bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Surgical Necrotizing Enterocolitis and Its Timing with Retinopathy of Prematurity
Authors: Fundora Jennifer B. , Binenbaum Gil , Tomlinson Lauren , Yu Yinxi , Ying Gui-shuang , Maheshwari Akhil , Donohue Pamela
Published: August 2021

Objective The study aimed to determine the association of surgical necrotizing enterocolitis (NEC) and its timing, with the development and timing of retinopathy of prematurity (ROP).

Study Design This was a secondary data analysis of 7,483 preterm infants from the Postnatal Growth and Retinopathy of Prematurity Study. Associations between infants with surgical NEC, early-onset surgical NEC (8–28 days), and late-onset surgical NEC (over 28 days) with ROP were evaluated by using multivariable logistic regression models, controlling for birth weight, gestational age, small for gestational age status, chronic lung disease, intraventricular hemorrhage, hydrocephalus, patent ductus arteriosus, and periventricular leukomalacia.

Results Three hundred fifty-six (4.8%) infants had surgical NEC, with 56% having early surgical NEC. Infants with surgical NEC had a higher risk of any ROP and severe ROP (adjusted odds ratio [OR]: 2.7; 95% CI: 1.9–3.7) and 2.5 (95% CI: 1.9–3.3), respectively; p < 0.001) compared with infants without surgical NEC. Infants with early surgical NEC were at the highest risk of developing ROP and severe ROP (adjusted OR: 3.1 [95% CI: 2.1–4.8], and 3.3 [95% CI: 2.3–4.7] respectively, p < 0.001). Infants with late surgical NEC were also at increased risk of developing ROP and severe ROP (adjusted OR: 2.1 [95% CI: 1.3–3.4], and 1.9 [95% CI: 1.3–2.8] respectively, p < 0.001) compared with infants without surgical NEC.

Conclusion Infants with surgical NEC, especially early surgical NEC, are at higher risk of ROP and severe ROP.

Key Points
An improved instrument for 39Ar dating of water samples
Authors: Kim Meeri
Published: August 2021

Upgrades to instrumentation resulted in faster measurement times and greater precision for radiometric 39Ar dating.
An investigation of plasma-driven decomposition of per- and polyfluoroalkyl substances (PFAS) in raw contaminated ground water
Authors: Groele Joseph R. , Sculley Nathaniel , Olson Terese M. , Foster John E.
Published: August 2021

Per- and polyfluoroalkyl substances (PFAS) are contaminants of emerging concern owing to their ability to bioaccumulate in the body and subsequently cause cancer. PFAS, while recalcitrant to advanced oxidation, can be degraded by plasma action. In this work, we investigate the efficacy of two plasma reactors on degrading PFAS in ground water derived from two different contaminated sites. The reactors included an array of underwater plasma jets and a dielectric barrier discharge (DBD) with water dielectric barriers. While both reactors showed effectiveness in removing PFAS, the DBD with water barriers was most efficient with regard to the rate of degradation and power consumed. This better performance was attributed to the increased plasma–liquid contact area. Experiments indicate that air is a suitable working gas alternative to argon, and both AC and ns-pulsed power sources can generate the plasmas for these reactors. Furthermore, it was found that for both reactors, the removal rate for low and high PFAS concentration in ground water was the same, suggesting that the reactors are most efficient at treating heavily contaminated water. In this respect, a concentration step followed by plasma treatment may be a cost-effective means to treat the PFAS-contaminated water.
Automatic water-level measurement system for confined-space applications
Authors: Kuo Lung-Chih , Tai Cheng-Chi
Published: August 2021

To prevent flooding from threatening people’s lives and property, surveillance cameras have been extensively installed along rivers to monitor the water level. In this study, an automatic water-level measurement system based on a single camera is proposed. The system uses the images captured by the camera to verify the water levels of the rivers. The preliminary positions of the current water marks are first identified from the images of the staff gauges installed on site using the basic digital image processing technology. To establish the correct water levels from the preliminary water mark positions, the system uses the image histogram of the staff gauge region of interest to provide a reference for the water-level determination mechanism. The camera position typically results in a nonorthogonal angle between the camera’s optical axis and the on-site staff gauge plane because it causes perspective distortion that eventually leads to deviations. When the water level is low, the distance of the water line deviation from the orthogonal position becomes larger, and the actual distance represented by the pixel also becomes larger, resulting in greater deviations. To address this issue, this system adopts the inverse perspective mapping method to rectify the perspective distortion. By setting the reference water level and control points, this system can accurately calculate water levels. Experimental results demonstrate that the proposed automatic water-level measurement system as applied in confined spaces can reduce the image measurement error caused by the perspective distortion as well as verify and identify the current water levels.
Split Casimir operator for simple Lie algebras, solutions of Yang–Baxter equations, and Vogel parameters
Authors: Isaev A. P. , Krivonos S. O.
Published: August 2021

