bluuebunny/crossref_metadata_2025_split huggingface dataset:
On-site in situ high-pressure ultrafast pump–probe spectroscopy instrument
Authors: Wu Y. L. , Yin X. , Hasaien J. Z. L. , Tian Z. Y. , Ding Yang , Zhao Jimin 
Published: November 2021

We conceive and construct an on-site in situ high-pressure time-resolved ultrafast optical spectroscopy instrument that facilitates ultrafast pump–probe dynamics measurements under high pressure conditions. We integrate an ultrafast pump–probe spectroscopy system with a diamond anvil cell (DAC) system. Significantly, both the DAC and the sample are fixed within the light path without motion and rotation throughout the whole ultrafast spectroscopy experiment, including tuning and calibrating the pressure. This instrument thus avoids introducing artifacts due to sample motion or rotation, enabling precision high-pressure ultrafast pump–probe dynamics investigations. As a demonstrating example, we compare the effect of on-site in situ conditions with off-site in situ conditions on the ultrafast dynamics of Sr2IrO4 under 0–44.5 GPa high pressure. Our data and analysis show that conventional possible artifacts are greatly reduced by using the on-site in situ layout. Our work helps the high-pressure ultrafast science investigation develop into a promising new area, which enables the exploration of nonequilibrium excited quantum states in the high-pressure regime.
Tillage and its temporal effects on soil organic matter and microbial characteristics in the semi-arid central South Africa
Authors: Loke P. F. , Heine H. G. , Rhode O. H. J. , Kotzé E. , Du Preez C. C. 
Published: November 2021

Context Tillage has temporal effects on soil organic matter and microbial attributes. Aim Three tillage systems (NT, no-tillage; MT, mulch tillage; MP, mouldboard ploughing) were used to assess the impact on soil quality indicators such as gravimetric soil water content (GSWC), soil organic carbon (SOC), total nitrogen (TN), easily extractable-glomalin (G EE), dehydrogenase (DHA), β-glucosidase (β-glu), urease (URE), acid-(AcP) and alkaline-(AlP) phosphatase over time in a sandy-loam Plinthustalf cropped annually with winter wheat and occasionally oat in eastern Free State. Methods Samples were collected during oat (October 2010, November 2010), fallow (February 2011, April 2011, May 2011) and wheat (August 2011, September 2011, October 2011) phases at 0–5 and 5–10 cm depth. Results When averaged over sampling dates, GSWC, SOC, TN and enzyme activities were 6–85% higher under NT than in MT and MP in the upper 5 cm soil. Trends changed at the 5–10 cm depth, with 20–32% higher enzyme activities recorded under MT. Soil quality indicators exhibited different trends over time, with GSWC, TN, DHA, AcP and AlP generally increasing during the fallow period and decreasing during oat and wheat phases, while β-glu was higher during both crop phases than at fallowing. URE was 33.6–174.3% higher during the oat phase than at the fallow and wheat phases. The opposite was observed with SOC, C/N ratio and G EE. Conclusions Enzyme activities were sensitive indicators, but SOC and TN can be used to assess temporal changes in soil quality in resource-limited countries. Implications However, temporal effects on SOC and TN were probably built in the long-term, hence further research focusing on multiple seasons is required.
Anammox bacteria drive fixed nitrogen loss in hadal trench sediments
Authors: Thamdrup Bo , Schauberger Clemens , Larsen Morten , Trouche Blandine , Maignien Lois , Arnaud-Haond Sophie , Wenzhöfer Frank , Glud Ronnie N. 
Published: November 2021

SignificanceHadal trenches represent the deepest part of the oceans, apparently offering adverse conditions for life, given their high hydrostatic pressure and wide separation from the productive surface waters. However, focusing of reactive organic matter in trench axis sediments potentially promotes complex yet unexplored microbial communities and associated biogeochemical processes. We demonstrate that hadal sediments at depths reaching 10 km are hotbeds for anaerobic nitrogen transformations, dominated by the anammox process, extending the known depth range of this process by ∼6 km. The diversity and phylogeny of identified hadal anammox bacteria suggest that high hydrostatic pressure has not been a major evolutionary driver. Our results provide insights into hadal biogeochemistry and the ability of microbes to adapt to hydrostatic pressure.
Fluid intelligence and the locus coeruleus–norepinephrine system
Authors: Tsukahara Jason S. , Engle Randall W. 
Published: November 2021

