bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of Handpiece Mounted Continuous Irrigation System for the Removal of Residual Pulpal Debris During Root Canal Preparation
Authors: Sarwar Huma , Qazi Fazal , Ahmed Shahbaz , Abidi Yawar , Naeem Meshal , Shabbir Juzer , Khurshid Zohaib
Published: May 2021

Objective The removal of residual pulpal debris (RPD) from the root canal walls, especially in necrotic teeth is important for successful endodontic outcome. The aim of this study was to evaluate the RPD removal efficacy of handpiece mounted continuous irrigation with simultaneous root canal preparation from the apical third of root canals as compared to conventional syringe irrigation (SI).

Materials and Methods Ninety extracted teeth were randomly divided into three groups: SI; handpiece mounted continuous irrigation (CI); and both syringe and continuous irrigation (CI+SI). After root canal preparation, roots were sectioned at 1 (a), 3 (b) and 5 (c) mm from apex and prepared for Hematoxylin-Eosin staining. Sections were microscopically examined for presence of RPD.

Statistical Analysis Intergroup difference in average percentage of RPD at different root levels was calculated by using analysis of variance test (ANOVA). Tuckey test was used for pairwise comparison.

Results ANOVA showed significant difference between all three groups (p < 0.05). SI group showed a significantly higher percentage of RPD as compared with CI and CI+ SI groups at all root levels (p < 0.01). At root level a, CI showed a significantly higher percentage of RPD as compared with CI+SI (p < 0.01).

Conclusion Handpiece mounted CI during rotary instrumentation showed a significant reduction in RPD as compared with conventional syringe irrigation. This technique was found to be an effective method for an enhanced root canal debridement.
Evidence-Based Health Informatics as the Foundation for the COVID-19 Response: A Joint Call for Action
Authors: Fernandez-Luque Luis , Kushniruk Andre W. , Georgiou Andrew , Basu Arindam , Petersen Carolyn , Ronquillo Charlene , Paton Chris , Nøhr Christian , Kuziemsky Craig E. , Alhuwail Dari , Skiba Diane , Huesing Elaine , Gabarron Elia , Borycki Elizabeth M. , Magrabi Farah , Denecke Kerstin , Peute Linda W. P. , Topaz Max , Al-Shorbaji Najeeb , Lacroix Paulette , Marcilly Romaric , Cornet Ronald , Gogia Shashi B. , Kobayashi Shinji , Iyengar Sriram , Deserno Thomas M. , Mettler Tobias , Vimarlund Vivian , Zhu Xinxin
Published: May 2021

Background As a major public health crisis, the novel coronavirus disease 2019 (COVID-19) pandemic demonstrates the urgent need for safe, effective, and evidence-based implementations of digital health. The urgency stems from the frequent tendency to focus attention on seemingly high promising digital health interventions despite being poorly validated in times of crisis.

Aim In this paper, we describe a joint call for action to use and leverage evidence-based health informatics as the foundation for the COVID-19 response and public health interventions. Tangible examples are provided for how the working groups and special interest groups of the International Medical Informatics Association (IMIA) are helping to build an evidence-based response to this crisis.

Methods Leaders of working and special interest groups of the IMIA, a total of 26 groups, were contacted via e-mail to provide a summary of the scientific-based efforts taken to combat COVID-19 pandemic and participate in the discussion toward the creation of this manuscript. A total of 13 groups participated in this manuscript.

Results Various efforts were exerted by members of IMIA including (1) developing evidence-based guidelines for the design and deployment of digital health solutions during COVID-19; (2) surveying clinical informaticians internationally about key digital solutions deployed to combat COVID-19 and the challenges faced when implementing and using them; and (3) offering necessary resources for clinicians about the use of digital tools in clinical practice, education, and research during COVID-19.

Discussion Rigor and evidence need to be taken into consideration when designing, implementing, and using digital tools to combat COVID-19 to avoid delays and unforeseen negative consequences. It is paramount to employ a multidisciplinary approach for the development and implementation of digital health tools that have been rapidly deployed in response to the pandemic bearing in mind human factors, ethics, data privacy, and the diversity of context at the local, national, and international levels. The training and capacity building of front-line workers is crucial and must be linked to a clear strategy for evaluation of ongoing experiences.
Trevino and Doh’s discourse-based view: Do we need a new theory of internationalization?
Authors: Ault Joshua K , Newenham-Kahindi Aloysius , Patnaik Sanjay
Published: May 2021

This counterpoint examines the relevance of Trevino and Doh’s proposed new discourse-based view of internationalization for the field of International Business (IB). Trevino and Doh introduce their framework to address gaps in Internationalization Process Theory (IPT), which does not account for the underlying processes that lead to the initial managerial decision to internationalize. Framing our counterpoint around recent debates on how interdisciplinary research fields determine which new ideas to adopt, we explore whether the introduction of the discourse-based view adds sufficient novelty to justify the risk of fragmentation within IB. To stimulate debate around this question, we explore a number of issues, such as (1) whether the constructs found in the discourse-based view are distinct from pre-existing IB concepts, (2) the relative value of isolating the initial decision to internationalize within the broader internationalization process, and (3) the degree to which Trevino and Doh have isolated discourse as a primary mechanism driving the decision to internationalize. We conclude with a call for more dialog around the questions of how IB can embrace greater openness while still maintaining coherence and advancing collective knowledge.
A review of diagnostic techniques for high-intensity negative ion sources
Authors: Tsumori K. , Wada M.
Published: May 2021