We construct characteristic identities for the split (polarized) Casimir operators of the simple Lie algebras in defining (minimal fundamental) and adjoint representations. By means of these characteristic identities, for all simple Lie algebras, we derive explicit formulas for invariant projectors onto irreducible subrepresentations in T⊗2 in two cases, when T is the defining and the adjoint representation. In the case when T is the defining representation, these projectors and the split Casimir operator are used to explicitly write down invariant solutions of the Yang–Baxter equations. In the case when T is the adjoint representation, these projectors and characteristic identities are considered from the viewpoint of the universal description of the simple Lie algebras in terms of the Vogel parameters.
Investigation of the dispersing characteristics of antral contraction wave flow in a simplified model of the distal stomach
Authors: Dufour D. , Tanner F. X. , Feigl K. A. , Windhab E. J.
Published: August 2021

The dispersing characteristics of antral contraction wave (ACW) flow in the antrum are investigated by reproducing the flow generated by an ACW and determining its effect on liquid drops. The goal is to gain information about the flow field and mechanical stresses, which are responsible for the food disintegration. Toward this end, a model antrum prototype was constructed, consisting of a cylinder that was closed at one end to represent the antrum and closed pylorus. A moving hollow piston with a parabolic inner contour was used to model an ACW. A computational model was developed that reflects this prototype. Experiments and simulations were first performed for fluids with different rheological properties, two relative occlusions (0.60 and 0.75), and several ACW speeds (1.0–7.5 mm/s). The simulations were validated with velocity measurements, and the characteristics of the retropulsive jet were quantified at different Reynolds numbers (0.5–105.3). Experiments were then performed in which liquid drops of different viscosity were placed in a highly viscous fluid with low interfacial tension, similar to conditions in a stomach. It was found that the viscosity ratio (0.001–0.1) influences the retraction dynamics of a drop's tail after stresses are relaxed. The flow and stress information from the simulations was used to analyze fluid transport in the antrum and to quantify drop breakup conditions. It was found that a drop broke up if both a critical capillary number of 0.51 was exceeded and the drop passed within a critical dimensionless distance of 0.3 to the wave apex.
Effects of the magnetic field topology on the co-extracted electron current in a negative ion source for fusion
Authors: Wünderlich D. , Montellano I. M. , Lindqvist M. , Mimo A. , Mochalskyy S. , Fantz U.
Published: August 2021

The negative hydrogen ion current that can be extracted from ion sources for neutral beam heating in fusion experiments can be strongly restricted by the amount of co-extracted electrons and their increase over time, particularly during long pulses (up to 1 h). Models describing the underlying physics of particle extraction from a low-temperature plasma with a high amount of negative ions are essential for identifying measures for reducing and stabilizing the co-extracted electrons. In this work, the 3D PIC-MCC code ONIX (Orsay Negative Ion eXtraction) for the plasma volume around one extraction aperture in the first grid of the extraction system is used for analyzing the effect of the magnetic field configuration on the co-extracted electrons and the extracted negative ions. The magnetic field topology is the result of superimposing two different fields that are perpendicular to each other, the filter field (dominant in the ion source volume) and the electron deflection field (dominant in the extraction system). A parametric study changing the relative intensity of these two fields is performed. It is demonstrated that on the local scale of the simulation, the strength of the filter field does not affect the amount of co-extracted electrons, while a significant reduction of the co-extracted electron current is observed when strengthening the electron deflection field.
Understanding terahertz emission properties from a metal–insulator–semiconductor structure upon femtosecond laser illumination
Authors: Yang Dongxun , Tonouchi Masayoshi
Published: August 2021

Metal–insulator–semiconductor (MIS) is an essential structure in semiconductor devices. Owing to the increasingly complex development of semiconductor devices, the local information of MIS, such as passivation, defects, and transient carrier dynamics, is becoming more challenging to characterize. Laser-excited terahertz (THz) emission spectroscopy and imaging are promising for investigating such local properties in a noncontact and nondestructive manner; however, the discussions are speculative and phenomenological. In this study, we formulate the mechanism of THz radiation based on a Si metal–oxide–semiconductor (MOS) structure to semi-quantitatively evaluate the MOS devices. A simplified model for both n- and p-type Si MOS structures is derived from Poisson's equation, which can effectively explain the dependence of THz emission amplitudes on external bias voltages considering external effects, including the flatband voltage, hot carrier diffusion, and quick recombination through interface states in addition to the photocurrent due to photocarrier field acceleration. The result reveals that one can estimate various “local” parameters such as the surface potential, semiconductor doping level, and dielectric constant of the passivation layer. The simplified model fills the gap between theory and observation, resulting in an advanced analytical tool for semiconductor research and development.
Investigation of the three-dimensional flow past a flatback wind turbine airfoil at high angles of attack
Authors: Manolesos Marinos , Papadakis George
Published: August 2021

