Valorisation of local agro-industrial processing waters as growth media for polyhydroxyalkanoates (PHA) production

International audiencePolyhydroxyalkanoates (PHA) are bacterial polyesters usually produced from costly sugars or volatile fatty acids (VFAs). In this work, two processing waters rich in vegetable proteins and reducing sugars, i.e., a mixture of saccharose and stachyose in Leguminous Processing Water (LPW) and a mixture of glucose and fructose in Fruit Processing Water (FPW), were tested as growth medium for PHA production in a two-stage fermentation with a unique marine bacterial species: Halomonas i4786. In preliminary shake flask experiments, it was shown that the two media can effectively support the bacterial growth and the accumulation of PHA (evaluated using Nile Red staining). In batch cultivation mode in a 5-L fermentor, PHA productivities of 1.6 g L−1 and 1.8 g L−1 were further achieved within 72 h, in LPW and FPW respectively. Polymer characterization by Differential Scanning Calorimetry and Steric Exclusion Chromatography indicated that the two substrates led to the biosynthesis of polymers with different chain length, distribution and crystallinity. To summarize, these results show that by-products derived from local agri-food industry can be used as a user-adapted and cost-effective source to produce bio-sourced and biodegradable plastic material

Predicting mental imagery based BCI performance from personality, cognitive profile and neurophysiological patterns

Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy— EEG), which is processed while they perform specific mental tasks. While very promising, MI-BCIs remain barely used outside laboratories because of the difficulty encountered by users to control them. Indeed, although some users obtain good control performances after training, a substantial proportion remains unable to reliably control an MI-BCI. This huge variability in user-performance led the community to look for predictors of MI-BCI control ability. However, these predictors were only explored for motor-imagery based BCIs, and mostly for a single training session per subject. In this study, 18 participants were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2 of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships between the participants’ BCI control performances and their personality, cognitive profile and neurophysiological markers were explored. While no relevant relationships with neurophysiological markers were found, strong correlations between MI-BCI performances and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive model of MI-BCI performance based on psychometric questionnaire scores was proposed. A leave-one-subject-out cross validation process revealed the stability and reliability of this model: it enabled to predict participants’ performance with a mean error of less than 3 points. This study determined how users’ profiles impact their MI-BCI control ability and thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of each user

Mechanisms of HsSAS-6 assembly promoting centriole formation in human cells

SAS-6 proteins are thought to impart the ninefold symmetry of centrioles, but the mechanisms by which their assembly occurs within cells remain elusive. In this paper, we provide evidence that the N-terminal, coiled-coil, and C-terminal domains of HsSAS-6 are each required for procentriole formation in human cells. Moreover, the coiled coil is necessary and sufficient to mediate HsSAS-6 centrosomal targeting. High-resolution imaging reveals that GFP-tagged HsSAS-6 variants localize in a torus around the base of the parental centriole before S phase, perhaps indicative of an initial loading platform. Moreover, fluorescence recovery after photobleaching analysis demonstrates that HsSAS-6 is immobilized progressively at centrosomes during cell cycle progression. Using fluorescence correlation spectroscopy and three-dimensional stochastic optical reconstruction microscopy, we uncover that HsSAS-6 is present in the cytoplasm primarily as a homodimer and that its oligomerization into a ninefold symmetrical ring occurs at centrioles. Together, our findings lead us to propose a mechanism whereby HsSAS-6 homodimers are targeted to centrosomes where the local environment and high concentration of HsSAS-6 promote oligomerization, thus initiating procentriole formation

Pourquoi les enfants en résidence alternée ont-ils mieux vécu le premier confinement ?

Les premiers travaux réalisés sur les effets du confinement du printemps 2020 sur les enfants ont établi que ceux qui étaient en résidence alternée l’avaient mieux vécu que les autres. L’objectif de cet article est de comprendre pourquoi. À partir de l’enquête Sapris (Santé, perception, pratiques, relations et inégalités sociales pendant la crise Covid-19) et plus particulièrement du sous-échantillon des enfants âgés de 8-9 ans des cohortes Elfe et Epipage2, nous comparons les conséquences du confinement sur les enfants selon la structure familiale dans laquelle ils vivaient (famille nucléaire, monoparentale ou en résidence alternée). Continu dans les familles nucléaires, le temps familial est habituellement beaucoup plus fractionné entre les résidences des parents pour les enfants de familles séparées. Le confinement est venu transformer les expériences habituelles du temps familial pour les enfants, aussi bien dans son organisation que dans sa texture. Il a modifié leur cadre de vie ordinaire, en réorganisant leurs occupations au quotidien et en modifiant leurs relations avec leurs parents. En observant particulièrement les différences apparues entre les résidences alternées qui ont continué et celles qui ont été interrompues, nous montrons que si les mouvements réguliers des enfants ont pu constituer une respiration bienvenue pour les différents acteurs concernés, les alternances interrompues ont ouvert des espaces exceptionnels dans lesquels il a été possible de renouer avec des formes passées de continuité familiale

Creating Accessible Interactive Audio-Tactile Drawings Using Spatial Augmented Reality

International audienceInteractive tactile graphics have shown a true potential for people with visual impairments, for instance for acquiring spatial knowledge. Until today, however, they are not well adopted in real-life settings (e.g. special education schools). One obstacle consists in the creation of these media, which requires specific skills, such as the use of vector-graphic software for drawing and inserting interactive zones, which is challenging for stakeholders (social workers, teachers, families of people with visual impairments, etc.). We explored how a Spatial Augmented Reality approach can enhance the creation of interactive tactile graphics by sighted users. We developed the system using a participatory design method. A user study showed that the augmented reality device allowed stakeholders (N=28) to create interactive tactile graphics more efficiently than with a regular vector-drawing software (baseline), independently of their technical background

Tangible interactions in control centres for railway traffic management

International audienceA current trend in rail industry control centres is to move towards an increase in the number of digitaltools to assist operators. Our observations show that the information used by rail controllers is distributedamong different interfaces. Operators must assemble all this information themselves to understand thestate of the system. This task is often done mentally, resulting in difficult information sharing and aslower decision process. It is in this search for improvement of the operational centres that we realizeda prototype of a tangible touch table presented in this article. The first tests are underway and allowus to have rather positive feedback on this technology that operators are not familiar with. The nextiterations will focus on refining the prototype and on experimenting with a larger group of users

Inclusive Adaptation of Existing Board Games for Gamers with and without Visual Impairments using a Spatial Augmented Reality Framework for Touch Detection and Audio Feedback

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Thiol-ene clickable hyaluronans: From macro-to nanogels

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