Perceiving Mass in Mixed Reality through Pseudo-Haptic Rendering of Newton's Third Law

In mixed reality, real objects can be used to interact with virtual objects. However, unlike in the real world, real objects do not encounter any opposite reaction force when pushing against virtual objects. The lack of reaction force during manipulation prevents users from perceiving the mass of virtual objects. Although this could be addressed by equipping real objects with force-feedback devices, such a solution remains complex and impractical.In this work, we present a technique to produce an illusion of mass without any active force-feedback mechanism. This is achieved by simulating the effects of this reaction force in a purely visual way. A first study demonstrates that our technique indeed allows users to differentiate light virtual objects from heavy virtual objects. In addition, it shows that the illusion is immediately effective, with no prior training. In a second study, we measure the lowest mass difference (JND) that can be perceived with this technique. The effectiveness and ease of implementation of our solution provides an opportunity to enhance mixed reality interaction at no additional cost

Additional Clues for a Protective Role ofVitamin D in Neurodegenerative Diseases: 1,25-Dihydroxyvitamin D3 Triggers an Anti-Inflammatory Response in BrainPericytes

International audienceEpidemiological and experimental studies suggest that 1,25-dihydroxyvitamin D3 (1,25D) plays a neuroprotectiverole in neurodegenerative diseases including Alzheimer's disease. Most of the experimental data regarding the genes regulatedby this hormone in brain cells have been obtained with neuron and glial cells. Pericytes play a critical role in brain function thatencompasses their classical function in blood-brain barrier control and maintenance. However, the gene response of brain pericyteto 1,25D remains to be investigated. Analyses of the transcriptomic response of human brain pericytes to 1,25D demonstrate thathuman brain pericytes in culture respond to 1,25D by regulating genes involved in the control of neuroinflammation. In addition,ericytes respond to the pro-inflammatory cytokines tumor necrosis factor and Interferon by inducing the expression of theCYP27B1 gene which is involved in 1,25D synthesis. Taken together, these results suggest that neuroinflammation could triggerthe synthesis of 1,25D by brain pericytes, which in turn respond to the hormone by a global anti-inflammatory response. Thesefindings identify brain pericytes as a novel 1,25D-responsive cell type and provide additional evidence for the potential value ofvitamin D in the prevention or therapy of Alzheimer's disease and other neurodegenerative/neuropsychiatric diseases associatedwith an inflammatory component

Comparative proteomic profiles of Aspergillus fumigatus and Aspergillus lentulus strains by surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS)

<p>Abstract</p> <p>Background</p> <p>Surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) was applied to analyze the protein profiles in both somatic and metabolic extracts of <it>Aspergillus </it>species. The study was carried out on some <it>Aspergillus </it>species within the <it>Fumigati </it>section (<it>Aspergillus fumigatus </it>wild-types and natural abnormally pigmented mutants, and <it>Aspergillus lentulus</it>). The aim was to validate whether mass spectrometry protein profiles can be used as specific signatures to discriminate different <it>Aspergillus </it>species or even mutants within the same species.</p> <p>Results</p> <p>The growth conditions and the SELDI-TOF parameters were determined to generate characteristic protein profiles of somatic and metabolic extracts of <it>Aspergillus fumigatus </it>strains using five different ProteinChips^®, eight growth conditions combining two temperatures, two media and two oxygenation conditions. Nine strains were investigated: three wild-types and four natural abnormally pigmented mutant strains of <it>A. fumigatus </it>and two strains of <it>A. lentulus</it>. A total of 242 fungal extracts were prepared. The spectra obtained are protein signatures linked to the physiological states of fungal strains depending on culture conditions. The best resolutions were obtained using the chromatographic surfaces CM10, NP20 and H50 with fractions of fungi grown on modified Sabouraud medium at 37°C in static condition. Under these conditions, the SELDI-TOF analysis allowed <it>A. fumigatus </it>and <it>A. lentulus </it>strains to be grouped into distinct clusters.</p> <p>Conclusions</p> <p>SELDI-TOF analysis distinguishes <it>A. fumigatus </it>from <it>A. lentulus </it>strains and moreover, permits separate clusters of natural abnormally pigmented <it>A. fumigatus </it>strains to be obtained. In addition, this methodology allowed us to point out fungal components specifically produced by a wild-type strain or natural mutants. It offers attractive potential for further studies of the <it>Aspergillus </it>biology or pathogenesis.</p

Translation of the ecological trap concept to glioma therapy: the cancer cell trap concept: The cancer cell trap concept.