Flatback airfoils are airfoils with a blunt trailing edge. They are currently commonly used in the inboard part of large wind turbine blades, as they offer a number of aerodynamic, structural, and aeroelastic benefits. However, the flow past them at high angles of attack (AoA) has received relatively little attention until now. This is important because they usually operate at high AoA at the inboard part of Wind Turbine blades. The present investigation uses Reynolds averaged Navier–Stokes (RANS) and hybrid RANS + large eddy simulation predictions to analyze the flow in question. The numerical results are validated against previously published wind tunnel experiments. The analysis reveals that to successfully simulate this flow, the spanwise extent of the computational domain is crucial, more so than the selection of the modeling approach. Additionally, a low-drag regime observed at angles of attack before stall is identified and analyzed in detail. Finally, the complex interaction between the three-dimensional separated flow beyond maximum lift (stall cells) with the vortex shedding from the blunt trailing edge is revealed.
Coupling between oxidation kinetics and anisothermal oil flow during deep-fat frying
Authors: Touffet Maxime , Allouche Mohamed Hatem , Ariane Mostapha , Vitrac Olivier
Published: August 2021

Deep-fat frying is a cooking technique that has been used continuously since prehistoric times. A domestic deep-fryer heated from the bottom develops significant convection inside the bath cavity. It is responsible for very high heat transfer coefficients and the exposure of the deep-frying oil to the atmospheric oxygen. The continuous conversion of gaseous dioxygen into unstable and reactive hydroperoxides and their subsequent advection throughout the bulk volume is at the origin of the main complaints made of frying which includes issues such as odors, fouling, and generation of several toxic compounds. This study analyzes the coupling between natural convection of triacylglycerols and the combinatorial chemistry controlling their autoxidation. At macroscopic scale, anisothermal flow within a typical kitchen appliance, including a cold zone beneath the heating element, was simulated in 3D under the Boussinesq approximation with a Eulerian description during initial heating and temperature holding. At molecular and intermediate scales, the endothermic decomposition of fatty-ester hydroperoxides in various mixtures was simulated over several hours using a Lagrangian description. Simulations and the proposed description of the combinatorial generation of hydroperoxides highlighted the complex relationship between deep-fryer design, residence times at different temperatures, and oil composition. The half-life of hydroperoxides (>15 min) is intermediate between vertical mixing times (<3 min) and longitudinal ones (>2 h). Hydroperoxides of unsaturated fatty esters are generated at the surface, which are preferentially decomposed in heated plumes and accumulate between production cycles in cold stagnant regions. Experimental validation is proposed for the eddy structure, temperature fluctuations, and hydroperoxides decomposition kinetics.
Enhancing elastic properties of single element amorphous solids through long-range interactions
Authors: Moon Jaeyun , Egami Takeshi
Published: August 2021

Elastic properties of amorphous solids remain a topic of intense interest due to their important roles in a wide range of applications. Prior works have focused on short-range, local structural features, such as number density and coordination number, to elucidate the underlying mechanism of elastic moduli in glasses. Here, we report strong correlations among the spatial extension of the interatomic potential, elastic moduli, and the coherence lengths of the medium-range structural order through molecular dynamics simulations for single element glasses. Our findings demonstrate an unconventional design principle to engineer elastic properties by extending the medium-range order and provide insights into the microscopic origin of elastic properties in amorphous solids.
Noble gas in densified liquid and amorphous silica and thermodynamic conditions for the emergence of bubbles
Authors: Micoulaut M. , Laurent O.
Published: August 2021

Different noble gases (He, Ne, and Ar) containing densified silica liquids and glasses are investigated from molecular dynamics simulations at different system densities using a dedicated force field. The results for pure silica are first compared to reference potentials prior to an investigation of the thermodynamic diagram, the diffusivity, and the structure under different (T, P) conditions. It is found that the equation of state and the diffusivity are weakly sensitive to the nature of the incorporated noble gas, leading to a similar trend with density for all systems. The network structure is weakly altered by the presence of the gas, and pressure induced structural changes are those usually found for amorphous and liquid silica, i.e., Si coordination increase, tetrahedral to octahedral conversion of the base geometry, and collapse of large rings under pressure. Ne- and Ar-based systems display an increased structuration, however, as preferential distances appear in gas–gas correlations at large densities in both the liquid and amorphous states. Finally, we focus on the conditions of heterogeneity that are driven by the formation of noble gas bubbles, and these appear for a threshold density ρc that is observed for all systems.
Numerically stable optimized effective potential method with standard Gaussian basis sets
Authors: Trushin Egor , Görling Andreas
Published: August 2021

We present a numerically stable optimized effective potential (OEP) method based on Gaussian basis sets. The key point of the approach is a sequence of preprocessing steps of the auxiliary basis set used to represent exchange or correlation potentials, the Kohn–Sham (KS) response function, and the right-hand side of the OEP equation in conjunction with a representation of exchange or correlation potentials via exchange or correlation charge densities whose electrostatic potentials generate the potentials. Due to the preprocessing, standard Gaussian basis sets from basis set libraries can be used in OEP calculations. As examples, we present numerical stable computational setups based on aux-cc-pwCVXZ basis sets with X = T, Q, 5 for the orbitals and aux-cc-pVDZ/mp2fit and aux-cc-pVTZ/mp2fit auxiliary basis sets and use them to calculate KS exchange potentials with the exact exchange-only KS method for various atoms and molecules. The resulting exchange potentials not only are numerically stable and physically reasonable but also show convergence with increasing quality of the orbital basis sets. The effect of incorporating exact conditions that the KS exchange potential has to obey is discussed. Moreover, it is briefly demonstrated that the presented approach not only works for KS exchange potentials but equally well for correlation potentials within the direct random phase approximation. Besides for OEP methods, the introduced preprocessing of auxiliary basis sets should also be beneficial in procedures to calculate back effective KS potentials from given electron densities.
Collapse transition of a heterogeneous polymer in a crowded medium
Authors: Jung Youngkyun , Ha Bae-Yeun
Published: August 2021

