bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiology of Ice Climbing Injuries Among Recreational Ice Climbers at the 2019 Ouray Ice Climbing Festival
Authors: Ganti Arun , Davis Hillary E. , Musi Martin E. , Spano Susanne J.
Published: May 2021

Introduction

As a close relative to the sports of mountaineering and rock climbing, water ice climbing has been traditionally considered “high risk.” There is little data to support or refute this assertion. Prior estimates of the injury rate range from 4.8 to 248 injuries per 1000 participation hours. In this study, we characterized the types of injuries and determined an injury incidence among water ice climbing participants at the 2019 Ouray Ice Festival climbing manmade ice walls.

Methods

A survey was distributed during the 2019 Ouray Ice Festival in Ouray, Colorado. Respondents were asked to include festival-related injuries and estimate their participation time at the 4-d festival. Individuals who reported an injury were asked to provide additional details with regard to injury type, location, and timing. The injury incidence rate was calculated as the total number of injuries reported divided by the total number of participation hours and is reported as injuries per 1000 participation hours.

Results

A total of 75 surveys were analyzed. A total of 16 injuries, all which were minor, and 912 participation hours were reported, resulting in an injury incidence of 17.6 injuries per 1000 participation hours.

Conclusions

This study reports an injury incidence based on an unselected sample of water ice climbers at an ice climbing festival. Water ice climbing at festivals appears to result in injuries of minor severity with no major accidents or fatalities. This study could be repeated to confirm its validity with a larger sample size.
The Cult of Castor and Pollux in Ancient Rome
Authors: Gartrell Amber
Published: May 2021

The Dioscuri first appeared at the Battle of Lake Regillus in 496 BC to save the new Republic. Receiving a temple in the Forum in gratitude, the gods continued to play an important role in Roman life for centuries and took on new responsibilities as the needs of the society evolved. Protectors of elite horsemen, boxers and sailors, they also served as guarantors of the Republic's continuation and, eventually, as models for potential future emperors. Over the course of centuries, the cult and its temples underwent many changes. In this book, Amber Gartrell explores the evolution of the cult. Drawing on a range of methodological approaches and a wide range of ancient evidence, she focuses on four key aspects: the gods' two temples in Rome, their epiphanies, their protection of varied groups, and their role as divine parallels for imperial heirs, revealing how religion, politics and society interacted and influenced each other.
Cosmography and the Idea of Hyperborea in Ancient Greece
Authors: Gagné Renaud
Published: May 2021

Cosmography is defined here as the rhetoric of cosmology: the art of composing worlds. The mirage of Hyperborea, which played a substantial role in Greek religion and culture throughout Antiquity, offers a remarkable window into the practice of composing and reading worlds. This book follows Hyperborea across genres and centuries, both as an exploration of the extraordinary record of Greek thought on that further North and as a case study of ancient cosmography and the anthropological philology that tracks ancient cosmography. Trajectories through the many forms of Greek thought on Hyperborea shed light on key aspects of the cosmography of cult and the cosmography of literature. The philology of worlds pursued in this book ranges from Archaic hymns to Hellenistic and Imperial reconfigurations of Hyperborea. A thousand years of cosmography is thus surveyed through the rewritings of one idea. This is a book on the art of reading worlds slowly.
Brothers and Sisters in Medieval European Literature
Authors: Larrington Carolyne
Published: May 2021

The literature of the European Middle Ages attends closely to the relationship of brother and sister, laying bare sibling behaviours in their most dramatic forms as models to emulate, to marvel at orto avoid. The literary treatment of siblings opens up multiple perspectives on brothers' and sisters' emotions: love, hate, rivalry, desire, nurturing and ambivalence underlie sibling stories. These narratives are in turn inflected by rank, social context and most crucially, gender. This book examines these sibling relationships, focusing on the important vernacular literatures of Iceland, France, England and Germany, and building on recent research on siblings in psychology, history and social science. Multiple and subtle patterns in sibling interaction are teased out, such as the essential sibling task of "borderwork" (the establishment of individuality despite genetic resemblance), and the tensions caused by the easy substitutability of one sibling for another in certain social situations. When the sibling bond is extended to the in-law relation, complex emotional, strategic and political forces and powerful ambivalences nuance the relationship still further. Quasi-siblings: foster- or sworn-brothers complete the sibling picture in ways which reflect and contrast with the sibling blood-tie.  Carolyne Larrington is a Fellow and Tutor in medieval English literatureat St John's College, University of Oxford.
Assessing Machine Learning Techniques for Identifying Field Line Resonance Frequencies From Cross‐Phase Spectra
Authors: Foldes Raffaello , Del Corpo Alfredo , Pietropaolo Ermanno , Vellante Massimo
Published: May 2021

