bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing x-ray transmission through filters used in high energy density physics diagnostics
Authors: Pearcy J. , Kabadi N. , Birkel A. , Adrian P. , Lahmann B. , Reichelt B. , Johnson T. M. , Sutcliffe G. , Kunimune J. , Gatu-Johnson M. , Bose A. , Li C. K.
Published: June 2021

We report on the design and implementation of a new system used to characterize the energy-dependent x-ray transmission curve, Θ(E), through filters used in high-energy density physics diagnostics. Using an Amptek X-123-CdTe x-ray spectrometer together with a partially depleted silicon surface barrier detector, both the energy spectrum and total emission of an x-ray source have been accurately measured. By coupling these detectors with a custom PROTO-XRD x-ray source with interchangeable cathodes, accurate characterizations of Θ(E) for filters of varying materials and thicknesses have been obtained. The validity of the technique has been confirmed by accurately reproducing areal densities for high-purity filters with known x-ray transmission properties. In this paper, the experimental setup is described and the results of absorption calibrations performed on a variety of different filters are presented.
InP-based single-photon sources operating at telecom C-band with increased extraction efficiency
Authors: Musiał A. , Mikulicz M. , Mrowiński P. , Zielińska A. , Sitarek P. , Wyborski P. , Kuniej M. , Reithmaier J. P. , Sęk G. , Benyoucef M.
Published: June 2021

In this work, we demonstrate a triggered single-photon source operating at the telecom C-band with photon extraction efficiency exceeding any reported values in this range. The non-classical light emission with low probability of the multiphoton events is realized with single InAs quantum dots (QDs) grown by molecular beam epitaxy and embedded directly in an InP matrix. Low QD spatial density on the order of 5 × 108 cm−2 to ∼2 × 109 cm−2 and symmetric shape of these nanostructures together with spectral range of emission make them relevant for quantum communication applications. The engineering of extraction efficiency is realized by combining a bottom distributed Bragg reflector consisting of 25 pairs of InP/In0.53Ga0.37Al0.1 As layers and cylindrical photonic confinement structures. Realization of such a technologically non-demanding approach even in a non-deterministic fashion results in photon extraction efficiency of (13.3 ± 2) % into 0.4 numerical aperture detection optics at approximately 1560 nm emission wavelength, i.e., close to the center of the telecom C-band.
Assessing locally range-separated hybrid functionals from a gradient expansion of the exchange energy density
Authors: Maier Toni M. , Ikabata Yasuhiro , Nakai Hiromi
Published: June 2021

Locally range-separated hybrid (LRSH) functionals feature a real-space-dependent range separation function (RSF) instead of a system-independent range-separation parameter, which thus enables a more flexible admixture of exact exchange than conventional range-separated hybrid functionals. In particular, the development of suitable RSF models and exploring the capabilities of the LRSH approach, in general, are tasks that require further investigations and will be addressed in this work. We propose a non-empirical scheme based on a detailed scaling analysis with respect to a uniform coordinate scaling and on a short-range expansion of the range-separated exchange energy density to derive new RSF models from a gradient expansion of the exchange energy density. After optimizing a small set of empirical parameters introduced to enhance their flexibility, the resulting second- and fourth-order RSFs are evaluated with respect to atomic exchange energies, atomization energies, and transition barrier heights.
Interferometric spectroscopy with quantum light: Revealing
out-of-time-ordering correlators
Authors: Asban Shahaf , Dorfman Konstantin E. , Mukamel Shaul
Published: June 2021

We survey the inclusion of interferometric elements in nonlinear spectroscopy performed with quantum light. Controlled interference of electromagnetic fields coupled to matter can induce constructive or destructive contributions of microscopic coupling sequences (histories) of matter. Since quantum fields do not commute, quantum light signals are sensitive to the order of light–matter coupling sequences. Matter correlation functions are thus imprinted by different field factors, which depend on that order. We identify the associated quantum information obtained by controlling the weights of different contributing pathways and offer several experimental schemes for recovering it. Nonlinear quantum response functions include out-of-time-ordering matter correlators (OTOCs), which reveal how perturbations spread throughout a quantum system (information scrambling). Their effect becomes most notable when using ultrafast pulse sequences with respect to the path difference induced by the interferometer. OTOCs appear in quantum-informatics studies in other fields, including black hole, high energy, and condensed matter physics.
Selection of laser pulse width for efficient generation of photoacoustic signals in liquid-filled thin capillary embedded in soft material
Authors: Qu Shili , Nakamura Kentaro
Published: June 2021

