TY - JOUR AB - Li-Nadler proposed a conjecture about traces of Hecke categories, which implies the semistable part of the Betti geometric Langlands conjecture of Ben-Zvi-Nadler in genus 1. We prove a Weyl group analogue of this conjecture. Our theorem holds in the natural generality of reflection groups in Euclidean or hyperbolic space. As a corollary, we give an expression of the centralizer of a finite order element in a reflection group using homotopy theory. AU - Li, Penghui ID - 6986 IS - 11 JF - Proceedings of the American Mathematical Society SN - 0002-9939 TI - A colimit of traces of reflection groups VL - 147 ER - TY - JOUR AB - Adult neural stem cells and multiciliated ependymalcells are glial cells essential for neurological func-tions. Together, they make up the adult neurogenicniche. Using both high-throughput clonal analysisand single-cell resolution of progenitor division pat-terns and fate, we show that these two componentsof the neurogenic niche are lineally related: adult neu-ral stem cells are sister cells to ependymal cells,whereas most ependymal cells arise from the termi-nal symmetric divisions of the lineage. Unexpectedly,we found that the antagonist regulators of DNA repli-cation, GemC1 and Geminin, can tune the proportionof neural stem cells and ependymal cells. Our find-ings reveal the controlled dynamic of the neurogenicniche ontogeny and identify the Geminin familymembers as key regulators of the initial pool of adultneural stem cells. AU - Ortiz-Álvarez, G AU - Daclin, M AU - Shihavuddin, A AU - Lansade, P AU - Fortoul, A AU - Faucourt, M AU - Clavreul, S AU - Lalioti, ME AU - Taraviras, S AU - Hippenmeyer, Simon AU - Livet, J AU - Meunier, A AU - Genovesio, A AU - Spassky, N ID - 6454 IS - 1 JF - Neuron SN - 0896-6273 TI - Adult neural stem cells and multiciliated ependymal cells share a common lineage regulated by the Geminin family members VL - 102 ER - TY - JOUR AU - Kopf, Aglaja AU - Sixt, Michael K ID - 6979 IS - 20 JF - Current Biology SN - 0960-9822 TI - Gut homeostasis: Active migration of intestinal epithelial cells in tissue renewal VL - 29 ER - TY - JOUR AB - Tissue morphogenesis in multicellular organisms is brought about by spatiotemporal coordination of mechanical and chemical signals. Extensive work on how mechanical forces together with the well‐established morphogen signalling pathways can actively shape living tissues has revealed evolutionary conserved mechanochemical features of embryonic development. More recently, attention has been drawn to the description of tissue material properties and how they can influence certain morphogenetic processes. Interestingly, besides the role of tissue material properties in determining how much tissues deform in response to force application, there is increasing theoretical and experimental evidence, suggesting that tissue material properties can abruptly and drastically change in development. These changes resemble phase transitions, pointing at the intriguing possibility that important morphogenetic processes in development, such as symmetry breaking and self‐organization, might be mediated by tissue phase transitions. In this review, we summarize recent findings on the regulation and role of tissue material properties in the context of the developing embryo. We posit that abrupt changes of tissue rheological properties may have important implications in maintaining the balance between robustness and adaptability during embryonic development. AU - Petridou, Nicoletta AU - Heisenberg, Carl-Philipp J ID - 6980 IS - 20 JF - The EMBO Journal SN - 0261-4189 TI - Tissue rheology in embryonic organization VL - 38 ER - TY - JOUR AB - Due to the importance of zero-shot learning, i.e. classifying images where there is a lack of labeled training data, the number of proposed approaches has recently increased steadily. We argue that it is time to take a step back and to analyze the status quo of the area. The purpose of this paper is three-fold. First, given the fact that there is no agreed upon zero-shot learning benchmark, we first define a new benchmark by unifying both the evaluation protocols and data splits of publicly available datasets used for this task. This is an important contribution as published results are often not comparable and sometimes even flawed due to, e.g. pre-training on zero-shot test classes. Moreover, we propose a new zero-shot learning dataset, the Animals with Attributes 2 (AWA2) dataset which we make publicly available both in terms of image features and the images themselves. Second, we compare and analyze a significant number of the state-of-the-art methods in depth, both in the classic zero-shot setting but also in the more realistic generalized zero-shot setting. Finally, we discuss in detail the limitations of the current status of the area which can be taken as a basis for advancing it. AU - Xian, Yongqin AU - Lampert, Christoph AU - Schiele, Bernt AU - Akata, Zeynep ID - 6554 IS - 9 JF - IEEE Transactions on Pattern Analysis and Machine Intelligence SN - 0162-8828 TI - Zero-shot learning - A comprehensive evaluation of the good, the bad and the ugly VL - 41 ER - TY - JOUR AB - The plant hormone auxin has crucial roles in almost all aspects of plant growth and development. Concentrations of auxin vary across different tissues, mediating distinct developmental outcomes and contributing to the functional diversity of auxin. However, the mechanisms that underlie these activities are poorly understood. Here we identify an auxin signalling mechanism, which acts in parallel to the canonical auxin pathway based on the transport inhibitor response1 (TIR1) and other auxin receptor F-box (AFB) family proteins (TIR1/AFB receptors)1,2, that translates levels of cellular auxin to mediate differential growth during apical-hook development. This signalling mechanism operates at the concave side of the apical hook, and involves auxin-mediated C-terminal cleavage of transmembrane kinase 1 (TMK1). The cytosolic and nucleus-translocated C terminus of TMK1 specifically interacts with and phosphorylates two non-canonical transcriptional repressors of the auxin or indole-3-acetic acid (Aux/IAA) family (IAA32 and IAA34), thereby regulating ARF transcription factors. In contrast to the degradation of Aux/IAA transcriptional repressors in the canonical pathway, the newly identified mechanism stabilizes the non-canonical IAA32 and IAA34 transcriptional repressors to regulate gene expression and ultimately inhibit growth. The auxin–TMK1 signalling pathway originates at the cell surface, is triggered by high levels of auxin and shares a partially overlapping set of transcription factors with the TIR1/AFB signalling pathway. This allows distinct interpretations of different concentrations of cellular auxin, and thus enables this versatile signalling molecule to mediate complex developmental outcomes. AU - Cao, Min AU - Chen, Rong AU - Li, Pan AU - Yu, Yongqiang AU - Zheng, Rui AU - Ge, Danfeng AU - Zheng, Wei AU - Wang, Xuhui AU - Gu, Yangtao AU - Gelová, Zuzana AU - Friml, Jiří AU - Zhang, Heng AU - Liu, Renyi AU - He, Jun AU - Xu, Tongda ID - 6259 JF - Nature SN - 0028-0836 TI - TMK1-mediated auxin signalling regulates differential growth of the apical hook VL - 568 ER - TY - CHAP AB - Cells are arranged into species-specific patterns during early embryogenesis. Such cell division patterns are important since they often reflect the distribution of localized cortical factors from eggs/fertilized eggs to specific cells as well as the emergence of organismal form. However, it has proven difficult to reveal the mechanisms that underlie the emergence of cell positioning patterns that underlie embryonic shape, likely because a systems-level approach is required that integrates cell biological, genetic, developmental, and mechanical parameters. The choice of organism to address such questions is also important. Because ascidians display the most extreme form of invariant cleavage pattern among the metazoans, we have been analyzing the cell biological mechanisms that underpin three aspects of cell division (unequal cell division (UCD), oriented cell division (OCD), and asynchronous cell cycles) which affect the overall shape of the blastula-stage ascidian embryo composed of 64 cells. In ascidians, UCD creates two small cells at the 16-cell stage that in turn undergo two further successive rounds of UCD. Starting at the 16-cell stage, the cell cycle becomes asynchronous, whereby the vegetal half divides before the animal half, thus creating 24-, 32-, 44-, and then 64-cell stages. Perturbing either UCD or the alternate cell division rhythm perturbs cell position. We propose that dynamic cell shape changes propagate throughout the embryo via cell-cell contacts to create the ascidian-specific invariant cleavage pattern. AU - McDougall, Alex AU - Chenevert, Janet AU - Godard, Benoit G AU - Dumollard, Remi ED - Tworzydlo, Waclaw ED - Bilinski, Szczepan M. ID - 6987 SN - 0080-1844 T2 - Evo-Devo: Non-model species in cell and developmental biology TI - Emergence of embryo shape during cleavage divisions VL - 68 ER - TY - JOUR AB - We present and study novel optimal control problems motivated by the search for photovoltaic materials with high power-conversion efficiency. The material must perform the first step: convert light (photons) into electronic excitations. We formulate various desirable properties of the excitations as mathematical control goals at the Kohn-Sham-DFT level of theory, with the control being given by the nuclear charge distribution. We prove that nuclear distributions exist which give rise to optimal HOMO-LUMO excitations, and present illustrative numerical simulations for 1D finite nanocrystals. We observe pronounced goal-dependent features such as large electron-hole separation, and a hierarchy of length scales: internal HOMO and LUMO wavelengths < atomic spacings < (irregular) fluctuations of the doping profiles < system size. AU - Friesecke, Gero AU - Kniely, Michael ID - 6762 IS - 3 JF - Multiscale Modeling and Simulation SN - 15403459 TI - New optimal control problems in density functional theory motivated by photovoltaics VL - 17 ER - TY - JOUR AB - In this article we prove an analogue of a theorem of Lachaud, Ritzenthaler, and Zykin, which allows us to connect invariants of binary octics to Siegel modular forms of genus 3. We use this connection to show that certain modular functions, when restricted to the hyperelliptic locus, assume values whose denominators are products of powers of primes of bad reduction for the associated hyperelliptic curves. We illustrate our theorem with explicit computations. This work is motivated by the study of the values of these modular functions at CM points of the Siegel upper half-space, which, if their denominators are known, can be used to effectively compute models of (hyperelliptic, in our case) curves with CM. AU - Ionica, Sorina AU - Kılıçer, Pınar AU - Lauter, Kristin AU - Lorenzo García, Elisa AU - Manzateanu, Maria-Adelina AU - Massierer, Maike AU - Vincent, Christelle ID - 10874 JF - Research in Number Theory KW - Algebra and Number Theory SN - 2522-0160 TI - Modular invariants for genus 3 hyperelliptic curves VL - 5 ER - TY - JOUR AB - We present microscopic derivations of the defocusing two-dimensional cubic nonlinear Schrödinger equation and the Gross–Pitaevskii equation starting froman interacting N-particle system of bosons. We consider the interaction potential to be given either by Wβ(x)=N−1+2βW(Nβx), for any β>0, or to be given by VN(x)=e2NV(eNx), for some spherical symmetric, nonnegative and compactly supported W,V∈L∞(R2,R). In both cases we prove the convergence of the reduced density corresponding to the exact time evolution to the projector onto the solution of the corresponding nonlinear Schrödinger equation in trace norm. For the latter potential VN we show that it is crucial to take the microscopic structure of the condensate into account in order to obtain the correct dynamics. AU - Jeblick, Maximilian AU - Leopold, Nikolai K AU - Pickl, Peter ID - 7100 IS - 1 JF - Communications in Mathematical Physics SN - 0010-3616 TI - Derivation of the time dependent Gross–Pitaevskii equation in two dimensions VL - 372 ER -