TranSTYLer: Multimodal Behavioral Style Transfer for Facial and Body Gestures Generation

This paper addresses the challenge of transferring the behavior expressivity style of a virtual agent to another one while preserving behaviors shape as they carry communicative meaning. Behavior expressivity style is viewed here as the qualitative properties of behaviors. We propose TranSTYLer, a multimodal transformer based model that synthesizes the multimodal behaviors of a source speaker with the style of a target speaker. We assume that behavior expressivity style is encoded across various modalities of communication, including text, speech, body gestures, and facial expressions. The model employs a style and content disentanglement schema to ensure that the transferred style does not interfere with the meaning conveyed by the source behaviors. Our approach eliminates the need for style labels and allows the generalization to styles that have not been seen during the training phase. We train our model on the PATS corpus, which we extended to include dialog acts and 2D facial landmarks. Objective and subjective evaluations show that our model outperforms state of the art models in style transfer for both seen and unseen styles during training. To tackle the issues of style and content leakage that may arise, we propose a methodology to assess the degree to which behavior and gestures associated with the target style are successfully transferred, while ensuring the preservation of the ones related to the source content

Zero-Shot Style Transfer for Gesture Animation driven by Text and Speech using Adversarial Disentanglement of Multimodal Style Encoding

Modeling virtual agents with behavior style is one factor for personalizing human agent interaction. We propose an efficient yet effective machine learning approach to synthesize gestures driven by prosodic features and text in the style of different speakers including those unseen during training. Our model performs zero shot multimodal style transfer driven by multimodal data from the PATS database containing videos of various speakers. We view style as being pervasive while speaking, it colors the communicative behaviors expressivity while speech content is carried by multimodal signals and text. This disentanglement scheme of content and style allows us to directly infer the style embedding even of speaker whose data are not part of the training phase, without requiring any further training or fine tuning. The first goal of our model is to generate the gestures of a source speaker based on the content of two audio and text modalities. The second goal is to condition the source speaker predicted gestures on the multimodal behavior style embedding of a target speaker. The third goal is to allow zero shot style transfer of speakers unseen during training without retraining the model. Our system consists of: (1) a speaker style encoder network that learns to generate a fixed dimensional speaker embedding style from a target speaker multimodal data and (2) a sequence to sequence synthesis network that synthesizes gestures based on the content of the input modalities of a source speaker and conditioned on the speaker style embedding. We evaluate that our model can synthesize gestures of a source speaker and transfer the knowledge of target speaker style variability to the gesture generation task in a zero shot setup. We convert the 2D gestures to 3D poses and produce 3D animations. We conduct objective and subjective evaluations to validate our approach and compare it with a baseline

Unsteady drag force on an immersed sphere oscillating near a wall

The unsteady hydrodynamic drag exerted on an oscillating sphere near a planar wall is addressed experimentally, theoretically and numerically. The experiments are performed by using colloidal-probe atomic force microscopy in thermal noise mode. The resonance frequencies and quality factors are extracted from the measurement of the power spectrum density of the probe oscillation for a broad range of gap distances and Womersley numbers. The shift in the resonance frequency of the colloidal probe as the probe goes close to a solid wall infers the wall-induced variations of the effective mass of the probe. Interestingly, a crossover from a positive to a negative shift is observed as the Womersley number increases. In order to rationalize the results, the confined unsteady Stokes equation is solved numerically using a finite-element method, as well as asymptotic calculations. The in-phase and out-of-phase terms of the hydrodynamic drag acting on the sphere are obtained and agree well with the experimental results. All together, the experimental, theoretical and numerical results show that the hydrodynamic force felt by an immersed sphere oscillating near a wall is highly dependent on the Womersley number

Non-Gaussian diffusion near surfaces

We study the diffusion of finite-size particles confined close to a single wall and in double-wall planar channel geometries. The local diffusion constants are modified near the confining boundaries and depend on the distance to the latter. Displacement parallel to the walls is diffusive as characterized by its second cumulant (the variance), but a non-Gaussian nature can be demonstrated by the fact that its fourth cumulant is non-zero. Establishing a link with the well-known problem of Taylor dispersion, we provide a general expression for the fourth cumulant for general diffusivity tensors and also in the presence of potentials generated by either the walls or externally, for instance due to gravity. We then analyse experimentally and numerically the motion of a colloid in the direction parallel to the wall, for which the measured fourth cumulant is correctly predicted by our theory. This system is a well-controlled physical realization of a Brownian yet non-Gaussian motion generated by a fluctuating diffusivity mechanism for which the local diffusivity is quantified. These results can be used to provide additional tests and constraints for the inference of force maps and local transport properties near surfaces

Blunted muscle angiogenic training-response in COPD patients versus sedentary controls