To design an instrumentation system for evaluating contrast agents of photoacoustic imaging, the optimal pulse width of the excitation laser is discussed in this paper. A pulsed semiconductor laser with a moderate pulse width (15–129 ns) and low peak power (1 W) is adopted in the proposed system. Black ink is selected as the reference sample, which is filled in a glass capillary embedded in a soft phantom. Our aim is that the pulse width matches the acoustic resonance of the target and the center frequency of the receiving transducer (5 MHz) to obtain sufficient strength of the ultrasonic signal with minimal laser power. A series of experiments reveal a clear relationship between the laser pulse width and the maximal amplitude of the resonance mode. Acoustic resonance occurs inside the capillary whose frequencies can be precisely predicted as the radial eigen mode. The laser pulse width and concentration of the sample showed little influence on these resonance frequencies as expected. To efficiently utilize the signal enhancement effect due to the resonance, several resonance mode candidates are investigated and discussed. It then becomes clear that the second angular and zeroth radial order mode is useful for capillaries with sub-millimeter inner diameters. It was demonstrated that the concentration of samples had very limited influence on the frequencies. Finally, consideration based on two delayed attenuating vibrations is successfully conducted to explain the experimental results.
Structure of the electrical double layer at the ice–water interface
Authors: Daigle Hugh
Published: June 2021

The surface of ice in contact with water contains sites that undergo deprotonation and protonation and can act as adsorption sites for aqueous ions. Therefore, an electrical double layer should form at this interface and existing models for describing the electrical double layer at metal oxide–water interfaces should be able to be modified to describe the surface charge, surface potential, and ionic occupancy at the ice–water interface. I used a surface complexation model along with literature measurements of the zeta potential of ice in brines of various strength and pH to constrain equilibrium constants. I then made predictions of ion site occupancy, surface charge density, and partitioning of counterions between the Stern and diffuse layers. The equilibrium constant for cation adsorption is more than 5 orders of magnitude larger than the other constants, indicating that this reaction dominates even at low salinity. Deprotonated OH sites are predicted to be slightly more abundant than dangling O sites, consistent with previous work. Surface charge densities are on the order of ±0.001 C/m2 and are always negative at the moderate pH values of interest to atmospheric and geophysical applications (6–9). In this pH range, over 99% of the counterions are contained in the Stern layer. This suggests that diffuse layer polarization will not occur because the ionic concentrations in the diffuse layer are nearly identical to those in the bulk electrolyte and that electrical conduction and polarization in the Stern layer will be negligible due to reduced ion mobility.
Identifying systematic errors in a power spectral analysis of simulated lipid membranes
Authors: Ergüder Muhammed F. , Deserno Markus
Published: June 2021

The elastic properties of lipid membranes can be measured by monitoring their thermal fluctuations. For instance, comparing the power spectra of membrane shape or lipid director fluctuations with predictions based on suitable continuum theories gives access to bending-, tilt-, and twist-moduli. However, to do so in a computer simulation, we must first define a continuum surface shape and lipid director field from the discrete configurations of lipid molecules in a typically fairly small box. Here, we show that the required mapping choices, as well as the details of the subsequent data analysis, can shift the measured values of these moduli by far more than their statistical uncertainties. We investigate the resulting systematic errors on the basis of atomistic simulation trajectories for 13 different lipids, previously published by Venable et al. [Chem. Phys. Lipids 192, 60–74 (2015)]. Specifically, we examine mapping choices for surface- and tilt-field definitions, normalizing and averaging lipid directors, accounting for wave vector dependent time autocorrelations, error propagation, and finding the right fitting range. We propose a set of criteria that may help to decide upon a particular combination of choices underlying the fluctuation analysis, and we make several recommendations based on these. While systematic shifts in observables that are extracted from large-wavelength limits vanish, in principle, for sufficiently large system size, no such exact limit exists for intrinsically local parameters, such as the twist modulus or the splay-tilt coupling, and so not all potential choices can be trivially verified.
Numerical study of high performance HTL-free CH3NH3SnI3-based perovskite solar cell by SCAPS-1D
Authors: Sunny Adil , Rahman Sabrina , Khatun Most. Marzia , Ahmed Sheikh Rashel Al
Published: June 2021

In this study, a hole transport layer (HTL)-free perovskite solar cell (PSC) structure with CH3NH3SnI3 as an active layer and TiO2 as an electron transport layer (ETL) has been proposed for the first time. The solar cell capacitance simulator in one dimension program has been carried out to design the proposed HTL-free CH3NH3SnI3-based PSC and simulate its performance. The output parameters of the proposed PSC, such as open circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), power conversion efficiency, and quantum efficiency, are evaluated by varying the physical parameters of various layers. The thermal stability of the proposed cell has also been analyzed. The thicknesses of the ETL and the absorber are optimized to be 0.05 and 1.0 µm, respectively. A conversion efficiency of 26.33% along with Voc of 0.98 V, Jsc of 31.93 mA/cm2, and an FF of 84.34% is obtained for the proposed HTL-free CH3NH3SnI3-based PSC. These simulation results would be helpful in fabricating highly efficient and inexpensive PSCs.
Recent progress on measurement of spin–charge interconversion in topological insulators using ferromagnetic resonance
Authors: Dey Rik , Roy Anupam , Register Leonard F. , Banerjee Sanjay K.
Published: June 2021

