. A. 
Published: March 2018

AbstractMonitoring of partial discharge (PD) activity within high‐voltage electrical environments is increasingly used for the assessment of insulation condition. Traditional measurement techniques employ technologies that either require off‐line installation or have high power consumption and are hence costly. A wireless sensor network is proposed that utilizes only received signal strength to locate areas of PD activity within a high‐voltage electricity substation. The network comprises low‐power and low‐cost radiometric sensor nodes which receive the radiation propagated from a source of PD. Results are reported from several empirical tests performed within a large indoor environment and a substation environment using a network of nine sensor nodes. A portable PD source emulator was placed at multiple locations within the network. Signal strength measured by the nodes is reported via WirelessHART to a data collection hub where it is processed using a location algorithm. The results obtained place the measured location within 2 m of the actual source location.
Evaluation of the Sq Magnetic Field Variation Calculated by GAIA
Authors: Fujita Shigeru , Murata Yuka , Fujii Ikuko , Miyoshi Yasunobu , Shinagawa Hiroyuki , Jin Hidekatsu , Fujiwara Hitoshi 
Published: March 2018

AbstractMagnetic variations calculated by the Ground‐to‐topside model of Atmosphere and Ionosphere for Aeronomy (GAIA) are compared with those observed at global magnetic observatory network in geomagnetic calm days in order to evaluate accuracy of the ionospheric current system calculated by GAIA. The calculated Y component magnetic variations can reproduce more than 50% of the observed variations at more than half observatories treated. In particular, GAIA can reproduce more than 75% of the observed Y component variations in the equinox, whereas there is tendency of low correlation of the waveform between the calculated and observed variations in the winter season. Next, GAIA reproduces so well of the X component variations at the low‐latitude observatories. Low correlation between the calculated and observed X component variations at middle‐latitude observatories seems to be caused by inaccurate determination of the position of the ionospheric Sq current vortex. Last, although the calculated Z component variations do not so well reproduce the observed ones compared with other component, GAIA can reproduce more than 50% of the observed Z component variation at about half observatories in general. Calculated amplitude of the horizontal magnetic variations (X and Y components) exhibit smaller than the observed one whereas that of the vertical variation (Z component) is larger than the observed one. This tendency is roughly explained by the induction effect of the Earth that is not considered in GAIA. Thus, GAIA considerably well reproduces the pure ionospheric current system that is not affected by the solid Earth.
Spatial and Temporal Variations in the Moment Tensor Solutions of the 2008 Wenchuan Earthquake Aftershocks and Their Tectonic Implications
Authors: Lin X. , Dreger D. , Ge H. , Xu P. , Wu M. , Chiang A. , Zhao G. , Yuan H. 
Published: March 2018

AbstractFollowing the mainshock of the 2008 M8 Wenchuan Earthquake, there were more than 300 ML ≥ 4.0 aftershocks that occurred between 12 May 2008 and 8 September 2010. We analyzed the broadband waveforms for these events and found 160 events with sufficient signal‐to‐noise levels to invert for seismic moment tensors. Considering the length of the activated fault and the distances to the recording stations, four velocity models were employed to account for variability in crustal structure. The moment tensor solutions show considerable variations with a mixture of mainly reverse and strike‐slip mechanisms and a small number of normal events and ambiguous events. We analyzed the spatial and temporal distribution of the aftershocks and their mechanism types to characterize the structure and the deformation occurring in the Longmen Shan fold and thrust belt. Our results suggest that the stress is very complex at the Longmen Shan fault zone. The moment tensors have both a spatial segmentation with two major categories of the moment tensor of thrust and strike slip; and a temporal pattern that the majority of the aftershocks gradually migrated to thrust‐type events. The variability of aftershock mechanisms is a strong indication of significant tectonic release and stress reorganization that activated numerous small faults in the system.
Tritium Records to Trace Stratospheric Moisture Inputs in Antarctica
Authors: Fourré E. , Landais A. , Cauquoin A. , Jean‐Baptiste P. , Lipenkov V. , Petit J.‐R. 
Published: March 2018

