Diemo Schwarz
email: schwarz@ircam.fr

Touch Interaction for Corpus-based Audio-Visual Synthesis

Keywords: audio-visual concatenative synthesis, cross-modal perception, 2D tactile interaction, audio and image descriptors CCS Concepts, Applied computing → Media arts, Sound and music computing, •Human-centered computing → Gestural input, •Computing methodologies → Visual content-based indexing and retrieval

Audio-visual corpus-based synthesis extends the principle of concatenative sound synthesis to the visual domain, where, in addition to the sound corpus (i.e. a collection of segments of recorded sound with a perceptual description of their sound character), the artist uses a corpus of still images with visual perceptual description (colour, texture, brightness), in order to create an audio-visual musical performance by navigating in real-time through these descriptor spaces, i.e. through the collection of sound grains in a space of perceptual audio descriptors, and at the same time through the visual descriptor space, i.e. selecting images from the visual corpus for rendering, and thus navigate in parallel through both corpora interactively with gestural control via touch sensing. The artistic-scientific question that is explored here is how to control at the same time the navigation through the audio and the image descriptor spaces with gestures, in other words, how to link the touch input to both descriptor spaces in order to create a multi-modal embodied audio-visual experience.

INTRODUCTION

This article presents a new method to create gesturecontrolled audio-visual live performances, based on crossmodal perception and mobilising inter-modal analogies. It relates the joint realisation of the artistic idea and the technological development in this practice-led research project, Licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0). Copyright remains with the author(s). NIME '23, 31 May-2 June, 2023, Mexico City, Mexico.

supported by an art-science residency at the IMéRA institute of advanced research in 2022 called CoCAVS, for Concatenative Corpus-based Audio-Visual Synthesis. Its aim was to develop a gesture-controlled audio-visual performance instrument, that can be used in the context of musical and visual improvisation, and as a device for interactive installations. The system was developed in symbiosis with its artistic use, collecting, and experimenting with, audio and image corpora, which informed the advancement of the technological development, and during which a piece for audio-visual concatenative synthesis and violin was produced and performed in public at the Marseille Observatory's planetarium. 1The scientific aim of the CoCAVS project is to extend the principle of corpus-based sound synthesis to the visual domain, where, in addition to the sound corpus (i.e. a collection of segments of recorded sound (called sound grains) with a perceptual description of their sound character, such as pitch, brilliance, roughness, noisiness), the artist would use a corpus of still images with perceptual description (colour, texture, brightness, entropy, and other content-based image descriptors).

The artist then creates an audio-visual musical performance by navigating through one of these descriptor spaces, e.g. through the collection of sound grains in a space of perceptual audio descriptors, and at the same time through the other descriptor space, i.e. select images from the visual corpus for rendering, and thus navigate in parallel through both corpora interactively with gestural control using a touch pad. This evokes an aesthetic of acoustic and visual collage or cut-up. When navigation is local, it generates linked audio and image sequence from the two corpora with small changes over time. When the navigation jumps to different parts of the linked sound/image descriptor space, it will oppose contrasting sounds/images.

For example, a navigation from the left of the gestural control interface (typically a touch-pad like the Sensel Morph), to the right, might play a sequence of short sound grains chosen to start with dull and to end with brilliant sounding grains, while the chosen image sequence would start with dark greyscale and end with bright and saturated images. Likewise, navigating from the top to the bottom might start at stable pitched sounds and gradually go to noisy sounds, while the image selection goes from plain uniform content to increasingly finely textured image choices.

The fascinating artistic-scientific question that is explored here is how to control at the same time the navigation through the audio and the image descriptor spaces with gesture sensors-in other words, how to link the gesture input to both the image descriptors and the sound descriptors in order to create multi-modal audio-visual embodied per-formances and installations. Here, the questions of multisensory correspondences and synaesthesia to be explored in the mapping could lead towards new research directions in cross-modal perception.

The article will briefly present the concept of audio-visual corpus-based synthesis and will then confront the original scientific and artistic idea (or ideal ) with the practical aspects of how to implement a technical system that allows to exploit and actually perform with audio-visual source material. It will notably address questions of making the joint navigation space maximally accessible for gestural control, for which we developed a new simple distribution method, and the question of pairing audio and visual elements (the A/V mapping).

This account sometimes takes a perspective inspired by autoethnography [START_REF] Bartlett | Music Autoethnographies: Making Autoethnography Sing/Making Music Personal[END_REF][START_REF] Chamberlain | Surfing with sound: An ethnography of the art of no-input mixing: Starting to understand risk, control and feedback in musical performance[END_REF], relating the subjective experience and knowledge gained during the elaboration of the idea, in the context of the author's 18 years of research and performance practice in audio CBCS with embodied gestural control, and the context of digital art.

Background and Related Work

The basis of this project is the scientific research on Corpusbased concatenative sound synthesis (CBCS) [START_REF] Schwarz | Corpus-based concatenative synthesis[END_REF][START_REF] Schwarz | The sound space as musical instrument: Playing corpus-based concatenative synthesis[END_REF], a method explored for the first time in a musical context in the author's PhD work [START_REF] Schwarz | Data-Driven Concatenative Sound Synthesis[END_REF] started in 1999. Here, sound synthesis is based on audio content descriptor analysis of any number of pre-existing or live-recorded sounds, and synthesis is guided by selection and playback of sound segments (units) from the database matching given sound characteristics. It is used in various contexts of music composition, live performance, sound design, installations, and allows to explore a corpus of sounds interactively or by composing paths in the timbre space, and thus to recreate novel timbral evolutions while keeping the richness and fine details of the original sound. CBCS can be seen as a content-based extension of granular synthesis, providing direct access to specific sound characteristics, allowing to create dense and lively textures with direct control of their timbre.

The open source CataRT software2 [START_REF] Schwarz | Real-Time Corpus-Based Concatenative Synthesis with CataRT[END_REF][START_REF] Schwarz | Principles and applications of interactive corpus-based concatenative synthesis[END_REF] created by the author, the ISMM team, and contributors, for the Max interactive media programming environment,3 put this idea in the hands of electronic musicians, composers, and sound designers [START_REF] Bevilacqua | MIMES: outil de prototypage et d'exploration pour la création sonore[END_REF], and with the help of gestural controllers, allows expressive and intuitive interaction with rich sound corpora [START_REF] Schwarz | The sound space as musical instrument: Playing corpus-based concatenative synthesis[END_REF]. Audio CBCS draws on the well-known artistic techniques of collage, cut-up, and citation, augmenting them by digital means, automatic content analysis, and computational models [START_REF] Schwarz | Concatenative sound synthesis: The early years[END_REF].

Visual collage in the avant-garde art movements [START_REF] Lachaud | De l'usage du collage en art au xxe siècle[END_REF] draws on a long history of artistic exploration based on film editing techniques by montage [START_REF] Genton | L'image libérée ou le cinéma selon[END_REF][START_REF] Moreau | De la perception à la représentation -Analyser l'oeuvre vidéomusicale[END_REF]. In digital visual arts, audio+video collage has been based on digital means in video samplers, such as VJAMM4 [START_REF] Mccarthy | Scratch video and rave: The rise of the live visuals performer (1985-2000[END_REF] created by the VJ artist Coldcut, or the klipp av [START_REF] Collins | Klipp AV: Live algorithmic splicing and audiovisual event capture[END_REF] system for synchronous and cross-mapped cut-up of live or composed audio and video streams. However, audio-visual collage has up to now only rarely been augmented by automatic content analysis or computational models. A first step in this direction of content-based processing of audio-visual data was taken by Collins [START_REF] Collins | Audiovisual Concatenative Synthesis[END_REF] on video footage as source for the linked audiovisual corpus, analysed by 5 audio and 5 visual descriptors.