Monitoring the plasmasphere is an important task to achieve in the Space Weather context. A consolidated technique consists of remotely inferring the equatorial plasma mass density in the inner magnetosphere using Field Line Resonance (FLR) frequencies estimates. FLR frequencies can be obtained via cross‐phase analysis of magnetic signals recorded from pairs of latitude separated stations. In the last years, machine learning (ML) has been successfully applied in Space Weather, but this is the first attempt to estimate FLR frequencies with these techniques. We survey several supervised ML algorithms for identifying FLR frequencies by using measurements of the European quasi‐Meridional Magnetometer Array. Our algorithms take as input the 2‐hour cross‐phase spectra of magnetic signals and return the FLR frequency as output; we evaluate the algorithm performance on four different station pairs from L = 2.4 to L = 5.5. Results show that tree‐based algorithms are robust and accurate models to achieve this goal. Their performance slightly decreases with increasing latitude and tend to deteriorate during nighttime. The estimation error does not seem to depend on the geomagnetic activity, although at high latitudes the error increases during highly disturbed geomagnetic conditions such as the main phase of a storm. Our approach may represent a prominent space weather tool included into an automatic monitoring system of the plasmasphere. This work represents only a preliminary step in this direction; the application of this technique on a more extensive data set and on more pairs of stations is straightforward and necessary to create more robust and accurate models.
Gravity Gradient Inversion of Gravity Field and Steady‐State Ocean Circulation Explorer Satellite Data for the Lithospheric Density Structure in the Qinghai‐Tibet Plateau Region and the Surrounding Regions
Authors: Tian Yu , Li Honglei , Wang Yong , Ye Qing , Guo Aizhi
Published: May 2021

The continuous uplift and evolution of the Qinghai‐Tibet Plateau region (TPR) represents one of the most important Cenozoic geological events on Earth. The deformation mechanism of the lithosphere in the TPR is still under debate. Relevant viewpoints can be informed by investigations of the lithospheric density structure in the Qinghai‐Tibet Plateau and surrounding regions (TP‐SRs). Considering investigating the fine‐scale lithospheric density structure of the large‐scale areas, the GOCE satellite data covering entire TP‐SRs are used in this study. GOCE gravity gradient data are first subjected to several corrections. Then, based on gravity gradient curvature (SI) calculation complemented with the preconditioned conjugate gradient algorithm, the distribution of SI and the lithospheric density structure at depths of 0–80 km in TP‐SRs are obtained. The effects of temperature differences and material composition on the lithospheric density distribution are further distinguished. The results show that in the crust, the density anomalies in the TPR are blocked by the surrounding hard blocks. In the upper mantle, the distribution of the density anomalies in the TPR is predominantly affected by the northward subduction of the Indian Plate and the high heat flux environment. The Longmen Shan Thrust Belt is found to have penetrated the lower crust but has not reached the depth of the upper mantle. The density anomalies in the basins on the northern side of the TPR exhibit features indicative of independent stable blocks.
Seasonal Cycle of the Coastal West Greenland Current System Between Cape Farewell and Cape Desolation From a Very High‐Resolution Numerical Model
Authors: Gou Ruijian , Feucher Charlène , Pennelly Clark , Myers Paul G.
Published: May 2021

The shelf based West Greenland Current System carries both Arctic Water and Greenland meltwater around Cape Farewell, the southern tip of Greenland, where it may impact the deep water formation in the Labrador Sea. Nevertheless, this current system remains largely unknown due to limited observations. Using a very high‐resolution (1°/60°) numerical simulation integrated from 2005 to 2014, the annual cycle of the current structure in the vicinity of southern Greenland is analyzed to present the seasonal variability of the West Greenland Current System. A distinct shelf break West Greenland Coastal Current (WGCC) exists for about half the year between Cape Farewell and Cape Desolation, although it merges with the main jet of the West Greenland Current (WGC) in winter and separates in summer. The WGC has three components at Juliannehaab Bight: A shelf component, a shelf‐break component and a main slope jet. The shelf system is most energetic in fall, when the freshwater transport is also the greatest in a range of 25–40 mSv, with a broad transport minimum in spring in a range of 15–25 mSv. The seasonal cycle is strongest near Cape Farewell and weakest at Cape Desolation. The strength of the shelf system decreases as one moves north as water is lost offshore, with strongest transports of 0.61 Sv to the east of Cape Farewell and weakest of 0.41 Sv at Cape Desolation. This decrease in transport between Cape Farewell and Cape Desolation suggests substantial exchange between WGCC and WGC in this region.
Large‐Scale Scour in Response to Tidal Dominance in Estuaries
Authors: Leuven J. R. F. W. , van Keulen D. , Nienhuis J. H. , Canestrelli A. , Hoitink A. J. F.
Published: May 2021

Channel beds in estuaries and deltas often exhibit a local depth maximum close to the river mouth. There are two known mechanisms of large‐scale (i.e., >10 river widths along‐channel) channel bed scours: width constriction and draw‐down during river discharge extremes, both creating flow acceleration. Here, we study a potential third mechanism: tidal scour. We use a 1D‐morphodynamic model to reproduce tidal dynamics and scours in estuaries that are in morphologic equilibrium. A morphologic equilibrium is reached when the net (seaward) sediment transport matches the upstream supply along the entire reach. The residual (river) current and river‐tide interactions create seaward transport. Herein, river‐tide interactions represent the seaward advection of tide‐induced suspended sediment by the river flow. Tidal asymmetry typically creates landward transport. Scours form when tidal flow is amplified through funneling of tidal energy. Scours simultaneously reduce the residual (river) current and the river‐tide interaction contribution to sediment transport, thereby maintaining morphologic equilibrium. When tidal influence is relatively large, and when channel convergence is strong, an equilibrium is only obtained with a scouring profile. We propose a predictor dependent on the width convergence, quantified as SB, and on the ratio between the specific peak tidal discharge at the mouth and the specific river discharge at the landward boundary (qtide/qriver). Scours develop if (qtide/qriver)/SB exceeds 0.3. Scour conditions were found to occur globally across a range of scales, which allows its prediction in estuaries under future changes.
Making an Eclipse an Inclusive Multisensory Experience
Authors: Cartier Kimberly
Published: May 2021

