bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of multiply charged ions on microturbulence-driven electron transport in partially magnetized plasmas
Authors: Kumar P. , Tsikata S. , Hara K.
Published: November 2021

Nonlinear interaction between kinetic instabilities in partially magnetized plasmas in the presence of multiply charged ion streams is investigated using kinetic simulations. It was observed by Hara and Tsikata [Phys. Rev. E 102, 023202 (2020)] that the axial ion–ion two-stream instability due to singly and doubly charged ion streams, coupled with the azimuthal electron cyclotron drift instability (ECDI), enhances cross-field electron transport. In the present study, it is observed that the addition of triply charged ions (as a third ion species) contributes to damping of the excited modes, leading to a reduction in the cross-field electron transport. The net instability-driven electron transport is shown to be a function not only of the azimuthal modes, such as the ECDI, but of the multiple ion species that dictate the development of additional plasma waves. It is found that trapping of the higher ion charge states within the plasma waves results in broadening of the ion velocity distribution functions.
Labile soil carbon and nitrogen fractions under short and long-term integrated crop–livestock agroecosystems
Authors: Dhaliwal Jashanjeet Kaur , Laxmisagra Sagar Kavya , Chellappa Jemila , Sekaran Udayakumar , Kumar Sandeep
Published: November 2021

Context Labile soil C and N fractions are strongly influenced by agricultural management practices. Aims This study was conducted on three long-term (≥30 years) on-farm sites (sites 1–3), and one short-term (3 years) experimental site (site 4) to evaluate the impacts of integrated crop–livestock system (ICLS) on labile C and N fractions and β-glucosidase enzyme activity for the 0–5 cm soil depth. Methods Long-term management systems (ICLS, corn (Zea mays L.)/grazing–soybean (Glycine max (L.) Merr.)/grazing–cover crop/grazing), control (CNT, corn–soybean with no cover crop and no grazing), and a grazed pasture (GP) at sites 1–3 were compared. At site 4, the treatments included: ICLS (corn/grazing–soybean/grazing–oat (Avena sativa L.)–cover crop/grazing); CC (corn–soybean–oat–cover crop with no grazing); CNT (corn–soybean–oat–fallow with no grazing); and GP. Key results ICLS had higher hot water extractable organic carbon (HWC), cold water extractable organic carbon (CWC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), potential carbon mineralisation (PCM) and potassium permanganate oxidisable carbon (POXC) than CNT under long-term management system. Long-term ICLS also enhanced β-glucosidase activity compared to CNT. ICLS had 72%, 214% and 60% higher glucosidase activity than the CNT at sites 1, 2 and 3, respectively. However, the C and N fractions and β-glucosidase activity were not affected by short-term ICLS (site 4). GP always had higher C and N fractions than ICLS and the CNT. There was a significantly positive relationship between SOC and labile C and N fractions, except POXC. Conclusions and implications Long-term inclusion of cover crops and livestock grazing in corn–soybean system was effective in enhancing labile soil C and N fractions.
Olfactory lures in predator control do not increase predation risk to birds in areas of conservation concern
Authors: Klug Page E. , Yackel Adams Amy A. , Reed Robert N.
Published: November 2021

Abstract Context Lethal control of predators is often undertaken to protect species of conservation concern. Traps are frequently baited to increase capture efficacy, but baited traps can potentially increase predation risk by attracting predators to protected areas. This is especially important if targeted predators can escape capture due to low trap success. Snake traps using live mouse lures may be beneficial if traps effectively remove snakes in the presence of birds and do not attract additional snakes to the area. Aims The present study evaluated whether mouse-lure traps in areas occupied by birds (simulated by deploying bird-lure traps) could influence predation risk from an invasive snake on Guam. Methods Snake traps were used, with Japanese quail (Coturnix japonica) as a proxy for predation risk, to assess if an adjacent trap with a mouse (Mus musculus) would attract brown treesnakes (Boiga irregularis) to a focal area and increase contact between an invasive snake and avian prey. Catch per unit effort (CPUE) at stations containing either a bird-lure trap, mouse-lure trap or pair of traps (i.e. one bird-lure and one mouse-lure trap) was evaluated. Key results Bird-lure traps paired with mouse-lure traps did not differ in CPUE from isolated bird-lure traps. At paired stations, CPUE of snakes in mouse-lure traps was 2.3× higher than bird-lure traps, suggesting mouse lures were capable of drawing snakes away from avian prey. Bird-lure traps at paired stations experienced a decay in captures over time, whereas CPUE for isolated bird-lure traps increased after 9 weeks and exceeded mouse-lure traps after 7 weeks. Conclusions Mouse lures did not increase the risk of snakes being captured in bird-lure traps. Instead, mouse-lure traps may have locally suppressed snakes, whereas stations without mouse-lure traps still had snakes in the focal area, putting avian prey at greater risk. However, snakes caught with bird lures tended to be larger and in better body condition, suggesting preference for avian prey over mammalian prey in larger snakes. Implications Strategic placement of olfactory traps within areas of conservation concern may be beneficial for protecting birds of conservation concern from an invasive snake predator.
Reprogrammed transsulfuration promotes basal-like breast tumor progression via realigning cellular cysteine persulfidation
Authors: Erdélyi Katalin , Ditrói Tamás , Johansson Henrik J. , Czikora Ágnes , Balog Noémi , Silwal-Pandit Laxmi , Ida Tomoaki , Olasz Judit , Hajdú Dorottya , Mátrai Zoltán , Csuka Orsolya , Uchida Koji , Tóvári József , Engebraten Olav , Akaike Takaaki , Børresen Dale Anne-Lise , Kásler Miklós , Lehtiö Janne , Nagy Péter
Published: November 2021