Regarding human audio-visual perception, there is a large literature on cross-modal perception of images (or shapes) and sounds [START_REF] Wellek | Die Farbe-Ton-Forschung und ihr erster Kongreß[END_REF][START_REF] Grill | Visualization of perceptual qualities in textural sounds[END_REF][START_REF] Adeli | Audiovisual correspondence between musical timbre and visual shapes[END_REF][START_REF] Soraghan | A new timbre visualization technique based on semantic descriptors[END_REF][START_REF] Deroy | Crossmodal correspondences: Four challenges[END_REF][START_REF] Sun | An extended research of crossmodal correspondence between color and sound in psychology and cognitive ergonomics[END_REF][START_REF] Saitis | Timbre semantics through the lens of crossmodal correspondences: a new way of asking old questions[END_REF][START_REF] Guellaï | Sensus communis: Some perspectives on the origins of non-synchronous cross-sensory associations[END_REF]. Tsiros [START_REF] Tsiros | The dimensions and complexities of audio-visual association[END_REF] summarises the complexities of audio-visual associations to gather insights for their efficient and intuitive design, stressing structural and functional isomorphisms (linked to Gestalt theory). Indeed one can argue that very early onwards in the human neural processing pipeline, both acoustic and visual information is essentially represented in the same way [START_REF] Tsiros | The dimensions and complexities of audio-visual association[END_REF][START_REF] Tsiros | The parallels between the study of crossmodal correspondence and the design of cross-sensory mappings[END_REF].

However, in this project, we are not interested in multimodal integration per se, but rather in intermodal analogies, mobilising amodal, i.e. intersensory qualities. CoCAVS plays with human multi-modal perception and the expectation of cross-modal correspondence, but tests its limits by sometimes going against it, i.e. exploring all three levels of audio-visual correspondence in multimedia proposed by Cook [8]: conformance (one-to-one correlation), complementation (of the broad meaning but not contained events), and contest (opposition).

SYSTEM OVERVIEW

The CoCAVS project has the following components, shown in figure 1 which will be described in detail in the next sections:

1. an audio corpus, populated by sound files, segmented and analysed by a number of audio content descriptors,

2. an image corpus, populated by a collection of images, each image analysed by a number of image content descriptors,

3. an audio-visual mapping M , linking some of the audio descriptors with image descriptors, possibly with weightings and inversions, 4. a control input that provides a target position in the AV space (linked by mapping M ) (this is typically coming from a gestural input on a 2D touch input device, allowing to create trajectories with dynamics through pressure sensing), 5. a selection algorithm that finds the audio or visual element closest to the position given by the control input above, 6. a granular rendering engine for the audio part that plays the selected audio segment with possible transformations of envelope, pitch, spectrum, and dynamics, 7. an image rendering engine that displays the selected image with a video fade in and fade out, blended with the possibly still visible previous images,

Audio Analysis

When sound files are imported into the audio corpus, they are put through an analysis stage which calculates the na = 8 audio descriptors listed in table 1: fundamental frequency (pitch), periodicity (corresponding to the continuum between tonal and noisy sounds), and first order autocorrelation coefficient (expressing spectral tilt), estimated by the time-based yin algorithm [START_REF] De Cheveigné | Fundamental Frequency Estimation of Musical Sounds[END_REF]; loudness, and spectral descriptors centroid (corresponding to the perceived brightness of a sound), spread, skewness, kurtosis (describing the overall shape and distribution of the spectrum). The segmentation of the source audio files depends on the type of content. Material with clearly defined events and transients are segmented by an onset detection algorithm based on the loudness descriptor. More uniform material can be segmented by regular intervals.

The time-varying instantaneous descriptors calculated at a period of 6 ms have to be condensed to summarise each of the varying-length segments by a fixed number of values. This temporal modeling stage typically calculates the mean value of each descriptor over each segment, but the standard deviation, min, max, or slope can also be used to more precisely summarise the evolution of each descriptor over the duration of a segment.

Finally, for each segment, the temporal position and extent, source sound index, and summary descriptor values are stored in data tables, constituting, together with the source sounds themselves, the audio corpus.

Visual Descriptors

The image corpus is constituted of digital still images, and nv = 7 image descriptors, listed in table 2, which characterise the perceptive qualities of each image with numerical values. These are calculated as the mean and standard deviation of each channel of the HSL colour representation over all pixels, expressing the average colour (hue), saturation, and luminosity of an image, and the degree of their disparity (variance). As the average hue does not necessarily correspond to any colour existing in the image, the dominant colour descriptor is calculated as the mode of the hue histogram weighted by luminance, i.e. the hue which occurs in the most pixels in the image, where bright pixels count more than dark pixels.

The last five image descriptors are derived from a keypoint or salient feature computer vision analysis of the image by cv.jit, detecting "interesting" image details by edges and their intersections. The number of these keypoints found expresses the overall complexity of the image, and their av-erage position and variance the spatial centre and extent of the region with the most salient details in the image.

Selection and Rendering

Both audio and image corpora are visualised separately as 2D scatterplots by choosing two descriptor dimensions as x and y axis, and two more for size and colour of the points, each point representing one unit, i.e. an audio segment or an image. Fig. 2 shows examples of audio and image corpora 2D visualisations. This visualisation also serves as the navigation interface for interactive concatenative audio or video synthesis, described in section 2.5, where an external controller such as a 2D touch pad allows the player to point to a position in the 2D visualisation. This position is taken as the selection target, i.e. while moving through the 2D space, the segment or image closest to the target position is rendered once.

Audio is rendered by playing the selected audio segment with a given fade in and out envelope to avoid clicks in the audio signal. When the movement through the audio corpus is fast, this can generate clouds of overlapping sound grains. The selected grains can be transformed prior to rendering by filtering or transposition, both with fixed or randomised values, and are typically played at a position in the stereo or surround sound panorama corresponding to their position in the 2D navigation space, possibly also with randomisation. This way, the continuum between preciseness and diffuseness in grain timbre and spatialisation can be explored artistically in expressive performance.

A grain can be triggered when a new point comes closest to the target position, akin to strumming strings, or be triggered at a regular period for repetitive sound or expressive accelerandi or decelerandi, allowing for a rich and varied creation of temporal structure.

The visual rendering uses the simple but efficient scheme of the framebuffer fade out effect to achieve mixing of any number of images, where the newly selected image is superposed on the current framebuffer content with a certain

Audio-Visual Mapping

The key aspect of artistic research of the CoCAVS project is to create and explore links and correspondences between the audio and visual perceptual modalities in the media streams originating from independent source corpora by joint navigation in linked descriptor spaces. The concrete mapping choice and implementation presents three practical problems due to the discreteness, multi-dimensionality, and unrelatedness of the audio and visual source corpora, discussed in the following.

Cross-modal Linking of Perceptual Dimensions

The audio-visual mapping needs to assign the audio descriptor dimensions to the visual descriptor dimensions.

Rather than being strictly grounded on human cross-modal perception, these links can mobilise intermodal analogies [START_REF] Daurer | Audiovisual perception[END_REF] (for instance, audio brightness as expressed by spectral centroid is mapped to image brightness expressed by average luminance). They also are subject of artistic exploration and development of narrative, and can thus change over the duration of a piece. They can create surprise by possibly being the opposite of the "expected" link (e.g. audio brightness being mapped to inverse image brightnesssuch that a brilliant sound will be accompanied by a dark image, and vice versa), thus underlining the independence of each medium by mutually creating space for the other. Technically, in the short time frame of the author's artscience residency, an explicit one-to-one mapping from a subset of the audio perceptual dimensions to visual perceptual dimensions was chosen. For the concert performance at the end of the residency, 1 the two descriptor spaces were linked in 2D for clarity, with the mappings and image corpora per section of the resulting piece shown in table 3. The mappings were chosen empirically to exploit as best as possible salient differences in the rather small image corpora. Indeed, the image corpora used in the residency were mostly collected on site, and counted from around 50 to 450 images, while the audio corpora typically range in the thousands of segments.