International audienceThe impaired skeletal muscle of chronic obstructive pulmonary disease (COPD) patients reduces exercise capacity. Similar to the oxidative muscle fibres, the angio-adaptation of muscle to training may be blunted in these patients, as in other chronic conditions. We therefore compared muscle functional responses and angio-adaptations after training in COPD patients and sedentary healthy subjects (SHS). 24 COPD patients (forced expiratory volume in 1 s 45.6¡17.5% predicted) and 23 SHS (,150 min?week-1 of moderate-to-vigorous exercise) completed a 6-week rehabilitation programme based on individualised moderate-intensity endurance training. Histomorphological muscle analysis and measurements of pro-angiogenic vascular endothelial growth factor (VEGF)-A and anti-angiogenic thrombospondin (TSP)-1 were conducted before and after training. COPD patients and SHS showed improved symptom-limited oxygen consumption and muscle endurance, although improvements were lower in COPD patients (+0.96¡2.4 versus +2.9¡2.6 mL?kg-1 ?min-1 , p,0.05, and +65% versus +108%, p50.06, respectively). The capillary-to-fibre (C/F) ratio increased less in COPD patients than SHS (+16¡10% versus +37¡20%, p,0.05) and no fibre type switch occurred in COPD patients. The VEGF-A/TSP-1 ratio increased in COPD patients and SHS (+65% versus +35%, p,0.05). Changes in C/F and symptom-limited oxygen consumption were correlated (r50.51, p,0.05). In addition to a lack of fibre switch, COPD patients displayed a blunted angiogenic response to training

Evaluation of Azido 3-Deoxy- d - Manno-oct-2-ulosonic Acid (Kdo) Analogues for Click Chemistry-Mediated Metabolic Labeling of Myxococcus xanthus DZ2 Lipopolysaccharide

[Image: see text] Metabolic labeling paired with click chemistry is a powerful approach for selectively imaging the surfaces of diverse bacteria. Herein, we explored the feasibility of labeling the lipopolysaccharide (LPS) of Myxococcus xanthus—a Gram-negative predatory social bacterium known to display complex outer membrane (OM) dynamics—via growth in the presence of distinct azido (-N(3)) analogues of 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo). Determination of the LPS carbohydrate structure from strain DZ2 revealed the presence of one Kdo sugar in the core oligosaccharide, modified with phosphoethanolamine. The production of 8-azido-8-deoxy-Kdo (8-N(3)-Kdo) was then greatly improved over previous reports via optimization of the synthesis of its 5-azido-5-deoxy-d-arabinose precursor to yield gram amounts. The novel analogue 7-azido-7-deoxy-Kdo (7-N(3)-Kdo) was also synthesized, with both analogues capable of undergoing in vitro strain-promoted azide–alkyne cycloaddition (SPAAC) “click” chemistry reactions. Slower and faster growth of M. xanthus was displayed in the presence of 8-N(3)-Kdo and 7-N(3)-Kdo (respectively) compared to untreated cells, with differences also seen for single-cell gliding motility and type IV pilus-dependent swarm community expansion. While the surfaces of 8-N(3)-Kdo-grown cells were fluorescently labeled following treatment with dibenzocyclooctyne-linked fluorophores, the surfaces of 7-N(3)-Kdo-grown cells could not undergo fluorescent tagging. Activity analysis of the KdsB enzyme required to activate Kdo prior to its integration into nascent LPS molecules revealed that while 8-N(3)-Kdo is indeed a substrate of the enzyme, 7-N(3)-Kdo is not. Though a lack of M. xanthus cell aggregation was shown to expedite growth in liquid culture, 7-N(3)-Kdo-grown cells did not manifest differences in intrinsic clumping relative to untreated cells, suggesting that 7-N(3)-Kdo may instead be catabolized by the cells. Ultimately, these data provide important insights into the synthesis and cellular processing of valuable metabolic labels and establish a basis for the elucidation of fundamental principles of OM dynamism in live bacterial cells

Submicroscopic Deletions at 13q32.1 Cause Congenital Microcoria.

International audienceCongenital microcoria (MCOR) is a rare autosomal-dominant disorder characterized by inability of the iris to dilate owing to absence of dilator pupillae muscle. So far, a dozen MCOR-affected families have been reported worldwide. By using whole-genome oligonucleotide array CGH, we have identified deletions at 13q32.1 segregating with MCOR in six families originating from France, Japan, and Mexico. Breakpoint sequence analyses showed nonrecurrent deletions in 5/6 families. The deletions varied from 35 kbp to 80 kbp in size, but invariably encompassed or interrupted only two genes: TGDS encoding the TDP-glucose 4,6-dehydratase and GPR180 encoding the G protein-coupled receptor 180, also known as intimal thickness-related receptor (ITR). Unlike TGDS which has no known function in muscle cells, GPR180 is involved in the regulation of smooth muscle cell growth. The identification of a null GPR180 mutation segregating over two generations with iridocorneal angle dysgenesis, which can be regarded as a MCOR endophenotype, is consistent with the view that deletions of this gene, with or without the loss of elements regulating the expression of neighboring genes, are the cause of MCOR