bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-stage crash process in resistive drift ballooning mode driven ELM crash
Authors: Seto H. , Xu X. Q. , Dudson B. D. , Yagi M.
Published: March 2024

We report a two-stage crash process in edge localized mode (ELM) driven by resistive drift-ballooning modes (RDBMs) numerically simulated in a full annular torus domain with a scale-separated four-field reduced MHD (RMHD) model using the BOUT++ framework. In the early nonlinear phase, the small first crash is triggered by linearly unstable RDBMs, and m/n=2/1 magnetic islands are nonlinearly excited by nonlinear coupling of RDBMs as well as their higher harmonics. Here, m is the poloidal mode number, n is the toroidal mode number, the q = 2 rational surface exists near the pressure gradient peak, and q is the safety factor. Simultaneously, middle-n RDBM turbulence develops but is poloidally localized around X-points of the magnetic islands, leading to the small energy loss. The second large crash occurs in the late nonlinear phase. Higher harmonics of m/n=2/1 magnetic islands well develop around the q = 2 surface via nonlinear coupling and make the magnetic field stochastic by magnetic island overlapping. Turbulence heat transport develops at X-points of higher harmonics of m/n=2/1 magnetic islands, resulting in the turbulence spreading in the poloidal direction. The large second crash is triggered when the turbulence covers the whole poloidal region so that the magnetic island generation and magnetic field stochastization before the large crash can be interpreted as ELM precursors. It is concluded that the ELM trigger is attributed to the turbulent spreading in the poloidal direction in synchronization with the magnetic field stochastization and the crash is driven by E × B convection rather than the conventional Rechester–Rosenbluth anomalous electron heat transport.
Research on tradable green certificate contracts under the renewable portfolio standard
Authors: Lingzhi Ren , Ning Yi , Zhanghua Chen , Zhiying Li , Hui Wang , Xiaopeng Li
Published: March 2024

The implementation of renewable portfolio standards inevitably affects the strategic behavior and performance of tradable green certificate (TGC) market participants and brings policy risks and market risks. Contract is considered an effective governance tool to avoid the risks of TGC trading and helps TGC market participants to make scientific decisions. The article built a TGC contract model while considering the uncertainty of TGC supply and demand and provided a scientific analysis for designing TGC contracts. Finally, a numerical example was given to verify the optimal solution of the TGC contract model. The main results of this study are as follows: (1) higher electricity retail price could contribute to increasing the optimal trading volume and price of the TGC contract; (2) an increase in the wholesale price of electricity could decrease the optimal trading price of the TGC contract, but its impact on the optimal trading volume depends on the quota ratio designed by the government; (3) the impact of unit fines on the TGC contract is completely different from that of a lower price limit, where a low unit penalty and a high lower price limit for the TGC trading system could improve the trading volume of the TGC contract while reducing its price; and (4) transaction costs inhibit the trading volume of TGC contracts, but the impact on the optimal price depends on the size of transaction costs shared by different market participants; the transaction costs should be equally borne between the different market participants in order to eliminate the impact of transaction costs on the trading price of the TGC contract.
Spatial control of hybridization-induced spin-wave transmission stop band
Authors: Vilsmeier Franz , Riedel Christian , Back Christian H.
Published: March 2024

Spin-wave (SW) propagation close to the hybridization-induced transmission stop band is investigated within a trapezoid-shaped 200 nm thick yttrium iron garnet film using time-resolved magneto-optic Kerr effect microscopy and broadband spin-wave spectroscopy, supported by micromagnetic simulations. The gradual reduction of the effective field within the structure leads to local variations of the SW dispersion relation and results in a SW hybridization at a fixed position in the trapezoid where the propagation vanishes, since the SW group velocity approaches zero. By tuning external field or frequency, spatial control of the spatial stop band position and spin-wave propagation is demonstrated and utilized to gain transmission control over several microstrip lines.
A comparative study of impact ionization and avalanche multiplication in InAs, HgCdTe, and InAlAs/InAsSb superlattice
Authors: Tempel S. , Winslow M. , Kodati S. H. , Lee S. , Ronningen T. J. , Krishna S. , Krishnamurthy S. , Grein C. H.
Published: March 2024

We use an ensemble Monte Carlo transport approach to calculate and compare the impact ionization and avalanche photodiode excess noise characteristics in three materials—a band-engineered InAlAs/InAsSb type-II superlattice, bulk InAs, and HgCdTe—all with an identical bandgap of 370 meV at 250 K. The electronic band structures and energy–momentum conservation conditions are used to calculate the impact ionization rates, carrier histories, multiplication gains, and excess noise characteristics. The calculated impact ionization coefficients and excess noise factors indicate a single carrier species multiplication in all three materials under low applied electric fields. We find the ratio of impact ionization coefficients to be k=7×10−4 for InAs and 3×10−4 for HgCdTe under an applied field of 50 kV/cm, and the superlattice to be k<10−6 at fields up to 400 kV/cm. The bulk materials experience avalanche breakdown as the applied field increases, transitioning to Geiger mode behavior at gains above 103 for InAs and 104 for HgCdTe. However, this breakdown is absent from the superlattice at the highest fields considered in this study due to hole confinement, indicating superior performance compared to the bulk materials. Our results demonstrate the role of superlattice band engineering in designing quality avalanche photodiode materials.
Reducing reflection of down-shifting solar cells through scattering by particles
Authors: Diao Han , Lou Chaogang , Song Guoxiang , Zhu Ruiqi
Published: March 2024