Cross-modal Pairing of Sound to Image Units

Once the perceptual dimensions have been linked between audio and image corpora, another question arises: How to link the selection and triggering of sound and image units from the two corpora? There are two different ways to realise this pairing: pre-or post-selection. Pre-selection pairing will use the player-controlled 2D position in the navigation space to derive separate audio and visual target positions. The closest audio and visual units will then be selected separately, which means that there isn't a one-to-one correspondence between audio and visual units.

Post-selection pairing uses the target position from navigation for audio selection, and the selected unit i's audio descriptors ai are then mapped to the visual target position tv via the cross-modal mapping above. The visual unit j closest to tv is then selected. This leads to a unique injective mapping from the audio to the visual corpus: each audio unit corresponds to one specific visual unit (although the same visual unit can be associated to different audio units, and vice versa, and some visual units might not be mapped to any audio unit).

Density Equalisation

A third problem arises from the unequal typical distribution patterns of units in audio and image corpora, as can be seen in figure 2. There are actually two aspects to this problem: First, the touch input controller's navigation space is underused, and second, the cross-modal pairing is highly distorted and uneven, as can be seen in figure 4 (left).

Existing solutions use mass-spring models and triangulation to completely equalise the density of a point cloud [18, Figure 2: Example of an audio corpus (left), visualised using fundamental frequency (x), periodicity (y), and an image corpus (right), visualised using average luminance (x), dominant colour (y). Colour and size of the points reuse the same descriptors as x and y to illustrate the distortion, compared to figure 3 Table 3: List of audio to visual descriptor mappings used in the performance for the 7 pairs of audio and image corpora. In the third part, the performer did not play sounds, but only controlled the image selection.

21]

. This certainly fully optimises the use of the navigation space, but the distortion of the perceptual descriptor spaces is quite high, exacerbating as a result the distortion of the cross-modal pairing. Therefore, a simple but sufficiently efficacious intermediate approach to density equalisation was chosen, which sorts, separately for each dimension, the descriptor values, and replaces them by their sort index (or rank ). For instance, the smallest pitch value will be replaced by zero, and the highest one by the number of units minus one. Fig. 3 shows the corpora from figure 2 after density equalisation by sorting. One can see that this approach keeps clusters of similar units together and thus allows better visual navigation and cluster-to-cluster cross-modal pairing: The vertical lines in the top-left corner of figure 2 (left) are stable individual notes from the bowed piano corpus, which can be accessed deliberately to play expressive melodies. These notes stay together in slightly oblique clumps in figure 3 (left). This distribution also clearly improves the crossmodal pairing in figure 4 (right).

Interaction

The normalised touch input coordinates from the gesture sensing device, here a Sensel Morph 5 pressure-sensitive 2D touch pad to be played with one or more fingers, are mapped to the audio and/or visual navigation space by a direct translation to normalised coordinates in the chosen 2D projection of the audio and visual descriptor spaces.

5 https://sensel.com Multiple finger touches very naturally trigger multiple streams of audio grains. On the video side, there is currently no special handling for these multiple target positions (which would assign a separate layer for parallel rendering of multiple images to each touch input). Yet, the current implementation will cycle through the touch points at each rendering frame, which, together with the framebuffer fadeout technique, leads to mixed streams of images per finger when the attack strength and decay factors are at medium values.

The pressure measurement of each touch point is mapped to a per-grain gain factor for audio rendering, and to the attack strength for image rendering. This leads to the fundamental link of the performer's gesture energy (physical pressure) to overall loudness of the audio stream and overall brightness of the image stream, i.e. to acoustic and visual intensity. This mapping built into the CataRT musical instrument is a foundational element of the author's music performance work, and, augmented by the visual stream, allows to play intertwined audio-visual forms as dynamic musical gestures.

IMPLEMENTATION

The CoCAVS performance system is implemented in Max6 , with the MuBu7 [START_REF] Schnell | MuBu & friends -assembling tools for content based real-time interactive audio processing in Max/MSP[END_REF] and CataRT8 [START_REF] Schwarz | Real-Time Corpus-Based Concatenative Synthesis with CataRT[END_REF][START_REF] Schwarz | Principles and applications of interactive corpus-based concatenative synthesis[END_REF] extension libraries, and making use of Max's Jitter operators for han- dling, processing, and rendering image data (on the CPU and GPU).

It was straightforward to adapt CataRT and its underlying MuBu container for time-based media and data to handle image references and descriptors, instead of audio segments, keeping the same structuring (one MuBu buffer for each external file, one data frame for each unit). This can later be extended to handle multiple sub-images in one image file, or frames extracted from a video file. The only difference is that the image data itself is stored in a Jitter matrix set, and MuBu just stores the matrix index as a reference. CataRT's architecture for importing, analysing, selecting, and rendering audio units was easily adapted to handle image data. Especially the scalable kNN unit selection [START_REF] Schwarz | Scalability in content-based navigation of sound databases[END_REF] is completely agnostic of the media type, since it finds nearest neighbours in a Euclidean descriptor space and outputs the ID of the closest unit(s), which is a segment ID for audio, and an image index for visual corpora.

The image rendering part of CoCAVS runs in the Ableton Live performance sequencer as a Max for Live (M4L) device. The device receives control data via the Open Sound Control (OSC) protocol from the audio rendering part running in a separate Max instance. This is to distribute the CPU load of graphical rendering and UI feedback for the audio part over multiple processors.

DISCUSSION AND FUTURE WORK

In preparing and rehearsing the performance with the Co-CAVS system, one important observation was that the experience of the cross-modal AV mapping between descriptor spaces was almost always overshadowed by the dynamics mapping of touch pressure to audio volume and image intensity. Presumably, this is due to the strong congruence of this mapping (from gesture physical intensity to audio and visual intensity) and its familiar use in musical performance. This could in the future be balanced by a deliberate but not too demonstrative introduction of the AV mapping, with fixed intensity, at some early part of the performance.

Another experience is that the explicit, understandable, and perceptually valid descriptor dimensions of the two corpora are an important enabling feature for the design and artistic creation of cross-modal performances or compositions. This should in future work be compared to datadriven methods from machine learning, e.g. mapping the anonymous dimensions of two latent spaces from two variational auto-encoder (VAE) deep neural networks, one for each modality, as has been explored recently for mapping drawn shapes to temporal sequencer patterns [START_REF] Warren | Latent Drummer: A New Abstraction for Modular Sequencers[END_REF]. However, more literature research needs to be done here to find the most appropriate network architectures for linking disjoint discrete spaces, or even where the mapping could be conditioned on a few human-provided examples.

Regarding the technical development, the next steps could be to complement the image descriptors by, first, an image texturedness estimation [START_REF] Tupin | Definition of a spatial entropy and its use for texture discrimination[END_REF], also usable in the audio domain [START_REF] Fraj | Audio texturedness indicator based on a direct and reverse short listening time analysis[END_REF], second, the detection of salient object(s) with their size, position, and shape, and third, technical image metadata recorded by the camera (year, time of day, focal length, shutter speed, light measurement, zoom factor).

Further, the corpus navigation view of the project, produced at the moment by projection, can be extended in a number of ways of increasing complexity: The techniques of dimensionality reduction such as Principal Component Analysis (PCA), Self-Organising Maps (SOM), t-Distributed Stochastic Embedding (t-SNE), or Uniform Manifold Approximation and Projection (UMAP) [START_REF] Roma | Adaptive mapping of sound collections for data-driven musical interfaces[END_REF], already in use for corpus-based sound synthesis, could be applied analogously to the visual descriptor space, to allow to exploit the full set and structuring of descriptors for multi-modal expressive navigation in both the audio and visual descriptor spaces from a touch controller.