Significance

Basal-like breast cancers (BLBC) have poor prognosis. Here, we present evidence that reprogrammed transsulfuration is a hallmark of BLBC. Human BLBC tumors exhibit elevated levels of cystathione β-synthetase (CBS) but diminished expressions of oxidative Cys-catabolizing enzymes supporting a Cys-addicted phenotype. We demonstrated that in BLBC cells, CBS plays a role in cellular proliferation and invasiveness, HIF1-α activation under hypoxia, and protection against oxidative stress and CySSCy deprivation–induced ferroptosis. Tumor progression and angiogenesis was impaired in shCBS xenograft tumors, which had larger intratumoral necrotic areas. Mechanistic analyses largely based on sulfur metabolome and proteomics data revealed that realigned Cys persulfidation is a determining factor in this Cys-addicted phenotype of BLBC tumors, which holds promise for drug development.
Revisiting the theory behind AFM indentation procedures. Exploring the physical significance of fundamental equations
Authors: Kontomaris Stylianos-Vasileios , Malamou Anna
Published: November 2021

Fundamental contact mechanics models concerning the interaction of an axisymmetric indenter and an elastic half-space are usually employed in atomic force microscopy (AFM) indentation methods. In this paper, a simplified ‘equivalent’ physical system is used to correlate basic magnitudes such as the applied force on an elastic half space, the Young’s modulus, the contact radius and the indentation depth. More specifically, the equations correlating the above magnitudes are derived using fundamental physics instead of the typical rigorous mathematical process with a small error. In addition, the relation between a force-indentation curve and the indenter’s shape is also presented in detail in order to help students and non-specialists in contact mechanics to obtain a strong background to the AFM indentation theory.
Angular distributions in the double ionization of argon by fast electron impact
Authors: Herbadji A , Kada I , Mansouri A , Cappello C Dal
Published: November 2021

In this paper, a model describing the two electrons ejected by distorted waves is applied to the study of the double ionization of argon by fast electrons (∼5500 eV). The correlation is also partially taken into account both in the final state and in the initial state. The results obtained by our model as well as by other models that are also based on the first Born approximation are compared with the available experimental data.
Kinetic Monte Carlo method applied to micrometric particle detachment mechanisms by aerodynamic forces
Authors: Villagrán Olivares Marcela C , Benito Jesica G , Uñac Rodolfo O , Vidales Ana M
Published: November 2021

The formulation of a kinetic Monte Carlo simulation to account for the different possible mechanisms present in the problem of resuspension of aerosol particles is addressed as an extension of a former model Benito et al (2016 J. Aerosol Sci.
100 26–37). The re-entrainment of micrometer particles to airflow when detached from a surface by aerodynamic forces is modeled using the similitude of the problem with the desorption process from heterogeneous surfaces. Depending on the relative role of the intervening forces, three main mechanisms for movement initiation can be present: rolling, sliding and lifting-off. Three different transition probabilities are defined for each mechanism and the corresponding transition rates calculated for the kinetic process to be simulated. The decisive factor for the development of the model is to set an appropriate dynamical hierarchy to simulate correctly the evolution of the transition rates as the airflow velocity increases, reflecting the stochastic nature of the process, not always fully captured by other Monte Carlo approaches. The model is applied to spherical and elongated particles on a flat surface, reproducing qualitatively well the experimental trends found by other authors for the case of particles with different shapes. It is also demonstrated that, for elongated particles, the main mechanism assisting the detachment is not rolling but sliding, underscoring the need for an adequate choice of the particles shape and detachment mechanism when looking for the critical conditions for particle removal from surfaces.
Two-step gradient-assisted phase-shifting demodulation algorithm for fast 3D reconstruction
Authors: Wu Yanxue , Wu Gaoxu , Yang Shichao , Yang Tian , Liu Fei
Published: November 2021

The conventional multi-frequency heterodyne method is one of the most widely used methods in non-contact 3D measurement. However, it needs to project different phase-shifting patterns with different frequencies, so a large number of patterns are required. For most conventional methods, the fringe period number of the projected patterns is usually small due to its limited noise tolerance, though a larger fringe period number always means higher accuracy. We propose a two-step phase-shifting demodulation algorithm based on an intensitygradient. In this method, only two patterns for each frequency are required. With the intensity gradient of the two patterns, we obtain the wrapped phase of each frequency. Next, the absolute phase is retrieved from the three wrapped phases with the heterodyne algorithm. Because only two patterns are required for each frequency, the proposed method is more robust and has higher measuring speed compared with the traditional three-frequency four-step heterodyne method. Simulations and experiments prove the feasibility and effectiveness of the method, and demonstrate that the proposed method extends the noise tolerance and achieves highprecision with only half of the patterns required by the traditional three-frequency four-step method.
MiniCarb: a passive, occultation-viewing, 6U CubeSat for observations of CO2, CH4, and H2O
Authors: Wilson Emily L , Riot Vincent J , DiGregorio A J , Ramu Guru , Cleveland Paul , Simms Lance M , Carter Darrell , Bruner Bill , Young Jennifer , Villanueva Geronimo
Published: November 2021

