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1. Individual differences and long-term consequences of tDCS augmented cognitive training

   Katz, B.; Au, J.; Buschkuehl, M.; Abagis, T.; Zabel, C.; Jaeggi, S.; Jonides, J. (October 2017, Journal of cognitive neuroscience)

   A gr e at d e al of i nt er e st s urr o u n d s t h e u s e of tr a n s cr a ni al dir e ct c urr e nt sti m ul ati o n (t D C S) t o a u g m e nt c o g niti v e tr ai ni n g. H o w e v er, eff e ct s ar e i n c o n si st e nt a cr o s s st u di e s, a n d m et aa n al yti c e vi d e n c e i s mi x e d, e s p e ci all y f o r h e alt h y, y o u n g a d ult s. O n e m aj or s o ur c e of t hi s i n c o n si st e n c y i s i n di vi d u al diff er e n c e s a m o n g t h e p arti ci p a nt s, b ut t h e s e diff er e n c e s ar e r ar el y e x a mi n e d i n t h e c o nt e xt of c o m bi n e d tr ai ni n g/ sti m ul ati o n st u di e s. I n a d diti o n, it i s u n cl e ar h o w l o n g t h e eff e ct s of sti m ul ati o n l a st, e v e n i n s u c c e s sf ul i nt er v e nti o n s. S o m e st u di e s m a k e u s e of f oll o w- u p a s s e s s m e nt s, b ut v er y f e w h a v e m e a s ur e d p erf or m a n c e m or e t h a n a f e w m o nt hs aft er a n i nt er v e nti o n. H er e, w e utili z e d d at a fr o m a pr e vi o u s st u d y of t D C S a n d c o g niti v e tr ai ni n g [ A u, J., K at z, B., B u s c h k u e hl, M., B u n arj o, K., S e n g er, T., Z a b el, C., et al. E n h a n ci n g w or ki n g m e m or y tr ai ni n g wit h tr a n scr a ni al dir e ct c urr e nt sti m ul ati o n. J o u r n al of C o g niti v e N e u r os ci e n c e, 2 8, 1 4 1 9 – 1 4 3 2, 2 0 1 6] i n w hi c h p arti ci p a nts tr ai n e d o n a w or ki n g m e m or y t as k o v er 7 d a y s w hil e r e c ei vi n g a cti v e or s h a m t D C S. A n e w, l o n g er-t er m f oll o w- u p t o a ss es s l at er p erf or m a n c e w a s c o n d u ct e d, a n d a d diti o n al p arti ci p a nt s w er e a d d e d s o t h at t h e s h a m c o n diti o n w a s b ett er p o w er e d. W e a s s e s s e d b a s eli n e c o g niti v e a bilit y, g e n d er, tr ai ni n g sit e, a n d m oti v ati o n l e v el a n d f o u n d si g nifi c a nt i nt er a cti o ns b et w e e n b ot h b as eli n e a bilit y a n d m oti v ati o n wit h c o n diti o n ( a cti v e or s h a m) i n m o d els pr e di cti n g tr ai ni n g g ai n. I n a d diti o n, t h e i m pr o v e m e nt s i n t h e a cti v e c o nditi o n v er s u s s h a m c o n diti o n a p p e ar t o b e st a bl e e v e n a s l o n g a s a y e ar aft er t h e ori gi n al i nt er v e nti o n. ■ 

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2. Sensitivity of resonance frequency in the detection of thin layer using nano-slit structures

   https://doi.org/10.1093/imamat/hxaa041  

   Lin, Junshan; Oh, Sang-Hyun; Zhang, Hai (November 2020, IMA Journal of Applied Mathematics)

   null (Ed.)

   Abstract We derive the formulas for the resonance frequencies and their sensitivity when the nano-slit structures are used in the detection of thin layers. For a thin layer with a thickness of $$H$$ deposited over the nanostructure, we show quantitatively that for both single and periodic slit structures with slit aperture size $$\delta $$, the sensitivity of resonance frequency reduces as $$H$$ increases. Specifically, the sensitivity is of order $$O(\delta /H)$$ if $$H>\delta $$ and of order $$O(1+\ln H/\delta )$$ otherwise. The evanescent wave modes are present along the interface between the thin dielectric film and ambient medium above. From the mathematical derivations, it is observed that the sensitivity of the resonance frequency highly depends on the effect of evanescent wave modes on the tiny slit apertures. 

