bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Bi nanoparticles supported on activated carbon for efficient photocatalytic degradation of high concentration Rhodamine B
Authors: Li Yingliu , Zhu Jianzhong
Published: May 2020

Bismuth (Bi) micro, nanoparticles are an emerging non‐noble metal catalyst, but they are prone to agglomeration due to the large surface energy, which weakens its function and limits its application. Bi nanoparticles were immobilised on activated carbon by the impregnation reduction method to prevent the agglomeration. The prepared material exhibited enhanced photocatalytic efficiency compared to Bi nanoparticles alone. The origin of photocatalytic efficiency enhancement was investigated. It was attributed to the large specific surface area of the composite and more exposed active sites. This research proposes a new strategy for the photocatalytic application of Bi nanoparticles.
Green sol–gel synthesis of CoMnCrO4 spinel nanoparticles and their photocatalytic application
Authors: Moradnia Farzaneh , Taghavi Fardood Saeid , Ramazani Ali , Osali Samira , Abdolmaleki Ilnaz
Published: May 2020

CoMnCrO4 spinel nanoparticles were prepared using the green and efficient sol–gel method. The synthesised nanoparticles were fully characterised by Fourier‐transform infrared spectroscopy, X‐ray powder diffraction with Rietveld refinement, transmission electron microscopy, scanning electron microscopy, and diffuse reflectance spectroscopy analysis. The characterisation of the sample showed that the CoMnCrO4 NPs have a spinel cubic structure with a crystallite size of 14 nm, narrow bandgap (1.75 eV), and uniform spherical morphology with particle size about 25–30 nm. The CoMnCrO4 NPs demonstrated high photocatalysis capability towards the Congo red dye as a pollutant with a high and fast efficiency degradation of 90% after 30 min under the visible light irradiation. Also, the impacts of different parameters consisting of nanoparticle amount, initial dye concentration, irradiation time, light and dark on dye degradation efficiency were assessed.
Probing binary neutron star mergers in dense environments using afterglow counterparts
Authors: Duque Raphaël , Beniamini Paz , Daigne Frédéric , Mochkovitch Robert
Published: May 2020

The only binary neutron star merger gravitational wave event with detected electromagnetic counterparts recorded to date is GRB170817A. This merger occurred in a rarefied medium with a density smaller than 10−3 − 10−2 cm−3. Since kicks are imparted to neutron star binaries upon formation, and due to their long delay times before merger, such low-density circum-merger media are generally expected. However, there is some indirect evidence for fast-merging or low-kick binaries, which would coalesce in denser environments. Nonetheless, present astronomical data are largely inconclusive on the possibility of these high-density mergers. We describe a method to directly probe this hypothetical population of high-density mergers through multi-messenger observations of binary neutron star merger afterglows, exploiting the high sensitivity of these signals to the density of the merger environment. This method is based on a sample of merger afterglows that has yet to be collected. Its constraining power is large, even with a small sample of events. We discuss the method’s limitations and applicability. In the upcoming era of third-generation gravitational wave detectors, this method’s potential will be fully realized as it will allow us to probe mergers that occurred soon after the peak of cosmic star formation, provided the follow-up campaigns are able to locate the sources.
New multi-part collisional model of the main belt: the contribution to near-Earth asteroids
Authors: Zain P. S. , de Elía G. C. , Di Sisto R. P.
Published: May 2020

Aims. We developed a six-part collisional evolution model of the main asteroid belt (MB) and used it to study the contribution of the different regions of the MB to the near-Earth asteroids (NEAs).

Methods. We built a statistical code called ACDC that simulates the collisional evolution of the MB split into six regions (namely Inner, Middle, Pristine, Outer, Cybele and High-Inclination belts) according to the positions of the major resonances present there (ν6, 3:1J, 5:2J, 7:3J and 2:1J). We consider the Yarkovsky effect and the mentioned resonances as the main mechanism that removes asteroids from the different regions of the MB and delivers them to the NEA region. We calculated the evolution of the NEAs coming from the different source regions by considering the bodies delivered by the resonances and mean dynamical timescales in the NEA population.

Results. Our model is in agreement with the major observational constraints associated with the MB, such as the size distributions of the different regions of the MB and the number of large asteroid families. It is also able to reproduce the observed NEAs with H < 16 and agrees with recent estimations for H < 20, but deviates for smaller sizes. We find that most sources make a significant contribution to the NEAs; however the Inner and Middle belts stand out as the most important source of NEAs followed by the Outer belt. The contributions of the Pristine and Cybele regions are minor. The High-Inclination belt is the source of only a fraction of the actual observed NEAs with high inclination, as there are dynamical processes in that region that enable asteroids to increase and decrease their inclinations.
Perfectly parallel cosmological simulations using spatial comoving Lagrangian acceleration
Authors: Leclercq F. , Faure B. , Lavaux G. , Wandelt B. D. , Jaffe A. H. , Heavens A. F. , Percival W. J.
Published: May 2020

Context.Existing cosmological simulation methods lack a high degree of parallelism due to the long-range nature of the gravitational force, which limits the size of simulations that can be run at high resolution.

Aims.To solve this problem, we propose a new, perfectly parallel approach to simulate cosmic structure formation, which is based on the spatial COmoving Lagrangian Acceleration (sCOLA) framework.