Spin–orbit coupling (SOC) in materials plays a crucial role in interconversion between spin and charge currents. In reduced dimensions, SOC effects are enhanced and have been the focus of intensive experimental and theoretical research, both for their novel spin-dependent phenomena and for their potential exploitation in new spintronics devices. Thanks to the discovery of a family of two-dimensional materials, extensive research has been conducted to explore potential material systems to achieve high spin–charge interconversion rates as well as to allow detection and accurate measurement. This article reviews the prospect of topological insulators as a reliable material system for efficient spin–charge interconversion and recent experimental advances in detecting the charge-to-spin and spin-to-charge conversions on topological insulator surfaces via spin-torque ferromagnetic resonance and spin-pumping techniques, respectively.
Giant magnetoresistance effect due to the tunneling between quantum anomalous Hall edge states
Authors: Xu Yong , Wang Jun , Liu Jun-Feng , Xu Hu
Published: June 2021

A recent work predicted the tunneling effect between topological edge states where the tunneling probability is tuned by a transverse electric field [Xu et al., Phys. Rev. Lett. 123, 206801 (2019)]. Here we study this tunneling effect between quantum anomalous Hall edge states under a perpendicular magnetic field. It is shown that the tunneling probability depends exponentially on the magnetic field. We propose a magnetic transistor based on a quantum anomalous Hall ribbon to observe this effect experimentally. Numerical simulations show that the conductance of the device is very sensitive to the strength and direction of the magnetic field. The positive/negative magnetic field results in the on/off state of the transistor. A giant magnetoresistance is found, and the on/off ratio reaches up to greater than 1010 for a long ribbon. These findings should be useful for potential applications in magnetic read heads and magnetic field sensors.
Three-dimensional computational fluid dynamics simulation of the hollow-cone spray process: The stability of the conical liquid sheet
Authors: Di Martino Massimiliano , Ahirwal Deepak , Maffettone Pier Luca
Published: June 2021

The characterization of atomization in small-scale applications, such as those typical of the consumer goods industry, is not widely investigated, despite its enormous interest as in the case of sanitation. In this field, the features of the atomizer are selected to achieve a wide spray pattern. This is the case of the pressure-swirl atomizer, where the swirl flow leads the liquid sheet to exhibit a distinctive hollow-cone shape. The configuration of the atomizer and the properties of the multiphase system (liquid–gas) affect the spray morphology and the droplets/ligaments distribution. The aim of the work is to investigate through computational fluid dynamics the stability of the gas–liquid interface produced by a swirling liquid injection. By implementing the volume-of-fluid method, we show transient simulations, in which the liquid–gas interactions take place within and outside the nozzle simultaneously. Depending on the different liquid properties and geometric features, we examine the hollow-cone spray performance in terms of cone angle and liquid sheet morphology. A stability analysis allows to determine whether spraying or jetting conditions are attained depending on Reynolds and Ohnesorge numbers, as the hollow-cone shape can degenerate into a straight jet under specific operating conditions. Viscosity is known to be a relevant parameter in fluid formulation, which impacts on both relevant dimensionless parameters. Newtonian and non-Newtonian rheologies are here considered for their ubiquitous presence in detergent or sanitation fluids. In both cases, we find a critical condition that marks the switch from the spraying to the jetting regime.
Exciton linewidth broadening induced by exciton–phonon interactions in CsPbBr3 nanocrystals
Authors: Yu Buyang , Zhang Chunfeng , Chen Lan , Huang Xinyu , Qin Zhengyuan , Wang Xiaoyong , Xiao Min
Published: June 2021

Quantum dephasing of excitonic transitions in CsPbBr3 nanocrystals has been studied using two-dimensional electronic spectroscopy at cryogenic temperatures. The exciton–phonon interactions for acoustic and optical modes exhibit different effects on the coherent dynamics of excitonic transitions. The homogeneous linewidth shows a proportional dependence on the temperature, suggesting the primary dephasing channel of the elastic scattering between exciton and acoustic modes. The exciton–optical mode interaction is manifested as the beatings of off-diagonal signals in the population time domain at the frequencies of 29 and 51 cm−1, indicating phonon replicas of excitonic transitions arising from coherent exciton–phonon interaction. The insight information of exciton homogeneous broadening in perovskite nanocrystals is essential for the potential application of quantum light sources.
Explosive crystallization of sputter-deposited amorphous germanium films by irradiation with an electron beam of SEM-level energies
Authors: Nakamura R. , Matsumoto A. , Ishimaru M.
Published: June 2021

The crystallization of sputter-deposited substrate-free films of amorphous germanium was induced by electron irradiation at SEM-level energies of less than 20 keV at ambient temperature using an electron probe microanalyzer. Instantaneous crystallization, referred to as explosive crystallization, occurred consistently at 2–20 keV; the threshold of electron fluxes is 1015–1016 m−2 s−1, which is five to six orders of magnitude lower than those at 100 keV reported previously. This process is expected to be advantageous in the production of polycrystalline Ge films since it is rapid, requires little energy, and results in negligible damage to the substrate.
Studying the kinetics of gas mixture sorption–desorption by a liquid through the phase interface
Authors: Boryaev A. A.
Published: June 2021