We present the final design, environmental testing, and launch history of MiniCarb, a 6U CubeSat developed through a partnership between NASA Goddard Space Flight Center and Lawrence Livermore National Laboratory. MiniCarb’s science payload, developed at Goddard, was an occultation-viewing, passive laser heterodyne radiometer for observing methane, carbon dioxide, and water vapor in Earth’s atmosphere at ∼1.6 µm s−1. MiniCarb’s satellite, developed at Livermore, implemented their CubeSat Next Generation Bus plug-and-play architecture to produce a modular platform that could be tailored to a range of science payloads. Following the launch on 5 December 2019, MiniCarb traveled to the International Space Station and was set into orbit on 1 February 2020 via Northrop Grumman’s Cygnus capsule which deployed MiniCarb with tipoff rotation of about 20° s−1 (significantly higher than the typical rate of 3° s−1 from prior CubeSats), from which the attitude control system was unable to recover resulting in a loss of power. In spite of this early failure, MiniCarb had many successes including rigorous environmental testing, successful deployment of its solar panels, and a successful test of the radio and communication through the Iridium network. This prior work and enticing cost (approximately $2 M for the satellite and $250 K for the payload) makes MiniCarb an ideal candidate for a low-cost and rapid rebuild as a single orbiter or constellation to globally observe key greenhouse gases.
The model of synchronization between internal reconnections and edge-localized modes
Authors: Bulanin V V , Kurskiev G S , Solokha V V , Yashin A Yu , Zhiltsov N S
Published: November 2021

A new model for interaction between the internal reconnections caused by sawtooth and the edge-localized modes (ELM) was presented. The experimental evidence of the coupling between sawtooth crash and ELM events were observed in the Globus-M and Globus-M2 tokamaks. The numerical analysis of magnetic equilibrium showed that internal reconnections can induce the excess current density near the separatrix during the several hundreds of μs. The excess current destabilizes the peeling-ballooning (PB) instability. The PB stability analysis showed that the penetration depth of the induced current should be in the range of ψ
norm = 0.8–0.95 to trigger the instability.
FSI and non-FSI studies on a functionally graded temperature-responsive hydrogel bilayer in a micro-channel
Authors: Mazaheri Hashem , Khodabandehloo Amin
Published: November 2021

Taking into account both fluid-structure interaction (FSI) and non-FSI simulations, the deformation of a bilayer is investigated in this paper. The bilayer, which is utilized in a micro-channel, consists of a Functionally-graded (FG) temperature-responsive hydrogel layer and an incompressible elastomeric one. Allocating two different positions to the elastomeric layer, we make two different bilayers where in one of them, the elastomer layer is located on the left (LSE) and on the right (RSE) in another one. Also, to see the effect of grading, two bilayers with homogenous hydrogel layers with different amounts of cross-linking density are considered. For FG cases in which the hydrogel layer’s properties vary through thickness direction, both ascending and descending arrangements are analyzed. Each simulation, whether it is FSI or non-FSI, is conducted utilizing three software. FLUENT for fluid domain examinations, ABAQUS for finite element method analysis, and MpCCI to couple two aforementioned simulation domains. By extracting and comparing both simulations results, it is observed that the influence of the fluid flow is very significant and should not be ignored. Moreover, it is discovered that the fluid flow affects more the RSE configuration and also the bilayers with lower amounts of cross-linking density. Finally, we investigate how some parameters, such as inlet pressure, can affect the behavior of the bilayer.
Study on improving the resolution of an H-shaped piezoelectric ultrasonic actuator by stick-slip principle
Authors: Tian Xinqi , Chen Weishan , Liu Yingxiang , Deng Jie , Li Kai
Published: November 2021

Improving the performance of the motion stages driven by piezoelectric actuators is an enduring topic for expanding their applications. For the motion stage with a travel range of tens of millimeters, trade-offs are inevitable between getting high speed (hundreds of millimeters per second) and high resolution (tens of nanometers), due to the inherent limitations of the operating principles of the piezoelectric actuators. In order to improve the output resolution of an H-shaped piezoelectric ultrasonic actuator, sawtooth excitation voltages are used in this work rather than the conventional sinusoidal voltages in previous works. The configuration and operating principle of the actuator are discussed in detail. The actuator consists of two vertical and two horizontal longitudinal transducers. The ends of the vertical transducers act as the driving tips and drive the stage forward with the alternating slow extensions and rapid contraction, during which stick motions and slip motions of the stage are acquired. An analytic model is developed to estimate the horizontal and vertical output displacement of the driving tip. The maximum error between the predicted value of the analytical model and the experimental value is about 14%. A prototype of the motion stage is fabricated and experiments are carried out to evaluate its output characteristics. The experiment results confirm the operating principle and show that the resolution is upgraded to tens of nanometers. The prototype obtains a resolution of 19 nm, a maximum speed of 2.22 μm s−1, and a maximum carrying load of 16.94 kg.
Temperature-driven transition from skyrmion to bubble crystals in centrosymmetric itinerant magnets
Authors: Hayami Satoru
Published: November 2021

