bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy Metal and Rock in Space: Cluster RAPID Observations of Fe and Si
Authors: Haaland Stein , Daly Patrick W. , Vilenius Esa 
Published: February 2021

AbstractMetallic and silicate ions carry essential information about the evolution of the Earth and near‐Earth small bodies. Despite this, there has so far been very little focus on ions with atomic masses higher than oxygen in the terrestrial magnetosphere. In this paper, we report on abundances and properties of energetic ions with masses corresponding to that of silicon (Si) and iron (Fe) in Earth's geospace. The results are based on a newly derived data product from the Research with Adaptive Particle Imaging Detectors on Cluster. We find traces of both Si and Fe in all of the regions covered by the spacecraft, with the highest occurrence rates and highest intensities in the inner magnetosphere. We also find that the Fe and Si abundances are modulated by solar activity. During solar maximum, the probability of observing Fe and Si in geospace increases significantly. On the other hand, we find little or no direct correlation between geomagnetic activity and Si and Fe abundance in the magnetosphere. Both Si and Fe in the Earth's magnetosphere are inferred to be primarily of solar wind origin.
Slope‐Intensified Storm‐Induced Near‐Inertial Oscillations in the South China Sea
Authors: Li Ruixiang , Chen Changsheng , Dong Wenjie , Beardsley Robert C. , Wu Zhongxiang , Gong Wenping , Liu Yuqiang , Liu Tongmu , Xu Danya 
Published: February 2021

AbstractThe South China Sea (SCS) is a region vulnerable to tropical cyclones (TCs). An array of moored current meters and meteorological buoys was deployed within major pathways of TCs across the slope of the northern shelf of the SCS from September 1, 2017 through September 30, 2018. Three TCs, Khanun, SonTinh, and Mangkhut, traversed by the storm‐monitoring array in October 2017, July, and September 2018, respectively. Storm‐generated near‐inertial oscillations (NIOs) were observed at the moorings. These oscillations exhibited a slope‐intensified feature regardless of the trajectories and intensities of TCs. In the stratified area, the NIOs was characterized by a two‐layer structure, with large amplitudes in the mixed layer and beneath thermoclines. The phases of these oscillations changed rapidly through thermoclines. No significant nonlinear interactions were found between near‐inertial and tidal currents. The low‐frequency flow over the slope was characterized by a southwestward current in the along‐shelf direction and an onshore current above the bottom boundary, and a weak offshore current near the bottom in the cross‐shelf direction. The flow‐induced negative vorticity was intensified during the TCs and appearances of mesoscale eddies. Slope‐intensified NIOs can be explained by topographic inertial waves and energy trapping due to the negative vorticity of the slope flow. The strongest NIOs always occur during an adjustment period of the low‐frequency flow to a pre‐storm condition, suggesting a significant energy transfer from the low‐frequency flow to the inertial motion.
Characterization of complete lncRNAs transcriptome reveals the functional and clinical impact of lncRNAs in multiple myeloma
Authors: Carrasco-Leon Arantxa , Ezponda Teresa , Meydan Cem , Valcárcel Luis V. , Ordoñez Raquel , Kulis Marta , Garate Leire , Miranda Estíbaliz , Segura Victor , Guruceaga Elisabeth , Vilas-Zornoza Amaia , Alignani Diego , Pascual Marién , Amundarain Ane , Castro-Labrador Laura , Martín-Uriz Patxi San , El-Omri Halima , Taha Ruba Y. , Calasanz Maria J. , Planes Francisco J. , Paiva Bruno , Mason Christopher E. , San Miguel Jesús F. , Martin-Subero José I. , Melnick Ari , Prosper Felipe , Agirre Xabier 
Published: February 2021