Methods.Building upon a hybrid analytical and numerical description of particles’ trajectories, our algorithm allows for an efficient tiling of a cosmological volume, where the dynamics within each tile is computed independently. As a consequence, the degree of parallelism is equal to the number of tiles. We optimised the accuracy of sCOLA through the use of a buffer region around tiles and of appropriate Dirichlet boundary conditions around sCOLA boxes.

Results.As a result, we show that cosmological simulations at the degree of accuracy required for the analysis of the next generation of surveys can be run in drastically reduced wall-clock times and with very low memory requirements.

Conclusions.The perfect scalability of our algorithm unlocks profoundly new possibilities for computing larger cosmological simulations at high resolution, taking advantage of a variety of hardware architectures.
Stress and Coping in Caregivers of Children with RASopathies: Assessment of the Impact of Caregiver Conferences
Authors: Ganetsos Athena , Farrelly Ellyn , Magoulas Pilar , Stevenson David A.
Published: May 2020

The study aimed to assess baseline stress and coping mechanisms among caregivers of children with RASopathies (i.e., cardiofaciocutaneous and Costello's syndrome) and the impact of attending biennial caregiver conferences. Caregivers completed the Perceived Stress Scale, Coping Health Inventory for Parents, and demographic surveys prior to family conferences, and 1- and 6-month postconferences. Baseline stress was increased and associated with child age, parental age, and number of conferences attended. After 1 month, caregiver stress was lowered among men and caregivers attending ≥2 support conferences.
Growth of AlN on sapphire: Predicting the optimal nucleation density by surface kinetics modeling
Authors: Rathkanthiwar Shashwat , Kalra Anisha , Muralidharan Rangarajan , Nath Digbijoy N. , Raghavan Srinivasan
Published: May 2020

We report on the growth of AlN epilayers at reasonably low temperatures of 1050–1110 °C on non-miscut c-plane sapphire by metal organic chemical vapor deposition (MOCVD). A systematic study of growth parameters revealed that the thickness of the low temperature (LT) nucleation layer (NL) plays a critical role in improving the screw and edge dislocation densities and surface morphology of the AlN epilayer. A surface kinetics based physico-chemical model is proposed to optimize the crystalline quality and is found to correlate well to the experimental observations. Using a 7 nm nominally-thick LT NL, a 0.5 μm thick AlN epilayer with an rms roughness of 0.15 nm, and (002) and (102) omega scan widths of 18 arc sec and 970 arc sec, respectively, was realized. A grain coalescence model for stress generation is used to correlate the change in AlN growth stress with variation in the NL thickness, and it is shown that in-situ stress measurement can be employed as an early signature for reproducibility of the crystalline quality. This study suggests that AlN/sapphire templates can potentially be realized for a reasonably low thickness (0.5 μm) and at temperatures as low as 1050 °C, which is accessible by most of the III-nitride MOCVD systems.
Self-suspended carbon nanotube/polyimide composite film with improved photothermal properties
Authors: Zhou Lang , Wang Xin , Zhang Jinying , Yang Suhui , Hao Kaizi , Gao Yanze , Li Defang , Li Zhuo
Published: May 2020

Self-suspended polyimide (PI) composite films were fabricated. Their diameter and thickness were 2.5 in. and 260 nm, respectively. A high ratio of diameter to thickness of 2.4 × 105 was obtained. The multiwalled carbon nanotubes (MWCNTs) were filled into PI to improve the optical absorption and the photothermal response. By using the N-methyl pyrrolidone solvent for both MWCNTs and poly(amic acid), a homogeneous dispersion of MWCNTs with up to 15% content was obtained. Under the thermal treatment of 300 °C, the composite films were successfully synthesized, which was proved by the measurements of Fourier transform infrared spectrum and x-ray diffraction. Compared with the pure PI film, the optical absorption of the composite films at 532 nm wavelength increased from 10% to 28%. The steady and transient photothermal properties of the composite films were investigated. In the steady state, a temperature rise of 145 °C was obtained under 0.7 W/cm2 illuminating laser power density. The temperature increased by 29 times compared with that of the pure PI film. The corresponding photothermal conversion efficiency improved to 70.8%. In the transient state, the photothermal response time was 7.5 ms, which was only half that of the pure PI film. The excellent photothermal properties of these self-suspended MWCNT/PI composite films highlight their potential applications in micro- and nanoscale devices for photo detection and thermal imaging.
Temperature and frequency dependent dielectric response of C3H7NH3PbI3: A new hybrid perovskite
Authors: Sengupta Payal , Sadhukhan Priyabrata , Ray Apurba , Ray Ruma , Bhattacharyya Satyaranjan , Das Sachindranath
Published: May 2020