Plasma and beam diagnostic methods for high-current-density negative ion sources are reviewed. The pulse laser–induced photodetachment method was widely used to measure negative ion density in the ion source plasma. The method was used to understand fundamental processes of negative hydrogen (H−) ion formation and destruction in hydrogen plasmas. Species composition and plasma parameters in H− ion sources can be estimated from optical emission spectroscopy data, while electrostatic probes are utilized to obtain local plasma parameters in the ion source. Plasma transport toward the extractor is studied by combining a laser beam for photodetachment and a structured electrostatic probe to visualize a flow pattern of H− ions. Spatial distributions of large-area H− ion beams are monitored by infrared thermography images, showing interactions among multiple beamlets. These diagnostic methods deepen the understanding of how H− ions are produced and extracted through beam-forming apertures. The acquired knowledge on ion source plasma and beam transport improves the ion source design of the next-generation H− ion sources for fusion experiments and accelerators. The essence of research and development for negative ion source study is summarized through briefly tracing the history.
Multiple topological interface states in broadband locally resonant phononic crystals
Authors: Zheng Zhoufu , Yin Jianfei , Wen Jihong , Yu Dianlong
Published: May 2021

We design a one-dimensional locally resonant phononic crystal (LRPC) comprised of a substrate beam periodically attached with twin resonators. By alternating the position of the resonators, the bandgap forming mechanisms of the LRPC, namely, the band folding-induced bandgaps (BFBGs) and the locally resonant bandgap (LRBG), are analyzed. A broadband “pseudo-bandgap” formed by the LRBG and BFBG can be achieved. The topological properties of the LRPC are then studied, and it is found that the topological interface states can occur only in the BFBGs but not in the LRBG. By constructing a finite LRPC formed by two PCs with distinct topological properties connecting with each other, we numerically and experimentally demonstrate the existence of multiple topological interface states in the BFBGs. The interface state within the subwavelength regime can be achieved with strong energy localization and is little affected by material damping, while for the interface state at high frequencies, it is shown that damping could considerably weaken the energy localization. This work provides guidelines for the design of low-frequency elastic topological systems.
Forward scattering and filamentation of a spatially smoothed laser pulse in the hydrodynamic and kinetic frameworks
Authors: Ruyer C. , Debayle A. , Loiseau P. , Masson-Laborde P. E. , Fuchs J. , Casanova M. , Marquès J. R. , Romagnani L. , Antici P. , Bourgeois N. , Nakatsutsumi M. , Safronova M. , Starodubtsev M. , Lin T.
Published: May 2021

We address the scattering of a high energy laser pulse on a large wavelength acoustic turbulence of relevance for Laser M'egajoule or National Ignition Facility-class experiments. Both kinetic and hydrodynamic frameworks are adopted and combined with a linearized description of the laser propagation. The resulting dispersion relations display important kinetic contributions to the growth of the forward Brillouin instability. Moreover, proof is made that the spatial incoherence often used in high energy laser facilities is, for cold enough plasmas or in the multi-ion species case, not enough to reach full control of the laser filamentation. Comparisons with experimental results and dedicated hydrodynamic simulations confirm our results. The derived dispersion relations present new tools for assessing the propagation quality and energy deposition region of high energy laser pulses. They also underline the importance of accounting for kinetic effects, even in the millimeter and nanosecond scale of many inertial confinement fusion or high-energy-density experiments.
Theoretical insights to excitonic effect in lead bromide perovskites
Authors: Jain Manjari , Gill Deepika , Bhumla Preeti , Basera Pooja , Bhattacharya Saswata
Published: May 2021

Exciton binding energy is an important factor in photovoltaics as the formation of excitons influences the charge separation in solar cells. However, a detailed theoretical study of excitonic properties is rather demanding due to huge computational cost. We have systematically applied several state-of-the-art advanced first-principles based methodologies, viz., hybrid density functional theory combined with Spin–Orbit Coupling (SOC), Many Body Perturabtion Theory (MBPT), model-BSE, Wannier–Mott, and Density Functional Perturbation Theory (DFPT) approaches, to understand the excitonic properties by taking a prototypical model system of lead bromide perovskites, viz., APbBr3 [A = CH3NH3+ (MA), HC(NH2)2+ (FA), Cs+]. We show that via conventional procedure using GW/BSE approach along with SOC effect, it is very challenging to converge the BSE calculation to obtain the correct position of the excitonic peak to compute the exciton binding energy (EB) accurately. Therefore, we have employed Wannier–Mott and DFPT approaches to compute EB, where we find that the contribution of ionic dielectric screening is essential. In addition, we have calculated the exciton lifetime, which is in agreement with the trend observed (FAPbBr3 > MAPbBr3 > CsPbBr3) for electron–phonon coupling. The role of cation “A” for achieving the long-lived exciton lifetime is also explained and well understood.
Study of the radioactive contamination of the ion source complex in the Selective Production of Exotic Species (SPES) facility
Authors: Centofante L. , Donzella A. , Zenoni A. , Ferrari M. , Ballan M. , Corradetti S. , D’Agostini F. , Lilli G. , Manzolaro M. , Monetti A. , Morselli L. , Scarpa D. , Andrighetto A.
Published: May 2021