International audienceViewing tumors as ecosystems offers the opportunity to consider how ecological concepts can be translated to novel therapeutic perspectives. The ecological trap concept emerged approximately half a century ago when it was observed that animals can prefer an environment of low quality for survival over other available environments of higher quality. The presence of such a trap can drive a local population to extinction. The cancer cell trap concept is the translation of the ecological trap into glioma therapy. It exploits and diverts the invasive potential of glioma cells by guiding their migration towards specific locations where a local therapy can be delivered efficiently. This illustrates how an ecological concept can change therapeutic obstacles into therapeutic tools

Analysis of Locally Coupled 3D Manipulation Mappings Based on Mobile Device Motion

We examine a class of techniques for 3D object manipulation on mobile devices, in which the device's physical motion is applied to 3D objects displayed on the device itself. This "local coupling" between input and display creates specific challenges compared to manipulation techniques designed for monitor-based or immersive virtual environments. Our work focuses specifically on the mapping between device motion and object motion. We review existing manipulation techniques and introduce a formal description of the main mappings under a common notation. Based on this notation, we analyze these mappings and their properties in order to answer crucial usability questions. We first investigate how the 3D objects should move on the screen, since the screen also moves with the mobile device during manipulation. We then investigate the effects of a limited range of manipulation and present a number of solutions to overcome this constraint. This work provides a theoretical framework to better understand the properties of locally-coupled 3D manipulation mappings based on mobile device motion

Increased Phosphorylation of Vimentin in Noninfiltrative Meningiomas

International audienceBACKGROUND: Tissue invasion or tissue infiltration are clinical behaviors of a poor-prognosis subset of meningiomas. We carried out proteomic analyses of tissue extracts to discover new markers to accurately distinguish between infiltrative and noninfiltrative meningiomas. METHODOLOGY/PRINCIPAL FINDINGS: Protein lysates of 64 different tissue samples (including two brain-invasive and 32 infiltrative tumors) were submitted to SELDI-TOF mass spectrometric analysis. Mass profiles were used to build up both unsupervised and supervised hierarchical clustering. One marker was found at high levels in noninvasive and noninfiltrative tumors and appeared to be a discriminative marker for clustering infiltrative and/or invasive meningiomas versus noninvasive meningiomas in two distinct subsets. Sensitivity and specificity were 86.7% and 100%, respectively. This marker was purified and identified as a multiphosphorylated form of vimentin, a cytoskeletal protein expressed in meningiomas. CONCLUSIONS/SIGNIFICANCE: Specific forms of vimentin can be surrogate molecular indicators of the invasive/infiltrative phenotype in tumors

MicroRNA and Target Protein Patterns Reveal Physiopathological Features of Glioma Subtypes

Gliomas such as oligodendrogliomas (ODG) and glioblastomas (GBM) are brain tumours with different clinical outcomes. Histology-based classification of these tumour types is often difficult. Therefore the first aim of this study was to gain microRNA data that can be used as reliable signatures of oligodendrogliomas and glioblastomas. We investigated the levels of 282 microRNAs using membrane-array hybridisation and real-time PCR in ODG, GBM and control brain tissues. In comparison to these control tissues, 26 deregulated microRNAs were identified in tumours and the tissue levels of seven microRNAs (miR-21, miR-128, miR-132, miR-134, miR-155, miR-210 and miR-409-5p) appropriately discriminated oligodendrogliomas from glioblastomas. Genomic, epigenomic and host gene expression studies were conducted to investigate the mechanisms involved in these deregulations. Another aim of this study was to better understand glioma physiopathology looking for targets of deregulated microRNAs. We discovered that some targets of these microRNAs such as STAT3, PTBP1 or SIRT1 are differentially expressed in gliomas consistent with deregulation of microRNA expression. Moreover, MDH1, the target of several deregulated microRNAs, is repressed in glioblastomas, making an intramitochondrial-NAD reduction mediated by the mitochondrial aspartate-malate shuttle unlikely. Understanding the connections between microRNAs and bioenergetic pathways in gliomas may lead to identification of novel therapeutic targets

Nouvelles approches pour la portabilité, la non-intrusivité et l'accessibilité des interfaces de manipulation 3D