New tools are helping make solar eclipse experiences and research accessible to people who are blind or low vision, communities often excluded from historically visually based sciences like astronomy.
Plain Language Summaries Explained in Plain Language
Authors: Halprin Amanda
Published: May 2021

Find out what a Plain Language Summary is, how to write an effective one, and how it benefits publications.
The Effect of Midnight Temperature Maximum Winds on Post‐Midnight Equatorial Spread F
Authors: Krall J. , Hickey D. , Huba J. D. , Dandenault P. B.
Published: May 2021

The SAMI3/equatorial spread F (Sami3 is also a model of the ionosphere/ESF) code is used to simulate the growth of equatorial plasma bubbles in the presence of a background wind field based on measured winds. The measured winds exhibit the well‐known “midnight temperature maximum” (MTM) pattern, in which an equatorward wind occurs simultaneously with a cessation in the zonal wind. The MTM is often preceded by strong equatorward winds (about 100 m/s). The circumstance where the MTM winds are symmetric across the equator is considered; here the meridional wind component in the southern hemisphere is the reverse of the northern meridional wind. The timing of the wind pattern relative to the imposition of a seed for the ESF instability is explored. We find that the simultaneous occurrence of a seed wave and a strong converging meridional wind pattern can produce post‐midnight ESF. We further find that the seed wave and the sudden cessation of the zonal winds can also produce post‐midnight ESF. The Magnetic mEridional NeuTrAl Thermospheric code verifies the occurrence of converging meridional wind patterns such as those simulated here, based on ionosonde data. Results suggest that regional‐scale wind measurements would aid in the prediction signal‐disrupting ionospheric bubbles.
Excitation spectral microscopy for highly multiplexed fluorescence imaging and quantitative biosensing
Authors: Chen Kun , Yan Rui , Xiang Limin , Xu Ke
Published: May 2021

The multiplexing capability of fluorescence microscopy is severely limited by the broad fluorescence spectral width. Spectral imaging offers potential solutions, yet typical approaches to disperse the local emission spectra notably impede the attainable throughput. Here we show that using a single, fixed fluorescence emission detection band, through frame-synchronized fast scanning of the excitation wavelength from a white lamp via an acousto-optic tunable filter, up to six subcellular targets, labeled by common fluorophores of substantial spectral overlap, can be simultaneously imaged in live cells with low (~1%) crosstalks and high temporal resolutions (down to ~10 ms). The demonstrated capability to quantify the abundances of different fluorophores in the same sample through unmixing the excitation spectra next enables us to devise novel, quantitative imaging schemes for both bi-state and Förster resonance energy transfer fluorescent biosensors in live cells. We thus achieve high sensitivities and spatiotemporal resolutions in quantifying the mitochondrial matrix pH and intracellular macromolecular crowding, and further demonstrate, for the first time, the multiplexing of absolute pH imaging with three additional target organelles/proteins to elucidate the complex, Parkin-mediated mitophagy pathway. Together, excitation spectral microscopy provides exceptional opportunities for highly multiplexed fluorescence imaging. The prospect of acquiring fast spectral images without the need for fluorescence dispersion or care for the spectral response of the detector offers tremendous potential.
Region-level epimutation rates in Arabidopsis thaliana
Authors: Denkena Johanna , Johannes Frank , Colomé-Tatché Maria
Published: May 2021

Failure to maintain DNA methylation patterns during plant development can occasionally give rise to so-called “spontaneous epimutations”. These stochastic methylation changes are sometimes heritable across generations and thus accumulate in plant genomes over time. Recent evidence indicates that spontaneous epimutations have a major role in shaping patterns of methylation diversity in plant populations. Using single CG dinucleotides as units of analysis, previous work has shown that the epimutation rate is several orders of magnitude higher than the genetic mutation rate. While these large rate differences have obvious implications for understanding genome-methylome co-evolution, the functional relevance of single CG methylation changes remains questionable. In contrast to single CG, solid experimental evidence has linked methylation gains and losses in larger genomic regions with transcriptional variation and heritable phenotypic effects. Here we show that such region-level changes arise stochastically at about the same rate as those at individual CG sites, are only marginal dependent on region size and cytosine density, but strongly dependent on chromosomal location. We also find consistent evidence that region-level epimutations are not restricted to CG contexts but also frequently occur in non-CG regions at the genome-wide scale. Taken together, our results support the view that many differentially methylated regions (DMRs) in natural populations originate from epimutation events and may not be effectively tagged by proximal SNPs. This possibility reinforces the need for epigenome-wide association studies (EWAS) in plants as a way to identify the epigenetic basis of complex traits.
Formation of various-axis-oriented wurtzite nuclei and enlargement of the a-axis-oriented region in AlFeN films deposited on Si(100) substrates
Authors: Imada Saki , Isshiki Toshiyuki , Tatemizo Nobuyuki , Nishio Koji , Mamishin Shuichi , Suzuki Yuya , Ito Katsuji , Nitta Kiyofumi , Suga Hiroki , Sekizawa Oki , Tamenori Yusuke
Published: May 2021