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3. Unidirectional microwave transduction with chirality selected short-wavelength magnon excitations

   https://doi.org/10.1063/5.0156369  

   Li, Yi; Lo, Tzu-Hsiang; Lim, Jinho; Pearson, John E.; Divan, Ralu; Zhang, Wei; Welp, Ulrich; Kwok, Wai-Kwong; Hoffmann, Axel; Novosad, Valentine (July 2023, Applied Physics Letters)

   Nonreciprocal magnon propagation has recently become a highly potential approach of developing chip-embedded microwave isolators for advanced information processing. However, it is challenging to achieve large nonreciprocity in miniaturized magnetic thin-film devices because of the difficulty of distinguishing propagating surface spin waves along the opposite directions when the film thickness is small. In this work, we experimentally realize unidirectional microwave transduction with sub-micrometer-wavelength propagating magnons in a yttrium iron garnet (YIG) thin-film delay line. We achieve a non-decaying isolation of 30 dB with a broad field-tunable bandpass frequency range up to 14 GHz. The large isolation is due to the selection of chiral magnetostatic surface spin waves with the Oersted field generated from the coplanar waveguide antenna. Increasing the geometry ratio between the antenna width and YIG thickness drastically reduces the nonreciprocity and introduces additional magnon transmission bands. Our results pave the way for on-chip microwave isolation and tunable delay line with short-wavelength magnonic excitations. 

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4. Controlling the shape and topology of two-component colloidal membranes

   https://doi.org/10.1073/pnas.2204453119  

   Khanra, Ayantika; Jia, Leroy L.; Mitchell, Noah P.; Balchunas, Andrew; Pelcovits, Robert A.; Powers, Thomas R.; Dogic, Zvonimir; Sharma, Prerna (August 2022, Proceedings of the National Academy of Sciences)

   Changes in the geometry and topology of self-assembled membranes underlie diverse processes across cellular biology and engineering. Similar to lipid bilayers, monolayer colloidal membranes have in-plane fluid-like dynamics and out-of-plane bending elasticity. Their open edges and micrometer-length scale provide a tractable system to study the equilibrium energetics and dynamic pathways of membrane assembly and reconfiguration. Here, we find that doping colloidal membranes with short miscible rods transforms disk-shaped membranes into saddle-shaped surfaces with complex edge structures. The saddle-shaped membranes are well approximated by Enneper’s minimal surfaces. Theoretical modeling demonstrates that their formation is driven by increasing the positive Gaussian modulus, which in turn, is controlled by the fraction of short rods. Further coalescence of saddle-shaped surfaces leads to diverse topologically distinct structures, including shapes similar to catenoids, trinoids, four-noids, and higher-order structures. At long timescales, we observe the formation of a system-spanning, sponge-like phase. The unique features of colloidal membranes reveal the topological transformations that accompany coalescence pathways in real time. We enhance the functionality of these membranes by making their shape responsive to external stimuli. Our results demonstrate a pathway toward control of thin elastic sheets’ shape and topology—a pathway driven by the emergent elasticity induced by compositional heterogeneity. 

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5. Revisiting the Vertical Distribution of H i Absorbing Clouds in the Solar Neighborhood. II. Constraints from a Large Catalog of 21 cm Absorption Observations at High Galactic Latitudes

   https://doi.org/10.3847/1538-4357/ad79f7  

   Rybarczyk, Daniel R; Wenger, Trey V; Stanimirović, Snežana (October 2024, The Astrophysical Journal)

   The cold neutral medium (CNM) is where neutral atomic hydrogen (H I) is converted into molecular clouds, so the structure and kinematics of the CNM are key drivers of galaxy evolution. Here we provide new constraints on the vertical distribution of the CNM using the recently developed kinematic_scaleheight software package and a large catalog of sensitive H I absorption observations. We estimate the thickness of the CNM in the solar neighborhood to be σ z ∼ 50–90 pc, assuming a Gaussian vertical distribution. This is a factor of ∼2 smaller than typically assumed, indicating that the thickness of the CNM in the solar neighborhood is similar to that found in the inner Galaxy, consistent with recent simulation results. If we consider only structures with H I optical depths τ > 0.1 or column densities N(H I) > 1019.5 cm‑2, which recent work suggests are thresholds for molecule formation, we find σ z ∼ 50 pc. Meanwhile, for structures with τ < 0.1 or column densities N(H I) < 1019.5 cm‑2, we find σ z ∼ 120 pc. These thicknesses are similar to those derived for the thin- and thick-disk molecular cloud populations traced by CO emission, possibly suggesting that cold H I and CO are well mixed. Approximately 20% of CNM structures are identified as outliers, with kinematics that are not well explained by Galactic rotation. We show that some of these CNM structures—perhaps representing intermediate-velocity clouds—are associated with the Local Bubble wall. We compare our results to recent observations and simulations, and we discuss their implications for the multiphase structure of the Milky Way's interstellar medium. 

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