SignificanceTo understand mind and behavior we must understand the biological basis of intelligence. Despite significant progress, we lack a complete picture that integrates different levels of brain function and explains individual differences in cognitive ability. We propose that the locus coeruleus, the source of norepinephrine for the brain, plays a key role in this puzzle. It does so at all levels of brain function, regulating processes of learning, memory, and attention. We use baseline pupil size, which covaries with locus coeruleus activity, to anchor the present analyses of the role of the locus coeruleus in cognitive ability. This work provides a foundation for future research integrating different levels of brain function with individual differences in cognitive ability.
The A39G FF domain folds on a volcano-shaped free energy surface via separate pathways
Authors: Tiwari Ved P. , Toyama Yuki , De Debajyoti , Kay Lewis E. , Vallurupalli Pramodh 
Published: November 2021

Significance
Protein molecules interconvert between multiple states, and this exchange process plays an important role in function and misfunction. Here, we use powerful NMR experiments that probe sparsely populated, transiently formed conformational states, which exchange with a highly populated, stable, folded conformer in order to elucidate the folding mechanism of a small protein domain. Notably, by analyzing the exchange profiles in detail, it becomes possible to obtain structural data for states that are about 10-fold less populated and less long lived than has previously been possible. Our results establish that the small FF domain folds via two partially structured intermediates and involves a pair of discrete pathways in which the unfolded state becomes increasingly structured along a volcano-shaped free energy surface.
Investigations of the linear and non-linear flow harmonics using the a multi-phase transport model
Authors: Magdy Niseem 
Published: November 2021

Abstract
The multi-phase transport model (AMPT) is used to study the effects of the parton-scattering cross-sections (σ
pp) and hadronic re-scattering on the linear contributions to the flow harmonic v
4, the non-linear response coefficients, and the correlations between different order flow symmetry planes in Au + Au collisions at 200 GeV. The model results, which agree with current experimental measurements, indicate that the higher-order flow harmonics are sensitive to the σ
pp variations. However, the non-linear response coefficients and the correlations between different order flow symmetry planes are σ
pp independent. These results suggest that further detailed experimental measurements which span a broad range of collision systems and beam energies could serve as an additional constraint for the theoretical models’ calculations.
A novel method based on the Otsu threshold for instantaneous elimination of light reflection in PIV images
Authors: Amaral Rodrigo de Lima , Bortolin Vítor Augusto Andreghetto , Lemos Bernardo Luiz Harry Diniz , Mazzeto Marcelo , Cestari Idágene Aparecida , Meneghini Julio Romano 
Published: November 2021

Abstract
The base of particle image velocimetry (PIV) is the maximization of the correlation between the distribution of particle images in an interrogation window or a volume separated by an instant of time. In real images, the unwanted reflection of light on fixed walls or moving objects can directly interfere with the correlation, deteriorating the PIV quality. In this work, a new method for generating instantaneous masks based on the Otsu threshold for instantaneous elimination of light reflection in PIV images is proposed. This method separates the saturated image caused by the unwanted scattering of light from the tracer particles images through the Otsu threshold combined with the Gauss filter and Wiener adaptive local filter. This new method, called Otsu–Gauss–Wiener (OGW), was first tested using synthetic PIV images. In these tests, the authors analyzed the reflection caused by an object regarding different sizes, shapes, and intensities to evaluate the performance of the proposed method. Later, the OGW method was tested in PIV experimental cases with real adversities, for example, scattering of light on a fixed wall in a channel with periodic hills (case B—4th PIV challenge), strong reflection in a centrifugal impeller (case C—1st PIV challenge) and light scattering caused by an out-of-plane motion of the diaphragm of a pulsatile pediatric ventricular assist device. The results show that the method can remove the reflections by static and moving objects using an automatic mask generated for each instantaneous image.
A dense RGB-D SLAM algorithm based on convolutional neural network of multi-layer image invariant feature
Authors: Su Yan , Yu Lei 
Published: November 2021