Long chain molecules can be entropically compacted in a crowded medium. We study the compaction transition of a heterogeneous polymer with ring topology by crowding effects in a free or confined space. For this, we use molecular dynamics simulations in which the effects of crowders are taken into account through effective interactions between chain segments. Our parameter choices are inspired by the Escherichia coli chromosome. The polymer consists of small and big monomers; the big monomers dispersed along the backbone are to mimic the binding of RNA polymerases. Our results show that the compaction transition is a two-step process: initial compaction induced by the association (clustering) of big monomers followed by a gradual overall compaction. They also indicate that cylindrical confinement makes the initial transition more effective; for representative parameter choices, the initial compaction accounts for about 60% reduction in the chain size. Our simulation results support the view that crowding promotes clustering of active transcription units into transcription factories.
How does switching synchronization of pitching parallel foils from out-of-phase to in-phase change their wake dynamics?
Authors: Gungor Ahmet , Khalid Muhammad Saif Ullah , Hemmati Arman
Published: August 2021

Alterations to the unsteady wake dynamics imposed by abrupt changes in the phase angle between two pitching side-by-side foils are computationally examined at the Reynolds number of 1000 and 4000 and Strouhal number of 0.25–0.5. Four hybrid modes are considered in this study inspired by the swimming habits of red nose tetra fish and burst-and-coast swimming phenomenon. At the higher Strouhal number of 0.50, abrupt changes in the phase angle result in the formation and growth of a secondary vortex street between the two primary streets, which enable and maintain a split-wake configuration. Furthermore, phase switching alters pressure levels on the top and bottom surfaces of both foils to similar levels, which attribute to lowering the side-force. The growth rate of the secondary vortex street remains consistent for all four hybrid modes. At lower Strouhal numbers (0.25–0.4), however, the abrupt change in the phase angle converts the wake to a single vortex street. Thus, this indicates that the wake reactions for such cases in synchronization substantially change at lower Strouhal number. Although a different behavior of total side force production is observed at a lower Reynolds number for Strouhal number of 0.50, the wake dynamics implies that phase alterations act as a similar flow control mechanism to stabilize the wake. Finally, it is identified that the suspension of oscillations significantly limits the implications of initiation of oscillations on wake dynamics and performance following abrupt changes in the phase angle.
Balance in non-hydrostatic rotating shallow-water flows
Authors: Jalali M. R. , Dritschel D. G.
Published: August 2021

Unsteady nonlinear shallow-water flows typically emit inertia-gravity waves through a process called “spontaneous adjustment-emission.” This process has been studied extensively within the rotating shallow-water model, the simplest geophysical model having the required capability. Here, we consider what happens when the hydrostatic assumption underpinning the shallow-water model is dropped. This assumption is in fact not necessary for the derivation of a two-dimensional or single-layer flow model. All one needs is that the horizontal flow field be independent of height in the fluid layer. Then, vertical averaging yields a single-layer flow model with the full range of expected conservation laws, similar to the shallow-water model yet allowing for non-hydrostatic effects. These effects become important for horizontal scales comparable to or less than the depth of the fluid layer. In a rotating flow, such scales may be activated if the Rossby deformation length (the ratio of the characteristic gravity-wave speed to the Coriolis frequency) is comparable to the depth of the fluid layer. Then, the range of frequencies supporting inertia-gravity waves is compressed, and the group velocity of these waves is reduced. We find that this change in wave properties has the effect of strongly suppressing spontaneous adjustment-emission and trapping inertia-gravity waves near regions of relatively strong circulation.
Spin–orbit torques in heavy metal/ferrimagnetic insulator bilayers near compensation
Authors: Liu Lin , Fan Ziqi , Chen Zhiren , Chen Zehan , Ye Zhixiang , Zheng Hongnan , Zeng Qi , Jia Wei , Li Shuoqi , Wang Ning , Liu Jing , Ma Lei , Lin Tao , Qiu Mingxia , Li Shunpu , Han Peigang , Shi Ji , An Hongyu
Published: August 2021

Spin–orbit torques (SOTs) in compensated ferrimagnets (FMs) have been widely studied due to their abundant advantages for the application in spintronic devices. Recently, the SOT in FM metals near compensation tuned by composition and temperature has been reported. However, the SOT in FM insulators (FMIs) near compensation still remains elusive. In this work, we report the study of the SOT in FMI near compensation tuned by the temperature. First, Pt/Gd3Fe5O12 (GdIG) bilayer films with high crystallinity and perpendicular magnetic anisotropy were fabricated by magnetron sputtering. Then, the SOT was measured by varying the temperature. It is found that the SOT generation is drastically enhanced close to the compensation temperature, which is verified to be caused by the decrease in the net magnetization. The effective spin Hall angle in Pt/GdIG bilayer films is estimated to be ∼0.0073, which is almost independent of the temperature. Our study provides a potential approach in emerging FMIs for spintronic devices with low-energy consumption.
Mechanism of wake-induced flow dynamics in tandem flapping foils: Effect of the chord and gap ratios on propulsion
Authors: Joshi Vaibhav , Mysa Ravi Chaithanya
Published: August 2021