In the paper, the author develops experimental research methods and studies the specifics of gas mixture dissolution in a liquid where gases have different Henry's constants as well as the mutual interference of gases with different solubilities in a liquid during the dissolution process. It is shown that the dissolution rate of the studied pure gases in a liquid is proportional to their Henry's constants, and the dissolution rate of a gas mixture in a liquid is close to the dissolution rate of that gas in the mixture that has a higher Henry's constant. It was found that when a gas mixture containing a highly soluble gas is dissolved, interfacial surface turbulence (interfacial surface convection) occurs, which leads to an increase in the dissolution rate of the gas with lower solubility, that is, to an increase in the mass transfer coefficient (β) for that gas. The experimental studies showed that when several gases dissolved in a liquid are simultaneously desorbed into a floating-up bubble, the contribution of each gas is proportional to its solubility coefficient and does not depend on the concentration of these gases in the liquid.
Special optical performance from single upconverting micro/nanoparticles
Authors: Yang Dandan , Qiu Jianrong , Dong Guoping
Published: June 2021

Rare-earth ion-doped upconversion (UC) micro/nanoparticles (UCM/NPs) could enable the conversion of near-infrared photons to high-energy emissions in the visible and ultraviolet regions. This unique property makes UCM/NPs highly attractive for applications in diverse fields, including materials science, photophysics, and biomedicine. However, ensemble spectroscopy ignores the heterogeneity in terms of size, shape, defects, surface groups, and charges of single UCM/NPs. Recently, the rapid development of single-particle spectroscopic techniques results in a gradual shift in the investigation of UC materials to heterogeneous nanoscale structures, unique photophysical phenomena, and advanced applications of single UCM/NPs, and the optical performance of a single UCM/NP has become a central topic in the community of UC materials. In this Perspective paper, we outline the characterization methods of a single UCM/NP and provide an overview of recent and on-going progress in investigations on single UCM/NPs, with a focus on their spectroscopic properties and applications in the polarization, waveguide, micro/nano-laser, super-resolution nanoscopy, and nanobarcode. Finally, current challenges and perspectives in this field are highlighted for future research.
Drop impact onto polarized dielectric surface for controlled coating
Authors: Sankaran A. , Wu J. , Granda R. , Yurkiv V. , Mashayek F. , Yarin A. L.
Published: June 2021

Control of surface wettability by means of electrowetting-on-dielectric (EWOD) is among the most effective methods of active enhancement of surface wettability. Here, electrohydrodynamics of drop impact onto a dielectric surface with electrodes embedded in the dielectric (or aligned and attached to it) is experimentally investigated. Drop impact of different liquids (water, n-butanol, and motor oil) onto different substrates (stretched Teflon, parafilm, and polypropylene) is studied. Water drop impact onto stretched Teflon (the only Teflon which revealed significant electrowetting) and un-stretched parafilm surfaces is studied in detail. The results for water drop impact indicate that drop spreading on such non-wettable surfaces can be significantly enhanced by the electric field application. In particular, water drop rebound can be suppressed by the electric force. Furthermore, impact dynamics and spreading of hydrocarbon liquids with electric field are explored. Partial suppression of splash phenomena was also observed with the application of the electric field in addition to enhancement of spreading. In addition, the experimental results for water drops are compared with the Cahn−Hilliard−Navier−Stokes (CHNS) simulations for static contact angles and drop impact dynamics, and the results are in close agreement for water drops. This study demonstrates that electrowetting-on-dielectric holds great promise for coating and spraying technologies.
ALD-passivated silicon nanowires for broadband absorption applications
Authors: Kimeu Felix , Albin Sacharia , Song Kyo , Santiago Kevin C.
Published: June 2021

Silicon photonics enables the fabrication of optical devices with standard semiconductor processing technology. With high transparency and modal confinement, Si has matured into a well-established infrared optical material. Nanostructured silicon has been studied extensively due to its optical properties, especially silicon nanowires due to the myriad of available fabrication techniques, the broad range of physical dimensions, and the resulting optical characteristics. In this study, we fabricate silicon nanowires using a wet chemical process and modify their absorptive properties via atomic layer deposition passivation. The passivated nanowires absorb 95% of light from the visible to infrared, with a minimal angular dependence, making them excellent candidates for broadband absorber applications.
Extreme synchronization events in a Kuramoto model: The interplay between resource constraints and explosive transitions
Authors: Frolov Nikita , Hramov Alexander
Published: June 2021

Many living and artificial systems possess structural and dynamical properties of complex networks. One of the most exciting living networked systems is the brain, in which synchronization is an essential mechanism of its normal functioning. On the other hand, excessive synchronization in neural networks reflects undesired pathological activity, including various forms of epilepsy. In this context, network-theoretical approach and dynamical modeling may uncover deep insight into the origins of synchronization-related brain disorders. However, many models do not account for the resource consumption needed for the neural networks to synchronize. To fill this gap, we introduce a phenomenological Kuramoto model evolving under the excitability resource constraints. We demonstrate that the interplay between increased excitability and explosive synchronization induced by the hierarchical organization of the network forces the system to generate short-living extreme synchronization events, which are well-known signs of epileptic brain activity. Finally, we establish that the network units occupying the medium levels of hierarchy most strongly contribute to the birth of extreme events emphasizing the focal nature of their origin.
Living cells on the move
Authors: Alert Ricard , Trepat Xavier
Published: June 2021