Abstract
Simultaneous localization and mapping (SLAM) is one of the key technologies used in sweepers, autonomous vehicles, virtual reality and other fields. This paper presents a dense three-channel color images composed of red, green and blue and depth images SLAM reconstruction algorithm based on convolutional neural network (CNN) of multi-layer image invariant feature transformation. The main contribution of the system lies in the construction of a CNN based on multi-layer image invariant feature, which optimized the extraction of Oriented FAST and Rotated Brief(ORB) feature points and the reconstruction effect. After the feature point matching, pose estimation, loop detection and other steps, the 3D point clouds were finally spliced to construct a complete and smooth spatial model. The system can improve the accuracy and robustness in feature point processing and pose estimation. Comparative experiments show that the optimized algorithm saves 0.093 s compared to the ordinary extraction algorithm while guaranteeing a high accuracy rate at the same time. The results of reconstruction experiments show that the spatial models have more clear details, smoother connection with no fault layers than the original ones. The reconstruction results are generally better than other common algorithms, such as Kintinuous, Elasticfusion and ORBSLAM2 dense reconstruction.
Analysis of relative changes in pulse shapes of intracranial pressure and cerebral blood flow velocity
Authors: Ziółkowski Arkadiusz , Pudełko Agata , Kazimierska Agnieszka , Czosnyka Zofia , Czosnyka Marek , Kasprowicz Magdalena 
Published: November 2021

Abstract

Objective. Analysis of relative changes in the shapes of pulse waveforms of intracranial pressure (ICP) and transcranial Doppler cerebral blood flow velocity (CBFV) may provide information on intracranial compliance. We tested this hypothesis, introducing an index named the ratio of pulse slopes (RPS) that is based on inclinations of the ascending parts of the ICP and CBFV pulse waveforms. It has hypothetically a simple interpretation: a value of 1 indicates good compliance and a value less than 1, reduced compliance. Here, we investigated the usefulness of RPS for assessment of intracranial compliance. Approach. ICP and CBFV signals recorded simultaneously in 30 normal-pressure hydrocephalus patients during infusion tests were retrospectively analysed. CBFV was measured in the middle cerebral artery. Changes in RPS during the test were compared with changes in the height ratio of the first and second peak of the ICP pulse (P1/P2) and the shape of the ICP pulse was classified from normal (1) to pathological (4). Values are medians (lower, upper quartiles). Main results. There was a significant correlation between baseline RPS and intracranial elasticity (R = −0.55, p = 0.0018). During the infusion tests, both RPS and P1/P2 decreased with rising ICP [RPS, 0.80 (0.56, 0.92) versus 0.63 (0.44, 0.80), p = 0.00015; P1/P2, 0.58 (0.50, 0.91) versus 0.52 (0.36, 0.71), p = 0.00009] while the ICP pulses became more pathological in shape [class: 3 (2, 3) versus 3 (3, 4), p = 0.04]. The magnitude of the decrease in RPS during infusion was inversely correlated with baseline P1/P2 (R = −0.40, p < 0.03). Significance. During infusion, the slopes of the ascending parts of ICP and CBFV pulses become increasingly divergent with a shift in opposite directions. RPS seems to be a promising methodological tool for monitoring intracranial compliance with no additional volumetric manipulation required.
Nonhomogeneous volume conduction effects affecting needle electromyography: an analytical and simulation study
Authors: Luo Xuesong , Wang Shaoping , Rutkove Seward B , Sanchez Benjamin 
Published: November 2021

Abstract

Objective. Needle electromyography (EMG) is used to study the electrical behavior of myofiber properties in patients with neuromuscular disorders. However, due to the complexity of electrical potential spatial propagation in nonhomogeneous diseased muscle, a comprehensive understanding of volume conduction effects remains elusive. Here, we develop a framework to study the conduction effect of extracellular abnormalities and electrode positioning on extracellular local field potential (LFP) recordings. Methods. The framework describes the macroscopic conduction of electrical potential in an isotropic, nonhomogeneous (i.e. two tissue) model. Numerical and finite element model simulations are provided to study the conduction effect in prototypical monopolar EMG measurements. Results. LFPs recorded are influenced in amplitude, phase and duration by the electrode position in regards to the vicinity of tissue with different electrical properties. Conclusion. The framework reveals the influence of multiple mechanisms affecting LFPs including changes in the distance between the source–electrode and tissue electrical properties. Clinical significance. Our modeled predictions may lead to new ways for interpreting volume conduction effects on recorded EMG activity, for example in neuromuscular diseases that cause structural and compositional changes in muscle tissue. These change will manifest itself by changing the electric properties of the conductor media and will impact recorded potentials in the area of affected tissue.
The ITB dynamics controlled by internal kink modes on HL-2A tokamak
Authors: He X X , Yan L W , Yu D L , Chen W , Yu L M , Ma Q , Liu L , Wei Y L , He X F , Zhang N , Li Y G , Sun T F , Nie L , Shi Z B , Zhong W L , Xu M , Duan X R 
Published: November 2021