The Isotope Separation On-Line (ISOL) technique is today established as one of the primary methods to produce high-intensity and high-quality radioactive beams. This technique produces, for a given amount of the desired isotope, many orders of magnitude of other radioactive species. Due to the activation generated by interactions of the primary beam, intense neutron fields, and deposition of the produced radioactive ions inside beam line elements, an ISOL facility in operation becomes an intense radioactive source. Therefore, the biological hazard imposes severe radiological safety challenges to the design, operation, maintenance, and final decommissioning of such facilities. A challenging component is the ion source complex, where the ion extraction electrode provides the extraction of radioactive ions from the ion source and the first acceleration to the extracted beam. The radioactive contamination of this sub-component is studied, by means of the FLUKA code, in the case of the Selective Production of Exotic Species facility, which is in the advanced construction phase at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padua, Italy. The developed model includes isotope production by the interactions of a 40 MeV energy proton beam on a 238UCx target, selection of radioactive isotopes that are able to stick on the electrode tip, time evolution of the deposited isotopes during the operation and cooling periods before maintenance interventions, and evaluation of the ambient dose equivalent rate generated by the contamination of the electrode tip. Based on these results, the possibility of manual interventions for maintenance and emergency vs the use of remote handling systems is discussed.
Ridge approximation for thin nematic polymer networks
Authors: Pedrini Andrea , Virga Epifanio G.
Published: May 2021

Nematic polymer networks (NPNs) are nematic elastomers within which the nematic director is enslaved to the elastic deformation. The elastic free energy of a NPN sheet of thickness h has both stretching and bending components (the former scaling like h, the latter scaling like h3). NPN sheets bear a director field m imprinted in them (usually, uniformly throughout their thickness); they can be activated by changing the nematic order (e.g., by illumination or heating). This paper illustrates an attempt to compute the bending energy of a NPN sheet and to show which role it can play in determining the activated shape. Our approach is approximate: the activated surface consists of flat sectors connected by ridges, where the unit normal jumps and the bending energy is concentrated. By increasing the number of ridges, we should get closer to the real situation, where the activated surface is smooth and the bending energy is distributed on it. The method is applied to a disk with imprinted a spiraling planar hedgehog. It is shown that upon activation the disk, like a tiny hand, is able to grab a rigid lamina.
Isolated Pd atoms in a silver matrix: Spectroscopic and chemical properties
Authors: Hartwig Caroline , Schweinar Kevin , Jones Travis E. , Beeg Sebastian , Schmidt Franz-Philipp , Schlögl Robert , Greiner Mark
Published: May 2021

Over the past decade, single-atom alloys (SAAs) have been a lively topic of research due to their potential for achieving novel catalytic properties and circumventing some known limitations of heterogeneous catalysts, such as scaling relationships. In researching SAAs, it is important to recognize experimental evidence of peculiarities in their electronic structure. When an isolated atom is embedded in a matrix of foreign atoms, it exhibits spectroscopic signatures that reflect its surrounding chemical environment. In the present work, using photoemission spectroscopy and computational chemistry, we discuss the experimental evidence from Ag0.98Pd0.02 SAAs that show free-atom-like characteristics in their electronic structure. In particular, the broad Pd4d valence band states of the bulk Pd metal become a narrow band in the alloy. The measured photoemission spectra were compared with the calculated photoemission signal of a free Pd atom in the gas phase with very good agreement, suggesting that the Pd4d states in the alloy exhibit very weak hybridization with their surroundings and are therefore electronically isolated. Since AgPd alloys are known for their superior performance in the industrially relevant semi-hydrogenation of acetylene, we considered whether it is worthwhile to drive the dilution of Pd in the inert Ag host to the single-atom level. We conclude that although site-isolation provides beneficial electronic structure changes to the Pd centers due to the difficulty in activating H2 on Ag, utilizing such SAAs in acetylene semi-hydrogenation would require either a higher Pd concentration to bring isolated sites sufficiently close together or an H2-activating support.
Dispersive electrostatic waves on a cold magnetized electron gas half-space
Authors: Moradi Afshin
Published: May 2021

Dispersive electrostatic waves on the plane interface between a vacuum and a cold magnetized homogeneous electron gas are predicted for the case where an applied static magnetic field is parallel to the surface and the direction of propagation of the wave, known as Faraday configuration, and also static magnetic field is weakly non-uniform in a direction which is perpendicular to the surface. An expression for dispersion relation of these surface waves is presented based on the Wentzel–Kramers–Brillouin approximation. The dispersion relation shows the importance of the influence of the external static magnetic field gradient on the surface wave behavior.
Temperature dependent thermal conductivity of IIa diamond by laser excited Raman spectroscopy
Authors: Guo Zhijian , Wang Liang , Wang Kaiyue , Ren Chunhui , Guo Ruiang , Zhang Yufei , Tian Yuming , Wang Hongxing
Published: May 2021