Spectacular collective phenomena, such as jamming, turbulence, wetting, and waves, emerge when living cells migrate in groups.
Accelerating progress in climate science
Authors: Schneider Tapio , Jeevanjee Nadir , Socolow Robert
Published: June 2021

Interdisciplinary teams that integrate theory, data, and computing can now produce urgently needed, action-oriented climate science.
Temporal regulation of nicotinic acetylcholine receptor subunits supports central cholinergic synapse development in
Drosophila
Authors: Rosenthal Justin S. , Yin Jun , Lei Jingce , Sathyamurthy Anupama , Short Jacob , Long Caixia , Spillman Emma , Sheng Chengyu , Yuan Quan
Published: June 2021

Significance

Cholinergic neurotransmission in the central nervous system contributes immensely to animal behavior and is linked to a multitude of neuropsychiatric disorders in humans. However, in contrast to the well-established role of glutamate receptor signaling in the developing brain, it remains unclear whether neurotransmission mediated by acetylcholine receptors is also a major effector in neural development and plasticity. Here, we address this question in the
Drosophila
system, where most central excitatory synapses use acetylcholine as the main neurotransmitter. Our genetic studies reveal the distinct functions and developmental control of two specific nAchR subunits,
Dα1
and
Dα6
, and illustrate how the temporal regulation of these subunits contributes to the structural and functional maturation of the cholinergic postsynaptic apparatus in the fly brain.
Toward the correction of muscular dystrophy by gene editing
Authors: Olson Eric N.
Published: June 2021

Recent advances in gene editing technologies are enabling the potential correction of devastating monogenic disorders through elimination of underlying genetic mutations. Duchenne muscular dystrophy (DMD) is an especially severe genetic disorder caused by mutations in the gene encoding dystrophin, a membrane-associated protein required for maintenance of muscle structure and function. Patients with DMD succumb to loss of mobility early in life, culminating in premature death from cardiac and respiratory failure. The disease has thus far defied all curative strategies. CRISPR gene editing has provided new opportunities to ameliorate the disease by eliminating DMD mutations and thereby restore dystrophin expression throughout skeletal and cardiac muscle. Proof-of-concept studies in rodents, large mammals, and human cells have validated the potential of this approach, but numerous challenges remain to be addressed, including optimization of gene editing, delivery of gene editing components throughout the musculature, and mitigation of possible immune responses. This paper provides an overview of recent work from our laboratory and others toward the genetic correction of DMD and considers the opportunities and challenges in the path to clinical translation. Lessons learned from these studies will undoubtedly enable further applications of gene editing to numerous other diseases of muscle and other tissues.
Genetic and molecular determinants of polymicrobial interactions in
Fusobacterium nucleatum
Authors: Wu Chenggang , Chen Yi-Wei , Scheible Matthew , Chang Chungyu , Wittchen Manuel , Lee Ju Huck , Luong Truc T. , Tiner Bethany L. , Tauch Andreas , Das Asis , Ton-That Hung
Published: June 2021

Significance

Fusobacterium nucleatum
interacts with many oral microbes and has the ability to spread to the placenta and amniotic fluid, promoting preterm birth. Yet, the molecular mechanisms underlying polymicrobial interactions, termed coaggregation, by Fusobacteria are poorly understood. Here, we revealed that the two-component signal transduction system CarRS regulates expression of genes encoding lysine utilization factors (e.g., KamA) and the coaggregation factor RadD. Extracellular lysine blocks RadD-mediated coaggregation by binding to RadD. Significantly, mutants lacking KamA or CarR (which up-regulates RadD) are attenuated in virulence in a preterm birth model, while mutants devoid of RadD or CarS (which down-regulates RadD) exhibit increased virulence. Our findings unveiled a molecular linkage between coaggregation and lysine metabolism via CarRS-mediated gene regulation that modulates bacterial virulence.
A minimally disruptive method for measuring water potential in planta using hydrogel nanoreporters
Authors: Jain Piyush , Liu Weizhen , Zhu Siyu , Chang Christine Yao-Yun , Melkonian Jeff , Rockwell Fulton E. , Pauli Duke , Sun Ying , Zipfel Warren R. , Holbrook N. Michele , Riha Susan Jean , Gore Michael A. , Stroock Abraham D.
Published: June 2021

Significance

Gaps in our ability to document local water relations in leaves compromise our ability to build complete models of leaf and plant function and our understanding of ecophysiological phenomena, such as response and adaptation to drought. Macroscopically, leaf water potential has been shown to impact vegetative growth and yield, susceptibility to disease, and, in extreme drought, plant viability, making it a promising candidate trait to improve water-use efficiency in plants. In this paper, we present a nanoscale sensor (AquaDust) that provides minimally disruptive measurements of water potential in leaves of intact plants at high spatial and temporal resolution. This creates opportunities for improving our understanding of the mechanisms coupling variations in water potential to biological and physical processes.
Generation of ordered protein assemblies using rigid three-body fusion
Authors: Vulovic Ivan , Yao Qing , Park Young-Jun , Courbet Alexis , Norris Andrew , Busch Florian , Sahasrabuddhe Aniruddha , Merten Hannes , Sahtoe Danny D. , Ueda George , Fallas Jorge A. , Weaver Sara J. , Hsia Yang , Langan Robert A. , Plückthun Andreas , Wysocki Vicki H. , Veesler David , Jensen Grant J. , Baker David
Published: June 2021

