TY - JOUR AB - Plants can regenerate their bodies via de novo establishment of shoot apical meristems (SAMs) from pluripotent callus. Only a small fraction of callus cells is eventually specified into SAMs but the molecular mechanisms underlying fate specification remain obscure. The expression of WUSCHEL (WUS) is an early hallmark of SAM fate acquisition. Here, we show that a WUS paralog, WUSCHEL-RELATED HOMEOBOX 13 (WOX13), negatively regulates SAM formation from callus in Arabidopsis thaliana. WOX13 promotes non-meristematic cell fate via transcriptional repression of WUS and other SAM regulators and activation of cell wall modifiers. Our Quartz-Seq2–based single cell transcriptome revealed that WOX13 plays key roles in determining cellular identity of callus cell population. We propose that reciprocal inhibition between WUS and WOX13 mediates critical cell fate determination in pluripotent cell population, which has a major impact on regeneration efficiency. AU - Ogura, Nao AU - Sasagawa, Yohei AU - Ito, Tasuku AU - Tameshige, Toshiaki AU - Kawai, Satomi AU - Sano, Masaki AU - Doll, Yuki AU - Iwase, Akira AU - Kawamura, Ayako AU - Suzuki, Takamasa AU - Nikaido, Itoshi AU - Sugimoto, Keiko AU - Ikeuchi, Momoko ID - 13259 IS - 27 JF - Science Advances TI - WUSCHEL-RELATED HOMEOBOX 13 suppresses de novo shoot regeneration via cell fate control of pluripotent callus VL - 9 ER - TY - JOUR AB - Conflicts and natural disasters affect entire populations of the countries involved and, in addition to the thousands of lives destroyed, have a substantial negative impact on the scientific advances these countries provide. The unprovoked invasion of Ukraine by Russia, the devastating earthquake in Turkey and Syria, and the ongoing conflicts in the Middle East are just a few examples. Millions of people have been killed or displaced, their futures uncertain. These events have resulted in extensive infrastructure collapse, with loss of electricity, transportation, and access to services. Schools, universities, and research centers have been destroyed along with decades’ worth of data, samples, and findings. Scholars in disaster areas face short- and long-term problems in terms of what they can accomplish now for obtaining grants and for employment in the long run. In our interconnected world, conflicts and disasters are no longer a local problem but have wide-ranging impacts on the entire world, both now and in the future. Here, we focus on the current and ongoing impact of war on the scientific community within Ukraine and from this draw lessons that can be applied to all affected countries where scientists at risk are facing hardship. We present and classify examples of effective and feasible mechanisms used to support researchers in countries facing hardship and discuss how these can be implemented with help from the international scientific community and what more is desperately needed. Reaching out, providing accessible training opportunities, and developing collaborations should increase inclusion and connectivity, support scientific advancements within affected communities, and expedite postwar and disaster recovery. AU - Wolfsberger, Walter AU - Chhugani, Karishma AU - Shchubelka, Khrystyna AU - Frolova, Alina AU - Salyha, Yuriy AU - Zlenko, Oksana AU - Arych, Mykhailo AU - Dziuba, Dmytro AU - Parkhomenko, Andrii AU - Smolanka, Volodymyr AU - Gümüş, Zeynep H. AU - Sezgin, Efe AU - Diaz-Lameiro, Alondra AU - Toth, Viktor R. AU - Maci, Megi AU - Bortz, Eric AU - Kondrashov, Fyodor AU - Morton, Patricia M. AU - Łabaj, Paweł P. AU - Romero, Veronika AU - Hlávka, Jakub AU - Mangul, Serghei AU - Oleksyk, Taras K. ID - 13976 JF - GigaScience TI - Scientists without borders: Lessons from Ukraine VL - 12 ER - TY - JOUR AB - We construct families of log K3 surfaces and study the arithmetic of their members. We use this to produce explicit surfaces with an order 5 Brauer–Manin obstruction to the integral Hasse principle. AU - Lyczak, Julian ID - 13973 IS - 2 JF - Annales de l'Institut Fourier SN - 0373-0956 TI - Order 5 Brauer–Manin obstructions to the integral Hasse principle on log K3 surfaces VL - 73 ER - TY - JOUR AB - The Tverberg theorem is one of the cornerstones of discrete geometry. It states that, given a set X of at least (d+1)(r−1)+1 points in Rd, one can find a partition X=X1∪⋯∪Xr of X, such that the convex hulls of the Xi, i=1,…,r, all share a common point. In this paper, we prove a trengthening of this theorem that guarantees a partition which, in addition to the above, has the property that the boundaries of full-dimensional convex hulls have pairwise nonempty intersections. Possible generalizations and algorithmic aspects are also discussed. As a concrete application, we show that any n points in the plane in general position span ⌊n/3⌋ vertex-disjoint triangles that are pairwise crossing, meaning that their boundaries have pairwise nonempty intersections; this number is clearly best possible. A previous result of Álvarez-Rebollar et al. guarantees ⌊n/6⌋pairwise crossing triangles. Our result generalizes to a result about simplices in Rd, d≥2. AU - Fulek, Radoslav AU - Gärtner, Bernd AU - Kupavskii, Andrey AU - Valtr, Pavel AU - Wagner, Uli ID - 13974 JF - Discrete and Computational Geometry SN - 0179-5376 TI - The crossing Tverberg theorem ER - TY - JOUR AB - We consider the spectrum of random Laplacian matrices of the form Ln=An−Dn where An is a real symmetric random matrix and Dn is a diagonal matrix whose entries are equal to the corresponding row sums of An. If An is a Wigner matrix with entries in the domain of attraction of a Gaussian distribution, the empirical spectral measure of Ln is known to converge to the free convolution of a semicircle distribution and a standard real Gaussian distribution. We consider real symmetric random matrices An with independent entries (up to symmetry) whose row sums converge to a purely non-Gaussian infinitely divisible distribution, which fall into the class of Lévy–Khintchine random matrices first introduced by Jung [Trans Am Math Soc, 370, (2018)]. Our main result shows that the empirical spectral measure of Ln converges almost surely to a deterministic limit. A key step in the proof is to use the purely non-Gaussian nature of the row sums to build a random operator to which Ln converges in an appropriate sense. This operator leads to a recursive distributional equation uniquely describing the Stieltjes transform of the limiting empirical spectral measure. AU - Campbell, Andrew J AU - O’Rourke, Sean ID - 13975 JF - Journal of Theoretical Probability SN - 0894-9840 TI - Spectrum of Lévy–Khintchine random laplacian matrices ER -