bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rerouting of ribosomal proteins into splicing in plant organelles
Authors: Wang Chuande , Fourdin Rachel , Quadrado Martine , Dargel-Graffin Céline , Tolleter Dimitri , Macherel David , Mireau Hakim 
Published: November 2020

Significance
Ribosomal proteins (RPs) are essential structural components of ribosomes. In many instances, RPs are encoded in small families of genes, suggesting possible neofunctionalization for some family members. This is the case of the uL18 family of proteins that developed during plant evolution and which is composed of eight members in most Angiosperms. Our study shows that two members associate with organellar ribosomes while two other uL18-Like proteins have become intron-specific splicing factors acting in mitochondria and plastids, respectively. Our study shows that the RNA binding capacity of RPs can be diverted to create factors acting in intron splicing.
Rapid reductions and millennial-scale variability in Nordic Seas sea ice cover during abrupt glacial climate changes
Authors: Sadatzki Henrik , Maffezzoli Niccolò , Dokken Trond M. , Simon Margit H. , Berben Sarah M. P. , Fahl Kirsten , Kjær Helle A. , Spolaor Andrea , Stein Ruediger , Vallelonga Paul , Vinther Bo M. , Jansen Eystein 
Published: November 2020

Significance
The last glacial period was marked by abrupt, high-amplitude Greenland warming events, known as Dansgaard–Oeschger (D-O) events, which were likely linked with Nordic Seas sea ice retreat. We reconstruct the sea ice variability during four D-O events ∼32–41 ka with unprecedented spatial representation and rigorous temporal constraints, using proxy records from two Norwegian Sea sediment cores and an East Greenland ice core. Our records reveal millennial-scale variations between extended sea ice conditions and reduced seasonal sea ice conditions, with rapid sea ice reductions at the onset of D-O events. Our findings imply that rapid sea ice reduction amplified ocean-atmosphere processes causing the abrupt D-O climate transitions, providing constraints for model simulations of abrupt climate changes and their mechanisms.
Geographies of insecure water access and the housing–water nexus in US cities
Authors: Meehan Katie , Jurjevich Jason R. , Chun Nicholas M. J. W. , Sherrill Justin 
Published: November 2020

SignificanceSecure water access is a fundamental human right. Our study reveals disparities in piped water access in urban areas in the United States. From 2013 to 2017, we find that an estimated 1,121,100 people (±25,500) in the United States had insecure water access, with nearly one-half (47%) located in the 50 largest metropolitan areas. Unplumbed households in cities, on balance, are more likely to be headed by people of color, earn lower incomes, live in mobile homes, rent their residence, and pay a higher share of their gross income toward housing costs. We offer clear evidence that gaps in urban water access are neither random nor accidental but underpinned by precarious housing conditions and systemic social and racialized inequality.
A climatic dipole drives short- and long-term patterns of postfire forest recovery in the western United States
Authors: Littlefield Caitlin E. , Dobrowski Solomon Z. , Abatzoglou John T. , Parks Sean A. , Davis Kimberley T. 
Published: November 2020

SignificanceRising temperatures and increasing drought may compromise ecosystems’ abilities to recover from disturbance. This study reveals how recurring, large-scale patterns in drought variability have short- and long-term effects on forest recovery from wildfire in the western United States. Annual juvenile ponderosa pine recruitment in the Northern Rockies and Southwest tracks a north–south climatic dipole that emerges approximately every 4 y and renders one region anomalously dry and the other anomalously wet. Anomalously dry conditions inhibit postfire recruitment in the short-term and shape recovery trajectories decades later. To date, the influence of climatic dipoles on large-scale, enduring patterns of forest recovery has remained largely unexplored and may improve predictions of both ecosystem transformations and species range dynamics under climate change.
Label-free adaptive optics imaging of human retinal macrophage distribution and dynamics
Authors: Hammer Daniel X. , Agrawal Anant , Villanueva Ricardo , Saeedi Osamah , Liu Zhuolin 
Published: November 2020