Abstract
The active control of internal transport barriers (ITBs) is an important issue to achieve high performance plasma in a fusion reactor. A critical challenge of ITB control is to increase the ITB position. The ITBs with internal kink modes (IKMs), such as fishbone (FB) instability and long-live mode (LLM) with mode number of m/n = 1/1 are frequently observed on HL-2A tokamak in neutral beam heated discharges. The correlation of FB instability/LLM with ITBs is analyzed in order to extend the ITB radius. It has been revealed that FB instability and LLM are often excited after the ITB formation. Therefore, FB instability and LLM play no role in triggering ITBs on HL-2A tokamak. On the other hand, they may slow down the outward radial expansion and then shrink the foot position of ITB, and damp the gradient growth of ion temperature and rotation velocity. Since the perturbation of LLM is weaker than that of FB instability, the shrinking effect of ITB foot and braking effect on gradient growth are slighter than those of FB instability. Compared with the LLM, FB instability routinely appears in plasmas with lower density, higher heating power and lower plasma current. In addition, large ITBs without IKMs are also discussed on HL-2A tokamak. The large ITB is the largest one, the FB ITB is the strongest one and the LLM ITB is the widest one in three ITBs, where the ‘large’, ‘strong’ and ‘wide’ qualifications correspond to ITB position ρ
ITB, the normalized temperature gradient R/LT, and its width W/a. Therefore, the large ITB position may be obtained if the IKMs are effectively controlled in a tokamak.
A new approach for displacement and stress monitoring of tunnel based on iFEM methodology
Authors: Savino Pierclaudio , Tondolo Francesco 
Published: November 2021

Abstract
Structural monitoring plays a key role for underground structures such as tunnels. Strain readings are expected to report structural conditions during construction and at the final delivery of the works. Furthermore, it is increasingly requested an extension to long-term monitoring from contractors with possible use of the same system in service during construction. A robust and efficient monitoring methodology from discrete strain measurements is the inverse finite element method (iFEM), which allows to reconstruct the structural response without input data on the load pattern applied to the structure as well as material and inertial properties of the elements and therefore it is interesting for structural configurations affected by uncertain loading conditions, such as the tunnel. The formulation presented in this paper, based on the iFEM theory, is improved from the previous work available in literature for both the shape functions used and the computational procedure. Indeed, the approach allows to overcome inconsistencies related to structural loading conditions and a pseudo-inverse matrix preserve all the rigid body modes without imposing specific constraints which is typical for tunnels. Numerical validation of the iFEM procedure is performed by simulating the input data coming from a tunnel working in a heterogeneous soil under different loading conditions with direct FEM analysis.
The Variability of the Narrow-line Seyfert 1 Galaxies from the Pan-STARRS’s View
Authors: Wang Hong-Tao , Su Yan-Ping , Ge Xue , Chen Yong-Yun , Yu Xiao-Ling 
Published: November 2021