The thermal conductivity of IIa diamond from low temperature (80 K) to room temperature was studied by laser-excited Raman spectroscopy. The laser has two complementary effects, one performing the Raman spectrum and the other resulting in the local heating on the surface of diamond. With the increase in measurement temperature on the surface of IIa diamond, the Raman peak shifts to the low energy side together with intensity quenching due to the strong electron–phonon coupling and lattice expansion, and the thermal conductivity of IIa diamond decreases as T−1, which is attributed to the creation and the annihilation of phonons.
Direct numerical simulation analysis of heat transfer deterioration of supercritical fluids in a vertical tube at a high ratio of heat flux to mass flowrate
Authors: Zhao Pinghui , Wan Teng , Jin Yixuan , Chen Zhansheng , Li Yuanjie , Peng Changhong
Published: May 2021

The heat transfer deterioration (HTD) of supercritical water in heated vertical tubes at high heat flux to mass flow rate ratios is investigated using direct numerical simulations at an inlet Reynolds number of Reb0=5400 based on the inlet bulk velocity and tube diameter. The heated tube has a length of 75 times the tube diameter. Both forced and mixed convections (upward and downward flows) are simulated. The results show that primary and secondary HTDs occur in all flows considered herein. The causes of the HTD are comprehensively analyzed using the Fukagata–Iwamoto–Kasagi identity, turbulent heat flux, turbulence production, and turbulent kinetic energy. The FIK decomposition shows that the turbulent contribution Nu2 is the dominant part of the total Nusselt number NuFIK. The turbulence reduction caused by flow acceleration is the main reason for the decrease in Nu2 and the occurrence of the primary HTD. Furthermore, buoyancy first damps the turbulence, exacerbating the HTD, and then forms an M-shaped velocity profile, which enhances the heat transfer. The secondary HTD, which is less pronounced than the primary one, comes from the decrease in the mean enthalpy gradient and enthalpy fluctuation caused by the position variation of the maximum specific heat.
Symmetry and conservation laws in non-holonomic mechanics
Authors: Massa Enrico , Pagani Enrico
Published: May 2021

A geometric environment for the study of non-holonomic Lagrangian systems is developed. A definition of admissible displacement valid in the presence of arbitrary non-linear kinetic constraints is proposed. The meaning of ideality for non-strictly mechanical systems is analyzed. The concepts of geometric and/or dynamical symmetry of a constrained system are discussed and embodied in a subsequent non-holonomic formulation of Noether theorem. A revisitation of the results in an “extrinsic” variational language is worked out. A few examples and an appendix illustrating some properties of the manifold of admissible kinetic states are presented.
Efficient light-emitting diodes from organic radicals with doublet emission
Authors: Hudson John M. , Hele Timothy J. H. , Evans Emrys W.
Published: May 2021

Organic light-emitting diodes (OLEDs) with doublet-spin radical emitters have emerged as a new route to efficient display technologies. In contrast to standard organic semiconductors, radical materials have unpaired electrons. This feature results in the most well-known examples of organic radicals being where they are reactive species in chemical reactions. Stabilized radicals can be used in optoelectronic applications, which exploit their optical and spin properties, allowing up to 100% internal quantum efficiency (IQE) for electroluminescence. Highly efficient OLEDs have been demonstrated, which operate in the doublet-spin electronic state manifold with doublet emission. The radical-based devices present a departure from the singlet- and triplet-level considerations that impose efficiency limits in OLEDs for typical organic semiconductors (25% IQE). This Perspective focuses on radical doublet emitters for optoelectronics, outlining how the photo- and spin-physics of unpaired electron systems present new avenues for research in light-emitting applications.
Probing the properties and mechanisms of failure waves in soda-lime glass
Authors: Joshi Akshay , Ravindran Suraj , Gandhi Vatsa , Ravichandran Guruswami
Published: May 2021

Soda-lime glass (SLG) and other silica glasses exhibit the failure wave phenomenon under shock compression. The mechanism responsible for this peculiar behavior of glasses is still unresolved. In this study, a series of plate impact experiments was performed at three different impact stresses of 6.4, 8.3, and 10.8 GPa to better understand the mechanisms underlying the failure wave phenomenon. Specifically, spall experiments were conducted to probe the speed and existence of failure waves at different stresses in SLG. A layered glass target was used to probe the possibility of a “renucleation” of the wave at the SLG–SLG interface. When it existed, the failure wave was inferred to propagate at a speed of 1.3 km/s. However, it was observed that the failure wave phenomenon ceases to exist for impact stresses higher than 10 GPa. In experiments with a 6.4 GPa impact stress, the peak free surface velocity was significantly less than what is predicted by stress-Hugoniot calculations. This velocity deficit and other important features of the measured free surface velocity profiles were simulated using finite element analysis by incorporating an abrupt densification of SLG at a critical stress in the equation of state. This densification feature is similar to what would be expected of a phase transition. Although unable to unambiguously reveal the mechanism causing the failure wave phenomenon, the results of the present work clearly indicate that the failure wave causes a secondary compression and densification in SLG.
Growth of nanostructured VO2 via controlling oxidation of V thin films: Morphology and phase transition properties
Authors: Nishikawa K. , Yoshimura M. , Watanabe Y.
Published: May 2021