The present study investigates the mechanisms of wake-induced flow dynamics in tandem National Advisory Committee for Aeronautics 0015 flapping foils at low Reynolds number of Re = 1100. A moving mesh arbitrary Lagrangian–Eulerian framework is utilized to realize the prescribed flapping motion of the foils while solving the flow via incompressible Navier–Stokes equations. The effect of the gap between the two foils on the thrust generation is studied for gaps of 1–10 times the chord of the downstream foil. The mean thrust as well as the propulsive efficiency vary periodically with the gap indicating alternate regions of higher and lower thrust generation, emphasizing the profound effect of upstream foil's wake interaction with the downstream foil. Five crucial wake–foil interactions leading to either favorable or unfavorable conditions for thrust generation are identified and different modes depending on the interactions are proposed for the tandem flapping foils. It is observed that the effect of the wake of the upstream foil on the downstream foil decreases with increasing gap. The study also focuses on the effect of the chord sizes of the upstream and the downstream foils on the propulsive forces, where the chord of the upstream foil is selected as 0.25–1 times the downstream foil's chord length. The effect of the chord size on the thrust is noticed to diminish as the chord size of the upstream foil decreases. Furthermore, the effect of the phase difference between the kinematics of the upstream and the downstream foils on flow dynamics is also explored along with its relationship with the chord sizes. For a fixed chord size, the effect of the phase difference on the propulsive performance is observed to be similar to that by varying the gap between the foils due to similar type of vortex interactions. The mechanisms of vortex interactions are linked to provide a comprehensive and generic understanding of the flow dynamics of tandem foils.
A method for simulating interfacial mass transfer on arbitrary meshes
Authors: Giustini Giovanni , Issa Raad I.
Published: August 2021

This paper presents a method for modeling interfacial mass transfer in Interface Capturing simulations of two-phase flow with a phase change. The model enables mechanistic prediction of the local rate of the phase change at the vapor–liquid interface on arbitrary computational meshes and is applicable to realistic cases involving two-phase mixtures with large density ratios. The simulation methodology is based on the volume of fluid representation of the flow, whereby an interfacial region in which mass transfer occurs is implicitly identified by a phase indicator, in this case the volume fraction of liquid, which varies from the value pertaining to the “bulk” liquid to the value of the bulk vapor. The novel methodology proposed here has been implemented using the Finite Volume framework and solution methods typical of “industrial” computational fluid dynamics practice. The proposed methodology for capturing mass transfer is applicable to arbitrary meshes without the need to introduce elaborate but artificial smearing of the mass transfer term as is often done in other techniques. The method has been validated via comparison with analytical solutions for planar interface evaporation and bubble growth test cases and against experimental observations of steam bubble growth.
On the Ge shallow-to-deep level transition in Al-rich AlGaN
Authors: Bagheri Pegah , Reddy Pramod , Mita Seiji , Szymanski Dennis , Kim Ji Hyun , Guan Yan , Khachariya Dolar , Klump Andrew , Pavlidis Spyridon , Kirste Ronny , Collazo Ramón , Sitar Zlatko
Published: August 2021

Contrary to the arsenides where donors undergo stable DX transition, we find that Ge in AlGaN does not suffer from the DX transition; instead, it undergoes a shallow donor (30 meV) to deep donor (150 meV) transition at ∼50% Al content in the alloy. This finding is of profound technological importance as it removes fundamental doping limitations in AlGaN and AlN imposed by the presumed DX−1 acceptor state. The charge state of Ge below and above the transition was determined by co-doping with Si, which remains a shallow donor in AlGaN for up to 80% Al. It was found that Ge occupied a donor state with a (0/+) thermodynamic transition for AlGaN alloys below and above the transition. Ge as a shallow donor was completely ionized at room temperature; however, the ionization of the deep donor required elevated temperatures, commensurate with its higher ionization energy. This behavior is not unique to Ge; preliminary findings show that Si and O in AlGaN may behave similarly.
Strong out-of-plane excitons in 2D hybrid halide double perovskites
Authors: Palummo Maurizia , Postorino Sara , Borghesi Costanza , Giorgi Giacomo
Published: August 2021

By means of an ab initio investigation, exploiting many-body perturbation theory approaches on top of ground-state density functional theory calculations, we disclose the impact of the electronic correlation on the band structure and optical properties of a class of recently synthesized Pb-free 2D-layered halide perovskites, namely, (BA)4AgBiBr8 and (BA)2CsAgBiBr7. We observe strong out-of-plane excitonic dipoles characterizing the optical spectra, a result that suggests the potential applicability of these layered hybrid materials in photonics and plasmonics, where the perpendicular field direction plays a relevant role.
Auto informing COVID-19 detection result from x-ray/CT images based on deep learning
Authors: Mahmood Ahlam Fadhil , Mahmood Saja Waleed
Published: August 2021