Regarding the cross-modal pairing problem in section 2.4.2, algorithms such as the Kuhn-Munkres ("Hungarian") algorithm for optimal assignment could produce a "better" pairing of audio to image units. However, to answer this question we would first need to define a metric that could capture the quality of a pairing.

Dynamic intermediate models [START_REF] Goudard | Dynamic intermediate models for audiographic synthesis[END_REF] such as massinteraction models could be explored, in order to generate analogous but slightly different navigation behaviours between the audio and visual modalities, from the same gesture input. As an example, the input gestures could move one light simulated mass the position of which determines the target position for navigating the audio descriptor space, closely following the gesture input, but in the visual descriptor space, excite a system of several larger masses with high inertia, to create slowly moving image superpositions that continue to oscillate even after the sound navigation has stopped moving. This allows to design the interaction with the audio and visual modalities such that the temporal dynamics and information flow can be controlled and adapted separately, and the human sensory capacities of each modality can be taken into account (while dense superposition of sound grains creates audio texture, the flicker of constantly changing images might create sensory fatigue in humans).

Lastly, although my artistic inkling tends towards using still images for the visual corpus, an extension to using short image sequences taken from videos as basic unit of visual synthesis can be envisaged. This would pose interesting and complex research questions of cross-modal correspondences not only between the timbre of static sounds and images, but time-varying audio and visual stimuli.

CONCLUSION

CoCAVS explores new ways to probe artistically human multi-modal perception by creating inter-modal associations in gestural navigation in joint audio and image corpora. Thus, it augments timbre-based sonic exploration by colour and texture-based image exploration, sometimes with congruent inter-modal associations, following universal percep-tive expectations [START_REF] Wellek | Die Farbe-Ton-Forschung und ihr erster Kongreß[END_REF], sometimes with contradictory ones. CoCAVS achieves this through a process of practice-based technological and artistic research leading to a software system usable by musicians, and an audio-visual performance piece. 1 The CoCAVS approach of linking the aesthetic surface features of audio and images suggests the extension of a technique of appreciation of musique concrète to images: that of reduced listening coined by Pierre Schaeffer [START_REF] Schaeffer | Traité des objets musicaux[END_REF][START_REF] Schaeffer | Solfège de l'objet sonore[END_REF], where, according to Chion, "The sound is listened to for itself, disregarding the real or supposed origin, and the meaning that it can convey" [START_REF] Chion | Guide des objets sonores[END_REF]. CoCAVS invites to apply this technique to visual perception, leading to what could be termed reduced seeing, where the viewer concentrates on the visual impression of colour, texture, balance, and where, adapting Chion's definition above to the visual domain, The images are seen for themselves, disregarding the real or supposed origin, and the meaning that they can convey.

The created piece revealed an important strand in my subconsious artistic aims when collecting audio and image corpora: My striving to find abstraction in the complexity of the real world such as acoustic scenes with a drone sound that could have been produced by a synthesiser, images of skies that appear like a colour gradient, or textures in nature that suddenly reveal their underlying abstract pattern.

Another telling characteristic of the project is that it is squarely opposed to all trends in modern computer graphics and sound synthesis, where everything is fluid, threedimensional, parametric, and generative. Instead, just short sound grains and still images are used, the appearance of which is not given by parameters of a generative model, but by specifying the desired visual descriptors, modeled after the human sensory perception. And last, images are not generated by a disembodied artificial intelligence, but chosen by the human sensibility of the musician/AV performer and articulated with embodied physical gestures. As such it offers an alternative approach to animation and narrative, creating evolution from instants, and movement out of stillness.

ACKNOWLEDGMENTS

This work has been funded by the Arts, Sciences, Societies residency program 2021-2022 of the IMéRA Institute for Advanced Study, Aix-Marseille Université, and supported by Laboratoire Perception, Représentations, Image, Son, Musique (PRISM), CNRS, Aix-Marseille Université.

ETHICAL STANDARDS

No conflicts of interest (financial or non-financial) have been observed.

Figure 1 :

 1 Figure 1: Data flow diagram of the CoCAVS system with its two parallel strands of processing, linked by the gesture input and AV mapping M . The upper analysis part runs offline, producing the audio and image corpora, while the lower part runs interactively in real time, using the corpora for real-time audio-visual rendering.

Figure 3 :

 3 Figure 3: Example of the corpora in figure 2 after density equalisation. The colour and sizes are mapped to the same descriptors as x/y to show the low distortion this method entails.

Figure 4 :

 4 Figure 4: Example of AV pairing of the corpora in figure 2 without (left), and with density equalisation (right), showing audio units as blue lozenges and image units as orange squares.

Table 1 :

 1 List of CoCAVS audio descriptors.

	Audio Descriptor Name Explanation
	Fundamental Frequency	Mean pitch over segment [Hz]
	Periodicity	Mean pitch strength over segment
	AC1	Mean first order autocorrelation coefficient over segment
	Loudness	Mean A-weighted loudness over segment [dB]
	Spectral Centroid	Mean brightness over segment [Hz]
	Spectral Spread	Mean spectral spread over segment
	Spectral Skewness	Mean spectral skewness over segment
	Spectral Kurtosis	Mean spectral skirt width over segment
	Image Descriptor Name	Explanation
	HueAvg, HueVar	Mean and standard deviation of pixel hue (colour value)
	SaturationAvg, SaturationVar	Mean and standard deviation of pixel saturation
	LuminanceAvg, LuminanceVar Mean and standard deviation of pixel brightness
	Color	Dominant colour
	Complexity	Number of keypoints
	XAvg, XVar	Mean and standard deviation of keypoint x positions
	YAvg, YVar	Mean and standard deviation of keypoint y positions

Table 2 :

 2 List of CoCAVS image descriptors.luminance scaling (attack strength), either replacing it or mixing in the new image. The framebuffer pixels' RGB values are then multiplied by a decay factor, achieving a fade out in a given time. When triggered, each image is added to the framebuffer during a number of frames given by the hold time parameter, which, together with the attack strength, can be used to achieve a fade in of a new image. As for audio rendering, either images are triggered based on movement, when the target position comes closer to a new point, or at regular intervals the currently closest image is triggered.

  .

	Audio Corpus Audio Descriptors X/Y	Image Descriptor Mapping X/Y Image Corpus
	Prepared Piano	SpectralCentroid FundamentalFrequency LuminanceAvg Color	Skies 1
	Wind, Waves			Complexity	SaturationAvg	Ruins
	-	-	-	LuminanceAvg SaturationAvg	Bioluminescence
	Metallic Attacks			XAvg	Complexity	Plants
	Prepared Piano			Color	SaturationAvg	Natural textures
	Bowed Piano			Complexity	Color	Flowers
	Extended Violin SpectralCentroid Periodicity	LuminanceAvg Color	Skies 2

Performance for Audio-Visual Concatenative Synthesis & Violin: https://youtu.be/EFAN9fOofd0

http://ismm.ircam.fr/catart

http://cycling74.com/max

https://www.vjamm.com

http://cycling74.com/max

https://forum.ircam.fr/projects/detail/mubu

http://ismm.ircam.fr/catart


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Cyril Verrecchia

SL Teacher: a Framework for teaching LSF on the Web

In this paper, we present SL Teacher, a framework for teaching French sign language using web 2.0 and virtual signer technologies. We present here the main features of the web-based framework that supports the sign lexicon animation and the dynamic sign language utterances generation. After describing the technical issues of our proposed framework, we discuss the tradeoffs and the ensuing simplifications applied in order to insure a good level of interactivity with the users in the low bandwidth context of web systems. We present the symbolic representation of the sign language utterances and the associated construction procedure. Finally the implementation, accessible on the web, is illustrated here with an example of a simple teaching task that requires all the features of the SL Teacher framework.