The improvement of down-shifting solar cells through reducing the reflection in short wavelength range by scattering is investigated experimentally and theoretically. Such down-shifting solar cells are fabricated by doping Y2O3 particles into down-shifting ethylene vinyl acetate films with CaAlSiN3:Eu2+ phosphors. Experimental results show that the scattering of Y2O3 particles can reduce the reflection of the down-shifting solar cells in the wavelength below 450 nm. It can be attributed to two reasons. The first is that the backscattering in the short wavelength is weaker than that in the middle and long wavelength. The second is that the scattering by Y2O3 particles allows more light reach the phosphors and increases their absorption. This means that more photons with poor spectral responses can be converted into the photons with better spectral responses. This work provides a way to realize simultaneously strengthening the down-shifting effect and suppressing the phosphor-induced reflection and can be used to further improve the down-shifting solar cells.
An improved theoretical model for the dynamics and stability of a vertical cantilevered pipe aspirating fluid
Authors: Ma Yongqi , Shen Yijun , Feng Aichun , You Yunxiang , Du Yanlian
Published: March 2024

In this paper, a new theoretical model for the dynamics and stability of a vertical cantilevered aspirating pipe is developed based on the Newtonian method. The effects of the hydrodynamic forces at the free end on the dynamics and stability of the cantilevered pipe are examined in detail. A new comprehensive governing equation is discretized using the Galerkin method. Numerical results are presented to demonstrate the effects of the axial flow velocity ratio, flow angle ratio, and tangential velocity ratio on the eigenfrequency and critical velocity of the cantilevered pipe system. The theoretical model results are also found to be in good quantitative agreement with experimental results.
Twin peaks: Matrix isolation studies of H2S·amine complexes shedding light on fundamental S–H⋯N bonding
Authors: Graneri Matthew H. V. , Spagnoli Dino , Wild Duncan A. , McKinley Allan J.
Published: March 2024

Noncovalent bonding between atmospheric molecules is central to the formation of aerosol particles and cloud condensation nuclei and, consequently, radiative forcing. While our understanding of O–H⋯B interactions is well developed, S–H⋯B hydrogen bonding has received far less attention. Sulfur- and nitrogen-containing molecules, particularly amines, play a significant role in atmospheric chemistry, yet S–H⋯N interactions are not well understood at a fundamental level. To help characterize these systems, H2S and methyl-, ethyl-, n-propyl-, dimethyl-, and trimethylamine (MA, EA, n-PA, DMA, and TMA) have been investigated using matrix isolation Fourier transform infrared spectroscopy and high-level theoretical methods. Experiments showed that H2S forms hydrogen bonded complexes with each of the amines, with bond strengths following the trend MA ≈ EA ≈ n-PA < TMA ≤ DMA, in line with past experimental work on H2SO4·amine complexes. However, the calculated results indicated that the trend should be MA < DMA < TMA, in line with past theoretical work on H2SO4·amine complexes. Evidence of strong Fermi resonances indicated that anharmonicity may play a critical role in the stabilization of each complex. The theoretical results were able to replicate experiment only after binding energies were recalculated to include the anharmonic effects. In the case of H2SO4·amine complexes, our results suggest that the discrepancy between theory and experiment could be reconciled, given an appropriate treatment of anharmonicity.
An ultracompact scanning tunneling microscope within a Φ 10 piezo tube in a 20 T superconducting magnet
Authors: Zhang Min , Wang Jihao , Meng Wenjie , Zhang Jing , Feng Qiyuan , Wang Ze , Lu Yalin , Hou Yubin , Lu Qingyou
Published: March 2024

Low-temperature scanning tunneling microscopy and spectroscopy (STM/S) help to better understand the fundamental physics of condensed matter. We present an ultracompact STM within a Φ 10 piezo tube in a 20 T superconducting magnet. The carefully cut piezo tube contains the STM’s coarse-positioning assembly. Loading an STM tip–sample mechanical loop into the piezo tube with special cut openings enables an ultracompact pencil-size dimension down to Φ 10 mm, in which fine-machined nonmagnetic parts are assembled to enable slide–stick motion and xyz-scanning procedures. The small size leads to a higher resonant frequency, a typical feature of a rigid STM instrument, increasing its vibration immunity. Scanning by moving the sample while keeping the tip stationary improves the stability of the tip–sample junction compared to moving the tip. Taking advantage of its high-field compatibility and rigid design, our STM captures the atomically resolved topography of highly oriented pyrolytic graphite (HOPG) at 1.5 K and in magnetic fields up to 17 T. The topography of graphene lattice and graphite is simultaneously recorded on an atomic terrace of HOPG, unveiling a modified local charge density at a surface defect. The superconducting energy gaps of layered type-II superconductors NbSe2 and PdBi2 are well resolved through dI/dV tunneling spectra at sub-2 K. Our unique STM is highly suitable for potential STM/S applications in world-class high-field facilities where the strong magnetic field can exceed 30 T.
Flow instability of an axial flow pump-as-turbine using relative streamline coordinates
Authors: Kan Kan , Zhang Qingying , Feng Jiangang , Zheng Yuan , Xu Hui , Rossi Mosè , Li Haoyu
Published: March 2024