It is no secret to all that the corona pandemic has caused a decline in all aspects of the world. Therefore, offering an accurate automatic diagnostic system is very important. This paper proposed an accurate COVID-19 system by testing various deep learning models for x-ray/computed tomography (CT) medical images. A deep preprocessing procedure was done with two filters and segmentation to increase classification results. According to the results obtained, 99.94% of accuracy, 98.70% of sensitivity, and 100% of specificity scores were obtained by the Xception model in the x-ray dataset and the InceptionV3 model for CT scan images. The compared results have demonstrated that the proposed model is proven to be more successful than the deep learning algorithms in previous studies. Moreover, it has the ability to automatically notify the examination results to the patients, the health authority, and the community after taking any x-ray or CT images.
Electric field driven controllable motility of metal-dielectric Janus particles with boojum defects in thin films of a nematic liquid crystal
Authors: Sahu Dinesh Kumar , Dhara Surajit
Published: August 2021

Creation of tiny self-propelled particles is a subject of intense current interest, and control on their direction of motion is critical for application. We study the effect of electric fields on the metal-dielectric Janus particles inducing boojum defect in thin films of a nematic liquid crystal. In a sharp contrast to the response of boojum non-Janus particles, we show that the boojum Janus particles are self-propelled under the action of an ac electric field, which is applied perpendicular to the director in a planar cell. The particles can be transported along any direction, in the plane of the sample, under a steady field. The direction of motion is controllable by changing the field amplitude and frequency. The particle motility is interpreted based on the symmetry breaking of liquid crystal-enabled electro-osmosis (LCEO) flows. The command demonstrated on the motility is promising for tunable transport and microrobotic applications.
Rheological characterization of complex dynamics in Na–Zn metaphosphate glass-forming liquids
Authors: Xia Yiqing , Chen Hao , Aitken Bruce , Sen Sabyasachi
Published: August 2021

The viscoelastic behavior and shear relaxation in supercooled [NaPO3]x[Zn(PO3)2]1−x metaphosphate liquids with 0.2 ≤ x ≤ 1.0 are investigated using a combination of small amplitude oscillatory and steady shear parallel plate rheometry, resonant ultrasound spectroscopy, and differential scanning calorimetry. The results demonstrate that these liquids are thermorheologically complex with the coexistence of a fast and a slow relaxation process, which could be attributed to the segmental motion of the phosphate chains and the Zn–O bond scission/renewal dynamics, respectively. The segmental motion of the phosphate chains is found to be the dominant process associated with the shear relaxation for all metaphosphate liquids. The compositional evolution of the calorimetric fragility of these liquids is shown to be related to the conformational entropy of the constituent phosphate chains, which is manifested by the width of the relaxation time distribution for the segmental chain motion. This entropy decreases and the temporal coupling between the chain dynamics and Zn–O bond scission-renewal increases with the increasing Zn content as the higher field strength Zn modifier ions provide more effective cross-linking between the phosphate chains.
Leading-edge flow sensing for detection of vortex shedding from airfoils in unsteady flows
Authors: Saini Aditya , Narsipur Shreyas , Gopalarathnam Ashok
Published: August 2021

Sensing of vortex shedding in unsteady airfoil flows can be beneficial in controlling and positively harnessing their effects for increased aerodynamic performance. The time variation of the leading-edge suction parameter (LESP), which is a non-dimensional measure of the leading-edge suction force, is shown to be useful in deducing the various events related to vortex shedding from unsteady airfoils. The recently developed leading-edge flow sensing (LEFS) technique, which uses a few pressures in the airfoil leading-edge region for deducing the aerodynamic state of an airfoil, is adapted to deduce the variation of LESP during an unsteady motion in incompressible flow. For this purpose, the flow over the airfoil is divided into an outer-region flow over the chord, modeled using thin airfoil theory, and an inner-region flow over the leading edge, modeled as a flow past a parabola. By matching these two flows, relations are derived for calculating the LESP from a few pressures at the leading edge. By studying the variations of the LEFS outputs and the calculated LESP for various unsteady motions, guidelines are presented for detecting events related to vortex shedding: initiation, pinch-off, and termination. Computational and experimental results for additional unsteady motions confirm the effectiveness of the LEFS as a sensing technique for events associated with vortex shedding on unsteady airfoils.
Molecular relationships of the red-bellied dasyure (
Authors: Westerman M. , Loke Stella , Tan Mun Hua
Published: August 2021

The mitochondrial genome of the rare endemic New Guinean dasyurid Phascolosorex doriae (Thomas 1886) has been used to clarify relationships within ‘phascolosoricinae’. The mitochondrial genome has the typical gene arrangement seen in other marsupials. Molecular analyses using complete mitogenomes of other dasyurids resolve the red-bellied dasyure as sister to the narrow-striped dasyure Phascolosorex dorsalis and show that these two species diverged in the early Pliocene. The invasion of emergent New Guinean rainforest habitats (in the late Miocene) by the common ancestor of Ph. doriae, Ph. dorsalis and Neophascogale lorentzii represents one of three separate such invasions by dasyurid lineages.
The effects of parasitism on ewes for prime lamb production in western Victoria
Authors: Kirk B. , Larsen J. W. A. , Anderson N. , Stevenson M. A.
Published: August 2021