Vanadium dioxide (VO2), which exhibits a metal–insulator phase transition at 70 °C, is known to alter its physical properties according to its surface morphology and fabrication process. The systematic investigation of a new fabrication method could not only clarify the origin of its phase transition but also advance progress in applications employing VO2 nanostructures. Here, we demonstrate the drastic enhancement of both the surface morphology and hysteresis of VO2 nanostructures composed of nanoparticles, by applying a sputtering deposition fabrication process, followed by lamp annealing. We investigated different growth conditions for VO2, especially using metallic precursor oxidation under a controlled pressure and temperature, and found that each growth condition led to different morphologies, nanoparticle sizes, and phase transition properties (hysteresis width). Despite a slight increase in particle diameter with annealing time and O2 pressure, the particle aggregation was found to substantially decrease. The temperature width of the hysteresis loop obtained by infrared light reflection measurements increased as the aggregation of VO2 nanoparticles decreased. During the cooling procedure, the transition of slightly aggregated VO2 nanoparticles was revealed to be a two-step process, with the lower transition temperature decreasing with an increase in particle isolation. Our results have the potential to elucidate the hysteresis-inducing mechanisms in VO2 and to aid the materialization of novel devices such as passive thermal control and thermal memory devices.
Dynamics of capillary flow in an undulated tube
Authors: Lei Jiechao , Xu Zhimin , Xin Fengxian , Lu Tian Jian
Published: May 2021

From biology to engineering, while numerous applications are based on capillary phenomena in tubes having roughened surfaces, such as blood transport, paper-based rapid diagnostics, microfluidic fuel cells, and shale gas transport, the dynamics of such capillary flow remains poorly understood. We present a theoretical model for a circular undulated tube that has an idealized cosine-type inner wall characterized by two key morphological parameters: undulation amplitude and axial wave number. With the tube oriented at an arbitrary angle, we first characterize the apparent contact angle of the fluid as a function of local distortion angle and then establish a theoretical model involving inertia, viscosity, and gravity to describe the dynamics of capillary flow. A dimensionless number combining the three forces is introduced to quantify their influence. The model predictions reveal that, in an undulated tube with large wave numbers, the capillary height in equilibrium state is generally lower than that in a smooth tube of similar dimensions, whereas the reverse holds if the wave number becomes relatively small. When the viscosity of fluid is sufficiently small, capillary oscillation in an undulated tube is alleviated relative to that in a smooth tube, and hence stable capillary flow forms more easily in the former.
Crystal growth of bcc titanium from the melt and interfacial properties: A molecular dynamics simulation study
Authors: Rozas R. E. , MacDowell L. G. , Toledo P. G. , Horbach J.
Published: May 2021

The crystal growth kinetics and interfacial properties of titanium (Ti) are studied using molecular dynamics computer simulation. The interactions between the Ti atoms are modeled via an embedded atom method potential. First, the free solidification method (FSM) is used to determine the melting temperature Tm at zero pressure where the transition from liquid to body-centered cubic crystal occurs. From the simulations with the FSM, the kinetic growth coefficients are also determined for different orientations of the crystal, analyzing how the coupling to the thermostat affects the estimates of the growth coefficients. At Tm, anisotropic interfacial stiffnesses and free energies as well as kinetic growth coefficients are determined from capillary wave fluctuations. The so-obtained growth coefficients from equilibrium fluctuations and without the coupling of the system to a thermostat agree well with those extracted from the FSM calculations.
Use of biodegradable colloids and carbon black nanofluids for solar energy applications
Authors: Kosinska A. , Balakin B. V. , Kosinski P.
Published: May 2021

The conversion of solar energy to heat can be performed in direct absorption solar collectors, where the radiation from the sun is absorbed by a fluid. There are various types of fluids that can be used, and recently, nanofluids (i.e., liquids with immersed nanoparticles) have been investigated by researchers. Nevertheless, nanofluids have inherent drawbacks such as cost, toxicity, and clogging. This paper considers the use of fluids that are inexpensive and neutral to the environment, namely, coffee colloids. These types of fluids have already been tested for solar energy applications, but they have not yet been compared with nanofluids. In this research, we conducted a series of simple experiments where both coffee colloids and carbon black nanofluids were analyzed under the same conditions. According to our results, the thermal efficiency of coffee colloid and the nanofluid systems is, respectively, 12% and 16% greater than that of pure water. In addition to the experiments, we developed a mathematical model that is based on the Beer–Lambert law and a heat balance equation. Despite its simplicity, the model predicts the results relatively well.
Whitebait conservation and protected areas at non-tidal rivermouths: integrating biogeography and environmental controls on īnanga (
Authors: Orchard Shane , Schiel David R.
Published: May 2021