Interplay between itinerant electrons and localized spins in itinerant magnets gives rise to a variety of noncoplanar multiple-Q spin textures, such as the skyrmion, hedgehog, meron, and vortex. We elucidate that another type of multiple-Q state consisting of collinear sinusoidal waves, a magnetic bubble crystal, appears at finite temperatures in a centrosymmetric itinerant electron system. The results are obtained for the classical Kondo lattice model with easy-axis single-ion anisotropy on a triangular lattice by a large-scale numerical simulation. We find that a finite-temperature topological phase transition between the skyrmion crystal and the bubble crystal occurs by changing the temperature. We obtain the minimal key ingredients for inducing the finite-temperature transition by analyzing an effective spin model where it is shown that the synergy between the multiple-spin interaction and magnetic anisotropy plays a significant role.
General interaction quenches in a Luttinger liquid
Authors: Wei You-Ming , Lu Hantao
Published: November 2021

We discuss a general interaction quench in a Luttinger liquid described by a paired bosonic Hamiltonian. By employing su(1, 1) Lie algebra, the post-quench time-evolved wavefunctions are obtained analytically, from which the time evolution of the entanglement in momentum space can be investigated. We note that depending on the choice of Bogoliubov quasiparticles, the expressions of wavefunctions, which describe time-evolved paired states, can take different forms. The correspondence between the largest entanglement eigenvalue in momentum space and the wavefunction overlap in quench dynamics is discussed, which generalizes the results of Dóra et al (2016, Phys. Rev. Lett.
117, 010 603). A numerical demonstration on an XXZ lattice model is presented via the exact diagonalization method.
Analysis on vibration characteristics of large-size rectangular piezoelectric composite plate based on quasi-periodic phononic crystal structure
Authors: Hu Li-Qing , Wang Sha , Lin Shu-Yu
Published: November 2021

Based on the theory of composite materials and phononic crystals (PCs), a large-size rectangular piezoelectric composite plate with the quasi-periodic PC structure composed of PZT-4 and epoxy is proposed in this paper. This PC structure can suppress the transverse vibration of the piezoelectric composite plate so that the thickness mode is purer and the thickness vibration amplitude is more uniform. Firstly, the vibration of the model is analyzed theoretically, the electromechanical equivalent circuit diagram of three-dimensional coupled vibration is established, and the resonance frequency equation is derived. The effects of the length, width, and thickness of the piezoelectric composite plate at the resonant frequency are obtained by the analytical method and the finite element method, the effective electromechanical coupling coefficient is also analyzed. The results show that the resonant frequency can be changed regularly and the electromechanical conversion can be improved by adjusting the size of the rectangular piezoelectric plate. The effect of the volume fraction of the scatterer on the resonant frequency in the thickness direction is studied by the finite element method. The band gap in X and Y directions of large-size rectangular piezoelectric plate with quasi-periodic PC structures are calculated. The results show that the theoretical results are in good agreement with the simulation results. When the resonance frequency is in the band gap, the decoupling phenomenon occurs, and then the vibration mode in the thickness direction is purer.
Impact of symmetric gate-recess length on the DC and RF characteristics of InP HEMTs
Authors: Feng Ruize , Wang Bo , Cao Shurui , Liu Tong , Su Yongbo , Ding Wuchang , Ding Peng , Jin Zhi
Published: November 2021

We fabricated a set of symmetric gate-recess devices with gate length of 70 nm. We kept the source-to-drain spacing (L
SD) unchanged, and obtained a group of devices with gate-recess length (L
recess) from 0.4 μm to 0.8 μm through process improvement. In order to suppress the influence of the kink effect, we have done SiN
X
passivation treatment. The maximum saturation current density (I
D_max) and maximum transconductance (g
m,max) increase as L
recess decreases to 0.4 μm. At this time, the device shows I
D_max=749.6 mA/mm at V
GS=0.2 V, V
DS=1.5 V, and g
m_max=1111 mS/mm at V
GS=−0.35 V, V
DS=1.5 V. Meanwhile, as L
recess increases, it causes parasitic capacitance C
gd and g
d to decrease, making f
max drastically increases. When L
recess = 0.8 μm, the device shows f
T=188 GHz and f
max=1112 GHz.
Environmental parameter estimation with the two-level atom probes
Authors: Luo Mengmeng , Liu Wenxiao , Chen Yuetao , Han Shangbin , Gao Shaoyan
Published: November 2021

A novel scheme is proposed to estimate three environmental parameters, the detuning, the temperature and the squeezing strength with one-qubit or two-qubit probes. Quantum Fisher information and the fidelity of the atom probes are calculated. When the detuning between the frequency of cavity field and the atomic transition frequency is estimated, the dynamics of quantum Fisher information shows oscillatory and rising behaviors. To estimate the temperature of the thermal reservoir, the one-qubit probe with the superposition initial state is more favorable than the two-qubit probe with the entangled initial state. When the squeezing strength of the squeezed vacuum reservoir is estimated, we find that the estimation precision is significantly improved by utilizing the two-qubit probe with the maximal entangled initial state. Our work provides a potential application in the open quantum system and quantum information processing.
Dispersion of neutron spin resonance mode in Ba0.67K0.33Fe2As2
*
Authors: Xie Tao , Liu Chang , Fennell Tom , Stuhr Uwe , Li Shi-Liang , Luo Hui-Qian
Published: November 2021