A-axis-oriented single-crystal AlFeN grains grew from randomly oriented small wurtzite grains with deposition time on Si(100). (a) Deposition time dependence of Al K-edge XANES spectra. (b) Theoretical spectra.
Self-assembly of trifunctional tripeptides to form neural scaffolds
Authors: Kulkarni Ketav , Kelderman Jenisi , Coleman Harold , Aguilar Marie-Isabel , Parkington Helena , Del Borgo Mark
Published: May 2021

A trifunctionalised tripeptide monomer self-assembles to form scaffolds that support the growth and maintenance of functional primary neurons.
Mechano-induced photoluminescence colour change in an alkyltolane-terminated cyanostilbene
Authors: Kondo Mizuho , Morita Yuya , Nishida Jun-ichi , Kawase Takeshi , Kawatsuki Nobuhiro
Published: May 2021

A novel alkyltolane-terminated cyanostilbene is synthesized. The photoluminescence colour changed depending on the precipitation method, with either a red shift or blue shift in the photoluminescence spectra observed upon mechanical grinding.
Methodology to detect oxidised phospholipids and their relevance in disease
Authors: Dushianthan Ahilanandan , Postle Anthony
Published: May 2021

Unsaturated membrane phospholipids are susceptible to oxidation, either by reactive oxygen species or enzymatically, to generate a complex mixture of peroxy and hydroxyl species. They can then spontaneously decompose to truncated oxidised phospholipids composed of aldehyde, carboxyl and hydroxyl species of five to nine carbon atoms chain length, many of which exhibit potent biological activities. In addition, aldehydes can form Schiff's base reactions with protein lysines to form oxidised lipid:protein adducts. While a selection of oxidised phospholipids have been characterised in detail by a range of mass spectrometry techniques, including direct infusion and liquid chromatography mass spectrometry, there are relatively few reports of comprehensive analyses of oxidised phospholipids in disease states. Oxidised phospholipid species are widely thought to be central to the pathology of many diseases, but there is relatively little direct evidence to confirm this in vivo. This review provides an overview of the various analytical methodologies and then summarises their application to examples of chronic and acute disease, cardiovascular disease and acute respiratory distress syndrome, respectively. It highlights the gaps in information and indicates directions for future research.
Systematic planning of moving target defence for maximising detection effectiveness against false data injection attacks in smart grid
Authors: Liu Bo , Wu Hongyu
Published: May 2021

Moving target defence (MTD) has been gaining traction to thwart false data injection attacks against state estimation (SE) in the power grid. MTD actively perturbs the reactance of transmission lines equipped with distributed flexible AC transmission system (D‐FACTS) devices to falsify the attacker's knowledge about the system configuration. However, the existing literature has not systematically studied what influences the detection effectiveness of MTD and how it can be improved based on the topology analysis. These problems are tackled here from the perspective of an MTD plan in which the D‐FACTS placement is determined. We first exploit the relation between the rank of the composite matrix and the detecting effectiveness. Then, we rigorously derive upper and lower bounds on the attack detecting probability of MTDs with a given rank of the composite matrix. Furthermore, we analyse existing planning methods and highlight the importance of bus coverage by D‐FACTS devices. To improve the detection effectiveness, we propose a novel graph theory–based planning algorithm to retain the maximum rank of the composite matrix while covering all necessary buses. Comparative results on multiple systems show the high detecting effectiveness of the proposed algorithm in both DC‐ and AC‐SE.
Coordination between the central control unit and local control function of a photovoltaic system under the uncertainties of sunlight and three‐phase unbalanced loads
Authors: Chanhome Anuwat , Chaitusaney Surachai
Published: May 2021

At present, high penetration of photovoltaic (PV) systems on low voltage (LV) distribution systems is increasing worldwide because of several favourable conditions, such as government policies, decreasing cost of PV technologies, and environmental awareness. However, varying sunlight and three‐phase unbalanced load conditions can result in voltage violation, especially an overvoltage problem, and voltage unbalanced conditions that deteriorate the power quality. Therefore, disconnection of PV systems, especially on the downstream node, can occur due to the overvoltage protection of the PV system, which results in PV owners losing revenue from selling electricity. Moreover, some electrical appliances can be damaged from voltage unbalanced conditions. To support a high PV penetration and prevent these adverse impacts, this study applies a control strategy involving coordination between the Central Control Unit (CCU) and Local Control Functions (LCFs) of PV systems. The CCU applies the Adaptive Tabu Search (ATS) technique to search for the optimal LCF parameter setting of PV systems and adjusted this weekly. The optimization problem is the maximization of real power generation from all PV systems under varying (uncertain) sunlight and three‐phase unbalanced loads. MATLAB programming is used for the Newton–Raphson power flow simulation on a modified 19‐node distribution system.
C–O-Selective Cross-Coupling of Chlorinated Phenol Derivatives
Authors: Neufeldt Sharon R. , Russell John E. A.
Published: May 2021

Chemoselective cross-coupling of phenol derivatives is valuable for generating products that retain halides. Here we discuss recent developments in selective cross-couplings of chloroaryl phenol derivatives, with a particular focus on reactions of chloroaryl tosylates. The first example of a C–O-selective Ni-catalyzed Suzuki–Miyaura coupling of chloroaryl tosylates is discussed in detail.