Significance

Designed protein assemblies have many applications in medicine and technology. A long-standing design paradigm generates assemblies through genetic fusion of homo-oligomers via α-helical linkers. Here, we introduce a rigid fusion strategy that finds a greater number of design solutions and reduces formation of unintended assembly states, and a method for doubly anchoring target binding domains in the resulting assemblies that could contribute to cryogenic electron microscopy structure determination of small proteins.
Paleo-ENSO influence on African environments and early modern humans
Authors: Kaboth-Bahr Stefanie , Gosling William D. , Vogelsang Ralf , Bahr André , Scerri Eleanor M. L. , Asrat Asfawossen , Cohen Andrew S. , Düsing Walter , Foerster Verena , Lamb Henry F. , Maslin Mark A. , Roberts Helen M. , Schäbitz Frank , Trauth Martin H.
Published: June 2021

Significance

Our results identify the prime driver of climate variation in Africa’s low latitudes over the past 620 ky—the key time frame for the evolution of our species. Warming and cooling of the tropical Pacific Ocean paced by insolation changes modulated the tropical Walker circulation, driving opposing wet–dry states in eastern and western Africa. We show that the effects of glacial/interglacial cycles were not the predominant source of environmental change in most of the continent. Africa’s environmental patchwork driven by low-latitude climate processes should therefore be a critical component in conceptual models of human evolution and early demography over the past 620 ky.
Overconfidence in news judgments is associated with false news susceptibility
Authors: Lyons Benjamin A. , Montgomery Jacob M. , Guess Andrew M. , Nyhan Brendan , Reifler Jason
Published: June 2021

Significance

Although Americans believe the confusion caused by false news is extensive, relatively few indicate having seen or shared it—a discrepancy suggesting that members of the public may not only have a hard time identifying false news but fail to recognize their own deficiencies at doing so. If people incorrectly see themselves as highly skilled at identifying false news, they may unwittingly participate in its circulation. In this large-scale study, we show that not only is overconfidence extensive, but it is also linked to both self-reported and behavioral measures of false news website visits, engagement, and belief. Our results suggest that overconfidence may be a crucial factor for explaining how false and low-quality information spreads via social media.
Sexual fate of murine external genitalia development: Conserved transcriptional competency for male-biased genes in both sexes
Authors: Kajioka Daiki , Suzuki Kentaro , Matsushita Shoko , Hino Shinjiro , Sato Tetsuya , Takada Shuji , Isono Kyoichi , Takeo Toru , Kajimoto Mizuki , Nakagata Naomi , Nakao Mitsuyoshi , Suyama Mikita , DeFalco Tony , Miyagawa Shinichi , Yamada Gen
Published: June 2021

Significance

Androgen plays essential roles for sex differentiation of external genitalia through regulating male-biased genes. Even females can differentiate into male-type external genitalia depending on the degree of androgenic exposure. However, the mechanisms underlying androgen responsiveness in females are poorly defined. Here, we demonstrate Sp1 regulates the enrichment of H3K27ac on androgen receptor-mediated regulatory elements in both males and females, indicating transcriptional competency for male-biased genes is conserved by Sp1 in both sexes. Compound-MafBmutant mice lacking a tissue-specific enhancer in theMafB3′ UTR show incomplete male-type external differentiation similar to female-type differentiation. These findings underscore the idea that transcriptional competency for male-biased genes is preserved in both sexes, thus helping define the potential sexual fate of external genitalia.
Krüppel-like factor 6–mediated loss of BCAA catabolism contributes to kidney injury in mice and humans
Authors: Piret Sian E. , Guo Yiqing , Attallah Ahmed A. , Horne Sylvia J. , Zollman Amy , Owusu Daniel , Henein Justina , Sidorenko Viktoriya S. , Revelo Monica P. , Hato Takashi , Ma’ayan Avi , He John Cijiang , Mallipattu Sandeep K.
Published: June 2021

Significance

The kidney proximal tubule is particularly susceptible to acute injury, which results in loss of fatty acid oxidation (FAO), their primary energy source. Here, we show that loss of the transcription factor KLF6 specifically in the proximal tubule in mice protects against acute injury and fibrosis, with preservation of transcripts that mediate branched-chain amino acid (BCAA) catabolism, which were down-regulated in injured control mice. BCAA may provide tricarboxylic acid cycle intermediates in the absence of FAO, and we show that loss of BCAA catabolism in vitro resulted in decreased ATP production, while pharmacological activation of BCAA catabolism increased mitochondrial oxygen consumption. Thus, preservation of BCAA catabolism may be a possible therapeutic target in acute kidney injury.
Interaction hot spots for phase separation revealed by NMR studies of a CAPRIN1 condensed phase
Authors: Kim Tae Hun , Payliss Brandon J. , Nosella Michael L. , Lee Ian T. W. , Toyama Yuki , Forman-Kay Julie D. , Kay Lewis E.
Published: June 2021