Propylammonium lead iodide (C3H7NH3PbI3), a promising hybrid perovskite, is successfully synthesized by a solgel technique. Structural, optical, and dielectric properties have been studied in detail. The dielectric constant, loss factor, electric modulus, and AC and DC conductivity of this hybrid perovskite exhibit strong temperature dependence over the frequency range of 10 Hz ≤ f ≤ 8 MHz. The Nyquist plot reveals the distinct contributions of grain and grain boundary to the total impedance. The dielectric constant is found to increase with temperature in the high frequency region. The modified Cole–Cole plot shows that the space charge and free charge conductivity increase with the elevation of temperature, whereas the relaxation time decreases with the rise in temperature. From the modified Kohlrausch–Williams–Watts equation, we perceived asymmetrical nature in electric modulus spectra at various temperatures, which corresponds to the non-Debye type nature of perovskite. It has also been found that, with the elevation of temperature, the imaginary part of electric modulus spectra shifts from the non-Debye type toward the Debye type nature, though failing to acquire exact Debye type response, and emerges as a semiconductor material. AC conductivity of PAPbI3 is illustrated on the basis of the correlated barrier hopping (CBH) mechanism. Activation energy estimated from both modulus spectra and DC conductivity matches well, affirming the similarity between relaxation behavior and conduction mechanism. Along with all these, PAPbI3 possesses a high dielectric constant associated with a small dielectric loss, making it a potential candidate for energy harvesting devices.
Numerical study of Taylor–Couette flow with longitudinal corrugated surface
Authors: Razzak Md Abdur , Cheong Khoo Boo , Lua Kim Boon
Published: May 2020

This study investigates the Taylor–Couette flow (TCF) with a longitudinal corrugated surface on a stationary outer cylinder and a rotating smooth inner cylinder using large eddy simulation for three values of amplitude to wavelength ratios (A*) (0.1875, 0.2149, and 0.25) to explore the influence of the corrugated surface on the flow structures and the variation of torque for a wider range of Reynolds numbers (Re) (60–650). From the results, four flow regimes are observed. At Re = 60, initially, a pair of secondary vortices appears at the inner wall of the minimum gap region and it evolves to a pair of axisymmetric stationary wall induced vortices (ASSWIVs) in the maximum gap region. As Re increases to 80, 85, and 103 for the three values of A* (0.1875, 0.2149, and 0.25), respectively, another pair of axisymmetric stationary secondary vortices is seen at the minimum gap region of the inner wall. A further increase in Re (Re > 125, 130, and 138 for the three values of A*, respectively) results in the appearance of axisymmetric periodic secondary axial flow. Increasing Re further (Re > 225, 240, and 260 for A* = 0.25, 0.2149, and 0.1875, respectively) leads to the emergence of non-axisymmetric and non-periodic secondary axial flow (NANPSAF) with an azimuthal wave. Generally, the torque in TCF with the corrugated surface is found to be lower than TCF with a smooth surface except for the occurrence of the ASSWIV flow regime and weak axial secondary flow in the NANPSAF regime.
Symmetry breaking of Kramers–Henneberger atoms by ponderomotive force
Authors: Zhang Yan , Wei Qi
Published: May 2020

It was believed that Kramers–Henneberger (KH) atoms in a linearly polarized superintense laser field exhibit the structure of “dichotomy.” At large quiver amplitude, the two lowest-lying eigenstates are degenerated and both have a dichotomous symmetric structure. However, this is not a common structure for KH atoms because KH atoms practically can only exist in the focused laser field. However, in a focused laser, KH state electrons usually experience the ponderomotive force, which will lift the degeneracy and break the symmetry.
An atomic-level study of the N2–N2 collision process at temperatures up to 2000 K
Authors: Kosyanchuk Vasily , Yakunchikov Artem
Published: May 2020

This article studies the mechanics of the N2–N2 collision process at temperatures up to 2000 K through an extensive set of classical trajectory calculations of binary collisions. It is found that key postcollision characteristics, namely, the deflection angle and the rotational–translational energy exchange rate, are significantly affected by precollision values of the rotational energies of the molecules, which is not addressed in commonly used collision models. On the macroscopic scale, such a behavior will lead to viscosity collision cross section and relaxation rate becoming dependent on both translational and rotational temperatures, as well as on the form of the nonequilibrium rotational energy distribution.
Scattering cross sections of acoustic nonlocal inclusions: A fractional dynamic approach
Authors: Buonocore Salvatore , Sen Mihir
Published: May 2020

In this work, we present numerical calculations of the acoustic scattering properties of inclusions characterized by fractional order behavior. Fundamental quantities, such as the differential and the total scattering cross sections, are calculated for a wide range of forcing frequencies, and their characteristics are analyzed in the perspective of remote sensing and material characterization applications. The numerical simulations show the occurrence of resonance frequencies related to the fractional order mismatch and suggest the ability of fractional inclusion to induce lensing effects similar to those observed in materials with a negative index of refraction. The tools developed in this framework offer a novel approach for modeling and predicting the transport of field quantities throughout complex inhomogeneous and highly scattering media.
High-efficiency, low-cost distributed Bragg reflector based on Al2O3/PbZr0.4Ti0.6O3 multilayer
Authors: Li Shimin , Zhao Wenchao , Sun Yan , Dai Ning , Hu Gujin
Published: May 2020

Ferroelectric oxides are kinds of materials for construction of tunable photonic crystals with remarkable electro-optical properties. However, it is a challenge to prepare high quality dielectric mirrors consisting of ferroelectric and dielectric materials. Herein, we report a simple and inexpensive PVP-based sol–gel technique for fabricating crack-free Al2O3/PbZr0.4Ti0.6O3 (PZT) Bragg reflectors. A high-reflection band with a 200-nm bandwidth and an average optical reflectivity of more than 75% is achieved by a periodic stack of only four Al2O3/PZT bilayers, making the multilayer structure potentially applicable in tunable dielectric mirrors, optical cavities, and selective filters.
Strong coupling between magnons confined in a single magnonic cavity
Authors: Dai Changting , Xie Kaile , Pan Zizhao , Ma Fusheng
Published: May 2020

