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1. Nectar, the original cocktail: an introduction to a Virtual Issue

   https://doi.org/10.1111/nph.70585  

   Gong, Yan; Kramer, Elena M; Liao, Irene T; Roy, Rahul (November 2025, New Phytologist)

   This Editorial introduces the Virtual Issue ‘Nectar and nectaries’ that includes the following papers: Ballarinet al.(2024), Griersonet al.(2024), Grof‐Tiszaet al.(2025), Landucci & Vannette (2025), Liaoet al.(2025), MacNeillet al.(2025), Magneret al.(2023, 2024, 2025), Minet al.(2019), Mouet al.(2025), Parkinsonet al.(2025), Quevedo‐Caraballoet al.(2025), Ramoset al.(2025), Romero‐Bravo & Castellanos (2024), Soareset al.(2025), Turneret al.(2025), Zhaiet al.(2025), Zhanget al.(2020). Access the Virtual Issue atwww.newphytologist.com/virtualissues. 

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2. (Digital Presentation) Oxide Memristors Based on SiO ₂ with Cu/Ag Alloy Metallization for Neuromorphic Computing

   https://doi.org/10.1149/MA2022-0215808mtgabs  

   Qin, Fei; Song, Han Wook; Qin, Fei (October 2022, ECS Meeting Abstracts)

   By mimicking biomimetic synaptic processes, the success of artificial intelligence (AI) has been astounding with various applications such as driving automation, big data analysis, and natural-language processing.[1-4] Due to a large quantity of data transmission between the separated memory unit and the logic unit, the classical computing system with von Neumann architecture consumes excessive energy and has a significant processing delay.[5] Furthermore, the speed difference between the two units also causes extra delay, which is referred to as the memory wall.[6, 7] To keep pace with the rapid growth of AI applications, enhanced hardware systems that particularly feature an energy-efficient and high-speed hardware system need to be secured. The novel neuromorphic computing system, an in-memory architecture with low power consumption, has been suggested as an alternative to the conventional system. Memristors with analog-type resistive switching behavior are a promising candidate for implementing the neuromorphic computing system since the devices can modulate the conductance with cycles that act as synaptic weights to process input signals and store information.[8, 9] The memristor has sparked tremendous interest due to its simple two-terminal structure, including top electrode (TE), bottom electrode (BE), and an intermediate resistive switching (RS) layer. Many oxide materials, including HfO₂, Ta₂O₅, and IGZO, have extensively been studied as an RS layer of memristors. Silicon dioxide (SiO₂) features 3D structural conformity with the conventional CMOS technology and high wafer-scale homogeneity, which has benefited modern microelectronic devices as dielectric and/or passivation layers. Therefore, the use of SiO₂as a memristor RS layer for neuromorphic computing is expected to be compatible with current Si technology with minimal processing and material-related complexities. In this work, we proposed SiO₂-based memristor and investigated switching behaviors metallized with different reduction potentials by applying pure Cu and Ag, and their alloys with varied ratios. Heavily doped p-type silicon was chosen as BE in order to exclude any effects of the BE ions on the memristor performance. We previously reported that the selection of TE is crucial for achieving a high memory window and stable switching performance. According to the study which compares the roles of Cu (switching stabilizer) and Ag (large switching window performer) TEs for oxide memristors, we have selected the TE materials and their alloys to engineer the SiO₂-based memristor characteristics. The Ag TE leads to a larger memory window of the SiO₂memristor, but the device shows relatively large variation and less reliability. On the other hand, the Cu TE device presents uniform gradual switching behavior which is in line with our previous report that Cu can be served as a stabilizer, but with small on/off ratio.[9] These distinct performances with Cu and Ag metallization leads us to utilize a Cu/Ag alloy as the TE. Various compositions of Cu/Ag were examined for the optimization of the memristor TEs. With a Cu/Ag alloying TE with optimized ratio, our SiO₂based memristor demonstrates uniform switching behavior and memory window for analog switching applications. Also, it shows ideal potentiation and depression synaptic behavior under the positive/negative spikes (pulse train). In conclusion, the SiO₂memristors with different metallization were established. To tune the property of RS layer, the sputtering conditions of RS were varied. To investigate the influence of TE selections on switching performance of memristor, we integrated Cu, Ag and Cu/Ag alloy as TEs and compared the switch characteristics. Our encouraging results clearly demonstrate that SiO₂with Cu/Ag is a promising memristor device with synaptic switching behavior in neuromorphic computing applications. Acknowledgement This work was supported by the U.S. National Science Foundation (NSF) Award No. ECCS-1931088. S.L. and H.W.S. acknowledge the support from the Improvement of Measurement Standards and Technology for Mechanical Metrology (Grant No. 22011044) by KRISS. References [1] Younget al.,IEEE Computational Intelligence Magazine,vol. 13, no. 3, pp. 55-75, 2018. [2] Hadsellet al.,Journal of Field Robotics,vol. 26, no. 2, pp. 120-144, 2009. [3] Najafabadiet al.,Journal of Big Data,vol. 2, no. 1, p. 1, 2015. [4] Zhaoet al.,Applied Physics Reviews,vol. 7, no. 1, 2020. [5] Zidanet al.,Nature Electronics,vol. 1, no. 1, pp. 22-29, 2018. [6] Wulfet al.,SIGARCH Comput. Archit. News,vol. 23, no. 1, pp. 20–24, 1995. [7] Wilkes,SIGARCH Comput. Archit. News,vol. 23, no. 4, pp. 4–6, 1995. [8] Ielminiet al.,Nature Electronics,vol. 1, no. 6, pp. 333-343, 2018. [9] Changet al.,Nano Letters,vol. 10, no. 4, pp. 1297-1301, 2010. [10] Qinet al., Physica Status Solidi (RRL) - Rapid Research Letters, pssr.202200075R1, In press, 2022. 