Significance

Many important biological processes occur within biomolecular condensates. Unlike many organelles, these condensates lack a surrounding membrane but are formed by phase separation due to interactions of their molecular components. Although the important role of intrinsically disordered protein regions (IDRs) in condensates is appreciated and contributing amino acids have been identified, experimentally derived site-specific information reporting on interactions between IDRs in condensed phases is lacking. Using a suite of NMR experiments with improved resolution and sensitivity for studies of condensed phases, we have obtained quantitative and site-specific information on interactions and hot spots that govern phase separation of the C-terminal IDR of CAPRIN1 and how phase separation can be modulated by posttranslational modifications, mutations, and interactions with ATP.
CRISPR-based targeting of DNA methylation in
Arabidopsis thaliana
by a bacterial CG-specific DNA methyltransferase
Authors: Ghoshal Basudev , Picard Colette L. , Vong Brandon , Feng Suhua , Jacobsen Steven E.
Published: June 2021

Significance

Site-specific modification of epigenetic marks such as DNA methylation to regulate gene expression is a unique approach to enhance economically important crop traits. This approach allows for the maintenance of the introduced modifications in the absence of the initial transgene inducer in subsequent generations and relies largely on methylation of cytosines in the CG-specific sequence context. We have developed a targeted DNA methylation tool based on a bacterial methyltransferase and the CRISPR-Cas9 platform to directly methylate cytosines at CG sites in
Arabidopsis
. These tools expand the currently available CRISPR-based targeted DNA methylation tools and provide an approach for the establishment of heritable targeted DNA methylation in plants.
National images and their reception through football literature
Authors: Snauwaert Erwin
Published: June 2021

As demonstrated extensively by translation studies, national images and their reception undergo significant changes in the transfer process to another culture. From this perspective,La pena máximaby Roncagliolo is an interesting case: not only is the plot tied in with the theme of football, which is widely believed to embody national identity, but it has also been commented on in different target cultures. The reception study displays how the images of Argentina and Peru, which the novel deconstructs by using the 1978 World Cup as a pretext to expose the atrocities perpetrated by their respective totalitarian regimes, are perceived in the Hispanic context and in the French and Dutch literary systems into which they have been translated. While the Argentinian and the French reviews skate over the gruesome reality, the Peruvian, the Spanish and the Dutch ones assume the negative images by emphasizing their socio-political relevance.
The ‘other’ Transylvanian count
Authors: McMartin Jack , Gracza Krisztina
Published: June 2021

This article discusses the contemporary Hungarian and Anglophone reception of a trilogy of recently ‘rediscovered’ novels chronicling the demise of the Austro-Hungarian Empire. Written by the Transylvanian author and statesman Miklós Bánffy (1873–1950), the trilogy was originally published in 1934–1940, was suppressed during the Communist period and was published in English translation only in 1999 after years of work by Bánffy’s daughter, Katalin Bánffy-Jelen, and her co-translator, Patrick Thursfield. Through an analysis of auto- and heteroimages, we explore how reviewers in the source and target cultures dealt with imagologically relevant items. The analysis shows that reviews in Hungarian-language Transylvanian newspapers focused on situating Bánffy and his work in the Hungarian canon and emphasized Bánffy’s regional role, whereas Anglophone reviewers used Bánffy’s life to frame a pan-European discourse, drawing comparisons to Anglophone and international writers. We also discuss a heteroimage that emerged despite playing no role in the story itself: vampires.
The polarizability of a confined atomic system: an application of the Dalgarno–Lewis method
Authors: Antão T V C , Peres N M R
Published: June 2021

In this paper we give an application of the Dalgarno–Lewis method, the latter not usually taught in quantum mechanics courses. This is very unfortunate since this method allows one to bypass the sum over states appearing in the usual perturbation theory. In this context, and as an example, we study the effect of an external field, both static and frequency-dependent, on a model atom at fixed distance from a substrate. This can happen, for instance, when some organic molecule binds from one side to the substrate and from the other side to an atom or any other polarizable system. We model the polarizable atom by a short range potential, a Dirac-δ, and find that the existence of a bound state depends on the ratio of the effective ‘nuclear charge’ to the distance of the atom from the substrate. Using an asymptotic analysis, previously developed in the context of a single δ-function potential in an infinite medium, we determine the ionization rate and the Stark shift of our system. Using Dalgarno–Lewis theory we find an exact expression for the static and dynamic polarizabilities of our system valid to all distances. We show that the polarizability is extremely sensitive to the distance from the substrate, creating the possibility of using this quantity as a nanometric ruler. Furthermore, the line shape of the dynamic polarizability is also extremely sensitive to the distance from the substrate, thus providing another route to measure nanometric distances. The didactic value of the δ-function potential is widely accepted in teaching activities due to its simplicity, while still keeping the essential ingredients of a given problem.
Acoustic measurement of the triple point of neon T
Ne and thermodynamic calibration of a transfer standard for accurate cryogenic thermometry
Authors: Pan Changzhao , Sparasci Fernando , Zhang Haiyang , Gambette Pascal , Plimmer Mark , Imbraguglio Dario , Gavioso Roberto M , Moldover Michael R , Gao Bo , Pitre Laurent
Published: June 2021