Strong coupling between magnons and cavity photons was studied extensively for quantum electrodynamics in the past few years. Recently, the strong magnon–magnon coupling between adjacent layers in magnetic multilayers has been reported. However, the strongly coupled magnons confined in a single nanomagnet remains to be revealed. Here, we report the interaction between different magnon modes in a single magnonic cavity. The intermodel coupling between edge and center magnon modes in the strong coupling regime was approached with a maximum coupling strength of 0.494 GHz and cooperativity of 60.1 with a damping of 1 × 10−3. Furthermore, it is found that the coupling strength is highly dependent on the geometric parameters of the magnonic cavity. Our findings could greatly enrich the still evolving field of quantum magnonics.
Temperature dependence of differential capacitance in the electric double layer.Symmetric valency 1:1 electrolytes
Authors: Islam Md. Siful , Lamperski Stanisław , Islam Md. Mominul , Henderson Douglas , Bhuiyan Lutful Bari
Published: May 2020

The differential capacitance of an electric double layer formed by an aqueous solution of KNO3 on a glassy carbon electrode is measured by impedance analysis at constant frequency. Results are obtained at electrolyte concentrations of 0.1 mol/dm3, 0.5 mol/dm3, and 1.0 mol/dm3, and at a series of temperatures, viz., 288 K, 298 K, 308 K, 318 K, and 328 K. The differential capacitance envelopes reveal a rich, complex pattern of maxima, minima, and local minima, whose magnitude and position change with a change in solution concentration. At the two lower concentrations, the temperature dependence of the capacitance, for example, at zero electrode potential, shows an alternating positive–negative behavior, while at the highest concentration of 1.0 mol/dm3, the slope of the differential capacitance–electrode potential curve is always positive. The experimental results are supplemented by a numerical grand canonical Monte Carlo simulation study of a restricted primitive model double layer but with an off-center cationic charge achieved by displacing the charge center from the ion sphere center toward its surface. The simulations, performed at the electrolyte concentration of 1.0 mol/dm3 and constant cation charge center displacement, and at varying electrode potentials and temperatures, show, in general, a negative temperature dependence of the differential capacitance. However, this temperature dependence can also be positive for a negative electrode charge and for a sufficiently large gradient of the cation charge center displacement with temperature. This feature is seen to be associated with an increase in the entropy of formation of the double layer.
Controlling antiferromagnetic domains in patterned La0.7Sr0.3FeO3 thin films
Authors: Lee Michael S. , Lyu Peifen , Chopdekar Rajesh V. , Scholl Andreas , Retterer Scott T. , Takamura Yayoi
Published: May 2020

Transition metal oxide thin films and heterostructures are promising platforms to achieve full control of the antiferromagnetic (AFM) domain structure in patterned features as needed for AFM spintronic devices. In this work, soft x-ray photoemission electron microscopy was utilized to image AFM domains in micromagnets patterned into La0.7Sr0.3FeO3 (LSFO) thin films and La0.7Sr0.3MnO3 (LSMO)/LSFO superlattices. A delicate balance exists between magnetocrystalline anisotropy, shape anisotropy, and exchange interactions such that the AFM domain structure can be controlled using parameters such as LSFO and LSMO layer thickness, micromagnet shape, and temperature. In LSFO thin films, shape anisotropy gains importance only in micromagnets where at least one extended edge is aligned parallel to an AFM easy axis. In contrast, in the limit of ultrathin LSFO layers in the LSMO/LSFO superlattice, shape anisotropy effects dominate such that the AFM spin axes at micromagnet edges can be aligned along any in-plane crystallographic direction.
Unveiling the role of short-range exact-like exchange in the optimally tuned range-separated hybrids for fluorescence lifetime modeling
Authors: Alipour Mojtaba , Damiri Samaneh
Published: May 2020

We propose and validate several variants of the optimally tuned range-separated hybrid functionals (OT-RSHs) including different density functional approximations for predicting the fluorescence lifetimes of different categories of fluorophores within the time-dependent density functional theory (TD-DFT) framework using both the polarizable continuum and state-specific solvation models. Our main idea originates from performing the optimal tuning in the presence of a contribution of the exact-like exchange at the short-range part, which, in turn, leads to the small values of the range-separation parameter, and computing the fluorescence lifetimes using the models including no or small portions of the short-range exact-like exchange. Particular attention is also paid to the influence of the geometries of emitters on fluorescence lifetime computations. It is shown that our developed OT-RSHs along with the polarizable continuum model can be considered as the promising candidates within the TD-DFT framework for the prediction of fluorescence lifetimes for various fluorophores. We find that the proposed models not only outperform their standard counterparts but also provide reliable data better than or comparable to the conventional hybrid functionals with both the fixed and interelectronic distance-dependent exact-like exchanges. Furthermore, it is also revealed that when the excited state geometries come into play, more accurate descriptions of the fluorescence lifetimes can be achieved. Hopefully, our findings can give impetus for future developments of OT-RSHs for computational modeling of other characteristics in fluorescence spectroscopy as well as for verification of the related experimental observations.
First-principles study of the adsorption of 3d transition metals on BaO- and TiO2-terminated cubic-phase BaTiO3(001) surfaces
Authors: Costa-Amaral Rafael , Gohda Yoshihiro
Published: May 2020

