Advantages and limitations of virtual reality for balance assessment and rehabilitation

International audienceVirtual reality (VR) is now commonly used in many domains because of its ability to provide a standardized, reproducible and controllable environment. In balance assessment, it can be used to control stimuli presented to patients and thus accurately evaluate their progression or compare them to different populations in standardized situations. In balance rehabilitation, VR allows the creation of new generation tools and at the same time the means to assess the efficiency of each parameter of these tools in order to optimize them. Moreover, with the development of low-cost devices, this rehabilitation can be continued at home, making access to these tools much easier, in addition to their entertaining and thus motivating properties. Nevertheless, and even more with low-cost systems, VR has limits that can alter the results of the studies that use it: the latency of the system (the delay cumulated on each step of the process from data acquisition on the patients to multimodal outputs); and distance perception, which tends to be underestimated in VR. After having described why VR is an essential tool for balance assessment and rehabilitation and illustrated this statement with a case study, this review discusses the previous works in the domain with regards to the technological limits of V

Unconventional surface plasmon resonance signals reveal quantitative inhibition of transcriptional repressor EthR by synthetic ligands

International audienceEthR is a mycobacterial repressor that limits the bioactivation of ethionamide, a commonly used anti-tuberculosis second-line drug. Several efforts have been deployed to identify EthR inhibitors abolishing the DNA-binding activity of the repressor. This led to the demonstration that stimulating the bioactivation of ETH through EthR inhibition could be an alternative way to fight Mycobacterium tuberculosis. We propose a new SPR methodology to study the affinity between inhibitors and EthR. Interestingly, the binding between inhibitors and immobilized EthR produced a dose dependent negative SPR signal. We demonstrated that this signal reveals the affinity of the small molecules for the repressor. The affinity constants (KD) correlated with their capacity to inhibit the binding of EthR to DNA. We hypothesize that conformational changes of EthR during ligand interaction could be responsible for this SPR signal. Practically, this unconventional result open perspectives to the development of SPR assay that would at the same time tough on the structural changes of the target upon binding with an inhibitor and on the binding constant of this interaction

High‐Throughput Miniaturized Screening of Nanoparticle Formation via Inkjet Printing

This is the peer reviewed version of the following article:Ioanna D. Styliari, et al, ‘High‐Throughput Miniaturized Screening of Nanoparticle Formation via Inkjet Printing’, Macromolecular Materials and Engineering, (2018), which has been published in final form at https://doi.org/10.1002/mame.201800146. Under embargo until 27 May 2019. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The self‐assembly of specific polymers into well‐defined nanoparticles (NPs) is of great interest to the pharmaceutical industry as the resultant materials can act as drug delivery vehicles. In this work, a high‐throughput method to screen the ability of polymers to self‐assemble into NPs using a picoliter inkjet printer is presented. By dispensing polymer solutions in dimethyl sulfoxide (DMSO) from the printer into the wells of a 96‐well plate, containing water as an antisolvent, 50 suspensions are screened for nanoparticle formation rapidly using only nanoliters to microliters. A variety of polymer classes are used and in situ characterization of the submicroliter nanosuspensions shows that the particle size distributions match those of nanoparticles made from bulk suspensions. Dispensing organic polymer solutions into well plates via the printer is thus shown to be a reproducible and fast method for screening nanoparticle formation which uses two to three orders of magnitude less material than conventional techniques. Finally, a pilot study for a high‐throughput pipeline of nanoparticle production, physical property characterization, and cytocompatibility demonstrates the feasibility of the printing approach for screening of nanodrug delivery formulations. Nanoparticles are produced in the well plates, characterized for size and evaluated for effects on metabolic activity of lung cancer cells.Peer reviewe

From preimplantation diagnosis to herd monitoring: what does genomics bring to breeders?