AbstractMultiple myeloma (MM) is an incurable disease, whose clinical heterogeneity makes its management challenging, highlighting the need for biological features to guide improved therapies. Deregulation of specific long non-coding RNAs (lncRNAs) has been shown in MM, nevertheless, the complete lncRNA transcriptome has not yet been elucidated. In this work, we identified 40,511 novel lncRNAs in MM samples. lncRNAs accounted for 82% of the MM transcriptome and were more heterogeneously expressed than coding genes. A total of 10,351 overexpressed and 9,535 downregulated lncRNAs were identified in MM patients when compared with normal bone-marrow plasma cells. Transcriptional dynamics study of lncRNAs in the context of normal B-cell maturation revealed 989 lncRNAs with exclusive expression in MM, among which 89 showed de novo epigenomic activation. Knockdown studies on one of these lncRNAs, SMILO (specific myeloma intergenic long non-coding RNA), resulted in reduced proliferation and induction of apoptosis of MM cells, and activation of the interferon pathway. We also showed that the expression of lncRNAs, together with clinical and genetic risk alterations, stratified MM patients into several progression-free survival and overall survival groups. In summary, our global analysis of the lncRNAs transcriptome reveals the presence of specific lncRNAs associated with the biological and clinical behavior of the disease.
The regulation of protein translation and its implications for cancer
Authors: Song Ping , Yang Fan , Jin Hongchuan , Wang Xian 
Published: February 2021

AbstractIn addition to the deregulation of gene transcriptions and post-translational protein modifications, the aberrant translation from mRNAs to proteins plays an important role in the pathogenesis of various cancers. Targeting mRNA translation are expected to become potential approaches for anticancer treatments. Protein translation is affected by many factors including translation initiation factors and RNA-binding proteins. Recently, modifications of mRNAs mainly N6-methyladenine (m6A) modification and noncoding RNAs, such as microRNAs and long noncoding RNAs are involved. In this review, we generally summarized the recent advances on the regulation of protein translation by the interplay between mRNA modifications and ncRNAs. By doing so, we hope this review could offer some hints for the development of novel approaches in precision therapy of human cancers.
Perineuronal nets are under the control of type-5 metabotropic glutamate receptors in the developing somatosensory cortex
Authors: Mascio Giada , Bucci Domenico , Notartomaso Serena , Liberatore Francesca , Antenucci Nico , Scarselli Pamela , Imbriglio Tiziana , Caruso Stefano , Gradini Roberto , Cannella Milena , Di Menna Luisa , Bruno Valeria , Battaglia Giuseppe , Nicoletti Ferdinando 
Published: February 2021

AbstractmGlu5 metabotropic glutamate receptors are highly functional in the early postnatal life, and regulate developmental plasticity of parvalbumin-positive (PV+) interneurons in the cerebral cortex. PV+cells are enwrapped by perineuronal nets (PNNs) at the closure of critical windows of cortical plasticity. Changes in PNNs have been associated with neurodevelopmental disorders. We found that the number ofWisteria Fluoribunda Agglutinin(WFA)+PNNs and the density of WFA+/PV+cells were largely increased in the somatosensory cortex of mGlu5−/−mice at PND16. An increased WFA+PNN density was also observed after pharmacological blockade of mGlu5 receptors in the first two postnatal weeks. The number of WFA+PNNs in mGlu5−/−mice was close to a plateau at PND16, whereas continued to increase in wild-type mice, and there was no difference between the two genotypes at PND21 and PND60. mGlu5−/−mice at PND16 showed increases in the transcripts of genes involved in PNN formation and a reduced expression and activity of type-9 matrix metalloproteinase in the somatosensory cortex suggesting that mGlu5 receptors control both PNN formation and degradation. Finally, unilateral whisker stimulation from PND9 to PND16 enhanced WFA+PNN density in the contralateral somatosensory cortex only in mGlu5+/+mice, whereas whisker trimming from PND9 to PND16 reduced WFA+PNN density exclusively in mGlu5−/−mice, suggesting that mGlu5 receptors shape the PNN response to sensory experience. These findings disclose a novel undescribed mechanism of PNN regulation, and lay the groundwork for the study of mGlu5 receptors and PNNs in neurodevelopmental disorders.
Coherent X-ray−optical control of nuclear excitons
Authors: Heeg Kilian P. , Kaldun Andreas , Strohm Cornelius , Ott Christian , Subramanian Rajagopalan , Lentrodt Dominik , Haber Johann , Wille Hans-Christian , Goerttler Stephan , Rüffer Rudolf , Keitel Christoph H. , Röhlsberger Ralf , Pfeifer Thomas , Evers Jörg 
Published: February 2021