The deposition of transition metals (TM) on barium titanate (BaTiO3, BTO) surfaces is involved in the development of several BTO-based devices, such as diodes, catalysts, and multiferroics. Here, we employ density functional theory to investigate the adsorption of 3d TM on both BaO- (type-I) and TiO2-terminated (type-II) surfaces of cubic BaTiO3(001) at low levels of surface coverage, which is important to comprehend the initial stages of the formation and growth of TM overlayers on BTO. The most stable adsorption site is identified for each adatom on both surfaces. Our discussion is based on analyses of structural distortions, Bader charge, electron density difference, magnetic moments, work function, density of states, and adsorption energies. For the type-I surface, most of the adatoms bind covalently on top of the surface oxygens, except for Sc, Ti, and V atoms, which adsorb preferentially on the bridge site, between O ions, to form two polar TM–O bonds. On the type-II surface, the TM are located at the fourfold hollow site, which allows the formation of four TM–O interactions that are predominantly ionic. Upon the adsorption, we noticed the formation of in-gap states originated mostly from the adatom. When electrons are transferred to the substrates, their conduction bands become partially occupied and metallic. We observed a decrease in the work function of the type-II surface that is fairly proportional to the charge gained, which suggests that the BTO work function can be manipulated by the controlled deposition of TM.
Infinite-pressure phase diagram of binary mixtures of (non)additive hard disks
Authors: Fayen Etienne , Jagannathan Anuradha , Foffi Giuseppe , Smallenburg Frank
Published: May 2020

One versatile route to the creation of two-dimensional crystal structures on the nanometer to micrometer scale is the self-assembly of colloidal particles at an interface. Here, we explore the crystal phases that can be expected from the self-assembly of mixtures of spherical particles of two different sizes, which we map to (additive or non-additive) hard-disk mixtures. We map out the infinite-pressure phase diagram for these mixtures using Floppy Box Monte Carlo simulations to systematically sample candidate crystal structures with up to 12 disks in the unit cell. As a function of the size ratio and the number ratio of the two species of particles, we find a rich variety of periodic crystal structures. Additionally, we identify random tiling regions to predict random tiling quasicrystal stability ranges. Increasing non-additivity both gives rise to additional crystal phases and broadens the stability regime for crystal structures involving a large number of large-small contacts, including random tilings. Our results provide useful guidelines for controlling the self-assembly of colloidal particles at interfaces.
Full-dimensional quantum mechanical calculations of the reaction probability of the H + CH4 reaction based on a mixed Jacobi and Radau description
Authors: Zhang Zhaojun , Gatti Fabien , Zhang Dong H.
Published: May 2020

A full-dimensional time-dependent wave packet study using mixed polyspherical Jacobi and Radau coordinates for the title reaction has been reported. The non-reactive moiety CH3 has been described using three Radau vectors, whereas two Jacobi vectors have been used for the bond breaking/formation process. A potential-optimized discrete variable representation basis has been employed to describe the vibrational coordinates of the reagent CH4. About one hundred billion basis functions have been necessary to achieve converged results. The reaction probabilities for some initial vibrational states are given. A comparison between the present approach and other methods, including reduced and full-dimensional ones, is also presented.
Population dynamics and sustainability of the spiny lobster (Panulirus meripurpuratus Giraldes & Smyth, 2016) fishery on the Amazon continental shelf
Authors: Peixoto Ualerson I. , Mesquita Esther M. C. , Cintra Israel A. I. , Klautau Alex G. M. , Gouveia Nelson A. , Paes Eduardo T. , Isaac Victoria J.
Published: May 2020

The assessment of fishery resources is key to the development of management strategies for exploited stocks. Analysis of specific parameters provides information regarding the state of the stock and indicators of exploitation levels. The aim of the present study was to analyse the growth and mortality parameters, as well as investigate the exploitation status, of Panulirus meripurpuratus caught on the Amazon coast, northern Brazil. Growth parameters and stock assessment were estimated using R with bootstrapping and FISAT II, based on cephalothorax length–distribution frequency. Specimens were collected by the commercial lobster fishery off the coast of the states of Pará and Amapá between 2001 and 2002. The results indicate that the P. meripurpuratus stock assessed is composed of individuals with low growth rates and high estimates of maximum asymptotic length, with relative longevity of 21.37 years. The exploitation rate was operating at near the maximum limit of sustainability in 2001 and 2002. This is the first estimate of the exploitation status of P. meripurpuratus on the Amazon coast. We strongly recommend new monitoring efforts and further studies to support the conservation and management of the spiny lobster stock.
Ultrastructural evidence for self-replication of Alzheimer-associated Aβ42 amyloid along the sides of fibrils
Authors: Törnquist Mattias , Cukalevski Risto , Weininger Ulrich , Meisl Georg , Knowles Tuomas P. J. , Leiding Thom , Malmendal Anders , Akke Mikael , Linse Sara
Published: May 2020