When axial flow pumps-as-turbines (PATs) operate under off-design conditions, unstable and unsteady flow structures appear in the internal flow field, resulting in suboptimal functioning. These operating conditions not only decrease the efficiency of the hydraulic machines but also affect their mechanical reliability. This study establishes relative streamline coordinates, based on the blade's mean camber line, to investigate flow instabilities in axial flow PATs from a new perspective. Numerical simulations on an axial flow PAT were performed and validated using experimental data. The results show that flow separation is more likely to occur due to the more curved profile at the blade's suction surface, leading to considerable fluctuations in velocity along the flow direction and enstrophy amplitude near both the hub and impeller shroud. Moreover, the poor matching of the relative inflow angle of the impeller with the blade inlet angle leads to impingement losses near their leading edge, generating unstable flows and significant pressure pulsations, which induces hydraulic instability within the impeller. In addition to rotor-stator interference effects, the curvature of the blade suction surface profile and the bend structure of inlet conduit are significant factors that influence the pressure pulsation distribution of the PAT. An analysis of the enstrophy transport equation indicates that the relative vortex generation and the Reynolds stress dissipation terms play a key role in both vortex generation and dissipation, whereas the viscous term has a lower influence. These findings can serve as a reference for the optimization and efficient design of axial flow PATs.
Structural dynamics around a hydrogen bond: Investigating the effect of hydrogen bond strengths on the excited state dynamics of carboxylic acid dimers
Authors: Plackett E. , Robertson C. , De Matos Loja A. , McGhee H. , Karras G. , Sazanovich I. V. , Ingle R. A. , Paterson M. J. , Minns R. S.
Published: March 2024

The photochemical dynamics of the acetic acid and trifluoro-acetic acid dimers in hexane are studied using time-resolved infrared absorption spectroscopy and ab initio electronic structure calculations. The different hydrogen bond strengths of the two systems lead to changes in the character of the accessed excited states and in the timescales of the initial structural rearrangement that define the early time dynamics following UV excitation. The much stronger hydrogen bonding in the acetic acid dimer stabilizes the system against dissociation. Ground state recovery is mediated by a structural buckling around the hydrogen bond itself with no evidence for excited state proton transfer processes that are usually considered to drive ultrafast relaxation processes in hydrogen bonded systems. The buckling of the ring leads to relaxation through two conical intersections and the eventual reformation of the electronic and vibrational ground states on a few picosecond timescale. In trifluoro-acetic acid, the weaker hydrogen bonding interaction means that the dimer dissociates under similar irradiation conditions. The surrounding solvent cage restricts the full separation of the monomer components, meaning that the dimer is reformed and returns to the ground state structure via a similar buckled structure but over a much longer, ∼100 ps, timescale.
Numerical study on aerodynamic and noise performance of bionic asymmetric airfoil with surface grooves
Authors: Wen Mingjun , Wu Liming
Published: March 2024

Based on the asymmetric NACA4412 baseline airfoil, a bionic airfoil with surface grooves is presented. For the bio-inspired airfoil, non-smooth grooves are placed on the trailing edge of NACA4412 airfoil. To reveal the effects of non-smooth structures of the trailing edge on the aerodynamic and noise performance of airfoil, large eddy simulation and Ffowcs Williams–Hawkings acoustic analogy are adopted to investigate the aerodynamic performance and acoustic characteristics of the baseline NACA4412 airfoil and bionic airfoil at the chord-based Reynolds number, Re = 1.2 ×105. The numerical results show that the aerodynamic performance of the bionic airfoil is better than that of the baseline airfoil when the angle of attack is 14°. For all the sound frequencies studied in this study, the overall sound pressure level of the bionic airfoil is reduced by 2.0 dB at angle of attack is 14°. At the same time, the mechanisms of flow control and noise reduction of non-smooth surface grooves at the trailing edge are also revealed. As a result, the presence of surface grooves near the trailing edge of the airfoil can effectively improve the aerodynamic performance and reduce the aerodynamic noise of the traditional asymmetric airfoil, especially at high angles of attack.
The impact of operating temperatures on the fluctuating flow field and precessing vortex core in cyclone separator using large-eddy simulations
Authors: Brar Lakhbir Singh , Rahmani Faisal
Published: March 2024

The present study evaluates numerically the impact of the operating temperature of gas on the cyclone performance viz. the pressure drop, collection efficiency, and flow field details at an inlet velocity, Uin=15 m/s. The gas temperature in a range of 273–1073 K is considered to significantly vary the fluid density and viscosity. For an in-depth analysis, we use advanced closure large-eddy simulation (LES) with the standard Smagorinsky model for treating the unresolved scales. LES can accurately provide additional details on the precessing vortex core phenomena that give rise to enhanced fluctuations in the core region of the cyclone. Apart from the traditional fast Fourier transformation analysis to evaluate the periodicity in the signal, we also perform continuous wavelet transformation and empirical mode decomposition operation on the temporal velocity signals for a better understanding of the flow instabilities—the signals reveal variations of frequency components with time, indicating a non-stationary behavior. It has been observed that an increase in the gas temperature causes lateral contraction of the inner vortex followed by the reduction in its precessional frequency about the cyclone axis with a significantly increased level of noise in the spectra. Furthermore, both pressure losses and collection efficiency largely reduce due to the weakening of swirling strength and enhancement in the fluctuating velocity components with an increase in the gas temperature.
Wavelet-based photoacoustic viscoelastographic microscopy using photoacoustic damped oscillation effect
Authors: Liu Yang , Zou Zilong , Wang Simin , Tao Chao , Hu Zizhong , Liu Xiaojun
Published: March 2024