Significance
Microglia, a type of macrophage, were discovered a little more than a century ago by Pío del Río-Hortega. Since that time, we have gained an immense amount of knowledge on their origin and multifaceted function with the aid of labeling techniques and animal models, among other tools. Only recently have macrophage cells been imaged in living humans. Here we characterize macrophage spatial distribution and temporal dynamics in live human eyes using a label-free adaptive optics imaging approach. This investigation lays a foundation to better understand the body’s immune response not only to ocular diseases like glaucoma, but also to a vast array of neurological diseases with ocular manifestations, including Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis.
High-resolution land value maps reveal underestimation of conservation costs in the United States
Authors: Nolte Christoph 
Published: November 2020

SignificanceThis paper presents high-resolution maps of the estimated value of private lands in the contiguous United States. The estimates permit the prediction of the cost of conservation interventions at a much higher accuracy than proxies used in previous nationwide conservation planning studies. A close look at two recent studies on US-wide floodplain protection and species conservation planning for climate change suggests that the use of previous cost proxies led to the underestimation of policy budgets necessary to achieve environmental goals by a factor of 2 and a factor of 37.5, respectively. This can undermine the validity of findings. Future analyses of conservation policies can and should use high-resolution cost estimates in their justification and spatial prioritization of interventions.
Regulating kinetics and thermodynamics of electrochemical nitrogen reduction with metal single-atom catalysts in a pressurized electrolyser
Authors: Zou Haiyuan , Rong Weifeng , Wei Shuting , Ji Yongfei , Duan Lele 
Published: November 2020

SignificanceThe present-day industrial ammonia synthesis is overreliance on the Haber–Bosch process, yet consumes more than 1% of the global energy supply along with gigatonne greenhouse-gas emission per year. Electrochemical nitrogen reduction reaction (ENRR) offers a sustainable path to produce ammonia under mild conditions, while its efficiency achieved by far is fairly low, which requires the development of both catalysts and electrolyzers. Here, by the cooperation of densely populated metal single atoms on graphdiyne substrate with the pressurized electrocatalytic system, the kinetics and the thermodynamic driving force of ENRR are effectively regulated, leading to a record-high ammonia yield rate. This work motivates the technological and material coevolution for the ENRR toward its envisioned application.
Enhanced and stabilized hydrogen production from methanol by ultrasmall Ni nanoclusters immobilized on defect-rich h-BN nanosheets
Authors: Zhang Zhuolei , Su Ji , Matias Ana Sanz , Gordon Madeleine , Liu Yi-Sheng , Guo Jinghua , Song Chengyu , Dun Chaochao , Prendergast David , Somorjai Gabor A. , Urban Jeffrey J. 
Published: November 2020

Significance
While transition metal-based catalysts promise lower-cost alternatives to traditional precious metals, their low activity and stability limit their deployment within industrial dehydrogenation. Here, we report the design and synthesis of ultrasmall nickel nanoclusters (∼1.5 nm) deposited on defect-rich BN nanosheet (Ni/BN) catalysts with excellent methanol dehydrogenation activity and selectivity. We found an idiosyncratic metal–support interaction not only plays a vital role in promoting the one-pot synthesis of ultrasmall Ni nanoclusters with high catalytic activity, helping to disperse and anchor the nanoclusters but also strongly enhancing the resistance to sintering and coking during methanol dehydrogenation. Calculated turnover frequency (TOF) is among the best compared with some other dehydrogenation catalysts reported previously.
Reshaping circadian metabolism in the suprachiasmatic nucleus and prefrontal cortex by nutritional challenge
Authors: Tognini Paola , Samad Muntaha , Kinouchi Kenichiro , Liu Yu , Helbling Jean-Christophe , Moisan Marie-Pierre , Eckel-Mahan Kristin L. , Baldi Pierre , Sassone-Corsi Paolo 
Published: November 2020

Significance
Nutrition and the body clock are deeply intertwined, both impinging on our physiological health. Food composition can dramatically rewire peripheral clock metabolism; however, whether food challenges can impact circadian metabolism of the master clock in the suprachiasmatic nucleus (SCN) or other brain areas has not been fully explored. Here we analyzed the complete diurnal metabolome of the SCN and medial prefrontal cortex (mPFC) in mice fed a balanced diet or a high-fat diet (HFD). Strikingly, our data reveal unexpected daily rhythmicity in both SCN and mPFC metabolites that is significantly impacted by HFD in a region-specific manner. Our findings unveil an unsuspected sensitivity of brain clocks to nutrition.
Generalizing the Mach cone for sources traveling along arbitrary trajectories
Authors: Carpena Pedro , Coronado Ana V 
Published: November 2020