AbstractCoherent control of quantum dynamics is key to a multitude of fundamental studies and applications1. In the visible or longer-wavelength domains, near-resonant light fields have become the primary tool with which to control electron dynamics2. Recently, coherent control in the extreme-ultraviolet range was demonstrated3, with a few-attosecond temporal resolution of the phase control. At hard-X-ray energies (above 5–10 kiloelectronvolts), Mössbauer nuclei feature narrow nuclear resonances due to their recoilless absorption and emission of light, and spectroscopy of these resonances is widely used to study the magnetic, structural and dynamical properties of matter4,5. It has been shown that the power and scope of Mössbauer spectroscopy can be greatly improved using various control techniques6–16. However, coherent control of atomic nuclei using suitably shaped near-resonant X-ray fields remains an open challenge. Here we demonstrate such control, and use the tunable phase between two X-ray pulses to switch the nuclear exciton dynamics between coherent enhanced excitation and coherent enhanced emission. We present a method of shaping single pulses delivered by state-of-the-art X-ray facilities into tunable double pulses, and demonstrate a temporal stability of the phase control on the few-zeptosecond timescale. Our results unlock coherent optical control for nuclei, and pave the way for nuclear Ramsey spectroscopy17 and spin-echo-like techniques, which should not only advance nuclear quantum optics18, but also help to realize X-ray clocks and frequency standards19. In the long term, we envision time-resolved studies of nuclear out-of-equilibrium dynamics, which is a long-standing challenge in Mössbauer science20.
The structural basis of function and regulation of neuronal cotransporters NKCC1 and KCC2
Authors: Zhang Sensen , Zhou Jun , Zhang Yuebin , Liu Tianya , Friedel Perrine , Zhuo Wei , Somasekharan Suma , Roy Kasturi , Zhang Laixing , Liu Yang , Meng Xianbin , Deng Haiteng , Zeng Wenwen , Li Guohui , Forbush Biff , Yang Maojun 
Published: February 2021

AbstractNKCC and KCC transporters mediate coupled transport of Na++K++Cl− and K++Cl− across the plasma membrane, thus regulating cell Cl− concentration and cell volume and playing critical roles in transepithelial salt and water transport and in neuronal excitability. The function of these transporters has been intensively studied, but a mechanistic understanding has awaited structural studies of the transporters. Here, we present the cryo-electron microscopy (cryo-EM) structures of the two neuronal cation-chloride cotransporters human NKCC1 (SLC12A2) and mouse KCC2 (SLC12A5), along with computational analysis and functional characterization. These structures highlight essential residues in ion transport and allow us to propose mechanisms by which phosphorylation regulates transport activity.
How creating one additional well can generate Bose-Einstein condensation
Authors: Máté Mihály , Legeza Örs , Schilling Rolf , Yousif Mason , Schilling Christian 
Published: February 2021

AbstractThe realization of Bose-Einstein condensation in ultracold trapped gases has led to a revival of interest in this fascinating quantum phenomenon. This experimental achievement necessitated both extremely low temperatures and sufficiently weak interactions. Particularly in reduced spatial dimensionality even an infinitesimal interaction immediately leads to a departure to quasi-condensation. We propose a system of strongly interacting bosons, which overcomes those obstacles by exhibiting a number of intriguing related features: (i) The tuning of just a single control parameter drives a transition from quasi-condensation to complete condensation, (ii) the destructive influence of strong interactions is compensated by the respective increased mobility, (iii) topology plays a crucial role since a crossover from one- to ‘infinite’-dimensionality is simulated, (iv) a ground state gap opens, which makes the condensation robust to thermal noise. Remarkably, all these features can be derived by analytical and exact numerical means despite the non-perturbative character of the system.
Robust wideband adaptive beamforming based on covariance matrix reconstruction in the spatial‐frequency domain
Authors: Lu Jian , Yang Jian , Yao Zhicheng , Zhu Fengchao , Yu Zhiyong , Liu Guangbin 
Published: February 2021