Viscoelastic characterization of biological tissue has significant biomedical value. In this study, we propose a wavelet-based photoacoustic viscoelastographic microscopy to characterize the viscoelasticity of tissues beneath the optical scattering depth from photoacoustic oscillation signals. Irradiated by laser pulses, biological tissue absorbs energy, expands, continues oscillating, and emits damped transient ultrasonic waves, i.e., photoacoustic oscillation signals, for a short time. A damped oscillation wavelet is applied to map photoacoustic oscillation signals into a representation of time, frequency, and decay rate. We can evaluate the frequency and decay rate of the photoacoustic oscillation signals. By considering the interrelationships among frequency, decay rate, shear modulus, and shear viscosity coefficient, we can generate images that depict the shear modulus image and shear viscosity coefficient image within the tissue. These images of the shear modulus and shear viscosity coefficient collectively form the viscoelastogram of the tissue, offering a comprehensive portrayal of its viscoelastic properties. Our study has potential biomedical value and may improve the accurate diagnosis of diseases and achieve more effective early interventions.
Self-assembly plasmonic gold nanoribbons on few-layer PtSe2 under femtosecond laser irradiation
Authors: Chu Lingrui , Zhu Han , Lv Hengyue , Juodkazis Saulius , Chen Feng
Published: March 2024

Functional two-dimensional (2D) materials have been extensively explored for a wide range of applications such as energy generation, low-power computing, and biosensing. In this work, we present an approach involving the integration of six-layer platinum diselenide (PtSe2) as an interlayer between the thin gold film and SiO2 substrate to induce spontaneous formation of plasmonic nanostructures (nanoribbons) on the upper gold film (∼8 nm) under 1030 nm femtosecond laser irradiation. The formation of periodic nanostructures is attributed to the periodic energy deposition that occurs in the PtSe2 layers under intense femtosecond laser pulses. Notably, the self-assembled gold nanostructures exhibit a distinctive polarization-dependent plasmonic response in the near-infrared spectral region and could be directly fabricated in a centimeter scale within several minutes. This straightforward method for self-assembling plasmonic nanostructures using layered materials may expand the utility of functional 2D materials and advance the cost-effective and large-area fabrication of plasmonic thin-film nanostructures in a simplified manner.
Over 20% wall plug efficiency of on-wafer GaN-based vertical-cavity surface-emitting laser
Authors: Watanabe Ruka , Kobayashi Kenta , Yanagawa Mitsuki , Takeuchi Tetsuya , Kamiyama Satoshi , Iwaya Motoaki , Kamei Toshihiro
Published: March 2024

We demonstrated an over 20% wall plug efficiency of an on-wafer GaN-based vertical-cavity surface-emitting laser (VCSEL) with a 5 μm aperture. The cavity length of the VCSEL was 4λ optical length, containing a 3.7λ part of GaN-based layers controlled with an in situ reflectivity spectra measurement and a 0.3λ part of an ITO electrode and a Nb2O5 spacer layer adjusted with an ex situ measurement. In order to calibrate the thickness of ITO and N2O5, we directly evaluated resonance wavelength shifts of a 4λ GaN cavity test structure with additional ITO or N2O5 depositions on the cavity. We then fabricated GaN-based VCSELs with various aperture sizes from 5 to 20 μm by implementing the tuned ITO electrode and the tuned N2O5 spacer layer into the 4λ cavity of the VCSELs. The GaN-based VCSEL with an 8 μm aperture showed a light output power of 13.1 mW and an emission wavelength of 417.7 nm, which was only a 0.3 nm away from a designed wavelength.
Exploring the boundary layer transition of hypersonic flow over a compound delta wing
Authors: Ullah Habib , Qiu Hongtian , Yu Ganglong , Ijaz Khan M. , Lee Cunbiao
Published: March 2024

The boundary layer transition on a compound delta wing for Mach 6 has been studied experimentally and numerically. The experiment was performed at Peking University quiet wind tunnel using the Rayleigh scattering flow visualization and infrared thermography. Direct numerical simulations, under the same flow conditions, are applied to analyze the transition mechanism. The results show that the traveling cross flow vortices first appear near the leading edge of compound delta wing. These vortices modulate the mean profile of the flow due to which a rope-like structure appear in the streamwise direction, which is typical of Mack's second-mode. As Mack's second-mode grows to a sufficiently large amplitude, it triggers secondary instability, which behaves as secondary finger like structures. At the end of the transition process, low-frequency waves are excited by Mack's second-mode through an interaction mechanism with their phase speed approaching each other. It is also found that increasing the unit Reynolds number greatly promotes the aerodynamic heating as well as local hot streaks appear on both sides of the compound delta wing in the streamwise direction. The appearance of hot streaks on the compound delta wing is strongly correlated with Mack's second-mode.
Force-induced tail-autotomy mitochondrial fission and biogenesis of matrix-excluded mitochondrial-derived vesicles for quality control
Authors: Liu Xiaoying , Xu Linyu , Song Yutong , Zhao Zhihao , Li Xinyu , Wong Cheuk-Yiu , Chen Rong , Feng Jianxiong , Gou Yitao , Qi Yajing , Chow Hei-Man , Yao Shuhuai , Wang Yi , Gao Song , Liu Xingguo , Duan Liting
Published: March 2024