The nucleation of Alzheimer-associated Aβ peptide monomers can be catalyzed by preexisting Aβ fibrils. This leads to autocatalytic amplification of aggregate mass and underlies self-replication and generation of toxic oligomers associated with several neurodegenerative diseases. However, the nature of the interactions between the monomeric species and the fibrils during this key process, and indeed the ultrastructural localization of the interaction sites have remained elusive. Here we used NMR and optical spectroscopy to identify conditions that enable the capture of transient species during the aggregation and secondary nucleation of the Aβ42 peptide. Cryo-electron microscopy (cryo-EM) images show that new aggregates protrude from the entire length of the progenitor fibril. These protrusions are morphologically distinct from the well-ordered fibrils dominating at the end of the aggregation process. The data provide direct evidence that self-replication through secondary nucleation occurs along the sides of fibrils, which become heavily decorated under the current solution conditions (14 µM Aβ42, 20 mM sodium phosphate, 200 µM EDTA, pH 6.8).
Plasmodium vivaxspleen-dependent genes encode antigens associated with cytoadhesion and clinical protection
Authors: Fernandez-Becerra Carmen , Bernabeu Maria , Castellanos Angélica , Correa Bruna R. , Obadia Thomas , Ramirez Miriam , Rui Edmilson , Hentzschel Franziska , López-Montañés Maria , Ayllon-Hermida Alberto , Martin-Jaular Lorena , Elizalde-Torrent Aleix , Siba Peter , Vêncio Ricardo Z. , Arevalo-Herrera Myriam , Herrera Sócrates , Alonso Pedro L. , Mueller Ivo , del Portillo Hernando A.
Published: May 2020

Plasmodium vivax, the most widely distributed human malaria parasite, causes severe clinical syndromes despite low peripheral blood parasitemia. This conundrum is further complicated as cytoadherence in the microvasculature is still a matter of investigations. Previous reports inPlasmodium knowlesi, another parasite species shown to infect humans, demonstrated that variant genes involved in cytoadherence were dependent on the spleen for their expression. Hence, using a global transcriptional analysis of parasites obtained from spleen-intact and splenectomized monkeys, we identified 67P. vivaxgenes whose expression was spleen dependent. To determine their role in cytoadherence, twoPlasmodium falciparumtransgenic lines expressing two variant proteins pertaining to VIR and Pv-FAM-D multigene families were used. Cytoadherence assays demonstrated specific binding to human spleen but not lung fibroblasts of the transgenic line expressing the VIR14 protein. To gain more insights, we expressed fiveP. vivaxspleen-dependent genes as recombinant proteins, including members of three different multigene families (VIR, Pv-FAM-A, Pv-FAM-D), one membrane transporter (SECY), and one hypothetical protein (HYP1), and determined their immunogenicity and association with clinical protection in a prospective study of 383 children in Papua New Guinea. Results demonstrated that spleen-dependent antigens are immunogenic in natural infections and that antibodies to HYP1 are associated with clinical protection. These results suggest that the spleen plays a major role in expression of parasite proteins involved in cytoadherence and can reveal antigens associated with clinical protection, thus prompting a paradigm shift inP. vivaxbiology toward deeper studies of the spleen during infections.
Complete encapsulation of sulfur through interfacial energy control of sulfur solutions for high-performance Li−S batteries
Authors: Gueon Donghee , Ju Min-Young , Moon Jun Hyuk
Published: May 2020

Significance

Complete encapsulation of high-content sulfur into porous carbon or carbon composites is crucial for high-performance Li−S cells. However, the low-to-moderate compatibility of sulfur-dissolved solution with carbon causes difficulty in completely loading sulfur into the porous host. We control the interfacial energy of the sulfur solution by adding a solvent with high compatibility with the carbon surface. The use of NMP improves the infiltration of sulfur solution effectively, resulting in complete sulfur encapsulation. We observe that the control of sulfur loading greatly affects Li−S battery performance. We identify significantly superior cell performance in the complete encapsulation. Our method can also be applied to effectively load active materials for next-generation energy storage devices.
Cognitive science and the controversy of anthropogenic climate change
Authors: Hohenberger Annette
Published: May 2020

This paper takes a cognitive science perspective on the controversy of anthropogenic climate change (ACC) between deniers and advocates. It argues that cognitive science is a suitable framework due to its interdisciplinarity, experience with controversies, and appeal to meta-principles of cognition. From a Bayesian perspective, deniers seem to reason irrationally (belief polarization) and from an epistemic virtue ethics perspective act viciously. Yet, their behavior can be modelled as rational when taking the factor “worldview” into account and become virtuous in terms of “mandevillian intelligence” at the collective level. Insofar as deniers’ conservatism aims at stability but advocates’ liberalism at change, they jointly resolve the “stability-plasticity dilemma”. A number of outstanding questions are addressed at the end of the paper.
Human evolution
Authors: Abrantes Paulo C.
Published: May 2020

This paper presents a range of approaches going from the complete rejection of any role culture could have played in human evolution, to the other extreme in the range in which the very dichotomy between nature and culture is rejected. We will also go through middle-range standpoints, such as that of gene-culture coevolution theorists, that attach to culture a central role in human evolution. The clash between these approaches is still going on in the contemporary scene, with implications for the way boundaries are set inside disciplines such as Anthropology, as well as for conceiving how it is related to Psychology and Biology, among other disciplines. We will show that some debates in the Philosophy of Biology, concerning an extension of the neo-Darwinian theory of evolution, have contributed to clarify the issues, and have been followed by some anthropologists who are also concerned by the way human development and evolution are separately addressed in orthodox approaches.
A historical controversy about politeness and public argument
Authors: Saltamacchia Francesca , Rocci Andrea
Published: May 2020