1 Introduction

2 Density Functional Theory Studies on Oxidative Addition at Nickel(0)

3 Stoichiometric Oxidative Addition Studies

4 Development of a Tosylate-Selective Suzuki Coupling

5 Conclusion and Outlook
Axially Substituted Silicon Phthalocyanine Payloads for Antibody–Drug Conjugates
Authors: Yamatsugu Kenzo , Kanai Motomu , Takahashi Kazuki , Sugiyama Akira , Ohkubo Kei , Tatsumi Toshifumi , Kodama Tatsuhiko
Published: May 2021

IR700, a silicon phthalocyanine (SiPc) photosensitizer, is an antibody–drug conjugate payload used clinically. It is, however, the sole SiPc payload to date, possibly due to the difficulty of its synthesis, resulting from its asymmetric phthalocyanine skeleton. Here, we report a new axially substituted SiPc payload that is more easily synthesized. Trastuzumab conjugated with the SiPc showed light- and antigen-dependent cytotoxicity in HER2-overexpressing cancer cell lines.
Electronic phase separation induced non-volatile bi-polar resistive switching in spatially confined manganite microbridges
Authors: Jeon J , Jung J , Chow K H
Published: May 2021

Correlated manganite films exhibit functional transport properties due to the co-existence of the competing electronic phase domains which are energetically similar. Here, we investigate very large bi-polar resistive switching (RS) in spatially confined La0.3Pr0.4Ca0.3MnO3 films. In this system, non-volatile bi-polar RS (up to ∼2× 106%) takes place via electric field induced expansion/shrinkage of metallic phase domains, which are separated by an insulating phase domain. These effects are observed without the need of a pre-forming process. We suggest the modification of a memristor model for phase separated systems to explain the observed non-volatile bi-polar I–V characteristics. Investigations of the endurance of the RS over many switching cycles (more than 2.7 × 104 switching) show that it does not decay and full switching occurs with a high success rate. Furthermore, the ability to carry out switching between a number of distinct resistance levels is demonstrated.
Improvement of the floating probe method for ion density and electron temperature measurement without compensation due to voltage reduction across the sheath
Authors: Lee Moo-Young , Seo Jong-In , Eo Hyundong , Kim Tae-Woo , Jung Jiwon , Lim Yeong-Min , Chung Chin-Wook
Published: May 2021

The floating probe method (FPM) applicable for processing plasma diagnostics was developed for the measurement of ion density and electron temperature (J. Appl. Phys. 101 033305). When an AC voltage is applied to a floating probe, harmonic currents are generated due to the nonlinearity of the sheath. The electron temperature and ion density are obtained using the harmonic currents and the voltage across the sheath. However, in the FPM, when the sensing resistance becomes similar to the sheath resistance, iterative calculations must be performed to compensate for the voltage reduction across the sheath due to the sensing resistor. In this paper, the voltage across a DC blocking capacitor is measured to directly obtain the voltage across the sheath. Therefore, it is not necessary to compensate for the voltage reduction across the sheath through iterative calculations. The electron temperature was increasingly overestimated as the capacity of the DC blocking capacitor became smaller. This overestimation was caused by the capacitive load effect and was compensated for using a correction for the second harmonic current. The measured electron temperature and ion density were compared with those from electron energy distribution functions (EEDFs) in an inductively coupled plasma, and they were in good agreement.
Ion heating in the PISCES-RF liquid-cooled high-power, steady-state, helicon plasma device
Authors: Thakur S Chakraborty , Paul M , Hollmann E M , Lister E , Scime E E , Sadhu S , Steinberger T E , Tynan G R
Published: May 2021

Radio frequency (RF) driven helicon plasma sources are commonly used for their ability to produce high-density argon plasmas (n > 1019 m−3) at relatively moderate powers (typical RF power < 2 kW). Typical electron temperatures are <10 eV and typical ion temperatures are <0.6 eV. A newly designed helicon antenna assembly (with concentric, double-layered, fully liquid-cooled RF-transparent windows) operates in steady-state at RF powers up to 10 kW. We report on the dependence of argon plasma density, electron temperature and ion temperature on RF power. At 10 kW, ion temperatures >2 eV in argon plasmas are measured with laser induced fluorescence, which is consistent with a simple volume averaged 0D power balance model. 1D Monte Carlo simulations of the neutral density profile for these plasma conditions show strong neutral depletion near the core and predict neutral temperatures well above room temperatures. The plasmas created in this high-power helicon source (when light ions are employed) are ideally suited for fusion divertor plasma-material interaction studies and negative ion production for neutral beams.
Preparation and optimization of PVDF thin films for miniaturized sensor and actuator applications
Authors: Sarkar Lisa , Singh Shiv Govind , Krishna Vanjari Siva Rama
Published: May 2021