Mitochondria constantly fuse and divide for mitochondrial inheritance and functions. Here, we identified a distinct type of naturally occurring fission, tail-autotomy fission, wherein a tail-like thin tubule protrudes from the mitochondrial body and disconnects, resembling autotomy. Next, utilizing an optogenetic mitochondria-specific mechanostimulator, we revealed that mechanical tensile force drives tail-autotomy fission. This force-induced fission involves DRP1/MFF and endoplasmic reticulum tubule wrapping. It redistributes mitochondrial DNA, producing mitochondrial fragments with or without mitochondrial DNA for different fates. Moreover, tensile force can decouple outer and inner mitochondrial membranes, pulling out matrix-excluded tubule segments. Subsequent tail-autotomy fission separates the matrix-excluded tubule segments into matrix-excluded mitochondrial-derived vesicles (MDVs) which recruit Parkin and LC3B, indicating the unique role of tail-autotomy fission in segregating only outer membrane components for mitophagy. Sustained force promotes fission and MDV biogenesis more effectively than transient one. Our results uncover a mechanistically and functionally distinct type of fission and unveil the role of tensile forces in modulating fission and MDV biogenesis for quality control, underscoring the heterogeneity of fission and mechanoregulation of mitochondrial dynamics.
The β2-adrenergic receptor associates with CXCR4 multimers in human cancer cells
Authors: Liang Junyi , Seghiri Mohamed , Singh Pradeep Kumar , Seo Hyeon Gyu , Lee Ji Yeong , Jo Yoonjung , Song Yong Bhum , Park Chulo , Zalicki Piotr , Jeong Jae-Yeon , Huh Won-Ki , Caculitan Niña G. , Smith Adam W.
Published: March 2024

While the existence and functional role of class C G-protein-coupled receptors (GPCR) dimers is well established, there is still a lack of consensus regarding class A and B GPCR multimerization. This lack of consensus is largely due to the inherent challenges of demonstrating the presence of multimeric receptor complexes in a physiologically relevant cellular context. The C-X-C motif chemokine receptor 4 (CXCR4) is a class A GPCR that is a promising target of anticancer therapy. Here, we investigated the potential of CXCR4 to form multimeric complexes with other GPCRs and characterized the relative size of the complexes in a live-cell environment. Using a bimolecular fluorescence complementation (BiFC) assay, we identified the β2 adrenergic receptor (β2AR) as an interaction partner. To investigate the molecular scale details of CXCR4-β2AR interactions, we used a time-resolved fluorescence spectroscopy method called pulsed-interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS). PIE-FCCS can resolve membrane protein density, diffusion, and multimerization state in live cells at physiological expression levels. We probed CXCR4 and β2AR homo- and heteromultimerization in model cell lines and found that CXCR4 assembles into multimeric complexes larger than dimers in MDA-MB-231 human breast cancer cells and in HCC4006 human lung cancer cells. We also found that β2AR associates with CXCR4 multimers in MDA-MB-231 and HCC4006 cells to a higher degree than in COS-7 and CHO cells and in a ligand-dependent manner. These results suggest that CXCR4-β2AR heteromers are present in human cancer cells and that GPCR multimerization is significantly affected by the plasma membrane environment.
Quantum correlation and squeezing in pulses propagating in dispersion oscillating fibers
Authors: I Konyukhov Andrey , G Konyukhova Julia , A Melnikov Leonid
Published: March 2024

We consider the squeezing and correlation of quantum fluctuations in pulse pairs arising due to soliton fission in dispersion oscillating fibers. The dispersion oscillation acts as a time-domain pulse splitter. After the split, the pulses interact via their tails and acquire nonzero correlations. We analyze the correlation pattern using Karhunen–Loève mode expansion. The regime of high intrapulse and interpulse correlations can be described using single Karhunen–Loève mode. The regime with partial pulse-to-pulse correlation requires to take into account at least two Karhunen–Loève modes. We found that the soliton fission in dispersion oscillating fibers allows to generate squeezed states with highly correlated fluctuations in the output pulses.
The geometry of photopolymerized topography influences neurite pathfinding by directing growth cone morphology and migration
Authors: Vecchi Joseph T , Rhomberg Madeline , Guymon C Allan , Hansen Marlan R
Published: March 2024