Abstract
The concept of Mach cone arises when a wave source travels along a linear trajectory through a given medium with speed larger than the wave speed in that medium, and a shock wave is created. It is commonly associated to mechanical waves (specially sound), although also appears in electromagnetic waves as in the case of Cerenkov radiation. In all cases, the conical shape (or arrow tip shape in 2D media) is a consequence of the linear trajectory of the source. Here, we generalize this situation and determine the shape of the Mach wave front for sources traveling along arbitrary trajectories. To do so, instead of waves, we consider that the source emits rays as in geometrical optics, and determine the equations describing the points in the space that are reached simultaneously by the rays, which form the Mach wave front. To show the applicability of our general results, we obtain explicitly the Mach wave fronts for three different trajectories: linear, circular and sinusoidal.
Tunable reflected acoustic wave front modulated with piezoelectric metasurfaces
Authors: Li Shilong , Xu Jiawen , Yao Yixin , Tang J 
Published: November 2020

Abstract
Wave front engineering realized through metasurface synthesis has attracted considerable attention in recent years. Acoustic metasurfaces in deep subwavelength scale have promising potentials in applications such as acoustic focal lenses and acoustic cloaking. Most existing devices, however, lack the tunability in real time. In this paper, an adaptive acoustic metasurface taking advantage of the two-way electro-mechanical coupling of piezoelectric transducers is developed, which enables the manipulation of acoustic waves adaptively. The proposed metasurface consists of units constructed from membranes with back air cavities, wherein the membrane strength is controlled by piezoelectric transducer. With membrane strengths tailored in a tunable manner, an accurate phase profile along the acoustic metasurfaces can be designed, yielding acoustic metasurfaces to steer reflected acoustic waves online without modification of the underlying physical structures. We demonstrate that the adaptive acoustic metasurfaces can successfully achieve abnormal reflections, planar focal lenses and self-accelerating beams. The acoustic cloaking realized by our adaptive acoustic metasurfaces is also illustrated to further manifest the design versatility.
Accessing topological surface states and negative MR in sculpted nanowires of Bi2Te3 at ultra-low temperature
Authors: Yadav Reena , Bhattacharyya Biplab , Pandey Animesh , Kaur Mandeep , Aloysius R P , Gupta Anurag , Husale Sudhir 
Published: November 2020

Abstract
Milling of 2D flakes is a simple method to fabricate nanomaterial of any desired shape and size. Inherently milling process can introduce the impurity or disorder which might show exotic quantum transport phenomenon when studied at the low temperature. Here we report temperature dependent weak antilocalization (WAL) effects in the sculpted nanowires of topological insulator in the presence of perpendicular magnetic field. The quadratic and linear magnetoconductivity (MC) curves at low temperature (>2 K) indicate the bulk contribution in the transport. A cusp feature in magnetoconductivity curves (positive magnetoresistance) at ultra low (<1 K) temperature and at magnetic field (<1 T) represent the WAL indicating the transport through surface states. The MC curves are discussed by using the 2D Hikami–Larkin–Nagaoka theory. The cross-over/interplay nature of positive and negative magnetoresistance observed in the MR curve at ultra-low temperature. Our results indicate that transport through topological surface states (TSS) in sculpted nanowires of Bi2Te3 can be achieved at mK range and linear MR observed at ∼2 K could be the coexistence of electron transport through TSS and contribution from the bulk band.
Prussian blue-carboxylated MWCNTs/ZIF-67 composite: a new electrochemical sensing platform for paracetamol detection with high sensitivity
Authors: Gao Feng , Zou Jin , Zhong Wei , Tu Xiaolong , Huang Xigen , Yu Yongfang , Wang Xiaoqiang , Lu Limin , Bai Ling 
Published: November 2020

