Mickey Mouse | EPFL Graph Search

Mickey Mouse is an American cartoon character co-created in 1928 by Walt Disney and Ub Iwerks. The longtime icon and mascot of The Walt Disney Company, Mickey is an anthropomorphic mouse who typically wears red shorts, large yellow shoes, and white gloves. Inspired by such silent film personalities as Charlie Chaplin and Douglas Fairbanks, Mickey is traditionally characterized as a sympathetic underdog who gets by on pluck and ingenuity in the face of challenges bigger than himself. The character’s depiction as a small mouse is personified through his diminutive stature and falsetto voice, the latter of which was originally provided by Disney. Mickey is one of the world's most recognizable and universally acclaimed fictional characters of all time. Created as a replacement for a prior Disney character, Oswald the Lucky Rabbit, Mickey first appeared in the short Plane Crazy, debuting publicly in the short film Steamboat Willie (1928), while it was third cartoon featuring Mickey to be p

Elucidating the role of Hmx1 during mouse development

Linda Bapst

This thesis focuses on the study of H6 homeobox 1 (HMX1) gene, a homeobox-containing transcription factor involved in sensory organ and eye development and responsible for the oculo-auricular syndrome of Schorderet-Munier-Franceschetti. The purpose of my study is to better understand the mechanism and role of this transcription factor. My thesis is divided into three parts. The first part proposes a predictive promoter model approach to identify new HMX1 target gene. The second part concerns an animal model of Hmx1 mutation, the dumbo mouse model, and brings a new insight into lethal craniofacial defects. The third part concerns the characterization of the visual capacity of the dumbo mice and a description of a new pattern of vision-linked defects. In the first part we propose a predictive promoter model approach based on transcriptomic analysis of post-natal day 15 mouse retina from dumbo and wild type mouse. This method revealed that Sgcg, Tshz2 and Slc6a9 were Hmx1 targets in the mouse retina. Ptpro, Sema3f, and Epha6 belong to the retinal axon guidance pathway and play an important role in retinotopic mapping. Significant enrichment of HMX1 binding site confirmed this pathway and we validated the transcriptional activity of Hmx1 on Ptpro, Sema3f and Sgcg by Luciferase assay. In the second part of the project we investigate the dumbo mouse model, carrying a stop codon in Hmx1, and representing the first animal model for the oculo-auricular syndrome of Schorderet-Munier-Franceschetti. The homozygous Hmx1dmbo is a semi-lethal mutation and stillborns present severe craniofacial defects, including cleft palate, chest defect and bone hypoplasia of maxilla, zygomatic process, mandible and frontal. In the third part of the thesis we provide a complete description of the vision in dumbo mouse. Despite a normal retinal phenotype, the vision of this mouse is completely impaired. We demonstrate that this was caused by abnormal retinotopic mapping and optic nerve hypoplasia. In dumbo mice the retinal ganglion cells axon projections failed to target the visual output, namely the dorsal lateral geniculate nucleus and the superior colliculus, and present abnormal patterning.

EPFL2015

Stress, genotype and norepinephrine in the prediction of mouse behavior using reinforcement learning

Wulfram Gerstner, Gediminas Luksys, Maria del Carmen Sandi Perez

Individual behavioral performance during learning is known to be affected by modulatory factors, such as stress and motivation, and by genetic predispositions that influence sensitivity to these factors. Despite numerous studies, no integrative framework is available that could predict how a given animal would perform a certain learning task in a realistic situation. We found that a simple reinforcement learning model can predict mouse behavior in a hole-box conditioning task if model metaparameters are dynamically controlled on the basis of the mouse's genotype and phenotype, stress conditions, recent performance feedback and pharmacological manipulations of adrenergic alpha-2 receptors. We find that stress and motivation affect behavioral performance by altering the exploration-exploitation balance in a genotype-dependent manner. Our results also provide computational insights into how an inverted U-shape relation between stress/arousal/norepinephrine levels and behavioral performance could be explained through changes in task performance accuracy and future reward discounting.

Nature Publishing Group2009

Spline-based framework for interactive segmentation in biomedical imaging

Ricard Delgado Gonzalo, Michaël Unser

Active contours constitute a computationally attractive framework for image segmentation. In this paper, we describe a fully parametric design that relies on B-spline bases and is specified by control points on the image. Our technique yields successful segmentation results even for challenging datasets where object contours are not well-defined. We can achieve this because our parametric approach uses few parameters and allows us to constrain the topology of the curve. We provide the details for an efficient implementation and discuss different design alternatives. This work comes with a companion software that gives the end user full control over the snakes. We demonstrate the features of our software which includes an interactive interface where the user can manipulate the position of control points by simple mouse actions.

Elsevier Science Inc2013

Elucidating the role of Hmx1 during mouse development

Linda Bapst

EPFL2015