Introduction 1.1 Objective

This paper presents the first step of a project dedicated to French Sign Language (LSF) learning supported by means of a Web environment. E-learning tools dedicated to sign language (SL) can be useful both for deaf and hearing people: as a first language to the deaf or as a second language to the hearing. As for any other natural language, learning the lexicon is not sufficient, and exercises, e.g. about utterance organization, are of primary importance. For SL, that entails 1) visual-based applications are required, due to the gestural/visual channel used by these languages, and 2) strong interactive capabilities are also required as in any e-learning tool.

New technologies such as Web 2.0, virtual signer, language processing and automatic generation allow now envisioning such applications. Hence the two main complementary features of the SL Teacher project are: 1) a web-based framework for teaching SL 2) by means of a virtual signer.

In section 1.2 we present several kinds of existing e-learning applications and technologies. Section 2 presents the technical issues of our proposed framework and section 3 describes the methodology developed for the dynamic construction and the animation of SL-utterances. Finally, section 4 gives an example of typical SL exercises that can be developed within this framework.

E-learning applications dedicated to SL

Today, SL tools have been deployed in two main environments: Web pages and standalone applications.

1 Most operational web-based applications dedicated to SL focus on bilingual dictionaries. They are based on the display of video recordings of human subjects. Up now, little work has been carried on web-based virtual signers. Virtual signer applications have been deployed in both Web pages and standalone environments. They rely on two main approaches: pre-synthesized animations and generated animations.

-Pre-synthesized animations are first synthesized, and then selected according to the context. For example, motion capture can be applied on realistic or non realistic virtual signers. The one in figure 1, is used in Mathsigner, an interactive learning tool to improve the mathematical abilities of deaf children [START_REF] Adamo-Villani | A natural interface for sign language mathematics[END_REF]. These animations are not accurate (many 'cleaning' post-processes have to be performed on the signal) and do not take into account significant features of SL: e.g. gaze, facial expressions, and torso movements. Moreover, as the animations rely on a numerical signal, it is hard to manipulate them, as opposed to language generated animation methods. -Generated animations are an alternative approach consisting in automatic and real-time generation of animations from description languages. For example, the SigML description language [START_REF] Elliott | An Overview of the SiGML Notation and SiGML Signing Software System[END_REF], based on the HamNoSys phonetic system dedicated to sign languages [START_REF] Prillwitz | Hamburg notation system for sign languages: An introductory guide[END_REF], is used as input in a given signing animation software. It allows the generation of animations that provide flexibility, but at the cost of realism. Java applets or VRML-based applications allow interaction within a web page, such as the Signing Science Dictionary [START_REF]Signing Science[END_REF] (see figure 2).

Figure 2: The Signing Science Dictionary.

Regardless the chosen approach for animation, he main drawback of all these applications is that the virtual signer is encased into a 'box', separated from the rest of the application, and its interaction with the content is minimalistic. Actually, it is limited to the control of the display of the virtual signer (moving, rotating, scale, speed control etc.). In these applications, the signing agents have no access to the informational content of the web page.

The architecture of any SL Teacher application entails two complementary main issues: 1) How can we propose an architecture that allows realistic virtual signers to be fully and effectively integrated onto web pages? So that people can have an easy internet-based access to SL tools.

2) How can we propose an architecture that allows the dynamic building and the subsequent animation of SL utterances? So that people can practice SL-utterance construction and can also observe (at leisure) their animation in lively exercises.

The two following sections present the way we have dealt with these issues.

2. An architecture for fully integration of virtual signer on web pages 2.1 Supporting framework: The DIVA toolkit DIVA stands for DOM Integrated Virtual Agents, emphasizing the unique feature of DIVA virtual agents that are completely integrated with the DOM (Document Object Model) tree structure of web pages. It has been designed at LIMSI laboratory [START_REF]DIVA toolkit homepage[END_REF] with the three main objectives:

-A toolkit dedicated to Assisting Conversational Agents, a subclass of Embodied Conversational Agents (ECAs) [START_REF]Embodied Conversational Agents[END_REF] whose function is to provide assistance for novice users in front of unfamiliar applications. Note: in this particular context, textual natural language interaction plays a primary role; this issue will not be discussed here even if it is relevant when multimodal deictic assisting agents are concerned; -An open programming framework, developed for teaching and research purposes, making it easy and quick to develop and deploy new experimental ECAs in web-based applications; -A completely DOM-integrated software architecture making it easy for the DIVA ECAs to access, both in read/modify modes, to the inner structure of the applications/services supported by the web pages.

The web architecture of DIVA is displayed in figure 3a. It is composed of two main layers:

-A server layer dedicated to data base resources management and symbolic computing; -A rich-client layer supporting: The specific application/service web page; the animation of the graphic characters; the process of the textual natural language interaction.

The DIVA toolkit is a full Web

DOM-integrated virtual characters

The first objective of the DIVA toolkit is to develop a fully DOM-integrated environment for animated graphic characters in order to provide a high degree of interaction with the DOM-structure and the informational content of the webpage. Therefore, DIVA characters are part of the DOM structure that contains several DOM objects of type <div> supporting various capabilities: display, drag&drop, resizing, iconifying, animation, speech display, etc. (see figure 3b.).

Due to the unique feature of DIVA agents where everything is supported by <div> objects in the DOM of the client page, users can interact with the agents while using multimodal inputs: by typing utterances in the chat box but also with the mouse acting upon the graphic display in various ways. Another advantage of the full integration of the DIVA agents in the DOM structure is that the rich-client application can have a direct and complete access to the structure and the runtime of the application.

The contributions of this approach are related to the interaction capabilities and the easiness to design new applications. The drawbacks are related to the animation engine.

For the time being, only pre-synthesized animations approach can be used. The key issues related to the SL utterance generation and animation, in this context, are discussed in the following section.

Dynamic building and animation of SL utterances

Key issues and simplifications

For the linguistic side, several complex issues have also to be taken into account when dealing with SL utterances generation. SL is a visual and gestural language that uses manual and non-manual features. A SL utterance is composed of a sequence of gestural units (signs) involving the upper body, the arms and hands, the face and gaze. All these elements are articulated in the space located in front of the signer, so-called signing space. Moreover, signs have variable realisations, highly depending on the meaning context [START_REF] Cuxac | The Expression of Spatial Relations and the Spatialization of Semantic Relations in French Sign Language. Language Diversity and Cognitive Representations[END_REF]. Thus, SL utterance synthesis implies to design specific spatio-temporal grammar rules, quite different from the ones in use for vocal language generation [START_REF] Braffort | Sign language applications: preliminary modeling[END_REF]. Moreover, the coarticulation process influences both manual and non-manual features when a sign is performed in an utterance. This phenomenon has been studied for few years in SL synthesis research field [START_REF] Segouat | A Study of Sign Language Coarticulation[END_REF], but there are several studies in SL recognition [START_REF] Vogler | Toward Scalability in ASL Recognition: Breaking Down Signs into Phonemes GW '99[END_REF] etc. It is a complex process that has not yet been modelled accurately so far.

For all these reasons, we have decided to manage the generation of the SL-utterances as follow:

-A SL utterance is built by concatenation of signs.

-Each sign is displayed as a predefined animation, built using the rotoscopy technique, allowing a good realistic rendering [START_REF] Sansonnet | Towards interactive web-based signing avatars[END_REF] for more details). -For all the signs the realisation of which varies regarding to the context (e.g. pointing), we predefine several realisations (e.g. six for pointing, three to the left and three to the right); note that their combinatory is limited because we restrict to context-dependent utterances. -For the coarticulation sign animations, we use one or more intermediary postures (chosen dynamically, according to the context): typically, hands are in front of the chest for signs, and the dominant hand is in front of the shoulder for dactylology. -Lastly, in order to build animations as realistic as possible, each utterance contains prologue and epilogue stances, allowing the virtual signer to begin and end the utterance in a rest posture (denoted 'Stand-still' where the avatar fidgets just a little to suggest life).