Objective. Cochlear implants provide auditory perception to those with severe to profound sensorineural hearing loss: however, the quality of sound perceived by users does not approximate natural hearing. This limitation is due in part to the large physical gap between the stimulating electrodes and their target neurons. Therefore, directing the controlled outgrowth of processes from spiral ganglion neurons (SGNs) into close proximity to the electrode array could provide significantly increased hearing function. Approach. For this objective to be properly designed and implemented, the ability and limits of SGN neurites to be guided must first be determined. In this work, we engineer precise topographical microfeatures with angle turn challenges of various geometries to study SGN pathfinding and use live imaging to better understand how neurite growth is guided by these cues. Main Results. We find that the geometry of the angled microfeatures determines the ability of neurites to navigate the angled microfeature turns. SGN neurite pathfinding fidelity is increased by 20%–70% through minor increases in microfeature amplitude (depth) and by 25% if the angle of the patterned turn is made obtuse. Further, we see that dorsal root ganglion neuron growth cones change their morphology and migration to become more elongated within microfeatures. Our observations also indicate complexities in studying neurite turning. First, as the growth cone pathfinds in response to the various cues, the associated neurite often reorients across the angle topographical microfeatures. Additionally, neurite branching is observed in response to topographical guidance cues, most frequently when turning decisions are most uncertain. Significance. Overall, the multi-angle channel micropatterned substrate is a versatile and efficient system to assess neurite turning and pathfinding in response to topographical cues. These findings represent fundamental principles of neurite pathfinding that will be essential to consider for the design of 3D systems aiming to guide neurite growth in vivo.
Ecological transition for the gas mixtures of the MRPC cosmic ray telescopes of the EEE Project
Authors: Ripoli C. , Abbrescia M. , Avanzini C. , Baldini L. , Baldini Ferroli R. , Batignani G. , Battaglieri M. , Boi S. , Bossini E. , Carnesecchi F. , Cavazza D. , Cicalò C. , Cifarelli L. , Coccetti F. , Coccia E. , Corvaglia A. , De Gruttola D. , De Pasquale S. , Galante L. , Garbini M. , Gnesi I. , Grazzi S. , Hatzifotiadou D. , La Rocca P. , Liu Z. , Lombardo L. , Mandaglio G. , Margotti A. , Maron G. , Mazziotta M.N. , Mulliri A. , Nania R. , Noferini F. , Nozzoli F. , Palmonari F. , Panareo M. , Panetta M.P. , Paoletti R. , Parvis M. , Pellegrino C. , Perasso L. , Pinazza O. , Pinto C. , Pisano S. , Riggi F. , Righini G. , Rizzi M. , Sartorelli G. , Scapparone E. , Schioppa M. , Scioli G. , Scribano A. , Selvi M. , Taiuti M. , Terreni G. , Trifirò A. , Trimarchi M. , Vistoli C. , Votano L. , Williams M.C.S. , Zichichi A. , Zuyeuski R.
Published: March 2024

The Extreme Energy Events (EEE) Collaboration is fully involved in an ecological transition. The use of the standard gas mixture, C2H2F4 + SF6, has stopped in favor of an alternative green mixture based on C3H2F4 with the addition of He or CO2.
The choise of these new mixtures is motivated by the significant lower Global Warming Potential (GWP) to reduce the emission of gases potentially contributing to the greenhouse effect.
The EEE experiment consists of 61 muon telescopes based on Multigap Resistive Plate Chambers (MRPCs), each telescope composed of 3 chambers filled with gas.
Several EEE detectors are today completely fluxed with the new ecological mixture. This contribution will report recent results about the telescope performance obtained from studies with the eco-friendly alternative mixture carried out in the last years.
How well does the implementation of corporate zero-deforestation commitments in Indonesia align with aims to halt deforestation and include smallholders?
Authors: Chandra Adelina , Garrett Rachael D , Carlson Kimberly M , Heilmayr Robert , Stigler Matthieu , Benedict Jason J , Grabs Janina
Published: March 2024

In response to growing scrutiny surrounding commodity-driven deforestation, companies have introduced zero-deforestation commitments (ZDCs) with ambitious environmental and social targets. However, such initiatives may not effectively reduce deforestation if they are not aligned with the spatial extent of remaining forests at risk. They may also fail to avert socio-economic risks if ZDCs do not consider smallholder farmers’ needs. We assess the spatial and functional fit of ZDCs by mapping commodity-driven deforestation and socio-economic risks, and comparing them to the spatial coverage and implementation of ZDCs in the Indonesian palm oil sector. Our study finds that companies’ ZDCs often underperform in four areas: traceability, compliance support for high-risk palm oil mills, transparency, and smallholder inclusion. In 2020, only one-third of companies sourcing from their own mills, and just 6% of those sourcing from external suppliers, achieved full traceability to plantations. Comparing the reach of ZDCs adopted by downstream buyers with those adopted by mill owners located further upstream, we find that high-quality ZDCs from buyers covered 62% of forests at risk, while mill owners’ ZDCs only covered 23% of forests at risk within the mill supply base. In Kalimantan and Papua, the current and future deforestation frontiers, the forests most at risk of conversion were predominantly covered by weak ZDCs lacking in policy comprehensiveness and implementation. Additionally, we find that only 46% of independent smallholder oil palm plots are in mill supply sheds whose owners offer programs and support for independent smallholders, indicating that smallholder inclusion is a significant challenge for ZDC companies. These results highlight the lack of spatial and functional alignment between supply chain policies and their local context as a significant gap in ZDC implementation and a challenge that the EU Deforestation Regulation will face.
Evaluating the impact of peat soils and snow schemes on simulated active layer thickness at pan-Arctic permafrost sites
Authors: Tao Jing , Riley William J , Zhu Qing
Published: March 2024