AbstractBetter assessing the dynamic of stratosphere‐troposphere exchange is a key point to improve our understanding of the climate dynamic in the East Antarctica Plateau, a region where stratospheric inputs are expected to be important. Although tritium (3H or T), a nuclide naturally produced mainly in the stratosphere and rapidly entering the water cycle as HTO, seems a first‐rate tracer to study these processes, tritium data are very sparse in this region. We present the first high‐resolution measurements of tritium concentration over the last 50 years in three snow pits drilled at the Vostok station. Natural variability of the tritium records reveals two prominent frequencies, one at about 10 years (to be related to the solar Schwabe cycles) and the other one at a shorter periodicity: despite dating uncertainty at this short scale, a good correlation is observed between 3H and Na+ and an anticorrelation between 3H and δ18O measured on an individual pit. The outputs from the LMDZ Atmospheric General Circulation Model including stable water isotopes and tritium show the same 3H‐δ18O anticorrelation and allow further investigation on the associated mechanism. At the interannual scale, the modeled 3H variability matches well with the Southern Annular Mode index. At the seasonal scale, we show that modeled stratospheric tritium inputs in the troposphere are favored in winter cold and dry conditions.
Eperythrozoon
Authors: Brown Daniel R. , Tasker Séverine , Messick Joanne B. , Neimark Harold 
Published: March 2018

Ep.e.ry.thro.zo'on. Gr. pref.epion; Gr. adj.erythrosred; Gr. neut. n.zoonliving being, animal; N.L. neut. n.Eperythrozoon(presumably intended to mean) animals on red (blood cells).Tenericutes / Mollicutes / Mycoplasmatales / incertae Sedis ‐ Family II / EperythrozoonThe taxonomy and nomenclature of hemotropic bacteria first assigned in 1928 to the genusEperythrozoonare matters of current controversy. It is now undisputed that, on the basis of their lack of a cell wall, small (typically 350–500 nm in diameter) cell size, low (27–34 mol%) G + C content, use of the codon UGA to encode tryptophan, regular association with vertebrate hosts, and 16S rRNA gene sequences most similar (80–84%) to species in genusMycoplasma, these organisms are properly affiliated with the orderMycoplasmatales. However, the proposed transfers ofEperythrozoonandHaemobartonellaspecies to genusMycoplasmawere opposed on the grounds that the degree of 16S rRNA gene sequence similarity is insufficient. The alternative of situating them in a new genus in familyMycoplasmataceaewould regrettably compound polyphyly within genusMycoplasmaon no other basis than a capacity to adhere to the surface of erythrocytesin vivo. A second alternative, transfer of the nomenclatural type speciesEperythrozoon coccoidesto the genusMycoplasma, is complicated by priority becauseEperythrozoonpredatesMycoplasma. However, the third alternative of uniting the genera by transferring all mycoplasmas to the genusEperythrozoonis completely unjustifiable considering the biological characteristics of the nonhemotropic majority ofMycoplasmaspecies. A provisional placement of the formerEperythrozoonspecies in the genusMycoplasmahas nevertheless been embraced by specialists in the molecular biology and clinical pathogenicity of these and similar hemotropic organisms.Type species:Eperythrozoon coccoidesSchilling 1928, 1854.DNA G+C content (mol%): 27–34.
Robust optimization in lung treatment plans accounting for geometric uncertainty
Authors: Zhang Xin , Rong Yi , Morrill Steven , Fang Jian , Narayanasamy Ganesh , Galhardo Edvaldo , Maraboyina Sanjay , Croft Christopher , xia Fen , Penagaricano Jose 
Published: March 2018

AbstractRobust optimization generates scenario‐based plans by a minimax optimization method to find optimal scenario for the trade‐off between target coverage robustness and organ‐at‐risk (OAR) sparing. In this study, 20 lung cancer patients with tumors located at various anatomical regions within the lungs were selected and robust optimization photon treatment plans including intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were generated. The plan robustness was analyzed using perturbed doses with setup error boundary of ±3 mm in anterior/posterior (AP), ±3 mm in left/right (LR), and ±5 mm in inferior/superior (IS) directions from isocenter. Perturbed doses for D99, D98, and D95 were computed from six shifted isocenter plans to evaluate plan robustness. Dosimetric study was performed to compare the internal target volume‐based robust optimization plans (ITV‐IMRT and ITV‐VMAT) and conventional PTV margin‐based plans (PTV‐IMRT and PTV‐VMAT). The dosimetric comparison parameters were: ITV target mean dose (Dmean), R95(D95/Dprescription), Paddick's conformity index (CI), homogeneity index (HI), monitor unit (MU), and OAR doses including lung (Dmean, V20 Gy and V15 Gy), chest wall, heart, esophagus, and maximum cord doses. A comparison of optimization results showed the robust optimization plan had better ITV dose coverage, better CI, worse HI, and lower OAR doses than conventional PTV margin‐based plans. Plan robustness evaluation showed that the perturbed doses of D99, D98, and D95 were all satisfied at least 99% of the ITV to received 95% of prescription doses. It was also observed that PTV margin‐based plans had higher MU than robust optimization plans. The results also showed robust optimization can generate plans that offer increased OAR sparing, especially for normal lungs and OARs near or abutting the target. Weak correlation was found between normal lung dose and target size, and no other correlation was observed in this study.
Development of clinically relevant QA procedures for the BrainLab ExacTrac imaging system
Authors: Iftimia Ileana , Halvorsen Per H. 
Published: March 2018