This article presents the Nineteenth-Century dispute arising from the criticism that the Italian philosopher Antonio Rosmini expressed against the arguments that the statesman Melchiorre Gioja supported in defense of fashion in his Apologia della moda ‘Apology of Fashion’ (1822) and against the utilitarian ideology that permeates the text. Gioja’s aggressive answer (in 1827) leads Rosmini to write a treatise on polite manners writers must have in public debate, thus offering an interesting ethical treatise. We aim to analyze the controversy adopting an interdisciplinary approach that investigates metapragmatic evaluative comments from the point of view of argumentation in order to reconstruct the argumentative justification behind each evaluation of (im)politeness and to show the principles defended by the disputants.
Controversial images
Authors: Neri Veronica
Published: May 2020

Communicating with controversial images may be a device to draw attention to issues that are key to the interest of people and society alike. A device that can raise public awareness, or, instead, anaesthetise it may lead to make responsible or irresponsible choices. It is this ability of images that will be emphasised by communicative events involving controversial images, astride three media revolutions ad imaginem: printing, photography and digital technology. Lastly, emphasis will be placed on the importance of communication ethics in the choice of a “good” controversial image, one that may enable viewers to see it, ‘listen to it’ and understand it and, thus, to act morally.
The role and the impact of interdisciplinarity on the relational models of intervention in the doctor-patient communication
Authors: Greco Roberto
Published: May 2020

This paper aims to evaluate the role and the impact of Interdisciplinarity on the relational models of intervention in the doctor-patient communication. Working Alliance may be one of the main models for the improvement of the relationship between the dyad, analysing the degree of the patient involvement in treatment and his alignment to the purposes of therapy itself. However, to tap into this construct, the performed kind of operation is similar to a specific form of Interdisciplinarity, Theoretical Interdisciplinarity. Theoretical ID begins from an exploration based on the practice, which respects an otherness not only physical (the doctor-patient relationship), but above all, conceptual (the doctor-patient system).
Teachers’ attitudes about gesture for learning and instruction
Authors: Nathan Mitchell J. , Yeo Amelia , Boncoddo Rebecca , Hostetter Autumn B. , Alibali Martha W.
Published: May 2020

We developed and tested a survey instrument to measure teachers’ attitudes about gesture in learning and instruction (TAGLI). Teachers (N = 192) generally believed that instructional gestures are beneficial for learning, and not distracting for students. Teachers had positive expectations, both for gestures that are redundant with (i.e., match) the accompanying speech, and gestures that are complementary to (i.e., mismatch) speech. However, teachers’ attitudes varied with teachers’ grade bands (middle v. high school) and curricular content areas (STEM v. non-STEM). Teachers endorsed a range of reasons for gesture’s pedagogical effectiveness. These reasons largely mirror the reasons teachers reported for why they produced gestures: gestures help make connections between representations and ideas, make abstract concepts more concrete, and they appropriately direct learners’ attention. Teachers reported that they frequently use gestures while teaching, explaining, and in everyday conversation.
Plurality and definiteness in Chengdu Chinese
Authors: Xiong Jiajuan , Huang Chu-Ren
Published: May 2020

The authors identify a plural marker -ɕiɛin Chengdu Chinese that can apply to both count and mass nouns, encoding plurality as well as definiteness. This post-nominal -ɕiɛdiffers from the pre-nominalɕiɛ, as the latter is purely plural but not inherently definite. Our analysis shows that the pre-nominalɕiɛfunctions as a quantifier, which occupies the [Spec, NumP] position, whereas the suffixal -ɕiɛ, by virtue of being a plural marker, is base-generated in the Num0position and move to D0to encode both plurality and definiteness. Moreover, the twoɕiɛs can co-occur in one and the same nominal phrase, exhibiting thedouble definiteness effect. The syntactic analysis ofɕiɛin Chengdu Chinese, coupled with the study ofdiin Cantonese, has theoretical impacts on nominal phrase structures, in particular, on “plurality” and “definiteness”. First, plural markers in classifier languages contrast with those in number languages, as the former, but not the latter, defies numerical modification. Second, definiteness can be expressed by a non-D element, which may check its [+def] feature either by undergoing an upward movement to D (or [Spec, DP]) or by agreeing with the [+def] feature of a demonstrative. Third, the DP-NP distinction is strongly supported by our account of Chengdu Chinese.
Phosphoregulation provides specificity to biomolecular condensates in the cell cycle and cell polarity
Authors: Gerbich Therese M. , McLaughlin Grace A. , Cassidy Katelyn , Gerber Scott , Adalsteinsson David , Gladfelter Amy S.
Published: May 2020