Permafrost stability is significantly influenced by the thermal buffering effects of snow and active-layer peat soils. In the warm season, peat soils act as a barrier to downward heat transfer mainly due to their low thermal conductivity. In the cold season, the snowpack serves as a thermal insulator, retarding the release of heat from the soil to the atmosphere. Currently, many global land models overestimate permafrost soil temperature and active layer thickness (ALT), partially due to inaccurate representations of soil organic matter (SOM) density profiles and snow thermal insulation. In this study, we evaluated the impacts of SOM and snow schemes on ALT simulations at pan-Arctic permafrost sites using the Energy Exascale Earth System Model (E3SM) land model (ELM). We conducted simulations at the Circumpolar Active Layer Monitoring (CALM) sites across the pan-Arctic domain. We improved ELM-simulated site-level ALT using a knowledge-based hierarchical optimization procedure and examined the effects of precipitation-phase partitioning methods (PPMs), snow compaction schemes, and snow thermal conductivity schemes on simulated snow depth, soil temperature, ALT, and CO2 fluxes. Results showed that the optimized ELM significantly improved agreement with observed ALT (e.g. RMSE decreased from 0.83 m to 0.15 m). Our sensitivity analysis revealed that snow-related schemes significantly impact simulated snow thermal insulation levels, soil temperature, and ALT. For example, one of the commonly used snow thermal conductivity schemes (quadratic Sturm or SturmQua) generally produced warmer soil temperatures and larger ALT compared to the other two tested schemes. The SturmQua scheme also amplified the model’s sensitivity to PPMs and predicted deeper ALTs than the other two snow schemes under both current and future climates. The study highlights the importance of accurately representing snow-related processes and peat soils in land models to enhance permafrost dynamics simulations.
The initial diversification of Greek dialects
Authors: Ringe Don
Published: March 2024

This chapter addresses the diversification of Greek into the attested groups of dialects. It demonstrates that a strict cladistic diversification cannot be proved—not surprisingly, as the Greek dialects remained in contact for centuries. But it also establishes that an Aiolic group and a South Greek group, both probably defined by changes spreading through a dialect continuum, are historically significant dialect groups. It is argued that West Greek and Arkado-Cyprian, by contrast, are conservative relic areas within Greek and South Greek respectively. Phonological and morphological evidence for each of these proposed groups is discussed. In addition, other widely shared phonological and morphological innovations are treated, especially the development of labiovelars and syllabic liquids. Finally, the relatively late creation of a preposition meaning ‘into’ is discussed.
Syntax
Authors: Ringe Don
Published: March 2024

This chapter discusses syntactic change in the prehistory and history of Ancient Greek. The most important change is a gradual shift in underlying constituent order spanning the whole attestation of Ancient Greek, which is outlined in some detail. Prohibitions are discussed in some detail because their structure might reveal something about the inherited verb system. Also discussed are the use of the moods, clitics, prepositions, univerbation of compound verbs, and the expression of reflexives.
Lexicon
Authors: Ringe Don
Published: March 2024

This chapter discusses the sources of the Ancient Greek lexicon. Innovations in derivational morphology are discussed first; then a look at the sources of the basic vocabulary of the language, using the Swadesh hundred-word list, is attempted.
Function and induction of the root barrier to radial O2 loss. A commentary on ‘Exogenous abscisic acid induces the formation of a suberized barrier to radial oxygen loss in adventitious roots of barley (Hordeum vulgare)’
Authors: Pedersen Ole , de la Cruz Jiménez Juan
Published: March 2024

This article comments on:

Katsuhiro Shiono and Haruka Matsuura, Exogenous abscisic acid induces the formation of a suberized barrier to radial oxygen loss in adventitious roots of barley (Hordeum vulgare), Annals of Botany, Volume 133, Issue 7, 6 June 2024, Pages 931–940 https://doi.org/10.1093/aob/mcae010
Review and meta-analysis of the genetic Minimal Cut Set approach for gene essentiality prediction in cancer metabolism
Authors: Olaverri-Mendizabal Danel , Valcárcel Luis V , Barrena Naroa , Rodríguez Carlos J , Planes Francisco J
Published: March 2024

Cancer metabolism is a marvellously complex topic, in part, due to the reprogramming of its pathways to self-sustain the malignant phenotype in the disease, to the detriment of its healthy counterpart. Understanding these adjustments can provide novel targeted therapies that could disrupt and impair proliferation of cancerous cells. For this very purpose, genome-scale metabolic models (GEMs) have been developed, with Human1 being the most recent reconstruction of the human metabolism. Based on GEMs, we introduced the genetic Minimal Cut Set (gMCS) approach, an uncontextualized methodology that exploits the concepts of synthetic lethality to predict metabolic vulnerabilities in cancer. gMCSs define a set of genes whose knockout would render the cell unviable by disrupting an essential metabolic task in GEMs, thus, making cellular proliferation impossible. Here, we summarize the gMCS approach and review the current state of the methodology by performing a systematic meta-analysis based on two datasets of gene essentiality in cancer. First, we assess several thresholds and distinct methodologies for discerning highly and lowly expressed genes. Then, we address the premise that gMCSs of distinct length should have the same predictive power. Finally, we question the importance of a gene partaking in multiple gMCSs and analyze the importance of all the essential metabolic tasks defined in Human1. Our meta-analysis resulted in parameter evaluation to increase the predictive power for the gMCS approach, as well as a significant reduction of computation times by only selecting the crucial gMCS lengths, proposing the pertinency of particular parameters for the peak processing of gMCS.
MIKE: an ultrafast, assembly-, and alignment-free approach for phylogenetic tree construction
Authors: Wang Fang , Wang Yibin , Zeng Xiaofei , Zhang Shengcheng , Yu Jiaxin , Li Dongxi , Zhang Xingtan
Published: March 2024

Motivation

Constructing a phylogenetic tree requires calculating the evolutionary distance between samples or species via large-scale resequencing data, a process that is both time-consuming and computationally demanding. Striking the right balance between accuracy and efficiency is a significant challenge.