This paper demonstrates the key process optimizations that need to be carried out in order to leverage the piezoelectric property of polyvinylidene diflouride (PVDF) thin films for miniaturized sensor and actuator applications. The emphasis of the paper is two fold. Firstly, innate material and piezoelectric properties of PVDF thin films were thoroughly investigated and the processing conditions for achieving minimally porous, smooth thin film exhibiting superior piezoelectric response was experimentally figured out. Along with that, as a proof of concept, a working prototype of piezoelectric micromachined ultrasonic transducer (PMUT) was fabricated and tested using optimized PVDF thin films. The key bottleneck of adhesion of PVDF with underlying metal layers is addressed by using adhesion promoter (3-aminopropyl)triethoxysilane. This small, yet significant modification enabled the fabrication of PMUT device using PVDF as membrane material. The fabricated device has exhibited a electromechanical coupling coefficient value of 15.66% and a resonance frequency of 129.5 kHz.
Abnormal transport properties of Bi-III superconducting phase in pressurized bismuth single crystal
Authors: Zhang Yufeng , Gouchi Jun , Ishigaki Kento , Nagasaki Shoko , Shi Zhixiang , Uwatoko Yoshiya
Published: May 2021

Resistivity, magnetoresistance, and upper critical field, have been comprehensively studied for the bismuth (Bi)-III superconducting phase in the pressure range of 2.9 GPa ⩽ P⩽ 6.2 GPa. It is discovered that the transition temperature T
c of the Bi-III phase is gradually suppressed with increasing pressure. Strikingly, the temperature-dependent resistivity above T
c in the Bi-III region reveals notable non-Fermi-liquid behaviors, resembling many unconventional superconducting systems. As the pressure increases, the magnetoresistance effect progressively grows and reaches a maximum value of 212% at pressure ∼6.2 GPa and field of 5 T, indicating a possible contribution to the charge conduction by Dirac electrons. Moreover, the zero-temperature upper critical field for the Bi-III phase displays relatively low values concerning the moderate T
c values, and the reduced upper critical field for different pressures deviates from the single-band Werthamer–Helfand–Hohenberg model. These unusual normal state transport properties and unique behavior of the upper critical field point to possible unconventional superconductivity for the Bi-III superconducting phase.
Dark Sector first results at Belle II
Authors: Campajola Marcello
Published: May 2021

Understanding the nature of dark matter is one of the most exciting challenges in fundamental physics nowadays, requiring the synergy of different search techniques, as well as theoretical inputs. An interesting opportunity for the investigation of dark matter is the one offered by the B-factories. The Belle II experiment, located at the interaction point of the SuperKEKB asymmetric energy e
+
e
− collider, is a new generation B-factory experiment operating at the Japanese KEK laboratory. With a machine design luminosity of 6 × 1035 cm−2
s
−1, Belle II aims to record 50 ab−1 of data within the next decade. Thanks to this large data-sample and by using dedicated triggers, Belle II is expected to explore dark sector candidates with unprecedented sensitivity in the mass range up to 10 GeV/c
2. During 2018, the experiment concluded a commissioning run, collecting a data-sample corresponding to an integrated luminosity of about 0.5 fb−1, while main operations started on March 2019 with an almost complete detector. So far the experiment collected an integrated luminosity of ∼ 90 fb−1. With these data-sets Belle II has already shown the possibility to search for a large variety of dark sector candidates in the GeV mass range. This paper reviews the status of the dark sector searches performed at the Belle II experiment, with a focus on the first obtained results and the discovery potential with the data-set available in the short term.
Light-controlled pulsed x-ray tube with photocathode*
Authors: Xuan Hao , Liu Yong-An , Qiang Peng-Fei , Su Tong , Yang Xiang-Hui , Sheng Li-Zhi , Zhao Bao-Sheng
Published: May 2021

Unstable mechanical structure, low energy efficiency, and cooling requirements limit the application of conventional x-ray tubes based on filament as cathode in several academic areas. In this paper, we demonstrate a light-controlled pulsed x-ray tube using multialkali cathode as electron generator. The photocathode active area of the light controlled x-ray tube is 13.2 cm2 (41 mm in diameter), which provides high photoelectron-emitting efficiency up to 0.288 mA/lm in 460-nm LED and 2.37-mA maximum tube current. Furthermore, the modulation ability from 1 kHz to 100 kHz of the x-ray tube is tested. The results suggest that the light-controlled pulsed x-ray tube has easy modulation and short x-ray pulse properties and is promising to be the next generation x-ray tube with wide applications in medical radiationtherapy as well as the calibration for detectors and scintillators.
PhotoinducedWeyl semimetal phase and anomalous Hall effect in a three-dimensional topological insulator*
Authors: Chen Meng-Nan , Chen Wen-Chao
Published: May 2021

Motivated by the fact that Weyl fermions can emerge in a three-dimensional topological insulator on breaking either time-reversal or inversion symmetries, we propose that a topological quantum phase transition to a Weyl semimetal phase occurs under the off-resonant circularly polarized light, in a three-dimensional topological insulator, when the intensity of the incident light exceeds a critical value. The circularly polarized light effectively generates a Zeeman exchange field and a renormalized Dirac mass, which are highly controllable. The phase transition can be exactly characterized by the first Chern number. A tunable anomalous Hall conductivity emerges, which is fully determined by the location of the Weyl nodes in momentum space, even in the doping regime. Our predictions are experimentally realizable through pump-probe angle-resolved photoemission spectroscopy and raise a new way for realizing Weyl semimetals and quantum anomalous Hall effects.
Fast qubit initialization in a superconducting circuit*
Authors: Huang Tianqi , Zheng Wen , Song Shuqing , Dong Yuqian , Yang Xiaopei , Han Zhikun , Lan Dong , Tan Xinsheng
Published: May 2021