Genomic selection is now fully implemented in breeding programs conducted by French breeding companies in Holstein, Normande and Montbeliard breeds. Initially, genotyping has been implemented by companies in selection schemes. This method enables to estimate the genetic potential of an animal at birth, thus shortening considerably the schedule of selection schemes and lowering its cost. In this context, optimizing reproductive biotechnologies has become a strategic priority. This may be achieved through different scenarii combining production of in vivo derived embryos and embryo transfer (ET) and the oocyte retrieval. Nowadays, one of the major challenges for reproductive biotechnologies is the realization of a pre-implantation diagnosis, from a small number of cells taken from the embryo, which opens new perspectives. In addition, since the opening of a genotyping service to French dairy farmers in 2011, genomic selection moved apace in farms from Montbeliard, Holstein, Red Pie and Normande breeds. In farms, genotyping of females is a new management tool enabling to sort heifers from birth, to refine the choice of bulls for an optimized breeding management, to control inbreeding together with genetic level and to anticipate breeding plans (choice of reproduction type and / or use of sexed semen). These tools may help to reach sustainable breeding practices, at collective and individual levels and are expected to evolve with the continuous optimization of genotyping toolsLa sélection génomique est aujourd’hui pleinement appliquée dans les programmes de sélection menés par les entreprises de sélection françaises Prim’Holstein, Normande et Montbéliarde. Dans un premier temps, le génotypage a été principalement valorisé par les entreprises dans la mise en oeuvre des schémas de sélection. Optimiser les techniques de reproduction est devenu un axe stratégique, en combinant la production d’embryons, l’utilisation de la superovulation et du transfert d’embryon (TE), ainsi que la ponction d’ovocytes. Aujourd’hui, un des défis majeurs des biotechnologies de la reproduction est la réalisation d’un diagnostic pré-implantatoire, à partir d’un petit nombre de cellules prélevées chez l’embryon, qui ouvre de nouvelles perspectives. En outre, depuis l’ouverture du service de génotypage aux éleveurs bovins laitiers français en 2011, la sélection génomique s’installe à grands pas au sein des élevages des races Montbéliarde, Prim’Holstein, Pie Rouge et Normande. En élevage, le génotypage des femelles est un nouvel outil de management, facilitant le tri des génisses de renouvellement, permettant d’affiner les accouplements par un choix des taureaux optimisé, de contrôler la consanguinité au niveau génétique et d’anticiper les plans d’accouplement (choix du mode de reproduction et/ou utilisation de semence sexée). Ces applications doivent permettre d’atteindre des pratiques de reproduction durables, au niveau collectif autant qu’individuel et devraient encore évoluer avec l’amélioration continue des outils de génotypag

Mechanical control of morphogenesis at the shoot apex

Morphogenesis does not just require the correct expression of patterning genes; these genes must induce the precise mechanical changes necessary to produce a new form. Mechanical characterization of plant growth is not new; however, in recent years, new technologies and interdisciplinary collaborations have made it feasible in young tissues such as the shoot apex. Analysis of tissues where active growth and developmental patterning are taking place has revealed biologically significant variability in mechanical properties and has even suggested that mechanical changes in the tissue can feed back to direct morphogenesis. Here, an overview is given of the current understanding of the mechanical dynamics and its influence on cellular and developmental processes in the shoot apex. We are only starting to uncover the mechanical basis of morphogenesis, and many exciting questions remain to be answere

Ligand-Induced Incompatible Curvatures Control Ultrathin Nanoplatelet Polymorphism and Chirality

The ability of thin materials to shape-shift is a common occurrence that leads to dynamic pattern formation and function in natural and man-made structures. However, harnessing this concept to design inorganic structures at the nanoscale rationally has remained far from reach due to a lack of fundamental understanding of the essential physical components. Here, we show that the interaction between organic ligands and the nanocrystal surface is responsible for the full range of chiral shapes seen in colloidal nanoplatelets. The adsorption of ligands results in incompatible curvatures on the top and bottom surfaces of NPL, causing them to deform into helico\"ids, helical ribbons, or tubes depending on the lateral dimensions and crystallographic orientation of the NPL. We demonstrate that nanoplatelets belong to the broad class of geometrically frustrated assemblies and exhibit one of their hallmark features: a transition between helico\"ids and helical ribbons at a critical width. The effective curvature $\bar{\kappa}$ is the single aggregate parameter that encodes the details of the ligand/surface interaction, determining the nanoplatelets' geometry for a given width and crystallographic orientation. The conceptual framework described here will aid the rational design of dynamic, chiral nanostructures with high fundamental and practical relevance.Comment: 16 pages, 8 figure

Impact of respiratory viruses in intensive care unit patient with community-acquired pneumonia : a one-year retrospective single-centre study.

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Multi-modality image simulation with the Virtual Imaging Platform: Illustration on cardiac echography and MRI

International audienceMedical image simulation is useful for biological modeling, image analysis, and designing new imaging devices but it is not widely available due to the complexity of simulators, the scarcity of object models, and the heaviness of the associated computations. This paper presents the Virtual Imaging Platform, an openly-accessible web platform for multi-modality image simulation. The integration of simulators and models is described and exemplified on simulated cardiac MRIs and ultrasonic images

Antarctic ice sheet paleo-constraint database

We present a database of observational constraints on past Antarctic Ice Sheet changes during the last glacial cycle intended to consolidate the observations that represent our understanding of past Antarctic changes, for state-space estimation, and paleo-model calibrations. The database is a major expansion of the initial work of Briggs and Tarasov (2013). It includes new data types and multi-tier data quality assessment. The updated constraint database “AntICE2” consists of observations of past grounded and floating ice sheet extent, past ice thickness, past relative sea level, borehole temperature profiles, and present-day bedrock displacement rates. In addition to paleo-observations, the present-day ice sheet geometry and surface ice velocities are incorporated to constrain the present-day ice sheet configuration. The method by which the data is curated using explicitly defined criteria is detailed. Moreover, the observational uncertainties are specified. The methodology by which the constraint database can be applied to evaluate a given ice sheet reconstruction is discussed. The implementation of the “AntICE2” database for Antarctic Ice Sheet model calibrations will improve Antarctic Ice Sheet predictions during past warm and cold periods and yield more robust paleo model spin ups for forecasting future ice sheet changes