We report an inelastic neutron scattering investigation on the spin resonance mode in the optimally hole-doped iron-based superconductor Ba0.67K0.33Fe2As2 with Tc= 38.2 K. Although the resonance is nearly two-dimensional with peak energy E
R ≈ 14 meV, it splits into two incommensurate peaks along the longitudinal direction ([H,0,0]) and shows an upward dispersion persisting to 26 meV. Such dispersion breaks through the limit of total superconducting gaps Δ
tot = |Δk
| + |Δ

k+Q
| (about 11–17 meV) on nested Fermi surfaces measured by high resolution angle resolved photoemission spectroscopy (ARPES). These results cannot be fully understood by the magnetic exciton scenario under s±-pairing symmetry of superconductivity, and suggest that the spin resonance may not be restricted by the superconducting gaps in the multi-band systems.
Role of compositional changes on thermal, magnetic, and mechanical properties of Fe-P-C-based amorphous alloys
Authors: Raya Indah , Chupradit Supat , Kadhim Mustafa M , Mahmoud Mustafa Z , Jalil Abduladheem Turki , Surendar Aravindhan , Ghafel Sukaina Tuama , Mustafa Yasser Fakri , Bochvar Alexander N
Published: November 2021

This work aimed to tune the comprehensive properties of Fe-P-C-based amorphous system through investigating the role of microalloying process on the crystallization behavior, glass forming ability (GFA), soft magnetic features, and mechanical properties. Considering minor addition of elements into the system, it was found that the simultaneous microalloying of Ni and Co leads to the highest GFA, which was due to the optimization of compositional heterogeneity and creation of near-eutectic composition. Moreover, the FeCoNiCuPC amorphous alloy exhibited the best anelastic/viscoplastic behavior under the nanoindentation test, which was owing to the intensified structural fluctuations in the system. However, the improved plasticity by the extra Cu addition comes at the expense of magnetic properties, so that the saturation magnetization of this alloying system is significantly decreased compared to the FeCoPC amorphous alloy with the highest soft magnetic properties. In total, the results indicated that a combination of added elemental constitutes,i.e., Fe69Co5Ni5Cu1P13C7composition, provides an optimized state for the comprehensive properties in the alloying system.
Photoproduction reaction γn → K
*0Λ in an effective Lagrangian approach *
Authors: Wei Neng-Chang , Zhu Yi-Ming , Huang Fei
Published: November 2021

In our previous work [Phys. Rev. C 101, 014003 (2020)], the photoproduction reaction

was investigated within an effective Lagrangian approach. The reaction amplitudes were constructed by including the t-channel K,

, and κ exchanges, u-channel Λ, Σ, and

exchanges, s-channel N,

, and

exchanges, and interaction current. The data on the differential cross sections and spin density matrix elements were described simultaneously. In this study, we investigate the photoproduction reaction

based on the same reaction mechanism as that of

to obtain a unified description of the data for

and

within the same model. All hadronic coupling constants, form factor cutoffs, and the resonance masses and widths in the present calculations remain the same as in our previous work for

. The available differential cross-section data for

are well reproduced. Further analysis shows that the cross sections of

are dominated by the contributions of the t-channel K exchange, while the s-channel

and

exchanges also provide considerable contributions.
Modified regular black holes with time delay and 1-loop quantum correction *
Authors: Ling Yi , Wu Meng-He
Published: November 2021

We develop the regular black hole solutions by incorporating the 1-loop quantum correction to the Newton potential and a time delay between an observer at the regular center and one at infinity. We define the maximal time delay between the center and the infinity by scanning the mass of black holes such that the sub-Planckian feature of the Kretschmann scalar curvature is preserved during the process of evaporation. We also compare the distinct behavior of the Kretschmann curvature for black holes with asymptotically Minkowski cores and those with asymptotically de-Sitter cores, including Bardeen and Hayward black holes. We expect that such regular black holes may provide more information about the construction of effective metrics for Planck stars.
Electrophysiological investigation of intact retina with soft printed organic neural interface
Authors: Vėbraitė Ieva , David-Pur Moshe , Rand David , Głowacki Eric Daniel , Hanein Yael
Published: November 2021

Objective. Understanding how the retina converts a natural image or an electrically stimulated one into neural firing patterns is the focus of on-going research activities. Ex vivo, the retina can be readily investigated using multi electrode arrays (MEAs). However, MEA recording and stimulation from an intact retina (in the eye) has been so far insufficient. Approach. In the present study, we report new soft carbon electrode arrays suitable for recording and stimulating neural activity in an intact retina. Screen-printing of carbon ink on 20 µm polyurethane (PU) film was used to realize electrode arrays with electrodes as small as 40 µm in diameter. Passivation was achieved with a holey membrane, realized using laser drilling in a thin (50 µm) PU film. Plasma polymerized 3.4-ethylenedioxythiophene was used to coat the electrode array to improve the electrode specific capacitance. Chick retinas, embryonic stage day 13, both explanted and intact inside an enucleated eye, were used. Main results. A novel fabrication process based on printed carbon electrodes was developed and yielded high capacitance electrodes on a soft substrate. Ex vivo electrical recording of retina activity with carbon electrodes is demonstrated. With the addition of organic photo-capacitors, simultaneous photo-electrical stimulation and electrical recording was achieved. Finally, electrical activity recordings from an intact chick retina (inside enucleated eyes) were demonstrated. Both photosensitive retinal ganglion cell responses and spontaneous retina waves were recorded and their features analyzed. Significance. Results of this study demonstrated soft electrode arrays with unique properties, suitable for simultaneous recording and photo-electrical stimulation of the retina at high fidelity. This novel electrode technology opens up new frontiers in the study of neural tissue in vivo.
Optimizing fibrin hydrogel toward effective neural progenitor cell delivery in spinal cord injury
Authors: Sudhadevi Tara , Vijayakumar Harikrishnan S , Hariharan Easwer V , Sandhyamani Samavedam , Krishnan Lissy K
Published: November 2021