Galaxias maculatus is a declining amphidromous fish that supports New Zealand’s culturally important whitebait fisheries targeting the migratory juvenile stage. Spawning ground protection and rehabilitation is required to reverse historical degradation and improve fisheries prospects alongside conservation goals. Although spawning habitat has been characterised in tidal rivers, there has been no previous study of spawning in non-tidal rivermouths that are open to the sea. We assessed seven non-tidal rivers over 4 months using census surveys to quantify spawning activity, identify environmental cues, and characterise fundamental aspects of the biogeography of spawning grounds. Results include the identification of compact spawning reaches near the rivermouths. Spawning events were triggered by periods of elevated water levels that were often of very short duration, suggesting that potential lunar cues were less important, and that rapid fish movements had likely occurred within the catchment prior to spawning events. Spawning grounds exhibited consistent vertical structuring above typical low-flow levels, with associated horizontal translation away from the river channel leading to increased exposure to anthropogenic stressors and associated management implications for protecting the areas concerned. These consistent patterns provide a sound basis for advancing protective management at non-tidal rivermouths. Attention to flood management, vegetation control, and bankside recreational activities is needed and may be assisted by elucidating the biogeography of spawning grounds. The identification of rapid responses to environmental cues deserves further research to assess floodplain connectivity aspects that enable fish movements in ephemeral flowpaths, and as a confounding factor in commonly used fish survey techniques.
Scars of human–elephant conflict: patterns inferred from field observations of Asian elephants in Sri Lanka
Authors: LaDue Chase A. , Vandercone Rajnish P. G. , Kiso Wendy K. , Freeman Elizabeth W.
Published: May 2021

Abstract Context Human–elephant conflict (HEC) is a major threat to Asian elephants as humans and elephants are forced to share common resources. In Sri Lanka, human-dominated landscapes adjacent to protected areas promote high rates of HEC, especially in the form of crop-foraging by elephants. Crop-foraging can be dangerous to both elephants and humans involved in the conflict. Gunfire is a common way for human communities to deter crop-foraging elephants, and gunshot wounds are commonly described in this elephant population on necropsy. Aims We sought to quantify and describe unique scar patterns among Asian elephants in a protected area, Wasgamuwa National Park, attributed to HEC. Methods We identified 38 adult female and 64 adult male elephants and recorded the age class and body condition of each with established standards. Using photographs, we counted the number, position, and relative size of all scars on each animal. Key results Male elephants had significantly more scars than did females, and for males, the number of scars increased progressively with age. Additionally, male elephants with higher body conditions had more scars. Finally, males tended to have more scars towards the head, especially at older ages. Conclusions Differences in total scar counts between the sexes in this population imply that male elephants in this area more frequently engage in HEC than do females, following observations previously described in the literature. Furthermore, the fact that male elephants acquired progressively more scars as they aged, and that fatter elephants had more scars, indicates that previous exposure to HEC may not have been a deterrent for future events among these males, and potentially, crops served as valuable food sources for these animals. Finally, the changing body locations of these scars with age in males possibly shows plastic behavioural responses during crop-foraging or lower tolerance by farmers towards habitual crop foragers. Implications These results emphasise the need for animal-based approaches to HEC mitigation. Similarly, conservation managers in Sri Lanka and other elephant range countries should investigate similar methods that estimate patterns of HEC to develop effective management strategies directly targeting animals most likely to engage in conflict.
Persulfidation of ATG18a regulates autophagy under ER stress inArabidopsis
Authors: Aroca Angeles , Yruela Inmaculada , Gotor Cecilia , Bassham Diane C.
Published: May 2021

Significance

Endoplasmic reticulum (ER) stress is a condition triggered by adverse environmental conditions, which in plants include extreme heat, pathogen infection, and drought. These stresses can have a devastating effect on agricultural productivity, and the appropriate responses of plants to stress are therefore critical. Autophagy is a macromolecular degradation pathway that is activated in response to stress, including ER stress, but the mechanism by which it is regulated is still unclear. Here, we describe a modification, persulfidation, of the key autophagy protein ATG18a that affects its binding to membranes and controls its activity. This tight regulation of autophagy therefore allows plants to control the tradeoff between growth and stress tolerance.
Reducing mask resistance among White evangelical Christians with value-consistent messages
Authors: DeMora Stephanie L. , Merolla Jennifer L. , Newman Brian , Zechmeister Elizabeth J.
Published: May 2021

Public health experts have advocated for wearing protective face masks to combat the COVID-19 pandemic, yet some populations are resistant. Can certain messages shift attitudes toward masks? We investigate the effect of value-consistent messages within a mask-skeptical population: White evangelicals in the United States. An experiment within a national survey of White evangelicals (
n
= 1,212) assigned respondents to one of three conditions: One group was given a religious message equating mask use with loving your neighbor, another was given a message by Donald Trump saying mask use is patriotic, and a control group received no message. Those exposed to the religious message were more likely to see mask use as important and were more supportive of mask mandates. Republican evangelicals exposed to the patriotism message had similar responses. These findings show that messages that align with individuals’ core values—in this case, religious tenets and patriotism—can shift certain views on mask use and government mask policies to combat COVID-19, even among a comparatively mask-resistant group.
Bilin-dependent regulation of chlorophyll biosynthesis by GUN4
Authors: Zhang Weiqing , Willows Robert D. , Deng Rui , Li Zheng , Li Mengqi , Wang Yan , Guo Yunling , Shi Weida , Fan Qiuling , Martin Shelley S. , Rockwell Nathan C. , Lagarias J. Clark , Duanmu Deqiang
Published: May 2021

