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Concept

Snake

Related publications (21)

How are cells instructed to form somite boundaries by the zebrafish segmentation clock?

Olivier François Venzin

In vertebrate embryos, the elongating body axis is patterned via the sequential and rhyth-mic production of segments from a posterior unsegmented tissue called the presomitic mesoderm (PSM). This process is controlled by a population of cellular oscillator ...

EPFL2023

Premature Vertebral Mineralization in hmx1-Mutant Zebrafish

Daniel Francis Schorderet

H6 family homeobox 1 (HMX1) regulates multiple aspects of craniofacial development, and mutations in HMX1 are linked to an ocular defect termed oculoauricular syndrome of Schorderet-Munier-Franceschetti (OAS) (MIM #612109). Recently, additional altered oro ...

2022

Modified snaking in plane Couette flow with wall-normal suction

Tobias Schneider, Sajjad Azimi

A specific family of spanwise-localised invariant solutions of plane Couette flow exhibits homoclinic snaking, a process by which spatially localised invariant solutions of a nonlinear partial differential equation smoothly grow additional structure at the ...

Cambridge University Press2021

Sprawling Quadruped Robot Driven by Decentralized Control With Cross-Coupled Sensory Feedback Between Legs and Trunk

Auke Ijspeert

Quadruped animals achieve agile and highly adaptive locomotion owing to the coordination between their legs and other body parts, such as the trunk, head, and tail, that is, body-limb coordination. This study aims to understand the sensorimotor control und ...

2021

Texture-driven parametric snakes for semi-automatic image segmentation

Michaël Unser, Adrien Raphaël Depeursinge, Anaïs Laure Marie-Thérèse Badoual

We present a texture-driven parametric snake for semi-automatic segmentation of a single and closed structure in an image. We propose a new energy functional that combines intensity and texture information. The two types of image information are balanced u ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2019

Multiresolution Subdivision Snakes

Michaël Unser, Daniel Andreas Schmitter, Virginie Sophie Uhlmann, Anaïs Laure Marie-Thérèse Badoual

We present a new family of snakes that satisfy the property of multiresolution by exploiting subdivision schemes. We show in a generic way how to construct such snakes based on an admissible subdivision mask. We derive the necessary energy formulations and ...

2017

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops

François Avellan, Audrey Paulette Solange Maertens

Purpose: We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. Methods: The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spher ...

Wichtig Editore2017

Embryonic timing, axial stem cells, chromatin dynamics, and the Hox clock

Denis Duboule

Collinear regulation of Hox genes in space and time has been an outstanding question ever since the initial work of Ed Lewis in 1978. Here we discuss recent advances in our understanding of this phenomenon in relation to novel concepts associated with larg ...

2017

Reorganisation of Hoxd regulatory landscapes during the evolution of a snake-like body plan

Denis Duboule

Within land vertebrate species, snakes display extreme variations in their body plan, characterized by the absence of limbs and an elongated morphology. Such a particular interpretation of the basic vertebrate body architecture has often been associated wi ...

Elife Sciences Publications Ltd2016

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors

Silvestro Micera, Grégoire Courtine, Lucia Florinda Friedli Wittler, Janine Beauparlant, Jacopo Rigosa, Julie Kreider

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlim ...

Soc Neuroscience2016

Tetrapod axial evolution and developmental constraints; Empirical underpinning by a mouse model

Denis Duboule

The tetrapod vertebral column has become increasingly complex during evolution as an adaptation to a terrestrial life. At the same time, the evolution of the vertebral formula became subject to developmental constraints acting on the size of the cervical a ...

Elsevier2015

New Parametric 3D Snake for Medical Segmentation of Structures with Cylindrical Topology

Michaël Unser, Daniel Andreas Schmitter

We propose a new parametric 3D snake with cylindrical topology. Its construction is based on interpolatory basis functions which facilitates user-interaction because the control points of the snake directly lie on the surface of the deformable cylinder. We ...

IEEE2015

Snakes with Tangent-Based Control and Energies for Bioimage Analysis

Michaël Unser, Ricard Delgado Gonzalo, Virginie Sophie Uhlmann

We propose a novel active contour for the analysis of filament-like structures and boundaries—features that traditional snakes based on closed curves have difficulties to delineate. Our method relies on a parametric representation of an open curve involvin ...

IEEE2014

Regulatory Switches Underlie Hoxd Gene Activation in Tetrapod Limbs

Guillaume Andrey

Accurate spatio-temporal control of Hox cluster genes expression is critical for the proper organization of body structures during vertebrate embryogenesis. In the limbs, Hoxd genes are critical in setting up the proximodistal and anteroposterior axes. Sev ...

EPFL2013

Role of a polymorphism in a Hox/Pax-responsive enhancer in the evolution of the vertebrate spine

Denis Duboule

Patterning of the vertebrate skeleton requires the coordinated activity of Hox genes. In particular, Hox10 proteins are essential to set the transition from thoracic to lumbar vertebrae because of their rib-repressing activity. In snakes, however, the thor ...

National Academy of Sciences2013

Snakes With an Ellipse-Reproducing Property

Michaël Unser, Philippe Thévenaz, Ricard Delgado Gonzalo, Chandra Sekhar Seelamantula

We present a new class of continuously defined parametric snakes using a special kind of exponential splines as basis functions. We have enforced our bases to have the shortest possible support subject to some design constraints to maximize efficiency. Whi ...

IEEE2012

Reaching and grasping kitchenware objects

Aude Billard, Ashwini Shukla, José Santos-Victor, Alexandre Bernardino

We integrate software components that allow ef- ficient and successful grasping of kitchenware objects. The contributed components include: The object pose detector, the gripper reaching motion and the grasp hypothesis selection. The object pose detector o ...

2012

Epigenetic temporal control of mouse Hox genes in vivo

Denis Duboule

During vertebrate development, the temporal control of Hox gene transcriptional activation follows the genomic order of the genes within the Hox clusters. Although it is recognized that this "Hox clock" serves to coordinate body patterning, the underlying ...

American Association for the Advancement of Science2009

Snakuscules

Michaël Unser, Philippe Thévenaz

A snakuscule (a minuscule snake) is the simplest active contour that we were able to design while keeping the quintessence of traditional snakes: an energy term governed by the data, and a regularization term. Our construction is an area-based snake, as op ...

IEEE2008

Parametric B-Spline Snakes on Distance Maps—Application to Segmentation of Histology Images

Michaël Unser, Philippe Thévenaz, François Aguet, Chandra Sekhar Seelamantula

We construct parametric active contours (snakes) for outlining cells in histology images. These snakes are defined in terms of cubic B-spline basis functions. We use a steerable ridge detector for obtaining a reliable map of the cell boundaries. Using the ...

EURASIP2008