Abstract
By means of the data sets from the Pan-STARRS1 survey, we have systematically examined the relationship between the variability characteristics and the physical parameters of the largest NLS1 galaxy sample up to now. The results are summarized as follows: (1). We find significant anti-correlations between variability amplitude and absolute magnitude in g, r, i, z and y bands, which are consistent with the results in previous works. (2) The correlations between the variability amplitude in optical band and many physical parameters (e.g., λ
L(5100 Å), black hole mass, Eddington ratio, R
4570 and R
5007) are investigated. The results show the variability amplitude is significantly anti-correlated with L(5100 Å), M
BH, Eddington ratio and R
4570, but positively correlated with R
5007. The relation could be explained by the simple standard accretion disk model. (3) We further investigate the relationship between optical variability and radio luminosity/radio-loudness. The results present weak positive correlation in g and r bands, but insignificant correlation in i, z and y bands. The large error of the approximate fraction of the host galaxy in i, z and y bands may lead to insignificant correlations.
Strong Spatial Aggregation of Martian Surface Temperature Shaped by Spatial and Seasonal Variations in Meteorological and Environmental Factors
Authors: Luo Yao-Wen , Li Fei , Yan Jian-Guo , Barriot Jean-Pierre 
Published: November 2021

Abstract
Spatio-temporal variation in the Martian surface temperature (MST) is an indicator of ground level thermal processes and hence a building block for climate models. However, the distribution of MST exhibits different levels of spatial aggregation or heterogeneity, and varies in space and time. Furthermore, the effect of regional differences in meteorological or environmental factors on the MST is not well understood. Thus, we investigated the degree of spatial autocorrelation of MST across the surface of Mars globally by Moran’s I, and identified the hot spots by GetisOrd

G

i

*

. We also estimated the regional differences in the influence of seasonally dominant factors including thermal inertia (TI), albedo, surface pressure, latitude, dust and slope on MST by a geographically weighted regression model. The results indicate (1) that MST is spatially aggregated and hot and cold spots varied over time and space. (2) Hemispheric differences in topography, surface TI and albedo were primarily responsible for the hemispheric asymmetry of hot spots. (3) The dominant factors varied by geographical locations and seasons. For example, the seasonal Hadley circulation dominates at the low-latitudes and CO2 circulation at the high-latitudes. (4) Regions with extreme variations in topography and low TI were sensitive to meteorological and environmental factors such as dust and CO2 ice. We conclude that the spatial autocorrelation of MST and the spatial and seasonal heterogeneity of influencing factors must be considered when simulating Martian climate models. This work provides a reference for further exploration of Martian climatic processes.
Spot and Facula Activity Variations of the Eccentric Detached Eclipsing Binary KIC 8098300 Based on the Time-series Orbital Solutions
Authors: Niu Hu-Biao , Fu Jian-Ning , Wang Jia-Xin , Li Chun-Qian 
Published: November 2021

Abstract
The LAMOST spectra and Kepler light curves are combined to investigate the detached eclipsing binary KIC 8098300, which shows the O’Connell effect caused by spot/facula modulation. The radial velocity (RV) measurements are derived by using the tomographic spectra disentangling technology. The mass ratio q = K
1/K
2 = 0.812 ± 0.007, and the orbital semimajor axis

a
sin
i
=
14.984
±
0.048

R

⊙

are obtained by fitting the RV curves. We optimize the binary model concerning the spot/facula activity with the code PHOEBE and obtain precise parameters of the orbit including the eccentricity e = 0.0217 ± 0.0008, the inclination i = 87.°71 ± 0.°04, and the angle of periastron ω = 284.°1 ± 0.°5. The masses and radii of the primary and secondary star are determined as M
1 = 1.3467 ± 0.0001 M
⊙, R
1 = 1.569 ± 0.003 R
⊙, and M
2 = 1.0940 ± 0.0001 M
⊙, R
2 = 1.078 ± 0.002 R
⊙, respectively. The ratio of temperatures of the two component stars is r
teff = 0.924 ± 0.001. We also obtain the periastron precession speed of 0.000024 ± 0.000001 day cycle−1. The residuals of out-of-eclipse are analyzed using the auto-correlation function and the discrete Fourier transform. The spot/facula activity is relatively weaker, but the lifetime is longer than that of most single main sequence stars in the same temperature range. The average rotation period of the spots P
rot = 4.32 days is slightly longer than the orbital period, which may be caused by either the migration of spots/faculae along the longitude or the latitudinal differential rotation. The activity may be spot-dominated for the secondary star and facula-dominated for the primary star. The method of this work can be used to analyze more eclipsing binaries with the O’Connell effect in the Kepler field to obtain the precise parameters and investigate the difference of spot behavior between binaries and single stars. It is helpful for a deeper understanding of the stellar magnetic activity and dynamo theory.