Constitution of SL-utterances

SL Teacher utterances are based on four kinds of entities:

1) Two coarticulation postures denoted: @ = the Stand-still posture (arms down near the waist); o = the SL-still posture (hands in front of the navel).

2) Two animations associated with the postures: PROLOG moves the arms from the Stand-still posture @ to the SL-still posture o; EPILOG moves the arms from the SL-still posture o to the Stand-still posture @;

3) Constant SL signs (taken from the LSF lexicon), for example: HOME denotes the animated movie associated with "home" in LSF; DOG denotes the animated movie associated with "dog" in LSF; EAT denotes the animated movie associated with "to eat" in LSF; Etc.

4) The _variable_ signs have a dynamically computed value which is a constant SL sign.

Variable signs are used when their value depends on the context. For example: _POINTING_ is a variable deictic gesture towards a clicked object: its value depends on the relative spatial position of the agent and the object so it has to be chosen between six different directions, entailing six different realisations; _SIGNNAME_ is a variable that contains the "sign name" animation associated with a specific person known in the application; _GOTO_ is a directional verb which beginning and ending spatial location depends on the beginning and ending towns, country etc. world locations in the signing space.

Example: Suppose we want the avatar to point with its finger on the picture of a specific person displayed on the screen and to give his/her associated sign-name in an utterance like "His sign-name is 'chirping-bird' (first author sign-name)". We dynamically build the following symbolic representation of the SL-utterance S which is composed of six animations containing three static signs and three variable signs:

S = [ @ PROLOG o _POINTING_ o SIGNNAME o _OFHIS_ o _SIGNNAME_ o EPILOG @ ]
In reaction to some GUI event (like the user clicking on the picture of a person on screen), the variables _POINTING_, _OFHIS_ and _SIGNNAME_ are instantiated in context.

Then the animation sequence S is built and played immediately.

Example: LSF teaching for hearing beginners

While designing an e-learning application, the main issue relates to pedagogical aspects which are not yet well ascertained. For example, in France, LSF has only been officially recognised in 2005. The pedagogical references are just being elaborated by working groups of the French Ministry of Education and are correlated to the European reference for the learning of language in general. Hence, pedagogical issues are not discussed in this paper but will be subject to further studies.

In order to put our framework to the test, we are developing several demos and experiments that can be accessed at the LIMSI Gestural Agents webpage [START_REF]Gestural Agents URL[END_REF]. In this section, we will restrict to the description of one typical experiment dedicated to the support of LSF teaching for hearing people which are beginners in LSF. The proposed page could be part of a future web-based course.

In the web page displayed in figure 4, the pedagogical intention is to make the student familiar with the specific ordering of the syntagms in a SL-utterance, namely the so-called "WHEN-WHERE-WHO-WHAT(ACTION)" typical order [START_REF] Companys | LSF mode d'emploi. L'expression par la pensée visuelle[END_REF] without forgetting that LSF being a natural language it cannot be restricted to strict formal rules; because of the naturalness and the iconicity of the language, there are other manners to perform those written sentences.

Figure 4: SL Teacher web-page with ELSI virtual signer playing a SL-utterance. Note that here the number of sign-words is limited for the experiment.

For example, the utterance: "Jeremie work at home this morning" is (preferably) expressed in LSF as: < MORNING -HOME -JEREMIE -TOWORK >. The table on screen enables the students to compose various SL-utterances by picking sign-words in the table (column after column), thus respecting a typical LSF ordering. Notice that we don't deal with French to LSF translation as we follow the sign order given by the user through the interface.

Then the students can make the character ELSI to play their dynamically composed SLutterances, at leisure, that is they can repeat, slow down, accelerate, etc., the animation.

Conclusion

This paper presents SLTeacher, a framework for the teaching of the French Sign Language using web 2.0 and virtual signer technologies. We discussed the key issues and the tradeoffs that were related to the constraints in a web environment: the SL utterances are composed of concatenated pre-defined animations of signs which realisations are chosen regarding the context. Intermediate stances are used as replacement of real coarticulation.

At this moment, the implementation on the DIVA framework of a first SL teaching page with a typical exercise has been done, and our first prototype can be accessed at the DIVA SL Teacher Web page [14]. In a preliminary qualitative evaluation by a deaf person (fourth author), animations are considered fluid, and intermediate postures do not disturb the clear understanding of the SL-utterances. Real evaluation by deaf users is planned during this year. This first actual experiment will allow us to start an evaluation process, in order to validate, adapt or correct some of the choices we made, such as those of the intermediate stances; the first step being to define an adequate evaluation methodology.

In a further step, we will have to extends SLTeacher capabilities, in collaboration with deaf SL teachers, and include SL processing in order to provide for example automatic corrections.

Figure 1 :

 1 Figure 1: Mathsigner: a) Motion capture phase b) Application interface.

Figure 3 :

 3 Figure 3: a) Web architecture of DIVA. b) The DOM structure of a signing avatar.

  2.0 rich client technology based on JavaScript, Java Server Pages and Mathematica from Wolfram Research. It was intended to work with IE 6+ and Mozilla-based navigators (Firefox, Safari and Chrome). DIVA can be deployed in two main modes: 1) the rich-client mode enables web-apps to work locally, i.e. without server

					Here is the Earth Globe …
	Mathematica	Wolfram Mathematica 6 SYMBOLIC COMPUTING
					Server
	Java	Apache Tomcat with JSP servlet
	JavaScript DHTML XML	Graphical Characters Animation Engine	Ajax Http link manager	English/French Chat bot	Client i

capabilities; 2) the symbolic-server mode offers more powerful web architecture but it requires an additional Mathematica engine. Main mouse-sensitive area: -mouse-clicks (select, iconifying, …) -mouse drags -mouse resizing Balloon: speech display area Head mouse-sensitive area (emits internal events when the mouse is over) Animation area Extra display area: plays animated .gifs It is resized with the character)


Cedric Ribeiro

Hui Guo

Lieselot De Smet

Khaled Belal

Aurelien Vebr

Aurélie Malfait

Gaëlle Le Fer

Joel Lyskawa

Jonathan Potier

Dominique Hourdet

Aurelien Vebr

Thermoresponsive

Aurélien Vebr

Aurelie Malfait

Gaelle Le Fer

François Stoffelbach

Alba Marcellan

Richard Hoogenboom

Patrice Woisel
email: patrice.woisel@centralelille.fr

Thermoresponsive polymers and host-guest chemistry: a win-win combination

Keywords: Thermoresponsive polymers, Host-guest complexation, memory function, synergistic control of the host reactivity

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The combination of heat-sensitivepolymers and supramolecular chemistry has recently led to the development of fascinating adaptive materials. In this context, most studies have focused on exploiting host-guest interactions to control the physicochemical properties of polymeric materials. 1 This approach has notably enabled the creation of materials with programmable thermosensitivity and sensor properties. 2 In contrast, the exploitation of polymer thermoresponsiveness to control the recognition properties of hostguest systems at the molecular level is much less developed, and a perfect understanding of the mechanisms triggering thermo-induced decomplexation or complexation is still elusive. In this communication, we will illustrate through three studies how the host-guest chemistry and the thermo-induced phase separation mechanisms can "talk together" to synergistically tune the coil↔globule transition and the complexation state of polymeric systems. The first example 3 concerns a comparative analysis of the behaviour of complexes formed from different naphthalene end-functionalized LCST or UCST polymers and the electron-deficient cyclobis(paraquat-p-phenylene) tetrachloride (CBPQT 4+ , 4Cl - ) 3 host when subjected to heat treatment. This study provided an understanding of the mechanisms triggering the thermo-induced (de)complexation of such complexes. The second study reports a supramolecular approach for developing an intelligent thermoresponsive polymeric hydrogel featuring a dual temperature and time memory function based on a kinetic control of the material's (de)complexation and (re) swelling behaviours. The last study illustrates how a thermo-induced phase separation mechanism can regulate on demand the Diels-alder reactivity of a synthetic self-complexing host-guest molecular switch CBPQT 4+ -Fu, consisting of an electron-rich furan unit covalently attached to the electrondeficient CBPQT 4+ host, with maleimide in water. Thanks to a supramolecular control over the topology of CBPQT 4+ -Fu combined with a thermoresponsive supramolecular regulator, we reported a rare example of decreased reactivity upon increasing temperature.