Abstract
In this study, the composite of Prussian blue-carboxylated MWCNTs/ZIF-67 (PB-MWCNTs-COOH/ZIF-67) was synthesized and used as modified electrode material to fabricate an electrochemical sensor for the determination of paracetamol (PAR). In this sensor system, negatively charged MWCNTs-COOH as support for the immobilization of positively charged PB can effectively avoid the agglomeration of PB and enhance the stability, conductivity and catalytic activity of the composite. ZIF-67 particles coating outside PB-MWCNTs-COOH promotes the concentration of PAR. Benefiting from the synergistic effect, the PB-MWCNTs-COOH/ZIF-67 based sensor exhibits significantly improved electrochemical sensing behavior toward the oxidation of PAR. Under the optimum conditions, the PAR sensor presents wide linear ranges of 0.01–70 μM with a low limit of detection of 3.3 nM (S/N = 3). The method also possesses long-term stability, good reproducibility and selectivity, and was employed to the determination of PAR contents in PAR tablets sample.
Investigation of the Bragg peak degradation caused by homogeneous and heterogeneous lung tissue substitutes: proton beam experiments and comparison to current clinical dose calculation
Authors: Hranek A , Resch A F , Georg D , Knäusl B 
Published: November 2020

Abstract
Submillimetre structures of lung tissue are not represented in computed tomography images used for radiotherapeutic dose calculation. In order to study the effect experimentally, lung substitutes with properties similar to lung tissue were chosen, namely two types of commercial lung tissue equivalent plates (LTEPs) (CIRS, USA), two types of cork, balsawood, floral foam and konjac sponge. Laterally integrated dose profiles were measured as a function of depth for proton pencil beams (PBs) with an initial nominal energy of 97.4 and 148.2 MeV, respectively. The obtained dose profiles were investigated for their shifting and degradation of the Bragg peak (BP) caused by the materials, expressed as water equivalent thickness (WET) and full width half maximum. The set-up was simulated in the treatment planning system (TPS) RayStation using the Monte Carlo (MC) dose calculation algorithm. While the WET between experiment and dose calculation agreed within 0.5 mm, except for floral foam, the full width half maximum was underestimated in the TPS by up to 2.3 mm. Normalisation to the same mass thickness of the lung substitutes allowed to classify LTEPs and balsawood as homogeneous and cork, floral foam and konjac sponge as heterogeneous materials. The material specific BP degradation was up to 3.4 times higher for the heterogeneous samples. The modulation power as a measure for the heterogeneity was compared to the spectrum of Hounsfield units (HU) of the materials. A clear correlation was not found, but with further improvements the HU spectrum may serve as an indicator for the material heterogeneity. Further, MC simulations of binary voxel models using GATE/Geant4 were performed to investigate the influence of grain size and mass density. For mass densities similar to lung tissue the BP degradation had a maximum at 3 and 7 mm grain size.
Accounting for prompt gamma emission and detection for range verification in proton therapy treatment planning
Authors: Tian Liheng , Huang Ze , Janssens Guillaume , Landry Guillaume , Dedes George , Kamp Florian , Belka Claus , Pinto Marco , Parodi Katia 
Published: November 2020