AbstractWithout the response variation constraint, the main‐lobe responses of wideband beamforming usually vary with the frequencies of interest, and the beam pointing may deviate from the incident angle of the desired signal. If the interference‐plus‐noise covariance matrix (INCM) is directly replaced by the sample covariance matrix, the desired signal in the sample data may result in self‐null problem, which can lead to the degradation of the performance of wideband beamformers. Through frequency division, a novel wideband adaptive beamforming is proposed by reconstructing the INCM and solving the convex optimisation problem. Using fast Fourier transform (FFT), the time‐domain samples are transformed into the frequency field, and the covariance matrix of each subband can be obtained from the frequency‐domain data. In the spatial‐frequency domain, the INCM and signal‐plus‐noise covariance matrix can be respectively reconstructed by integrating the stacked steering vector and the Capon spatial spectrum over the corresponding angular region. Then, we establish the optimisation criteria, that is, minimising the output interference‐plus‐noise power, minimising the main‐lobe spatial response variation, and constraining the response deviation of the desired signal. A novel convex optimisation model can be established, and then the weight coefficients for time‐domain wideband beamforming can be obtained by solving the optimisation problem. The simulation and experimental results demonstrate that the proposed beamformer can provide better performance compared with other tested beamformers and maintain good robustness in various applications.
Pyramid textured Si{100} surface with low reflectivity in CMOS compatible solution
Authors: Gupta Arti , Pal Prem , Sharma Chandra Shekhar 
Published: February 2021

Wet anisotropic etching of Si{100} results in micro‐pyramids/hillocks bounded by four {111} planes. These kinds of geometrical structures are needed to reduce the front surface reflectance from silicon by taking multiple internal reflections of the incident ray and thus increase the efficiency of the solar cells. In this work, surface texturing of Si{100} is performed at different temperatures in a very low concentration CMOS compatible tetramethylammonium hydroxide (TMAH) without using any additive and agitation. The present research is aimed to significantly reduce the etching time in an extremely low concentration TMAH to texture the silicon surface for obtaining the lowest possible reflectance. Etching temperature is varied from 80 to 95°C with a step of 5°C. For each temperature, the etching time is also varied from 5 to 40 min with an interval of 5 min, whereas etching concentration is made a fix to 0.5 wt%. Surface morphology with dense and uniform pyramidal structures is achieved on the silicon samples etched at 85°C for 25 min. These samples provide the average solar weighted reflectance (Rsw) of around 10% and the lowest reflectance of 6.7% at 790 nm.
Design, takeoff and steering torques modulation of an 80‐mg insect‐scale flapping‐wing robot
Authors: Wang Chenyang , Zhang Weiping , Zhao Jiaxin , Hu Junqi , Zou Yang 
Published: February 2021

An 80‐mg double piezo‐actuated insect‐inspired flapping‐wing robot is presented in this Letter. With the design of the two piezoelectric actuators placed back to back, each wing of this robot is independently driven and controlled, giving this robot the ability to achieve asymmetric flapping of the two wings to generate torques for steering. The piezoelectric actuators are designed with electrical insulation and structural reinforcement to improve the reliability under high‐voltage and high‐frequency drive mode. Fibre directions of each component of the robot are reasonably designed to enhance strength and stiffness. The average lift generated by the robot is measured by a customised lift measurement system found to be proportional to the square of the input voltage amplitude. The three steering torques generated by the robot are measured separately by a customised lift measurement system. Each steering torque can only be linearly modulated by its specific control variable of the input voltages. With a total weight of 80 mg and a wingspan of 3.5 cm, this robot can generate sufficient lift to take off and independently modulate all three steering torques with good decoupling, which is vital for the further controlled flight.
The DOA location deception effect of frequency diverse array on interferometer
Authors: Ge Jiaang , Xie Junwei , Wang Bo , Chen Chushu 
Published: February 2021

AbstractWith advances in radar localisation, especially the emergence and development of passive localisation, there is an urgent demand for countermeasure technology. To counteract the passive direction‐of‐arrival (DOA) location, this article studies the DOA location deception effect of a frequency diverse array (FDA) on an interferometer. By analysing the phase distribution model of the uniform linear FDA (ULFDA) signal and the DOA location principle of the one‐dimensional phase interferometer, it was found that the phase difference the FDA produces does not conform to the direction‐finding law of the interferometer, which provides a potential capability for the FDA to achieve localisation deception for the interferometer. Based on the proposed DOA location deception model and the instantaneous signal‐to‐noise‐ratio (ISNR), the CRLB and RMSE of the angle and x‐intercept deviation are investigated. The results show that, compared with conventional phased array signals, the FDA signal can achieve DOA location deception on the interferometer, and by properly configuring the frequency increment sequence, the FDA can perform better DOA location deception on the interferometer, which means that the FDA provides promising potential for radar security.
Machine learning technique for morphological classification of galaxies from the SDSS
Authors: Vavilova I. B. , Dobrycheva D. V. , Vasylenko M. Yu. , Elyiv A. A. , Melnyk O. V. , Khramtsov V. 
Published: February 2021