Transplantation of neural progenitor cell (NPC) possessing the potential to differentiate into neurons may guard against spinal cord injury (SCI)- associated neuronal trauma. We propose that autologous-like NPC may reduce post-transplant immune response. The study used the rat SCI model to prove this concept. For isolation and expansion of rat NPC for cell-based SCI therapy, the in vitro protocol standardized with human NPC seemed suitable. The primary aim of this study is to select a cell/neural tissue-compatible biomaterial for improving NPC survival in vivo. The composition of the fibrin hydrogel is adjusted to obtain degradable, porous, and robust fibrin strands for supporting neural cell attachment, migration, and tissue regeneration. This study employed NPC culture to evaluate the cytocompatibility and suitability of the hydrogel, composed by adding graded concentrations of thrombin to a fixed fibrinogen concentration. The microstructure evaluation by scanning electron microscope guided the selection of a suitable composition for delivering the embedded cells. On adding more thrombin, fibrinogen clotted quickly but reduced porosity, pore size, and fiber strand thickness. The high activity of thrombin also affected NPC morphology and the in vitro cell survival. The selected hydrogel carried viable NPC and retained them at the injury site post-transplantation. The fibrin hydrogel played a protective role throughout the transfer process by providing cell attachment sites and survival signals. The fibrin and NPC together regulated the immune response at the SCI site reducing ED1+ve/ED2+ve macrophages in the early period of 8–16 d after injury. Migration of β-III tubulin+ve neural-like cells into the fibrin-injected control SCI is evident. The continuous use of a non-neurotoxic fibrin matrix could be a convenient strategy for in vitro NPC preparation, minimally invasive cell delivery, and better transplantation outcome.
Quantifying aviation’s contribution to global warming
Authors: Klöwer M , Allen M R , Lee D S , Proud S R , Gallagher L , Skowron A
Published: November 2021

Growth in aviation contributes more to global warming than is generally appreciated because of the mix of climate pollutants it generates. Here, we model the CO2 and non-CO2 effects like nitrogen oxide emissions and contrail formation to analyse aviation’s total warming footprint. Aviation contributed approximately 4% to observed human-induced global warming to date, despite being responsible for only 2.4% of global annual emissions of CO2. Aviation is projected to cause a total of about 0.1 °C of warming by 2050, half of it to date and the other half over the next three decades, should aviation’s pre-COVID growth resume. The industry would then contribute a 6%–17% share to the remaining 0.3 °C–0.8 °C to not exceed 1.5 °C–2 °C of global warming. Under this scenario, the reduction due to COVID-19 to date is small and is projected to only delay aviation’s warming contribution by about five years. But the leveraging impact of growth also represents an opportunity: aviation’s contribution to further warming would be immediately halted by either a sustained annual 2.5% decrease in air traffic under the existing fuel mix, or a transition to a 90% carbon-neutral fuel mix by 2050.
Spatiotemporal dynamics of encroaching tall vegetation in timberline ecotone of the Polar Urals Region, Russia
Authors: Zhou Wenbo , Mazepa Valeriy , Shiyatov Stepan , Shalaumova Yulia V , Zhang Tianqi , Liu Desheng , Sheshukov Aleksey , Wang Jingfeng , El Sharif Husayn , Ivanov Valeriy
Published: November 2021

Previous studies discovered a spatially heterogeneous expansion of Siberian larch into the tundra of the Polar Urals (Russia). This study reveals that the spatial pattern of encroachment of tree stands is related to environmental factors including topography and snow cover. Structural and allometric characteristics of trees, along with terrain elevation and snow depth were collected along a transect 860 m long and 80 m wide. Terrain curvature indices, as representative properties, were derived across a range of scales in order to characterize microtopography. A density-based clustering method was used here to analyze the spatial and temporal patterns of tree stems distribution. Results of the topographic analysis suggest that trees tend to cluster in areas with convex surfaces. The clustering analysis also indicates that the patterns of tree locations are linked to snow distribution. Records from the earliest campaign in 1960 show that trees lived mainly at the middle and bottom of the transect across the areas of high snow depth. As trees expanded uphill following a warming climate trend in recent decades, the high snow depth areas also shifted upward creating favorable conditions for recent tree growth at locations that were previously covered with heavy snow. The identified landscape signatures of increasing tall vegetation, and the effects of microtopography and snow may facilitate the understanding of treeline dynamics at larger scales.
Spatial synchrony in the start and end of the thermal growing season has different trends in the mid-high latitudes of the Northern Hemisphere
Authors: Wu Fang , Jiang Yuan , Wen Yan , Zhao Shoudong , Xu Hui
Published: November 2021