Biomolecular condensation is a way of organizing cytosol in which proteins and nucleic acids coassemble into compartments. In the multinucleate filamentous fungus Ashbya gossypii, the RNA-binding protein Whi3 regulates the cell cycle and cell polarity through forming macromolecular structures that behave like condensates. Whi3 has distinct spatial localizations and mRNA targets, making it a powerful model for how, when, and where specific identities are established for condensates. We identified residues on Whi3 that are differentially phosphorylated under specific conditions and generated mutants that ablate this regulation. This yielded separation of function alleles that were functional for either cell polarity or nuclear cycling but not both. This study shows that phosphorylation of individual residues on molecules in biomolecular condensates can provide specificity that gives rise to distinct functional identities in the same cell.
The activation gate controls steady-state inactivation and recovery from inactivation in Shaker
Authors: Szanto Tibor G. , Zakany Florina , Papp Ferenc , Varga Zoltan , Deutsch Carol J. , Panyi Gyorgy
Published: May 2020

Despite major advances in the structure determination of ion channels, the sequence of molecular rearrangements at negative membrane potentials in voltage-gated potassium channels of the Shaker family remains unknown. Four major composite gating states are documented during the gating process: closed (C), open (O), open-inactivated (OI), and closed-inactivated (CI). Although many steps in the gating cycle have been clarified experimentally, the development of steady-state inactivation at negative membrane potentials and mandatory gating transitions for recovery from inactivation have not been elucidated. In this study, we exploit the biophysical properties of Shaker-IR mutants T449A/V474C and T449A/V476C to evaluate the status of the activation and inactivation gates during steady-state inactivation and upon locking the channel open with intracellular Cd2+. We conclude that at negative membrane potentials, the gating scheme of Shaker channels can be refined in two aspects. First, the most likely pathway for the development of steady-state inactivation is C→O→OI⇌CI. Second, the OI→CI transition is a prerequisite for recovery from inactivation. These findings are in accordance with the widely accepted view that tight coupling is present between the activation and C-type inactivation gates in Shaker and underscore the role of steady-state inactivation and recovery from inactivation as determinants of excitability.
Method-Driven Experiments and the Search for Dark Matter
Authors: De Baerdemaeker Siska
Published: May 2020

Since the discovery of dark matter in the 1980s, multiple experiments have been set up to detect dark matter particles through some other mode than gravity. Particle physicists provide detailed justifications as to why their experiments should be able to detect dark matter. I show that these justifications take on a structure different from what is often the case in experimental practice, and I argue that this is because of the limited description of dark matter. By illuminating this ‘method-driven logic’, I shed new light on questions surrounding measurement robustness and methodological pluralism in the context of dark matter research.
Measurement of layer thicknesses with an improved optimization method for depolarizing Mueller matrices
Authors: Grunewald Tobias , Wurm Matthias , Teichert Sven , Bodermann Bernd , Reck Johanna , Richter Uwe
Published: May 2020

There are some commonly-used optimization techniques for the analysis of measured data in spectroscopic Mueller matrix ellipsometry (MME) used, for example, to calculate the layer thicknesses of samples under test. Concentrating on the metrological aspects of MME, we identified a non-optimal treatment of depolarization in all these techniques. We therefore recently developed an improved optimization method to adequately take depolarization in MME into account. In a further step, we also included statistical measurement noise and derived a likelihood function, which enabled us to apply both the maximum likelihood method and Bayesian statistics as well as the Bayesian information criterion for data evaluation. In this paper we concentrate on the application of this new method to measurements of SiO2-layer thicknesses on silicon. With a state-of-the-art SENTECH SENresearch 4.0 Mueller ellipsometer, we measured standard samples of different SiO2-layer thicknesses, whose calibrated thicknesses were between about 6 nm and 1000 nm. The MME results were compared to the calibration data. For all samples, an SiO2-SiO double-layer model turned out to be optimal. The measured total oxide layer thicknesses matched excellently with the calibration values, within the estimated range of uncertainties. All the results are presented here. This is the first comparison with traceable reference measurements demonstrating the validity of our novel MME analysis method.
Novel, clinically applicable method to measure step-width during the swing phase of gait
Authors: Bäcklund Tomas , Öhberg Fredrik , Johansson Gudrun , Grip Helena , Sundström Nina
Published: May 2020

Objective: Step-width during walking is an indicator of stability and balance in patients with neurological disorders, and development of objective tools to measure this clinically would be a great advantage. The aim of this study was to validate an in-house-developed gait analysis system (Striton), based on optical and inertial sensors and a novel method for stride detection, for measuring step-width during the swing phase of gait and temporal parameters. Approach: The step-width and stride-time measurements were validated in an experimental setup, against a 3D motion capture system and on an instrumented walkway. Further, test-retest and day-to-day variability were evaluated, and gait parameters were collected from 87 elderly persons (EP) and four individuals with idiopathic normal pressure hydrocephalus (iNPH) before/after surgery. Main results: Accuracy of the step-width measurement was high: in the experimental setup mean error was 0.08 ± 0.25 cm (R = 1.00) and against the 3D motion capture system 0.04 ± 1.12 cm (R = 0.98). Test-retest and day-to-day measurements were equal within ±0.5 cm. Mean difference in stride time was −0.003 ± 0.008 s between Striton and the instrumented walkway. The Striton system was successfully applied in the clinical setting on individuals with iNPH, which had larger step-width (6.88 cm, n = 4) compared to EP (5.22 cm, n = 87). Significance: We conclude that Striton is a valid, reliable and wearable system for quantitative assessment of step-width and temporal parameters during gait. Initial measurements indicate that the newly defined step-width parameter differs between EP and patients with iNPH and before/after surgery. Thus, there is potential for clinical applicability in patients with reduced gait stability.