Context. Machine learning methods are effective tools in astronomical tasks for classifying objects by their individual features. One of the promising utilities is related to the morphological classification of galaxies at different redshifts.
Aims. We use the photometry-based approach for the SDSS data (1) to exploit five supervised machine learning techniques and define the most effective among them for the automated galaxy morphological classification; (2) to test the influence of photometry data on morphology classification; (3) to discuss problem points of supervised machine learning and labeling bias; and (4) to apply the best fitting machine learning methods for revealing the unknown morphological types of galaxies from the SDSS DR9 at z < 0.1.
Methods. We used different galaxy classification techniques: human labeling, multi-photometry diagrams, naive Bayes, logistic regression, support-vector machine, random forest, k-nearest neighbors.
Results. We present the results of a binary automated morphological classification of galaxies conducted by human labeling, multi-photometry, and five supervised machine learning methods. We applied it to the sample of galaxies from the SDSS DR9 with redshifts of 0.02 < z < 0.1 and absolute stellar magnitudes of −24m < Mr < −19.4m. For the analysis we used absolute magnitudes Mu, Mg, Mr, Mi, Mz; color indices Mu − Mr, Mg − Mi, Mu − Mg, Mr − Mz; and the inverse concentration index to the center R50/R90. We determined the ability of each method to predict the morphological type, and verified various dependencies of the method’s accuracy on redshifts, human labeling, morphological shape, and overlap of different morphological types for galaxies with the same color indices. We find that the morphology based on the supervised machine learning methods trained over photometric parameters demonstrates significantly less bias than the morphology based on citizen-science classifiers.
Conclusions. The support-vector machine and random forest methods with Scikit-learn software machine learning library in Python provide the highest accuracy for the binary galaxy morphological classification. Specifically, the success rate is 96.4% for support-vector machine (96.1% early E and 96.9% late L types) and 95.5% for random forest (96.7% early E and 92.8% late L types). Applying the support-vector machine for the sample of 316 031 galaxies from the SDSS DR9 at z < 0.1 with unknown morphological types, we found 139 659 E and 176 372 L types among them.
Detection of new O-type stars in the obscured stellar cluster Tr 16-SE in the Carina Nebula with KMOS
Authors: Preibisch T. , Flaischlen S. , Göppl C. , Ercolano B. , Roccatagliata V. 
Published: February 2021

Context.The Carina Nebula harbors a large population of high-mass stars, including at least 75 O-type and Wolf-Rayet (WR) stars, but the current census is not complete since further high-mass stars may be hidden in or behind the dense dark clouds that pervade the association.Aims.With the aim of identifying optically obscured O- and early B-type stars in the Carina Nebula, we performed the first infrared spectroscopic study of stars in the optically obscured stellar cluster Tr 16-SE, located behind a dark dust lane south ofηCar.Methods.We used the integral-field spectrograph KMOS at the ESO VLT to obtainH- andK-band spectra with a resolution ofR ≈ 4000 (Δλ≈ 5 Å) for 45 out of the 47 possible OB candidate stars in Tr 16-SE, and we derived spectral types for these stars.Results.We find 15 stars in Tr 16-SE with spectral types between O5 and B2 (i.e., high-mass stars withM ≥ 8 M⊙), only two of which were known before. An additional nine stars are classified as (Ae)Be stars (i.e., intermediate-mass pre-main-sequence stars), and most of the remaining targets show clear signatures of being late-type stars and are thus most likely foreground stars or background giants unrelated to the Carina Nebula. Our estimates of the stellar luminosities suggest that nine of the 15 O- and early B-type stars are members of Tr 16-SE, whereas the other six seem to be background objects.Conclusions.Our study increases the number of spectroscopically identified high-mass stars (M ≥ 8 M⊙) in Tr 16-SE from two to nine and shows that Tr 16-SE is one of the larger clusters in the Carina Nebula. Our identification of three new stars with spectral types between O5 and O7 and four new stars with spectral types O9 to B1 significantly increases the number of spectroscopically identified O-type stars in the Carina Nebula.