Results

To address this, we introduce a new algorithm, MIKE (MinHash-based k-mer algorithm). This algorithm is designed for the swift calculation of the Jaccard coefficient directly from raw sequencing reads and enables the construction of phylogenetic trees based on the resultant Jaccard coefficient. Simulation results highlight the superior speed of MIKE compared to existing state-of-the-art methods. We used MIKE to reconstruct a phylogenetic tree, incorporating 238 yeast, 303 Zea, 141 Ficus, 67 Oryza, and 43 Saccharum spontaneum samples. MIKE demonstrated accurate performance across varying evolutionary scales, reproductive modes, and ploidy levels, proving itself as a powerful tool for phylogenetic tree construction.

Availability and implementation

MIKE is publicly available on Github at https://github.com/Argonum-Clever2/mike.git.
Characterizing barriers and facilitators of metabolic bariatric surgery tourism: a systematic review
Authors: Zuberi Sharukh , Egiz Abdullah , Iqbal Hasan , Jambulingam Periyathambi , Whitelaw Douglas , Adil Tanveer , Jain Vigyan , Al-Taan Omar , Munasinghe Aruna , Askari Alan , Aly Mohamed K , Iqbal Fahad M
Published: March 2024

Background

Metabolic bariatric surgery tourism continues to rise and has become a growing concern for bariatric surgeons globally. With varying degrees of regulation, counselling and success, those that develop complications may have to deal with a multitude of challenges often distant from their country of operation. The aim of this study was to characterize the barriers and facilitators influencing individuals to undergo metabolic bariatric surgery tourism, in order to better understand the implications to the National Health Service and other healthcare systems.

Methods

A systematic literature search, restricted to the English language, was performed to identify relevant studies. All studies were included until December 2022, the last search date. Study quality was assessed with the validated mixed-methods appraisal tool. A Braun and Clarke thematic analysis was undertaken to identify themes and subthemes.

Results

A total of five studies met the inclusion criteria. Identified themes included: availability, accessibility, cost, eligibility, reputation, and stigma; the available evidence was of varying quality.

Conclusion

This work identifies a series of subthemes influencing the decision to undertake metabolic bariatric surgery tourism. The results highlight the limited literature available in understanding the complex motivational insights; the scale of the problem in the current healthcare system; cost and long-term outcomes. A National Emergency Bariatric Surgery audit would allow generation of more robust data to explore further the issues of clinical relationships and networks and to guide policy making.
Adherence to general national dietary guidelines and risk of psoriasis: results from a general population study of 105 332 individuals
Authors: Näslund-Koch Charlotte , Kjeldsen Emilie W , Vedel-Krogh Signe , Bojesen Stig E , Skov Lone
Published: March 2024

Background

It is unknown if an unhealthy diet can affect the risk of developing psoriasis.

Objectives

To test the hypothesis that individuals with an unhealthy diet have an increased risk of prevalent and incident psoriasis.

Methods

We included 105 332 adults from the Copenhagen General Population Study, who were invited to participate between 2003 and 2015. The response rate was 43%. An unhealthy vs. healthy diet was defined according to adherence to general national dietary guidelines. The participants were grouped into three groups: low, intermediate and high adherence to general national dietary guidelines; this was based on information from a food frequency questionnaire. Identification of psoriasis was made using International Classification of Diseases codes.

Results

Of the 105 332 individuals, 580 had a diagnosis of psoriasis at the time of enrolment and 640 received a diagnosis during the median follow-up of 9 years. Risk of prevalent psoriasis increased according to nonadherence to general national dietary guidelines in a stepwise manner with an age- and sex-adjusted odds ratio of 1.70 (95% confidence interval 1.26–2.30) in individuals with low vs. high adherence to dietary guidelines. Results were similar in a multivariable-adjusted model. Prospective analyses adjusted for age and sex showed a weak association between nonadherence to dietary guidelines and risk of incident psoriasis (P for trend 0.04). This association disappeared, when adjusting for multiple confounders (P for trend 0.50).

Conclusions

Although individuals with psoriasis have an unhealthier diet, diet alone does not appear to independently increase the risk of developing psoriasis.
Technical considerations and sizing of external annuloplasty in the Ross procedure
Authors: Myjavec Andrej , Gofus Jan , Zacek Pavel , Vobornik Martin , Shahin Youssef , Vojacek Jan
Published: March 2024

Pure aortic regurgitation and dilation of aortic annulus are the most significant risk factors for the failure of pulmonary autograft after the Ross procedure. Aortic annuloplasty has a positive effect on the durability of the autograft. Previously, we described a technique for external annuloplasty with dedicated CORONEO ring. In the present manuscript, we suggest the sizing of annuloplasty based on the diameter of pulmonary autograft annulus.
Imagining an anti-racist pronunciation pedagogy
Authors: Ramjattan Vijay A
Published: March 2024

This article is an initial imagining of what an anti-racist pronunciation pedagogy (APP) might look like in ELT contexts such as immigrant employment training and international students studying in North American higher-education institutions. Three possible foci of an APP are briefly explored. First, this pedagogy helps students refuse the idea of the phonological superiority of the white native speaker. Furthermore, it reinforces intelligibility as a joint goal of both speaker and listener, thereby acknowledging how race and racism inform listener perceptions of speakers. Finally, an APP is an activist pedagogy that seeks to address institutionalized racism with regard to speech accent.