We demonstrate an active reset protocol in a superconducting quantum circuit. The thermal population on the excited state of a transmon qubit is reduced through driving the transitions between the qubit and an ancillary qubit. Furthermore, we investigate the efficiency of this approach at different temperatures. The result shows that population in the first excited state can be dropped from 7% to 2.55% in 27 ns at 30 mK. The efficiency improves as the temperature increases. Compared to other schemes, our proposal alleviates the requirements for measurement procedure and equipment. With the increase of qubit integration, the fast reset technique holds the promise of improving the fidelity of quantum control.
Highly flexible and excellent performance continuous carbon nanotube fibrous thermoelectric modules for diversified applications*
Authors: Xia Xiao-Gang , Zhang Qiang , Zhou Wen-Bin , Xiao Zhuo-Jian , Xi Wei , Wang Yan-Chun , Zhou Wei-Ya
Published: May 2021

A highly flexible and continuous fibrous thermoelectric (TE) module with high-performance has been fabricated based on an ultra-long single-walled carbon nanotube fiber, which effectively avoids the drawbacks of traditional inorganic TE based modules. The maximum output power density of a 1-cm long fibrous TE module with 8 p–n pairs can reach to 3436 μW ⋅ cm−2, the power per unit weight to 2034 μW ⋅ g−1, at a steady-state temperature difference of 50 K. The continuous fibrous TE module is used to detect temperature change of a single point, which exhibits a good responsiveness and excellent stability. Because of its adjustability in length, the flexible fibrous TE module can satisfy the transformation of the temperature difference between two distant heat sources into electrical energy. Based on the signal of the as-fabricated TE module, a multi-region recognizer has been designed and demonstrated. The highly flexible and continuous fibrous TE module with excellent performance shows a great potential in diversified applications of TE generation, temperature detection, and position identification.
Does statistical model perform at par with computationally expensive general circulation model for decadal prediction?
Authors: Sahastrabuddhe Rishi , Ghosh Subimal
Published: May 2021

Decadal predictions have gained immense importance over the last decade because of their use in near-term adaption planning. Computationally expensive coupled model intercomparison project phase 5 general circulation models (GCMs) are initialized every 5 years and they generate the decadal hindcasts with moderate skill. Here we test the hypothesis that computationally inexpensive data-driven models, such as multi-variate singular spectrum analysis (MSSA), which takes care of trends and oscillations, performs similar to GCMs. We pick up one of the most complex variables having low predictability, Indian summer monsoon rainfall (ISMR) and its possible causal sea surface temperatures (SST). We find that the MSSA approach performs similar to the GCMs in simulating SSTs beyond their nonlinear limits of predictability, which is ∼12 months. These SSTs are used for decadal predictions of ISMR and show improved skills compared to the GCMs. We conclude that data-driven models are possible alternatives to computationally expensive GCMs for decadal predictions.
Plasmonic effect for photoluminescence enhancement in graphene/Au/ZnO hybrid structures: dependence on the surface lateral period of the Au layer
Authors: Dong Zuoru , Chen Peizong , Li Shujie , Jiang Zuimin , Xu Fei
Published: May 2021

The basic physics of the plasmonic effect of graphene in the UV region is fascinating but is not well understood. In this work, the influence of surface lateral period on the plasmonic effect of graphene for photoluminescence (PL) enhancement in graphene/Au/ZnO hybrid structures at a laser excitation wavelength of 325 nm is studied. In graphene/Au/ZnO hybrid structures, the Au layers act as corrugated surfaces, and their lateral period varies with the layer thickness. A reduction in PL intensity due to graphene was observed in the graphene/ZnO hybrid structure, and this was attributed to electron transfer from the ZnO to the graphene. The electron transfer was confirmed by a 10 cm−1 redshift for the 2D Raman peak of graphene in graphene/ZnO in comparison to that for graphene/SiO2(300 nm)/Si. In contrast, an enhancement in PL intensity by the graphene was observed when an Au layer was inserted between the graphene and the ZnO, and the enhancement ratio strongly depended on the surface lateral period of the Au layer. This enhancement is explained by effective excitation of the plasmon in the graphene at the momentum matching condition while the corrugated Au surface provides effective momentum compensation for excitation of the plasmon by the incident light in the graphene.
Judging phase purity of hematite (α-Fe2O3) nanoparticles through structural and magnetic studies
Authors: Justus J Sharmila , Dharma Roy S Dawn , Saravanakumar K , Ezhil Raj A Moses
Published: May 2021