Significance

Enzymes of the chlorophyll biosynthetic pathway, which bind protoporphyrin and Mg-porphyrins, are susceptible to damage by singlet oxygen production in the presence of light and oxygen. These studies show that heme-derived linear tetrapyrroles (bilins) both stimulate and protect the protoporphyrin-binding CHLH subunit of Mg chelatase, the first committed enzyme of the chlorophyll synthesis, from self-sensitized photodamage and turnover via formation of nonphotosensitizing GENOMES UNCOUPLED 4 (GUN4):bilin:porphyrin adducts, which deliver protoporphyrin to CHLH. GUN4:bilin adducts likely evolved to sustain chlorophyll biosynthesis in an oxic world, accounting for retention of bilin synthesis in nearly all oxygenic photosynthetic species on Earth.
Effects of relative permittivity on primary and secondary streamers in atmospheric pressure dielectric barrier discharge
Authors: Yoshida Keigo , Komuro Atsushi , Ando Akira
Published: May 2021

In this study, a two-dimensional simulation of atmospheric-pressure streamer discharge with a dielectric on the cathode was conducted to investigate the effects of relative permittivity on primary and secondary streamer characteristics. An electrode configuration with an air gap of 0.1 mm was employed. The input parameters of the simulations were the relative permittivity, dielectric thickness, and applied voltage, which were summarised with five simulation conditions. The propagation velocity and electric field strength of the primary streamer mostly depended on the initial electric field applied between the anode and the dielectric surface, which is determined by the relative permittivity, dielectric thickness, and applied voltage. Conversely, the length and electric field strength of the secondary streamer depended on the amount of charge supplied by the primary streamer and the capacitance of the dielectric, which is defined by the relative permittivity and dielectric thickness.
Mixed Mott–Hubbard and charge transfer nature of 4H–SrMnO3 thin film on Si (100)
Authors: Mandal Arup Kumar , Jana Anupam , Chowdhury Sourav , Tiwari Achyut , Choudhary R J , Phase D M
Published: May 2021

Room temperature electronic structure of polycrystalline 4H–SrMnO3 thin film grown on Si (100) substrate has been studied using resonance photo emission spectroscopy and soft x-ray absorption spectroscopy measurements. Presence of charge transfer screen Mn 3d

n

L
final state along with the 3d
n-1 final state at the valence band edge of 4H–SrMnO3 thin film confirms that the ground state is strongly mixed between Mn 3d and O 2p states. The estimated equivalent values of on-site Coulomb interaction energy (U) and O 2p to Mn 3d- charge transfer energy (Δ) (U ≈ Δ ≈ 4.8 eV) from the combination of occupied and unoccupied spectra further confirm the intermediate Mott–Hubbard and charge transfer insulator nature of 4H–SrMnO3 film. Despite having similar Mn 4+ valence state in 4H–SrMnO3 and cubic SrMnO3, 4H phase is observed to reveal much higher band gap ∼1.5 eV than the cubic phase (0.3 eV), which arises due to different MnO6 octahedra environment.
Large-scale MoS2(1−x)Se2x
monolayers synthesized by confined-space CVD
Authors: Zhang Jinming , Qian Yezheng , Nan Haiyan , Gu Xiaofeng , Xiao Shaoqing
Published: May 2021

Alloy engineering is efficient in modulating the electronic structure and physical and chemical properties of Transition metal dichalcogenides (TMDs). Here, we develop an efficient and simple confined-space CVD strategy by using a smaller quartz boat nested in a larger quartz boat for the preparation of ternary alloy MoS2(1−x)Se2x
monolayers on SiO2/Si substrates with controllable composition. The effect of hydrogen ratio of the mixed carrier gas (Ar/H2) on the resultant flakes are systematically investigated. A hydrogon ratio of 15% is demonstrated to be the most appropriate to synthesize large size (more than 400 μm) single crystalline MoS2(1−x)Se2x
alloy monolayers. The composition of the alloy can also be changed in a full range (2x = 0–2) by changing the weight ratio of Se and S powder. The as-grown monolayer MoS2(1−x)Se2x
alloys present continuously high crystal quality in terms of Raman and PL measurements. Furthermore, to visible light (532 nm), the MoS2(1−x)Se2x
based photodetectors display wonderful photoresponse with a fast response of less than 50 ms. Our work may be usedful in directing the synthesis of TMDs alloys as well as their optoelectronic applications.
A novel paper biosensor based on Fe3O4@SiO2–NH2 and MWCNTs for rapid detection of pseudorabies virus
Authors: Guo Xing , Hou Jianru , Yuan Zhongyun , Li Hongmei , Sang Shengbo
Published: May 2021