Abstract
Prompt gamma (PG) imaging is widely investigated as one of the most promising methods for proton range verification in proton therapy. The performance of this technique is affected by several factors like tissue heterogeneity, number of protons in the considered pencil beam and the detection device. Our previous work proposed a new treatment planning concept which boosts the number of protons of a few PG monitoring-friendly pencil beams (PBs), selected on the basis of two proposed indicators quantifying the conformity between the dose and PG at the emission level, above the desired detectability threshold. To further explore this method at the detection level, in this work we investigated the response of a knife-edge slit PG camera which was deployed in the first clinical application of PG to proton therapy monitoring. The REGistration Graphical User Interface (REGGUI) is employed to simulate the PG emission, PG detection as well as the corresponding dose distribution. As the PG signal detected by this kind of PG camera is sensitive to the relative position of the camera and PG signal falloff, we optimized our PB selection method for this camera by introducing a new camera position indicator identifying whether the expected falloff of the PG signal is centered in the field of view of the camera or not. Our camera-adapted PB selection method is investigated using computed tomography (CT) scans at two different treatment time points of a head and neck, and a prostate cancer patient under scenarios considering different statistics level. The results show that a precision of 0.8 mm for PG falloff identification can be achieved when a PB has more than 2 × 108 primary protons. Except for one case due to unpredictable and comparably large anatomical changes, the PG signals of most of the PBs recommended by all our indicators are observed to be reliable for proton range verification with deviations between the inter-fractional shift of proton range (as deduced from the PB dose distribution) and the detected PG signal within 2.0 mm. In contrast, a shift difference up to 9.6 mm has been observed for the rejected PBs. The magnitude of the proton range shift due to the inter-fractional anatomical changes is observed to be up to 23 mm. The proposed indicators are shown to be valuable for identifying and recommending reliable PBs to create new PG monitoring-friendly TPs. Comparison between our PB boosting method and the alternative PB aggregation, which combines the signal of nearby PBs to reach the desired counting statistics, is also discussed.
Moment approach of the multi-species non-linear Coulomb collision operator adapted to particle-in-cell codes
Authors: Donnel P , Gheller C , Brunner S , Villard L , Lanti E , Ohana N , Murugappan M 
Published: November 2020

Abstract
In this article an approximated version of the multi-species, non-linear Coulomb collision operator is derived via the use of a truncated moment expansion of the distribution function to compute the Rosenbluth potentials. The evolution of the distribution function due to the collision operator takes the form of a Fokker–Planck equation that can be efficiently solved by a Langevin approach in the particle-in-cell (PIC) framework. This kinetic collision operator is then implemented in the global gyrokinetic PIC code ORB5 while neglecting finite Larmor effects. This collision operator ensures exact conservation of density, total momentum and energy as expected. The neoclassical physics is also successfully retrieved by the code. Numerical aspects such as the noise control and the parallelisation of the code are presented in detail.
The role of photon self-absorption on the H (n
= 2) density determination by means of VUV emission spectroscopy and TDLAS in low pressure plasmas
Authors: Merk F , Friedl R , Briefi S , Fröhler-Bachus C , Fantz U 
Published: November 2020

Abstract
The H (n = 2) atomic density determination by means of vacuum ultra-violet (VUV) emission spectroscopy of the Lyman-α line in laboratory low pressure plasmas is strongly affected by self-absorption of emitted photons inside the plasma leading to an underestimation of this density. A correction of the densities obtained from VUV emission spectroscopy measurements is performed by using the escape factor method. The corrections applied can reach orders of magnitude even in low pressure plasmas. Assumptions on the spatial distribution of emitting and absorbing particles as well as on the corresponding line profiles have to be made. Consequently, additional measurements are performed, which raises the requirement of a benchmark of the applied correction procedure. In contrast, tunable diode laser absorption spectroscopy (TDLAS) on the Balmer-α line is a direct measurement of the H (n = 2) density and is thus suitable for a benchmark. For the ICP under consideration, H (n = 2) densities obtained via TDLAS are near 3 × 1015 m−3 whereas uncorrected VUV emission spectroscopy gives values in the range of roughly 1013 m−3 depending on pressure and applied RF power. The calculated escape factors are on the order of 2–8 × 10−3. An excellent agreement with TDLAS is observed by applying them to the results of the VUV emission spectroscopy.
Self-organization of touching-target current with ac voltage in atmospheric pressure plasma jet for medical application parameters
Authors: Schweigert I V , Alexandrov A L , Zakrevsky Dm E 
Published: November 2020

Abstract
In experiments with the cold atmospheric pressure plasma jet, the frequency of the current measured near the treated target shows a mismatch with the voltage frequency. The system including the plasma device and target organizes the plasma delivery differently with changing voltage frequency and amplitude. All electromagnetic and chemical processes near the target depend on the frequency of the plasma-target contacts. In experiments and in 2D fluid model simulations, the self-organization of touching-target current is studied for voltage frequencies of 10–50 kHz and amplitudes of 2.5–6 kV. The streamer propagation through the volumetric plasma cloud outside of discharge device and the mechanism responsible for variation of touching-target current frequency are discussed.