AbstractPurposeThe aim of this study was to develop Quality Assurance procedures for the BrainLab ExacTrac (ET) imaging system following the TG 142 recommendations for planar kV imaging systems.Materials and MethodsA custom‐designed 3D printed holder was used to position the Standard Imaging QCkV‐1 phantom at isocenter, facing the ET X ray tubes. The linac's light field (collimator at 45⁰) was used to position the phantom holder. The ET images were exported to ARIA where geometric distortion was checked. The DICOM images were analyzed in the PIPSpro software. The following parameters were recorded (technique 80 kV/2mAs): spatial resolution (Modulated Transfer Function (MTF) F50/F40/F30), contrast‐to‐noise ratio (CNR), and noise. A baseline was generated for future image analysis. Beam quality and exposure were measured using the Unfors R/F detector. Using a rod holder, the detector was placed at isocenter, facing each ET X‐ray tube. The measurements were performed for all preset protocols ranging from cranial low (80 kV/6.3 mAs) to abdomen high (145 kV/25 mAs). The total exposure was converted to dose.Results and DiscussionThe image quality parameters were close for the two tubes. A common baseline was therefore generated. The average baseline values (both tubes, both images/tube) were 1.06/1.18/1.30, 1.32, and 67.3 for the MTF F50/F40/F30, noise, and CNR respectively. The procedure described here was used for another 24 sets. Using a positioning template and 3D printed phantom holder, experimental reproducibility has been acceptably high. The measured phantom dimensions were within 1 mm from the nominal values. The measured kV values were within 2% of the nominal values. The exposure values for the two tubes were comparable. The range of total measured dose was 0.099 mGy (cranial low) to 1.353 mGy (abdomen high).ConclusionsA reliable process has been implemented for QA of the ET imaging system by characterizing the system's performance at isocenter, consistent with clinical conventions.
CSF/serum matrix metallopeptidase‐9 ratio discriminates neuro Behçet from multiple sclerosis
Authors: Aldinucci Alessandra , Bonechi Elena , Biagioli Tiziana , Repice Anna M. , D'Elios Mario M. , Emmi Lorenzo , Emmi Giacomo , Silvestri Elena , Barilaro Alessandro , Ballerini Clara 
Published: March 2018

AbstractIn neuro Behçet disease with multiple sclerosis‐like features, diagnosis could be challenging. Here, we studied the cerebrospinal fluid and serum inflammatory profile of 11 neuro Behçet and 21 relapsing‐remitting multiple sclerosis patients. Between the soluble factors analyzed (MMP9, TNFα, IL6, CXCL13, CXCL10, CXCL8, IFNγ, IL10, IL17, IL23, and others) we found MMP9 increased in neuro Behçet serum compared to multiple sclerosis and decreased in cerebrospinal fluid. Furthermore, neuro Behçet analysis of circulating natural killer CD56DIM subset suggests their potential involvement in increased MMP9 production. We believe that these findings may have a translational utility in clinical practice.
Myelin protein zero mutations and the unfolded protein response in Charcot Marie Tooth disease type 1B
Authors: Bai Yunhong , Wu Xingyao , Brennan Kathryn M. , Wang David S. , D'Antonio Maurizio , Moran John , Svaren John , Shy Michael E. 
Published: March 2018

AbstractObjectiveTo determine the prevalence of MPZ mutations that cause Charcot Marie Tooth neuropathy type 1B (CMT1B) and activate the unfolded protein Response (UPR).BackgroundCMT1B is caused by >200 heterozygous mutations in MPZ, the major protein in peripheral nerve myelin. Mutations Ser63del MPZ and Arg98Cys MPZ cause the mutant protein to be retained in the ER and activate the generally adaptive UPR. Treatments that modulate UPR activation have improved cellular and rodent models of CMT1B raising the possibility that other MPZ mutations that activate the UPR would also respond favorably to similar treatment. The prevalence of MPZ mutations that activate the UPR is unknown.MethodsWe developed a dual luciferase reporter assay of Xbp1 splicing using stably transfected RT4 Schwann cells to assay the ability of cDNA constructs bearing 46 distinct MPZ mutations to activate the UPR. Constructs also carried an HA tag to permit detection of ER retention of mutant proteins. UPR activation and ER retention were correlated with clinical phenotypes.ResultsEighteen mutations demonstrated ER retention and UPR activation to a similar degree as Ser63del and Arg98Cys MPZ. Thirty‐five of the mutations activated the UPR > 1.5 fold compared to that of wild‐type MPZ. Correlation was high between firefly and Nano‐luciferase reporters and between both reporters and ER localization. UPR activity did not correlate with clinical onset or severity.ConclusionMany CMT1B causing mutations activate the UPR and may be susceptible to therapeutic efforts to facilitate UPR function.
Nickel Catalyzed Ipso‐hydroxylation and Subsequent Cross Dehydrogenative Coupling of Arylboronic Acids with Tertiary Amines: A Facile Access to α‐phenolated Tertiary Amines
Authors: Kumar Promod , Kumar Sharma Anup , Singh Rahul , Guntreddi Tirumaleswararao , Nand Singh Krishna 
Published: March 2018