We used absolute primary acoustic gas thermometry (AGT) to calibrate a Pt–Co resistance thermometer on the thermodynamic temperature scale by measuring the speed of sound in helium at a temperature T* chosen to be near the temperature of the triple point of neon, T
Ne. Prior to the present AGT, the Pt–Co thermometer was used with a neon triple-point cell as part of an interlaboratory comparison. Taken together, the results of the interlaboratory comparison and the present AGT redetermined the thermodynamic temperature T
Ne = (24.555 15 ± 0.000 24) K. This new value of T
Ne is consistent with other recent determinations obtained with various primary methods. After completing the AGT thermodynamic calibration, we used the Pt–Co thermometer to link T* to the temperature ratios measured by single-pressure refractive-index gas thermometry (SPRIGT) in a different laboratory. (Gao et al 2020 Metrologia
57 065006) Now, the T*-linked SPRIGT system can calibrate other thermometers on the thermodynamic temperature scale T in the range 5 K ⩽ T ⩽ T
Ne without using the international temperature scale ITS-90. At most temperatures in this range, the uncertainties of the T*-linked SPRIGT system are smaller than those of the ITS-90 systems used by National Metrology Institutes to calibrate resistance thermometers.
Terahertz frequency counter based on a semiconductor-superlattice harmonic mixer with four-octave measurable bandwidth and 16-digit precision
Authors: Nagano Shigeo , Kumagai Motohiro , Ito Hiroyuki , Hanado Yuko , Ido Tetsuya
Published: June 2021

We have developed a broadband and high-precision terahertz (THz) frequency counter based on a semiconductor-superlattice harmonic mixer (SLHM). Comparison of two THz frequencies determined using two independent counters and direct measurement of frequency-stabilized THz-quantum cascade lasers by a single counter showed a measurement uncertainty of less than 1 × 10−16 over a four-octave range from 120 GHz to 2.8 THz. Further extension of this measurable range was indicated by the research regarding the higher-harmonics generation of a local oscillator for the SLHM. This compact and easy-to-handle THz counter operating at room temperature is available for high-resolution spectroscopy of ultracold molecules proposed for detecting temporal changes in physics constants as well as many THz applications requiring a wide measurement range without a bulky cryogenic apparatus.
Study on the impact of plastic pollution based on multiple regression model
Authors: Zhu Guanlin , Tang Chenyang , Zhang Benyin
Published: June 2021

Plastic has become an indispensable and important part of human beings. In the past decades years, using plastic we have found that their biggest advantage is the disadvantage of causing fatal effects on the environment. The worsening of plastic pollution also makes us learn the severity of the problem gradually. We have established an evaluation model and adopted a local analysis method to global analysis method to analyze the impact of plastic pollution.
Research on regional water demand prediction of the upper and middle reaches of The Pearl River Basin based on system dynamics
Authors: Huang Mutao , Li Xiaojuan , Wang Jinmeng
Published: June 2021

The prediction and calculation of water resource demand play a crucial role in the balance of water resource supply and demand in the research area. Only when the water demand of the research area is accurately and reasonably grasped, it is possible to make corresponding management and adjustment according to the actual situation in the process of water resource utilization, so as to ensure the sustainable development and utilization of water resource. In this paper, the upper and middle reaches of the Pearl River basin is taken as the research area. According to the relationship between supply and demand and the social and economic situation of the Pearl River basin, VENSIM PLE is used to establish the dynamic model of the water demand forecasting system of the Pearl River Basin. The model involves four subsystems of population, industry, agriculture and water resource, and the water resource demand of the three provinces is simulated. Compared with the results of the pearl River Basin planning report, the prediction error is small, which proves that the system dynamics model is feasible to predict the water demand of the Pearl River Basin.
Development of emission inventory of typical container port based on the real port investigation
Authors: Sun Xiaowei , Li Haibo , Ren Chuan
Published: June 2021

Investigations on ships’ and cargo handling equipments’ (CHEs) activities were carried out in this study, including time of ships at at-berth and shift state, working hours of CHEs, and the engine power of ships and CHEs. Meanwhile, the emission inventory was developed based on the power emission estimation methodology and the emission contributions of ships, different types of CHEs, various port areas and operation processes were compared with. The results indicated that ships contributed most to the air pollution among all the pollutant sources and should be given higher priority for the improvement of the air quality. Shore power technology can be applied to the air pollutant mitigation in the future. Yard tractor and the process between port front to yard contributed a lot due to the usage of liquefied natural gas (LNG) on yard tractors. The application of LNG on CHEs should be given further consideration.