In this study, a novel paper biosensor based on Fe3O4@SiO2–NH2 magnetic polymer microspheres and multi walled carbon nanotubes (MWCNTs) for rapid detection of pseudorabies virus (PRV) was first developed. Fe3O4@SiO2–NH2 were functionalized with PRV antibody and doped in cellulose nitrate paper to fabricate the magnetic paper biosensor with good magnetic response and biocompatibility. Using MWCNTs to build conductive network of sensors, PRV antigen binds specifically to the immunomagnetic microspheres on the sensor, and the resulting immune complex changes the magnetic domain structure of the sensor and the structural gap of MWCNTs, causing the magnetic property and impedance change. TEM and EDS characterization proved that the biosensor was successfully doped with Fe3O4@SiO2–NH2 and effectively recognized PRV. Under optimized conditions, the impedance variation was found to be linearly related to the logarithm value of PRV concentrations in the range of 10–1 mg ml−1, with the detection limit of 10 ng ml−1. This paper biosensor demonstrated advantages of portability, high sensitivity and specificity, providing a valuable method for early control of PRV.
Collapse of superradiant phase and Dicke phase transition at finite temperature in a hybrid optical-mechanical system
Authors: Huang Shan , Liu Ni , Liang J.-Q. , Li Hebin
Published: May 2021

In this paper, we theoretically investigate Dicke phase transition at finite temperature in a hybrid optical-mechanical system. The thermodynamic equilibrium states are presented by means of the functional path-integral approach. We plot the mean photon number of the two cavities and the corresponding phase diagram showing the effects of the coupling strength between the two cavities, the nonlinear photon-phonon interaction strength, the finite temperature, the detuning of the two cavities. The coupling strength between the two cavities can make the phase boundary of the normal phase (NP) to the superradiant phase (SP) shift left with the increase of the atom-field coupling strength. The region of the SP is suppressed completely and the SP disappears completely with the increase of the coupling strength between the two cavities or the nonlinear photon-phonon interaction strength, finally just the NP and the dynamically unstable state (DUS) exist. The nonlinear photon-phonon coupling strength just affects the turning curve, but not the phase boundary. The unstable non-zero photon number state and the SP are coexistent, similar to the optical bistability.
Particle Physics with the Cosmic Microwave Background with SPT-3G
Authors: Avva J S
Published: May 2021

The cosmic microwave background (CMB) encodes information about the content and evolution of the universe. The presence of light, weakly interacting particles impacts the expansion history of the early universe, which alters the temperature and polarization anisotropies of the CMB. In this way, current measurements of the CMB place interesting constraints on the neutrino energy density and mass, as well as on the abundance of other possible light relativistic particle species. We present the status of an on-going 1500 sq. deg. survey with the SPT-3G receiver, a new mm-wavelength camera on the 10-m diameter South Pole Telescope (SPT). The SPT-3G camera consists of 16,000 superconducting transition edge sensors, a 10x increase over the previous generation camera, which allows it to map the CMB with an unprecedented combination of sensitivity and angular resolution. We highlight projected constraints on the abundance of sterile neutrinos and the sum of the neutrino masses for the SPT-3G survey, which could help determine the neutrino mass hierarchy.
Analysis and Dark Matter Search Results from DEAP-3600 with 231 Live Days at SNOLAB
Authors: Westerdale S
Published: May 2021

DEAP-3600 is a dark matter direct detection experiment in SNOLAB (Sudbury, Canada). This single-phase detector consists of 3.3 tonnes of liquid argon, viewed by an array of 255 photomultiplier tubes through 50 cm of acrylic. The collaboration has recently released dark matter search results from the first year of running (Nov. 2016 to Oct. 2017), with a total live time of 231 days. These proceedings detail the analysis underlying these results, including the development of a background model, which constitute the most sensitive search performed with a LAr target for WIMPs with a mass greater than 30 GeV.
Dark Sector Physics at Belle II
Authors: MacQueen Caitlin
Published: May 2021

The first dark sector physics analyses for Belle II are currently underway. Belle II detects collisions at the SuperKEKB asymmetric-energy e
+
e
− collider in Tsukuba, Japan and has already collected 6.5 fb−1 of data at the ϒ(4S) resonance (√s = 10.58 GeV). The collider has a design luminosity of 8 × 1035 cm−2 s−1 and the detector will collect 50 ab−1 of data in its lifetime, making it the most luminous experiment in the world. In addition to early performance studies on particle identification, tracking quality, energy resolution, and more, Belle II is preparing to release its first physics results. These include the first official time-integrated luminosity measurements, as well as searches for the dark photon, A′, in a monophoton signature, and the invisible Z' in both Lμ
– Lτ
and Lepton Flavour Violation models. Even with this early data set, it is clear that Belle II is and will continue to be competitive in various dark sector searches at the MeV-GeV scale.
Observation of Complex Time Structures in the Cosmic-Ray Electron and Positron Fluxes by the Alpha Magnetic Spectrometer on the ISS
Authors: Vagelli V. , Graziani M. , Tomassetti N.
Published: May 2021

We present high-statistics, precision measurements by AMS of the detailed time and energy dependence of the primary cosmic-ray electron and positron fluxes over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during the solar maximum has been investigated in detail by leptons alone. We report the observation of short-term structures on the timescale of months which are not visible in the positron-to-electron flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over ˜ 800 days from one value to another.
Telescope Array search for EeV photons
Authors: Zhezher Y.
Published: May 2021

We present the results of a search for point sources of photons with energies higher than 1 EeV based on the Telescope Array surface detector data for 9 years. No significant excess of photon signal over UHECR background was found. The photon-flux upper limits were set for each direction in the Telescope Array field of view as well as for stacked directions of dwarf spheroidal galaxies.