AbstractA straightforward and new approach has been developed for the α‐functionalization of tertiary amines via sequential oxidative hydoxylation and cross‐dehydrogenative coupling (CDC) of arylboronic acids with tertiary amines to afford α‐phenolated tertiary amines. The results demonstrate an easy arylation of C(sp3)−H bond in the presence of an inexpensive and readily available nickel metal salt.magnified image
Rapid Formation of Fluoren‐9‐ones via Palladium‐Catalyzed External Carbon Monoxide‐Free Carbonylation
Authors: Konishi Hideyuki , Futamata Suguru , Wang Xi , Manabe Kei 
Published: March 2018

AbstractA Pd‐catalyzed carbonylation reaction for the synthesis of fluoren‐9‐ones from 2‐halogenated biphenyls using phenyl formate as a carbon monoxide surrogate was achieved. The combined use of cesium carbonate and o‐anisic acid resulted in a remarkable rate enhancement, where the reaction was complete within 3 min in some cases. Mechanistic studies indicated that the turnover‐limiting step of the reaction was the C−H bond‐cleaving step or the oxidative addition step, depending on the substrate used.magnified image
Nanofabricated Ultraflexible Electrode Arrays for High‐Density Intracortical Recording
Authors: Wei Xiaoling , Luan Lan , Zhao Zhengtuo , Li Xue , Zhu Hanlin , Potnis Ojas , Xie Chong 
Published: March 2018

AbstractUnderstanding brain functions at the circuit level requires time‐resolved simultaneous measurement of a large number of densely distributed neurons, which remains a great challenge for current neural technologies. In particular, penetrating neural electrodes allow for recording from individual neurons at high temporal resolution, but often have larger dimensions than the biological matrix, which induces significant damage to brain tissues and therefore precludes the high implant density that is necessary for mapping large neuronal populations with full coverage. Here, it is demonstrated that nanofabricated ultraflexible electrode arrays with cross‐sectional areas as small as sub‐10 µm2 can overcome this physical limitation. In a mouse model, it is shown that these electrodes record action potentials with high signal‐to‐noise ratio; their dense arrays allow spatial oversampling; and their multiprobe implantation allows for interprobe spacing at 60 µm without eliciting chronic neuronal degeneration. These results present the possibility of minimizing tissue displacement by implanted ultraflexible electrodes for scalable, high‐density electrophysiological recording that is capable of complete neuronal circuitry mapping over chronic time scales.
Vessel‐associated cells in angiosperm xylem: Highly specialized living cells at the symplast–apoplast boundary
Authors: Morris Hugh , Plavcová Lenka , Gorai Mustapha , Klepsch Matthias M. , Kotowska Martyna , Jochen Schenk H. , Jansen Steven 
Published: March 2018

BackgroundVessel‐associated cells (VACs) are highly specialized, living parenchyma cells that are in direct contact with water‐conducting, dead vessels. The contact may be sparse or in large tight groups of parenchyma that completely surrounds vessels. VACs differ from vessel distant parenchyma in physiology, anatomy, and function and have half‐bordered pits at the vessel‐parenchyma juncture. The distinct anatomy of VACs is related to the exchange of substances to and from the water‐transport system, with the cells long thought to be involved in water transport in woody angiosperms, but where direct experimental evidence is lacking.ScopeThis review focuses on our current knowledge of VACs regarding anatomy and function, including hydraulic capacitance, storage of nonstructural carbohydrates, symplastic and apoplastic interactions, defense against pathogens and frost, osmoregulation, and the novel hypothesis of surfactant production. Based on microscopy, we visually represent how VACs vary in dimensions and general appearance between species, with special attention to the protoplast, amorphous layer, and the vessel‐parenchyma pit membrane.ConclusionsAn understanding of the relationship between VACs and vessels is crucial to tackling questions related to how water is transported over long distances in xylem, as well as defense against pathogens. New avenues of research show how parenchyma‐vessel contact is related to vessel diameter and a new hypothesis may explain how surfactants arising from VAC can allow water to travel under negative pressure. We also reinforce the message of connectivity between VAC and other cells between xylem and phloem.