References :

1) V. R. de la Rosa and coll., Mater. Today, 2016, 19, 44-55; 2) N. Herzer and coll. J. Am. Chem. Soc. 2012, 134, 7608-7611; 3) H. Guo and coll.Polym. Chem. 2022,13;25, 3742-3749, 4) P. R. Ashton and coll. Angew. Chem., 1988Chem., , 27, 1550Chem., -1553 ; ;5)

  L. De Smet and coll.ACS Materials Letters, 2022,5;1, 235-242; 6) C. Ribeiro and coll. submitted


Mathilde Dacos

Guillaume Sicard

Dorian Protzenko

Sarah Giacometti

Joseph Ciccolini

Raphaelle Fanciullino Smartc

Crcm Compo

Nanoliposomes harness tumor immunity in breast cancer model

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

▪ Small size of the groups prevented statistical tests to be ran. ▪ However: ✓ No difference was found in GrMDSCs and MoMDSCs between treatment vs. control (data not shown).

✓ After two-weeks of treatment, MD ANC showed immunomodulating optimal features (i.e., higher CD8+ cells and reduction in Tregs). ✓ Single Dosing is not sufficient to trigger increase in CD8+ cells in tumors. ▪ Sequencing treatments with immunotherapy (i.e., 2-week delay after nanoparticles) could be the best strategy to achieve synergism.

DISCUSSION PERSPECTIVES

Contact : mathilde.dacos@ap-hm.fr

No clear impact of the nanoparticles was observed from D-1 to D-18.

On Day-7, SD ANC showed markedly lower Treg/CD45 ratio and higher CD8/Treg ratio CD8 Compared to control, treating with MD ANC leads to higher CD8/CD45 ratio in Blood, Spleen and Tumors.

▪

  of-concept study aimed at: ▪ Monitor the impact of lipidic nanoparticules on immune cells in immuno-competent mice bearing murine breast cancer. ▪ Identify the time-window during which immunomodulation is maximal. ▪ Compare single dose and multiple dose scheduling with nanoparticles. treatment once (single dose schedule SD) or every week (multiple dose schedule MD) over 3 weeks by IV retro-orbital injection Blank liposome (LIPO) Preliminary results suggest that tumor immunity could be reshaped with nanoparticles. ▪ Impact of MD ANC loaded with docetaxel is currently ongoing. ▪ Efficacy study with combined immune checkpoint inhibitor is ongoing.

  SD with nanoparticles leads to a reduction in CD8+ cells in Blood and Tumors.TregAll treatments induced a decrease in Tregs in Blood and Tumors. Conversely, more Tregs were found in spleen after MD ANC treatment.


Patrice Woisel

Thermoresponsive polymers and host-guest chemistry: a win-win combination

Keywords: Thermoresponsive polymers, Host-guest complexation, memory function, synergistic control of host reactivity

The combination of heat-sensitive polymers and supramolecular chemistry has recently led to the development of fascinating adaptive materials. In this context, most studies have focused on exploiting host-guest interactions to control the physicochemical properties of polymeric materials. 1 This approach has notably enabled the creation of materials with programmable thermosensitivity and sensor properties. 2 In contrast, the exploitation of polymer thermoresponsiveness to control the recognition properties of hostguest systems at the molecular level is much less developed, and a perfect understanding of the mechanisms triggering thermo-induced decomplexation or complexation is still elusive. In this communication, we will illustrate through three studies how the host-guest chemistry and the thermo-induced phase separation mechanisms can "talk together" to synergistically tune the coil↔globule transition and the complexation state of polymeric systems. The first example 3 will concern a comparative analysis of the behaviour of complexes formed from different naphthalene end-functionalized LCST or UCST polymers and the electron-deficient cyclobis(paraquat-p-phenylene) tetrachloride (CBPQT 4+ , 4Cl - ) 3 host when subjected to heat treatment. This study provided an understanding of the mechanisms triggering the thermo-induced (de)complexation of such complexes. The second study will report a supramolecular approach for developing an intelligent thermoresponsive polymeric hydrogel featuring a dual temperature and time memory function based on a kinetic control of the material's (de)complexation and (re) swelling behaviours. The last study will illustrate how a thermo-induced phase separation mechanism can regulate on demand the Diels-alder reactivity of a synthetic self-complexing host-guest molecular switch CBPQT 4+ -Fu, consisting of an electron-rich furan unit covalently attached to the electrondeficient CBPQT 4+ host, with maleimide in water. Thanks to a supramolecular control over the topology of CBPQT 4+ -Fu combined with a thermoresponsive supramolecular regulator, we reported a rare example of decreased reactivity upon increasing temperature. References :

  1) V. R. de laRosa and coll., Mater. Today, 2016, 19, 44-55; 2) N. Herzer and coll. J. Am. Chem. Soc. 2012, 134, 7608-7611; 3) H. Guo and coll. Polym. Chem. 2022,13;25, 3742-3749, 4) P. R. Ashton and coll. Angew. Chem., 1988, 27, 1550-1553; 5) L. De Smet and coll. ACS Materials Letters, 2022,5;1, 235-242; 6) C. Ribeiro and coll. submitted


Claudine Médigue

Alexandra Calteau

Stéphane Cruveiller

Mathieu Gachet

Guillaume Gautreau

Adrien Josso

Aurélie Lajus

Jordan Langlois

Hugo Pereira

Rémi Planel

David Vallenet

Mathieu Dubois

David Roche

Zoé Rouy

Mylène Beuvin

Céline Chevalier

Johan Rollin

Valentin Sabatet

MicroScope: an integrated platform for the annotation and exploration of microbial gene functions through genomic and metabolic comparative analysis

de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

• MicroScope is part of National infrastructures:

• France Génomique (www.france-genomique. • Computational results

• Genomic Object

• Primary databanks

Analyses Curations

Relational Database (PkGDB)

Users & Interactions

: users from France, : users from Europe, North America, South America, Africa, Asia, Oceania.

XX -XX : shared genome -annotators

Gene editor

Current annotation

Primary annotation

Method results

Genomic map of the annotated genome

  com) • IFB (www.france-bioinformatique.fr) • Collaborations with industrials & Biotech companies • ANR projects (Replay, BlueEnzyme) • European project (IS-Elixir)

within single/multiple tools • Search in single/multiple organisms Keyword search Group together homologous genes sharing the same local organization in compared genomes Collaborations & Services References

	>100 genomes
	50-100 genomes
	<50 genomes

• Search

CDSs Synteny map Coding prediction curve RNA Selection area Repeat Regions The

  Quality Management System of the LABGeM team has been certified according the ISO 9001:2015 and NF X50-900:2016 standards for its activities of research, developments, services and MicroScope trainings.

Genome completion and contamination:

CheckM Reference Database

• A genome tree of 5656 organisms (43 conserved genes)

• Lineage-specific markers (single copy genes and present in >97% of the genomes)


Adrien Fournier

Damien Fron

Michel Bonnevalle

Bernard Herbaux

Aurélie Mezel

Eric Nectoux
email: eric.nectoux@chru-lille.fr

Original bar fixation technique in minimally invasive repair of pectus excavatum in adolescents: a 36-case series

Keywords: Pectus excavatum, Nuss procedure, minimally invasive surgery, bar fixation

In pectus excavatum, minimally invasive endoscopic repair is the current gold standard in adolescents. The main postoperative pitfall is bar displacement, making fixation a major issue. We report an original transcostal technique using absorbable USP-2 suture in 36 patients.