The effect of post-growth annealing on the phase transformation leading to phase pure hematite (α-Fe2O3) nanoparticles is reported in this work. Co-precipitation technique was used to synthesise iron oxide nanoparticles by adjusting the pH of the solution. The xerogel was dried at 80 °C and the obtained powder was calcined in the temperature range 400–800 °C for 3 h. in air. Annealing temperature was prefixed on the basis of the thermal degradation pattern of the starting precursor. X-ray diffraction (XRD) study endorsed the presence of mixed phases FeO, FeO2 and α-Fe2O3 in the as-prepared sample. On annealing, the minor phases transform gradually to α-Fe2O3, as confirmed through thermal studies. Performed Rietveld analysis confirms the presence of impurity phases in samples annealed at low temperature. Phase pure sample crystallizes in the rhombohedral corundum structure (space group, R-3c) with a = 5.04044 Å, c = 13.7628 Å and c/a = 2.73048. FT-Raman spectral investigations allowed for a clear assignment of the α-Fe2O3 phase. Chemical analysis advocated the only presence of Fe3+ ions that octahedrally coordinated with hexagonally close packed O2- ions that constitute corundum structure. Electron microscopy (TEM) images proved the non-spherical particle distribution in the range 80–100 nm with mean particle size of 93 nm. Structural phase transition with annealing temperature was further confirmed through the fluctuations in the magnetic structure. In analogues to XRD, magnetic study also served as a judging tool to identify purity and the presence of mixed phases in hematite.
Roadmap on inorganic perovskites for energy applications
Authors: Irvine John , Rupp Jennifer L. M. , Liu Gang , Xu Xiaoxiang , Haile Sossina , Qian Xin , Snyder Alem , Freer Robert , Ekren Dursun , Skinner Stephen , Celikbilek Ozden , Chen Shigang , Tao Shanwen , Shin Tae Ho , O’Hayre Ryan , Huang Jake , Duan Chuancheng , Papac Meagan , Li Shuangbin , Celorrio Veronica , Russell Andrea , Hayden Brian , Nolan Hugo , Huang Xiubing , Wang Ge , Metcalfe Ian , Neagu Dragos , Martín Susana Garcia
Published: May 2021

Inorganic perovskites exhibit many important physical properties such as ferroelectricity, magnetoresistance and superconductivity as well their importance as energy materials. Many of the most important energy materials are inorganic perovskites and find application in batteries, fuel cells, photocatalysts, catalysis, thermoelectrics and solar thermal. In all these applications, perovskite oxides, or their derivatives offer highly competitive performance, often state of the art and so tend to dominate research into energy material. In the following sections, we review these functionalities in turn seeking to facilitate the interchange of ideas between domains. The potential for improvement is explored and we highlight the importance of both detailed modelling and in situ and operando studies in taking these materials forward.
PADI4 mediates autophagy and participates in the role of ganoderic acid A monomers in delaying the senescence of Alzheimer's cells through the Akt/mTOR pathway
Authors: Shen Shuhua , Wang Xiaoming , Lv Hang , Shi Yuan , Xiao Luwei
Published: May 2021

The effects of PADI4 and GAA on the senescence of Alzheimer's cells were explored in the present work. HT22 cells were treated with Aβ25-35 to establish an Alzheimer's model and were then treated with different concentrations of GAA and transfected with a siPADI4 lentiviral vector. GAA could reverse the effects of Aβ25-35 on inhibiting cell viability and promoting apoptosis and senescence. siPADI4 reduced Aβ25-35-induced cell viability and upregulated Aβ25-35-induced cell apoptosis and senescence, as well as partially reversed the effect of GAA on cells, and these results were confirmed by detecting the expressions of senescence- and apoptosis-related proteins. In addition, siPADI4 was found to promote the phosphorylation of Akt and mTOR, which was partially reversed by GAA. In conclusion, PADI4 mediates autophagy and participates in the role of GAA monomers in delaying the senescence of Alzheimer's cells through the Akt/mTOR pathway.
Red foxes avoid apex predation without increasing fear
Authors: Wooster Eamonn I F , Ramp Daniel , Lundgren Erick J , O’Neill Adam J , Wallach Arian D
Published: May 2021

Apex predators structure ecosystems by hunting mesopredators and herbivores. These trophic cascades are driven not only by the number of animals they kill, but also by how prey alter their behaviors to reduce risk. The different levels of risk navigated by prey has been likened to a “landscape of fear.” In Australia, dingoes are known to suppress red fox populations, driving a trophic cascade. However, most of what we know of this relationship comes from circumstances where predators are persecuted, which can affect their social and trophic interactions. Utilizing camera traps, we monitored fox behavior when accessing key resource points used by territorial dingoes, in a region where both predators are protected. We predicted that foxes would avoid and be more cautious in areas of high dingo activity. Indeed, foxes avoided directly encountering dingoes. However, contrary to our expectations, foxes were not more cautious or vigilant where dingo activity was high. In fact, fox activity and scent-marking rates increased where dingo scent-marking was concentrated. Further, foxes were increasingly confident with increasing levels of conspecific activity. Our results suggest that responses to the threat of predation are more complex than fear alone. In socially stable conditions, it is possible that prey may develop knowledge of their predators, facilitating avoidance, and reducing fear.
Spermatogonial Dio3 as a potential germ line sensor for thyroid hormone-driven epigenetic inheritance
Authors: Hernandez Arturo
Published: May 2021

Thyroid hormone-clearing type 3 deiodinase is located in spermatogonia, where it may serve as a critical modulator of the thyroid hormone exposure of the male germ line and its epigenetic information, with implications for neurodevelopmental and endocrine disorders in subsequent generations.