Changes in spatial synchrony in the growing season have notable effects on species distribution, cross-trophic ecological interactions and ecosystem stability. These changes, driven by non-uniform climate change were observed on the regional scale. It is still unclear how spatial synchrony of the growing season on the climate gradient of the mid-high latitudes of the Northern Hemisphere and ecoregions, has changed over the past decades. Therefore, we calculated the start, end, and length of the thermal growing season (SOS, EOS, and LOS, respectively), which are indicators of the theoretical plant growth season, based on the daily-mean temperature of the Princeton Global Forcing dataset from 1948 to 2016. Spatial variations in the SOS, EOS and LOS along spatial climate gradients were analyzed using the multivariate-linear regression model. The changes of spatial synchrony in the SOS, EOS and LOS were analyzed using the segmented model. The results showed that in all ecoregions, spatially, areas with higher temperature tended to have an earlier SOS, later EOS and longer LOS. However, not all the areas with higher precipitation tended to have a later SOS, later EOS, and shorter LOS. The spatial synchrony in the SOS decreased across the entire study area, whereas the EOS showed the opposite trend. Among the seven ecoregions, spatial synchrony in the SOS in temperate broadleaf/mixed forests and temperate conifer forests changed the most noticeably, decreasing in both regions. Conversely, spatial synchrony in the EOS in the taiga, temperate grasslands/savannas/shrublands and tundra changed the most noticeably, increasing in each region. These may have important effects on the structure and function of ecosystems, especially on the changes in cross-trophic ecological interactions. Moreover, future climate change may change the spatial synchrony in the SOS and EOS further; however, the actual impact of such ongoing change is largely unknown.
3D culture platform of human iPSCs-derived nociceptors for peripheral nerve modeling and tissue innervation
Authors: Malheiro Afonso , Harichandan Abhishek , Bernardi Joyce , Seijas-Gamardo Adrián , Konings Gonda F , Volders Paul G A , Romano Andrea , Mota Carlos , Wieringa Paul , Moroni Lorenzo
Published: November 2021

Functional humanized in vitro nerve models are coveted as an alternative to animal models due to their ease of access, lower cost, clinical relevance and no need for recurrent animal sacrifice. To this end, we developed a sensory nerve model using induced pluripotent stem cells-derived nociceptors that are electrically active and exhibit a functional response to noxious stimuli. The differentiated neurons were co-cultured with primary Schwann cells on an aligned microfibrous scaffold to produce biomimetic peripheral nerve tissue. Compared to glass coverslips, our scaffold enhances tissue development and stabilization. Using this model, we demonstrate that myelin damage can be induced from hyperglycemia exposure (glucose at 45 mM) and mitigated by epalrestat (1 µM) supplementation. Through fibrin embedding of the platform, we were able to create 3D anisotropic myelinated tissue, reaching over 6.5 mm in length. Finally, as a proof-of-concept, we incorporated pancreatic pseudoislets and endometrial organoids into our nerve platform, to demonstrate the potential in generating nociceptor innervation models. In summary, we propose here an improved tool for neurobiology research with potential applications in pathology modeling, drug screening and target tissue innervation.
Rays, waves, SU(2) symmetry and geometry: toolkits for structured light
Authors: Shen Yijie
Published: November 2021

Structured light refers to the ability to tailor optical patterns in all its degrees of freedom, from conventional 2D transverse patterns to exotic forms of 3D, 4D, and even higher-dimensional modes of light, which break fundamental paradigms and open new and exciting applications for both classical and quantum scenarios. The description of diverse degrees of freedom of light can be based on different interpretations, e.g. rays, waves, and quantum states, that are based on different assumptions and approximations. In particular, recent advances highlighted the exploiting of geometric transformation under general symmetry to reveal the ‘hidden’ degrees of freedom of light, allowing access to higher dimensional control of light. In this tutorial, I outline the basics of symmetry and geometry to describe light, starting from the basic mathematics and physics of SU(2) symmetry group, and then to the generation of complex states of light, leading to a deeper understanding of structured light with connections between rays and waves, quantum and classical. The recent explosion of related applications are reviewed, including advances in multi-particle optical tweezing, novel forms of topological photonics, high-capacity classical and quantum communications, and many others, that, finally, outline what the future might hold for this rapidly evolving field.
Using Numerical Methods to Design Simulations: Revisiting the Balancing Intercept
Authors: Robertson Sarah E , Steingrimsson Jon A , Dahabreh Issa J
Published: November 2021

In this paper, we consider methods for generating draws of a binary random variable whose expectation conditional on covariates follows a logistic regression model with known covariate coefficients. We examine approximations for finding a “balancing intercept,” that is, a value for the intercept of the logistic model that leads to a desired marginal expectation for the binary random variable. We show that a recently proposed analytical approximation can produce inaccurate results, especially when targeting more extreme marginal expectations or when the linear predictor of the regression model has high variance. We then formulate the balancing intercept as a solution to an integral equation, implement a numerical approximation for solving the equation based on Monte Carlo methods, and show that the approximation works well in practice. Our approach to the basic problem of the balancing intercept provides an example of a broadly applicable strategy for formulating and solving problems that arise in the design of simulation studies used to evaluate or teach epidemiologic methods.
Modelling the spreading of the SARS-CoV-2 in presence of the lockdown and quarantine measures by akinetic-type reactionsapproach
Authors: Sonnino Giorgio , Peeters Philippe , Nardone Pasquale
Published: November 2021