Context Internal parasites are estimated to cost the Australian sheep industry AUD436 million per annum (p.a.). Aims To assess the effects of parasitism in flocks producing prime lambs in the 500–700 mm p.a rainfall. area of Victoria. Methods Ewes on two farms that followed ‘best practice’ gastrointestinal parasite control programs (BP) and two farms that did not (regionally typical, TYP) were compared. Separate cohorts of ewes were monitored from pregnancy scanning to their subsequent joining each year for three consecutive seasons. Observations included worm egg count (WEC), bodyweight, condition score and presence of breech soiling (dag). These were compared between groups that were treated to suppress parasitism (SUP) and those treated according to the usual program used on that farm (NSUP). Data from individual ewes were analysed using a multivariable, mixed-effects regression model. Key results After adjusting for known confounders, SUP ewes were 1.2 (95% CI 0.80–1.6) kg heavier than NSUP ewes. Mature SUP ewes were significantly heavier than NSUP ewes at their next joining on 6 of 18 occasions, mostly following winters when ewes experienced nutritional stress. Ewe hoggets and Merino ewes were generally more susceptible to parasitism than mature non-Merino ewes; single-bearing ewes were less susceptible than those bearing twins. The effects of parasitism were reduced when peri-parturient ewes had an optimal condition score and grazed adequate pastures. Conclusions Ewes were more vulnerable to parasitism when immature, twin-bearing, or under nutritional stress. Some of the greatest differences between SUP and NSUP ewes occurred following periods of low feed availability and/or ewe condition score. The difference between the mean bodyweight of SUP and NSUP Merinos was not always greater than that of the non-Merinos. WECs are not a sole reliable indicator of the effects of parasitism in this class of sheep. Implications Immature or twin-bearing ewes, and those in suboptimal body condition, should be managed considering their increased vulnerability to parasitism, and WEC interpreted alongside other factors. Controlled release capsules were not cost effective in reducing production loss from gastrointestinal nematodes in most years but may be effective in reducing the effects of clinical parasitism in some cases.
The human cytomegalovirus protein pUL13 targets mitochondrial cristae architecture to increase cellular respiration during infection
Authors: Betsinger Cora N. , Jankowski Connor S.R. , Hofstadter William A. , Federspiel Joel D. , Otter Clayton J. , Jean Beltran Pierre M. , Cristea Ileana M.
Published: August 2021

Significance

Viruses rely on organelle remodeling for their replication and for the spread of infection. Alterations to mitochondrial functions and cellular metabolism are hallmarks of nearly all viral infections. However, how the widely spread HCMV remodels mitochondrial structure and function has presented a conundrum. It remained unclear how HCMV increases mitochondrial bioenergetics despite triggering mitochondrial fragmentation. Using a multidisciplinary approach, we address this question. We establish that the uncharacterized viral protein, pUL13, targets the mitochondria, interacts with the MICOS complex, and is sufficient for increasing oxidative phosphorylation during infection. Our findings provide evidence that viral pathogens have acquired mechanisms for manipulating cristae architecture and ETC function to achieve increased energy production and can have broad implications in understanding virus-driven pathologies.
Enhancing ion transport in charged block copolymers by stabilizing low symmetry morphology: Electrostatic control of interfaces
Authors: Min Jaemin , Jung Ha Young , Jeong Seungwon , Lee Byeongdu , Son Chang Yun , Park Moon Jeong
Published: August 2021

Significance

We show the enhancement of ion transport properties for charged block copolymers comprising nonstoichiometric ionic liquids by stabilizing the cubic Frank–Kasper A15 phases. The ionic liquid cations predominantly present near the micellar interfaces to increase stabilization energies of the A15 structures if they have strong attractive electrostatic interactions with the charged polymer chains. Unprecedented reentrant phase transitions between lamellar and A15 structures occur through the electrostatic control of interfaces, resulting in radical changes in the conductivity by an order of magnitude. This study is one of the rare demonstrations of a low symmetry morphology to establish a prospective avenue for advanced polymer electrolytes having tailor-made interfaces. Our findings will have implications for energy storage and transfer devices.
User-driven assessment of commercial term extractors
Authors: Kwong Oi Yee
Published: August 2021