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3. Microscopic reversibility and emergent elasticity in ultrastable granular systems

   https://doi.org/10.3389/fphy.2022.1048683  

   Zhao, Yiqiu; Zhao, Yuchen; Wang, Dong; Zheng, Hu; Chakraborty, Bulbul; Socolar, Joshua E. (November 2022, Frontiers in Physics)

   In a recent paper (Zhao et al., Phys Rev X, 2022, 12: 031,021), we reported experimental observations of “ultrastable” states in a shear-jammed granular system subjected to small-amplitude cyclic shear. In such states, all the particle positions and contact forces are reproduced after each shear cycle so that a strobed image of the stresses and particle positions appears static. In the present work, we report further analyses of data from those experiments to characterize both global and local responses of ultrastable states within a shear cycle, not just the strobed dynamics. We find that ultrastable states follow a power-law relation between shear modulus and pressure with an exponentβ≈ 0.5, reminiscent of critical scaling laws near jamming. We also examine the evolution of contact forces measured using photoelasticimetry. We find that there are two types of contacts: non-persistent contacts that reversibly open and close; and persistent contacts that never open and display no measurable sliding. We show that the non-persistent contacts make a non-negligible contribution to the emergent shear modulus. We also analyze the spatial correlations of the stress tensor and compare them to the predictions of a recent theory of the emergent elasticity of granular solids, the Vector Charge Theory of Granular mechanics and dynamics (VCTG) (Nampoothiri et al., Phys Rev Lett, 2020, 125: 118,002). We show that our experimental results can be fit well by VCTG, assuming uniaxial symmetry of the contact networks. The fits reveal that the response of the ultrastable states to additional applied stress is substantially more isotropic than that of the original shear-jammed states. Our results provide important insight into the mechanical properties of frictional granular solids created by shear. 

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4. Are seven amino acid substitutions sufficient to explain the evolution of high l ‐DOPA 4,5‐dioxygenase activity leading to betalain pigmentation? Revisiting the gain‐of‐function mutants of Bean et al . (2018)

   https://doi.org/10.1111/nph.18981  

   Guerrero‐Rubio, M. Alejandra; Walker‐Hale, Nathanael; Guo, Rui; Sheehan, Hester; Timoneda, Alfonso; Gandia‐Herrero, Fernando; Brockington, Samuel F. (September 2023, New Phytologist)

   Summary This work revisits a publication by Beanet al.(2018) that reports seven amino acid substitutions are essential for the evolution ofl‐DOPA 4,5‐dioxygenase (DODA) activity in Caryophyllales. In this study, we explore several concerns which led us to replicate the analyses of Beanet al.(2018).Our comparative analyses, with structural modelling, implicate numerous residues additional to those identified by Beanet al.(2018), with many of these additional residues occurring around the active site of BvDODAα1. We therefore replicated the analyses of Beanet al.(2018) to re‐observe the effect of their original seven residue substitutions in a BvDODAα2 background, that is the BvDODAα2‐mut3 variant.Multiplein vivoassays, in bothSaccharomyces cerevisiaeandNicotiana benthamiana, did not result in visible DODA activity in BvDODAα2‐mut3, with betalain production always 10‐fold below BvDODAα1.In vitroassays also revealed substantial differences in both catalytic activity and pH optima between BvDODAα1, BvDODAα2 and BvDODAα2‐mut3 proteins, explaining their differing performancein vivo.In summary, we were unable to replicate thein vivoanalyses of Beanet al.(2018), and our quantitativein vivoandin vitroanalyses suggest a minimal effect of these seven residues in altering catalytic activity of BvDODAα2. We conclude that the evolutionary pathway to high DODA activity is substantially more complex than implied by Beanet al.(2018). 

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5. Conveyor-belt magneto-optical trapping of molecules

   https://doi.org/10.1088/1367-2630/adc032  

   Li, Grace K; Hallas, Christian; Doyle, John M (April 2025, New Journal of Physics)

   Abstract Laser cooling is used to produce ultracold atoms and molecules for quantum science and precision measurement applications. Molecules are more challenging to cool than atoms due to their vibrational and rotational internal degrees of freedom. Molecular rotations lead to the use of type-II transitions ( $F\text{⩾}{F}^{\prime }$) for magneto-optical trapping (MOT). When typical red detuned light frequencies are applied to these transitions, sub-Doppler heating is induced, resulting in higher temperatures and larger molecular cloud sizes than realized with the type-I MOTs most often used with atoms. To improve type-II MOTs, Jarviset al(2018Phys. Rev. Lett.120083201) proposed a blue-detuned MOT to be applied after initial cooling and capture with a red-detuned MOT. This was successfully implemented (Burauet al2023Phys. Rev. Lett.130193401; Jorapuret al2024Phys. Rev. Lett.132163403; Liet al2024Phys. Rev. Lett.132233402), realizing colder and denser molecular samples. Very recently, Hallaset al(2024 arXiv:2404.03636) demonstrated a blue-detuned MOT with a ‘1+2’ configuration that resulted in even stronger compression of the molecular cloud. Here, we describe and characterize theoretically the conveyor-belt mechanism that underlies this observed enhanced compression. We perform numerical simulations of the conveyor-belt mechanism using both stochastic Schrödinger equation and optical Bloch equation approaches. We investigate the conveyor-belt MOT characteristics in relation to laser parameters,g-factors and the structure of the molecule, and find that conveyor-belt trapping should be applicable to a wide range of laser-coolable molecules. 

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