This work focuses on 3D interaction with virtual objects, more specifically on 3D manipulation: selection, translation, and rotation. The most commonly-used interaction platforms (personal computer, mobile device) were designed for 2D interaction and thus are not well suited to 3D manipulation. There is a more efficient alternative for this task: virtual reality. However, current virtual reality systems are too often bulky, expensive and/or intrusive to the user, and for these reasons remain underused. In this thesis, we propose and study new solutions to make this form of interaction more convenient without reducing its effectiveness. The main objectives we aim for are interface portability, non-intrusiveness, and the use of readily-available hardware. We propose a first approach to simultaneously meet the above criteria. It consists in combining a standard mobile device (for its portability and widespread availability) with passive tangible objects (for efficient 3D manipulation in a non-intrusive manner). Yet, this approach still has drawbacks: it is made of multiple parts that must always be carried together, and is not suitable for adding force-feedback using haptic devices. We thus introduce a new technique, called “decoupling”, that allows the user to perceive virtual forces through the visual modality alone. Based on the concept of “pseudo-haptics”, this technique makes it possible to provide force feedback without the constraints associated with actual haptic devices. We then study a different approach intended to be fully integrated, enhancing the portability aspect compared to an interface made of multiple parts. This approach consists in using the motion of the mobile device itself to manipulate 3D objects displayed on its own screen. However, this “locally-coupled” configuration presents several unique characteristics that make manipulation more complex. We thus investigate the questions raised by this specific configuration. Finally, we introduce a last approach, called the “tangible volume”, aimed at regaining the same directness of manipulation as with tangible objects but in a single integrated device. We describe an early implementation of such a device, and discuss its technical feasibility as well as its potential accessibility to end users in the short and medium term.Ce travail porte sur l'interaction avec des objets virtuels 3D, et plus particulièrement leur manipulation : sélection, translation et rotation. Les plates-formes les plus utilisées aujourd'hui pour ce type de tâche (ordinateur personnel et appareil mobile) ont été conçues avant tout pour l'interaction 2D, et sont donc peu adaptées à la manipulation 3D. Il existe pourtant une alternative plus efficace : les systèmes de réalité virtuelle. Cependant, les systèmes actuellement disponibles restent trop souvent encombrants, onéreux et/ou intrusifs pour l'utilisateur, et demeurent sous-utilisés pour cette raison. Dans cette thèse, nous étudions de nouvelles approches pour rendre ce type d'interaction moins contraignant, tout en conservant une bonne efficacité de manipulation. Les principaux axes explorés sont la portabilité de l'interface, sa non-intrusivité, et l'utilisation de dispositifs plus largement accessibles au grand public. Nous proposons une première approche visant à répondre simultanément aux critères ci-dessus. Celle-ci consiste à combiner un appareil mobile classique (pour sa portabilité et son accessibilité) avec des objets tangibles passifs (pour une manipulation 3D efficace et non-intrusive). Cette approche présente toutefois encore certaines contraintes : elle est constituée de multiples éléments qui doivent être transportés ensemble, et elle ne se prête pas à l'utilisation de dispositifs à retour de force. Nous introduisons donc dans un deuxième temps une nouvelle technique, appelée «découplage». Basée sur le principe du «pseudo-haptique», celle-ci permet à l'utilisateur de percevoir des forces virtuelles à travers la seule modalité visuelle. Il devient alors possible de se passer complètement de dispositifs haptiques, et des contraintes qui leur sont associées. Nous nous intéressons ensuite à une approche entièrement intégrée, visant à améliorer la portabilité par-rapport à une interface faite d'éléments séparés. Cette approche consiste à se servir des déplacements de l'appareil mobile lui-même dans l'espace réel pour manipuler des objets 3D affichés sur son propre écran. Cette configuration «localement couplée» présente cependant plusieurs particularités qui rendent la manipulation plus complexe. Nous examinons donc en détail les différentes questions que pose cette configuration spécifique. Nous proposons enfin une dernière approche, appelée le «volume tangible», visant à retrouver la simplicité de la manipulation par objets tangibles mais dans un unique dispositif intégré. Nous décrivons une première implémentation de ce dispositif, et discutons de sa faisabilité technique ainsi que de l'accessibilité de cette approche à court et moyen terme

ETUDE DE L'EXPRESSION DE PLUSIEURS CONSTITUANTS DU SYSTEME OXPHOS MITOCHONDRIAL

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF