TY - CONF AB - The notion of program sensitivity (aka Lipschitz continuity) specifies that changes in the program input result in proportional changes to the program output. For probabilistic programs the notion is naturally extended to expected sensitivity. A previous approach develops a relational program logic framework for proving expected sensitivity of probabilistic while loops, where the number of iterations is fixed and bounded. In this work, we consider probabilistic while loops where the number of iterations is not fixed, but randomized and depends on the initial input values. We present a sound approach for proving expected sensitivity of such programs. Our sound approach is martingale-based and can be automated through existing martingale-synthesis algorithms. Furthermore, our approach is compositional for sequential composition of while loops under a mild side condition. We demonstrate the effectiveness of our approach on several classical examples from Gambler's Ruin, stochastic hybrid systems and stochastic gradient descent. We also present experimental results showing that our automated approach can handle various probabilistic programs in the literature. AU - Wang, Peixin AU - Fu, Hongfei AU - Chatterjee, Krishnendu AU - Deng, Yuxin AU - Xu, Ming ID - 8324 IS - POPL T2 - Proceedings of the ACM on Programming Languages TI - Proving expected sensitivity of probabilistic programs with randomized variable-dependent termination time VL - 4 ER - TY - JOUR AB - Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as enlarged eyes and an increased orbital convergence. However, the actual role of binocular vision in nocturnal foraging is still debated. Nightjars (Aves: Caprimulgidae) are predators that actively pursue and capture flying insects in crepuscular and nocturnal environments, mainly using a conspicuous “sit-and-wait” tactic on which pursuit begins with an insect flying over the bird that sits on the ground. In this study, we describe the visual system of the band-winged nightjar (Systellura longirostris), with emphasis on anatomical features previously described as relevant for nocturnal birds. Orbit convergence, determined by 3D scanning of the skull, was 73.28°. The visual field, determined by ophthalmoscopic reflex, exhibits an area of maximum binocular overlap of 42°, and it is dorsally oriented. The eyes showed a nocturnal-like normalized corneal aperture/axial length index. Retinal ganglion cells (RGCs) were relatively scant, and distributed in an unusual oblique-band pattern, with higher concentrations in the ventrotemporal quadrant. Together, these results indicate that the band-winged nightjar exhibits a retinal specialization associated with the binocular area of their dorsal visual field, a relevant area for pursuit triggering and prey attacks. The RGC distribution observed is unusual among birds, but similar to that of some visually dependent insectivorous bats, suggesting that those features might be convergent in relation to feeding strategies. AU - Salazar, Juan Esteban AU - Severin, Daniel AU - Vega Zuniga, Tomas A AU - Fernández-Aburto, Pedro AU - Deichler, Alfonso AU - Sallaberry A., Michel AU - Mpodozis, Jorge ID - 7160 IS - 1-4 JF - Brain, Behavior and Evolution SN - 0006-8977 TI - Anatomical specializations related to foraging in the visual system of a nocturnal insectivorous bird, the band-winged nightjar (Aves: Caprimulgiformes) VL - 94 ER - TY - JOUR AB - We prove edge universality for a general class of correlated real symmetric or complex Hermitian Wigner matrices with arbitrary expectation. Our theorem also applies to internal edges of the self-consistent density of states. In particular, we establish a strong form of band rigidity which excludes mismatches between location and label of eigenvalues close to internal edges in these general models. AU - Alt, Johannes AU - Erdös, László AU - Krüger, Torben H AU - Schröder, Dominik J ID - 6184 IS - 2 JF - Annals of Probability SN - 0091-1798 TI - Correlated random matrices: Band rigidity and edge universality VL - 48 ER - TY - JOUR AB - Protein abundance and localization at the plasma membrane (PM) shapes plant development and mediates adaptation to changing environmental conditions. It is regulated by ubiquitination, a post-translational modification crucial for the proper sorting of endocytosed PM proteins to the vacuole for subsequent degradation. To understand the significance and the variety of roles played by this reversible modification, the function of ubiquitin receptors, which translate the ubiquitin signature into a cellular response, needs to be elucidated. In this study, we show that TOL (TOM1-like) proteins function in plants as multivalent ubiquitin receptors, governing ubiquitinated cargo delivery to the vacuole via the conserved Endosomal Sorting Complex Required for Transport (ESCRT) pathway. TOL2 and TOL6 interact with components of the ESCRT machinery and bind to K63-linked ubiquitin via two tandemly arranged conserved ubiquitin-binding domains. Mutation of these domains results not only in a loss of ubiquitin binding but also altered localization, abolishing TOL6 ubiquitin receptor activity. Function and localization of TOL6 is itself regulated by ubiquitination, whereby TOL6 ubiquitination potentially modulates degradation of PM-localized cargoes, assisting in the fine-tuning of the delicate interplay between protein recycling and downregulation. Taken together, our findings demonstrate the function and regulation of a ubiquitin receptor that mediates vacuolar degradation of PM proteins in higher plants. AU - Moulinier-Anzola, Jeanette AU - Schwihla, Maximilian AU - De-Araújo, Lucinda AU - Artner, Christina AU - Jörg, Lisa AU - Konstantinova, Nataliia AU - Luschnig, Christian AU - Korbei, Barbara ID - 15037 IS - 5 JF - Molecular Plant KW - Plant Science KW - Molecular Biology SN - 1674-2052 TI - TOLs function as ubiquitin receptors in the early steps of the ESCRT pathway in higher plants VL - 13 ER - TY - JOUR AB - The assembly of a septin filament requires that homologous monomers must distinguish between one another in establishing appropriate interfaces with their neighbors. To understand this phenomenon at the molecular level, we present the first four crystal structures of heterodimeric septin complexes. We describe in detail the two distinct types of G-interface present within the octameric particles, which must polymerize to form filaments. These are formed between SEPT2 and SEPT6 and between SEPT7 and SEPT3, and their description permits an understanding of the structural basis for the selectivity necessary for correct filament assembly. By replacing SEPT6 by SEPT8 or SEPT11, it is possible to rationalize Kinoshita's postulate, which predicts the exchangeability of septins from within a subgroup. Switches I and II, which in classical small GTPases provide a mechanism for nucleotide-dependent conformational change, have been repurposed in septins to play a fundamental role in molecular recognition. Specifically, it is switch I which holds the key to discriminating between the two different G-interfaces. Moreover, residues which are characteristic for a given subgroup play subtle, but pivotal, roles in guaranteeing that the correct interfaces are formed. AU - Rosa, Higor Vinícius Dias AU - Leonardo, Diego Antonio AU - Brognara, Gabriel AU - Brandão-Neto, José AU - D'Muniz Pereira, Humberto AU - Araújo, Ana Paula Ulian AU - Garratt, Richard Charles ID - 15036 IS - 21 JF - Journal of Molecular Biology KW - Molecular Biology KW - Structural Biology SN - 0022-2836 TI - Molecular recognition at septin interfaces: The switches hold the key VL - 432 ER -