In this paper, we address the system evaluation issue for commercial term extraction tools from the users’
perspective. We first revisit the gold standard approach commonly practised among researchers, and discuss the challenges it may
pose on end users, taking translators as a typical example. Considering the very different motivations and needs of users and
researchers, a user-driven approach is proposed as a variation and alternative to the gold standard approach to allow users to
assess and understand the performance of commercial tools more objectively. Its feasibility and usefulness are demonstrated by
deploying a benchmarking dataset of English-Chinese financial terms, produced by multiple annotators, in a case study with SDL
MultiTerm Extract. The results also provide insight for future development of term extractors designed for translators, which will
hopefully generate more accurate candidates, offer more customised features, enable better user experience, and enjoy wider
popularity as a computer-aided translation tool.
Nemorimyza maculosa
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Nemorimyza maculosa
(Malloch). Diptera: Agromyzidae. Hosts:
Chrysanthemum
, lettuce (
Lactuca sativa
) and other Asteraceae. Information is given on the geographical distribution in Europe (Portugal, Madeira, Spain, Canary islands), North America (Antigua and Barbuda, Bahamas, Barbados, Bermuda, Canada, Ontario, Cayman Islands, Costa Rica, Martinique, Mexico, Saint Kitts and Nevis, Trinidad and Tobago, United States, California, Connecticut, District of Columbia, Florida, Georgia, Hawaii, Indiana, Kentucky, Massachusetts, Mississippi, New York, North Carolina, Ohio, Oklahoma, Wisconsin), South America (Argentina, Bolivia, Brazil, Para, Pernambuco, Sao Paulo, Chile, Easter Island, Colombia, French Guiana, Guyana, Peru, Uruguay, Venezuela).
ASC deglutathionylation is a checkpoint for NLRP3 inflammasome activation
Authors: Li Shuhang , Wang Linlin , Xu Zhihao , Huang Yuanyuan , Xue Rufeng , Yue Ting , Xu Linfeng , Gong Fanwu , Bai Shiyu , Wu Qielan , Liu Jiwei , Lin Bolong , Zhang Huimin , Xue Yanhong , Xu Pingyong , Hou Junjie , Yang Xiaofei , Jin Tengchuan , Zhou Rongbin , Lou Jizhong , Xu Tao , Bai Li
Published: August 2021

Activation of NLRP3 inflammasome is precisely controlled to avoid excessive activation. Although multiple molecules regulating NLRP3 inflammasome activation have been revealed, the checkpoints governing NLRP3 inflammasome activation remain elusive. Here, we show that activation of NLRP3 inflammasome is governed by GSTO1-promoted ASC deglutathionylation in macrophages. Glutathionylation of ASC inhibits ASC oligomerization and thus represses activation of NLRP3 inflammasome in macrophages, unless GSTO1 binds ASC and deglutathionylates ASC at ER, under control of mitochondrial ROS and triacylglyceride synthesis. In macrophages expressing ASCC171A, a mutant ASC without glutathionylation site, activation of NLRP3 inflammasome is GSTO1 independent, ROS independent, and signal 2 less dependent. Moreover, AscC171A mice exhibit NLRP3-dependent hyperinflammation in vivo. Our results demonstrate that glutathionylation of ASC represses NLRP3 inflammasome activation, and GSTO1-promoted ASC deglutathionylation at ER, under metabolic control, is a checkpoint for activating NLRP3 inflammasome.
Experimental investigation of the limitations of polarisation optics for future gravitational wave detectors based on the polarisation Sagnac speedmeter
Authors: Spencer A P , Barr B W , Bell A S , Briggs J , Dupej P , Huttner S H , Sorazu B , Wright J , Strain K A
Published: August 2021

The polarisation Sagnac speedmeter interferometer has the potential to replace the Michelson interferometer as the instrumental basis for future generations of ground-based gravitational wave detectors. The quantum noise benefit of this speedmeter is dependent on high-quality polarisation optics, the polarisation beam-splitter (PBS) and quarter-waveplate (QWP) optics that are key to this detector configuration and careful consideration of the effect of birefringence in the arm cavities of the interferometer. A PBS with an extinction ratio of better than 4000 in transmission and 700 in reflection for a 41° angle of incidence was characterised along with a QWP of birefringence of

λ

4

+

λ

324

. The cavity mirror optics of a 10 m prototype polarisation Sagnac speedmeter were measured to have birefringence in the range 1 × 10−3 to 2 × 10−5 radians. This level of birefringence, along with the QWP imperfections, can be cancelled out by careful adjustment of the QWP angle, to the extent that the extinction ratio of the PBS is the leading limitation for the polarisation Sagnac speedmeter in terms of polarisation effects.
Resonant enhancement of Raman scattering by surface phonon polaritons in GaAs nanowires
Authors: Rybchenko Sergey I , Ali Sarfraz , Zhang Yunyan , Liu Huiyun
Published: August 2021

Surface optical phonons are normally considered as subtle and poorly reproducible features in the Raman spectra of nanostructured semiconductors, from which little or no information about the sample can be extracted. The present study demonstrates the potential for changing this situation. For a common type of GaAs semiconductor nanowire (NW), we have shown that due to a combination of size-resonant light concentration, tapered shape and favourable scattering geometry, the surface phonon polariton (SPhP) Raman signal can be enhanced by orders of magnitude. The high signal gain enables routine detailed characterisation of the SPhP peak on an individual NW level, revealing its polarisation properties and spectral shift under variation of the dielectric environment. This detailed characterisation was conducted using very low excitation power density despite high absorption of the excitation light in the NW material. The findings provide an effective way to use SPhP Raman scattering in the characterisation of dielectric NWs and the prospect of developing novel surface sensors.