We propose a realistic model for the evolution of the COVID-19 pandemic subject to the lockdown and quarantine measures, which takes into account the timedelay for recovery or death processes. The dynamic equations for the entire process are derived by adopting a kinetic-type reactions approach. More specifically, the lockdown and the quarantine measures are modelled by some kind of inhibitor reactions where susceptible and infected individuals can be trapped into inactive states. The dynamics for the recovered people is obtained by accounting people who are only traced back to hospitalized infected people. To get the evolution equation we take inspiration from the Michaelis Menten’s enzyme-substrate reaction model (the so-called MM reaction) where the enzyme is associated to the available hospital beds, the substrate to the infected people, and the product to the recovered people, respectively. In other words, everything happens as if the hospitals beds act as a catalyzer in the hospital recovery process. Of course, in our case, the reverse MM reaction has no sense in our case and, consequently, the kinetic constant is equal to zero. Finally, the ordinary differential equations (ODEs) for people tested positive to COVID-19 is simply modelled by the following kinetic scheme $S+I\Rightarrow 2I$ with $I\Rightarrow R$ or $I\Rightarrow D$, with $S$, $I$, $R$ and $D$ denoting the compartments susceptible, infected, recovered and deceased people, respectively. The resulting kinetic-type equations provide the ODEs, for elementary reaction steps, describing the number of the infected people, the total number of the recovered people previously hospitalized, subject to the lockdown and the quarantine measure and the total number of deaths. The model foresees also the second wave of infection by coronavirus. The tests carried out on real data for Belgium, France and Germany confirmed the correctness of our model.
High inclusion rates of hybrid rye instead of corn in diets for growing-finishing pigs do not influence the overall growth performance and most carcass traits are not influenced by hybrid rye
Authors: McGhee Molly L , Harsh Bailey N , Stein Hans H
Published: November 2021

It was hypothesized that hybrid rye may replace corn in diets for growing and finishing pigs without impacting growth performance, carcass characteristics, or meat quality. A total of 128 pigs (23.69 ± 2.51 kg) were allotted to four treatments with eight replicate pens per treatment. Phases 1 and 2 diets were fed for 35 d each and phase 3 diets were fed for 27 d. Within each phase, pigs were fed a control corn and soybean meal diet or a diet in which 33%, 66%, or 100% of the corn in the control diet was replaced with hybrid rye. Average daily gain (ADG) and average daily feed intake (ADFI) decreased (linear, P < 0.05) in phase 1 with increased dietary inclusion of hybrid rye. In phase 3, gain:feed (G:F) increased and then decreased (quadratic, P < 0.05) with more hybrid rye in the diet. Overall ADG, ADFI, and G:F did not differ among treatments. Diet did not impact most carcass traits, but loin (visual) and backfat (instrumental L*) color were paler (linear, P < 0.05) with greater inclusion of hybrid rye in the diet. Organ weights increased (linear, P < 0.05) with increased dietary hybrid rye. In conclusion, pigs fed hybrid rye consumed less feed in phase 1, resulting in reduced ADG, but growth performance for the entire growing-finishing period did not differ among treatments. Hybrid rye may replace all the corn in growing and finishing pig diets without diminishing growth performance or carcass quality, but feed intake may be reduced at high inclusion rates.
Thyroid hormone suppression in feeder pigs following polymicrobial or porcine reproductive and respiratory syndrome virus-2 challenge
Authors: Pasternak J Alex , MacPhee Daniel J , Lunney Joan K , Rowland Raymond R R , Dyck Michael K , Fortin Frédéric , Dekkers Jack C M , Plastow Graham S , Harding John C S ,   PigGen Canada
Published: November 2021

Thyroid hormones are powerful regulators of growth, development, and basal metabolic rate and can be dysregulated under conditions of severe stress or illness. To understand the role of these hormones in porcine disease response, serum samples were obtained from three batches of nursery-aged pigs (n = 208) exposed to a natural polymicrobial disease challenge with an array of bacterial and viral pathogens. Levels of total thyroxin (T4) and triiodothyronine (T3) assessed in sera by radioimmunoassay, decreased significantly by 14 days post-exposure (DPE). Levels of T3 partially rebounded by 48 DPE, while T4 levels remain depressed. Post-exposure T3 and T4 levels were positively correlated with acute and long-term average daily gain (ADG). Cross-sectional sampling of animals maintained at the high health source farms, showed no equivalent change in either hormone when managed under standard industrial conditions. To further elucidate the effect of porcine reproductive and respiratory syndrome virus (PRRSV)-infection on thyroid hormone levels, archived sera over 42 days post inoculation (DPI) from nursery pigs (N = 190) challenged with one of two PRRSV2 strains by the PRRS Host Genetics Consortium were similarly assessed, with animals selected in a two-by-two design, to investigate biological extremes in ADG and viral load (VL). All animals showed a similar decrease in both thyroid hormones reaching a minimum at 7 DPI and returning to near pre-challenge levels by 42 DPI. Post-challenge T3 and T4 levels were significantly greater in high ADG groups, with no significant association with VL or strain. The results of this study demonstrate porcine susceptibility to thyroid disruption in response to disease challenge and demonstrate a relationship between this response and growth performance.