There was a single case of bar displacement (2.78%; 95% CI, 0.07-14.53).

Bar stability was comparable to literature reports; but the present technique avoided the complications potentially incurred by use of metal wire, pericostal fixation points and stabilizers.

Introduction

Pectus excavatum mainly affects males [START_REF] Faglin | The unsightly chest: Analysis and anomaly. Curative or palliative approach?[END_REF] and is usually present from birth. The deformity persists or worsens during rapid thorax growth at puberty. Impact is mainly psychological, or more rarely cardiorespiratory. The Nuss procedure, also known as minimally invasive repair of pectus excavatum (MIRPE), is the gold standard in adolescence, providing lasting results [START_REF] Felts | Child pectus excavatum: Correction by minimally invasive surgery[END_REF][START_REF] Nuss | A 10-year review of a minimally invasive technique for the correction of pectus excavatum[END_REF]. It has become an attractive alternative to sternochondroplasty, with smaller lateral scars and conserved costal cartilage [START_REF] Wurtz | Simplified open repair for anterior chest wall deformities. Analysis of results in 205 patients[END_REF].

There are, however, complications: secondary bar displacement, with risk of recurrence and of mediastinal injury, and residual pain at the fixation points [START_REF] Felts | Child pectus excavatum: Correction by minimally invasive surgery[END_REF][START_REF] Nuss | A 10-year review of a minimally invasive technique for the correction of pectus excavatum[END_REF][START_REF] Wurtz | Simplified open repair for anterior chest wall deformities. Analysis of results in 205 patients[END_REF][START_REF] Nuss | Indications and technique of Nuss procedure for pectus excavatum[END_REF]. Kabbaj et al. [START_REF] Kabbaj | Minimally invasive repair of pectus excavatum using the Nuss technique in children and adolescents: indications, outcomes, and limitations[END_REF] described costal bar fixation by pericostal wire, with a single case of traumatic displacement in a series of 70 patients. Bond et al. [START_REF] Bond | Results of pectus excavatum correction using a minimally invasive approach with subxyphoid incision and three-point fixation[END_REF] described use of pericostal and subxyphoid absorbable suture, with only 2 cases of displacement in 73 patients. And Yoo et al. [START_REF] Yoo | Emerging Fixation Technique to Prevent Pectus Bar Displacement: Needlescope-Assisted 3-Point Fixation[END_REF] reported zero displacement in 44 patients, using "sutureless" fixation with 2 bars connected by metal devices. The present technique extends the range of bar fixation options, using absorbable transcostal suture. It seems technically easier than pericostal suture and less expensive than use of stabilizers, and facilitates hardware removal.

2.Surgical technique

Bar placement follows the princeps technique described by Nuss et al. [START_REF] Nuss | A 10-year review of a minimally invasive technique for the correction of pectus excavatum[END_REF].

The configuration between the ribs and the emergence of the bar is analyzed, and an absorbable USP (United States Pharmacopeia) size 2 polyglactin 910 transcostal suture is performed using a large needle under the positioned bar, facing the notches (Medxpert, Eschbach, Germany) intended for stabilizer fixation (Figures 1 and2). If possible, a second suture is made contralaterally. No drainage is used.

Movement and sport are restricted:

-no twist or lateral flexion of the trunk for 3 weeks; -no individual sports activity for 6 weeks; -no team sports for 3 months.

The bar is removed at 2 years.

Study population and results

Thirty-seven pectus excavatum patients operated on by this technique between January 2010 and December 2016 were included, 1 of whom was subsequently excluded for early bar ablation due to infection.

Table 1 shows results, and Table 2 complications. There was 1 case of neurologic deficit, in the left upper-limb C5 and C6 root territories due to bad sleep posture, in a patient receiving morphine derivatives. There was 1 case of bar displacement: 1/36, 2.78%; 95% CI, 0.07-14.53.

Discussion

Incidence of bar displacement was comparable to the 2.1% reported by Nuss and Kelly [START_REF] Nuss | Indications and technique of Nuss procedure for pectus excavatum[END_REF] for stabilizers associated to pericostal suture, within the present 95% confidence interval, suggesting no real difference.

The present technique has several advantages:

-Absorbable suture avoids the complications of metal wire breakage (subcutaneous irritation, pulmonary parenchyma lesion) and facilitates subsequent bar removal.

-Transcostal, unlike pericostal, suture avoids intercostal needle passage with risk of neurovascular bundle lesion (neuropathic pain, dysesthesia, bleeding with hemopneumothorax) or pulmonary parenchyma lesion.

-The absence of stabilizer reduces local discomfort and scar disorder, reduces procedural cost and shortens operative time.

Conclusion

The present study demonstrated the efficacy and safety of this bar fixation technique over follow-up until removal: only 1 displacement was observed, out of 36 cases.

Figure legends

Figure 1 :

 1 Figure 1: Bar fixation by absorbable transcostal suture. Left: cross-sectional view; bar in front, rib behind.

Figure 2 :

 2 Figure 2: Intraoperative photographs. 2A: Transcostal passage of suture, positioning the two ends in the notches on either side of the bar. 2B: Tying to bar.

Table 1 :

 1 Patient data (n=36).Qualitative variables reported as number (percentage), and quantitative variables as mean ±standard deviation (range).

	Male n(%)

Table 2 :

 2 Postoperative complications (n = 36)

	Bar displacement	1 (2,78)
	Thoracic drainage	2 (5.56)
	Neuropathic pain	4 (11.1)
	Hardware discomfort	0 (0.0)
	Pneumopathy	1 (2.78)
	Atelectasis	2 (5.56)
	Metal allergy	1 (2.78)
	Neurologic deficit	1 (2.78)
	Data reported as number (percentage).

Acknowledgments

Thanks to Pr Jean-Luc Jouve and Pr Henri Migaud for kindly re-editing the manuscript.

Thanks to Mr Martinet, medical illustrator, for his contribution to the illustrations.

Funding

The University of Lille 2 -Law and Health medical faculty provided funding for the illustrations.

Author contributions

Eric Nectoux: study concept and design, re-editing.

Adrien Fournier: data collection, analysis and interpretation, article writing.

Damien Fron, Michel Bonnevalle, Bernard Herbaux, Aurélie Mézel: re-editing and advice.

Conflicts of interest

The authors have no conflicts of interest to disclose.


Mathilde Dacos

Erwann Diroff

Sarah Giacometti

Loic Osanno

Joseph Ciccolini

Raphaëlle Fanciullino

Liposomal formulation of docetaxel: biodistribution and immunomodulatory benefit in HER2 breast cancer treatment

Small size of the groups prevented statistical tests to be ran After two-weeks of treatment, MD ANC showed immunomodulating optimal features (i.e., higher CD8+ cells and reduction in Tregs). Single Dosing is not sufficient to trigger increase in CD8+ cells in tumors Sequencing treatments with immunotherapy (i.e., 2-week delay after nanoparticles) could be the best strategy to achieve synergism.

ANC Multiple (n=12) & single dosing (n=14) (MD & SD) LIPO Multiple (n=14) & single dosing (n=12) (MD & SD) Group : CTL (n=13) vs

Plasma sample Flow Cytometry

HPLC UV

Compared to control, treating with MD ANC leads to higher CD8/CD45 ratio in Blood, Spleen and Tumors. SD with nanoparticles leads to a reduction in CD8+ cells in Blood and Tumors.

All treatments induced a decrease in Tregs in Blood and Tumors. Conversely, more Tregs were found in spleen after MD ANC treatment.

Liposomal docetaxel showed higher values of AUC compared to non-liposomal docetaxel due to the liposomal encapsulation These preliminary results suggest the development of a promising immunoliposome for :

Systemic administration of docetaxel in HER2+ breast cancer with optimal pharmacokinetics.

Reshaping tumor immunity