SyTroN: a virtual classroom for collaborative and distant e-learning systemby teleoperating real devices

Distant E-learning is a main issue nowadays, and it is strongly motivated by social and economical considerations. The increased people mobility and the reduction of educational costs push to develop ad hoc solutions enabling to access to knowledge regardless to geographical situation and economical capabilities. These parameters should not be limits for good training: learning material's pertinence and efficiency have to remain the core of educational activities. In this paper we address the problem through SyTroN: a tele-learning system. This system combines virtual reality and teleoperation techniques to offer an open platform with two main objectives. The first one is to propose intuitive virtual classrooms/desks, including a real teacher supervision and supporting collaborative and individual distant learning. The second goal is to place learners in real conditions with remote connections to real devices allowing distant experimentations. Both goals participate to increase learning impacts and to reduce costs, that is, sharing costly real devices from anywhere at any time. After 5 years of development, our work has been validated by an extensive use at a high engineering school. In situ tests and learning impact studies have been done. They show some advantages and some drawbacks of our global solution

A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions

The aim of this study was to develop a three-dimensional (3D) model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line). The model was characterised by transmission electron microscopy (TEM), immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity. Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D) substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium

Systemic virus distribution and host responses in brain and intestine of chickens infected with low pathogenic or high pathogenic avian influenza virus

<p>Abstract</p> <p>Background</p> <p>Avian influenza virus (AIV) is classified into two pathotypes, low pathogenic (LP) and high pathogenic (HP), based on virulence in chickens.</p> <p>Differences in pathogenicity between HPAIV and LPAIV might eventually be related to specific characteristics of strains, tissue tropism and host responses.</p> <p>Methods</p> <p>To study differences in disease development between HPAIV and LPAIV, we examined the first appearance and eventual load of viral RNA in multiple organs as well as host responses in brain and intestine of chickens infected with two closely related H7N1 HPAIV or LPAIV strains.</p> <p>Results</p> <p>Both H7N1 HPAIV and LPAIV spread systemically in chickens after a combined intranasal/intratracheal inoculation. In brain, large differences in viral RNA load and host gene expression were found between H7N1 HPAIV and LPAIV infected chickens. Chicken embryo brain cell culture studies revealed that both HPAIV and LPAIV could infect cultivated embryonic brain cells, but in accordance with the absence of the necessary proteases, replication of LPAIV was limited. Furthermore, TUNEL assay indicated apoptosis in brain of HPAIV infected chickens only. In intestine, where endoproteases that cleave HA of LPAIV are available, we found minimal differences in the amount of viral RNA and a large overlap in the transcriptional responses between HPAIV and LPAIV infected chickens. Interestingly, brain and ileum differed clearly in the cellular pathways that were regulated upon an AI infection.</p> <p>Conclusions</p> <p>Although both H7N1 HPAIV and LPAIV RNA was detected in a broad range of tissues beyond the respiratory and gastrointestinal tract, our observations indicate that differences in pathogenicity and mortality between HPAIV and LPAIV could originate from differences in virus replication and the resulting host responses in vital organs like the brain.</p

Transport Rankings of Non-Steroidal Antiinflammatory Drugs across Blood-Brain Barrier In Vitro Models

The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB) in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line) for proper data comparison

Group transport study of NSAIDs across RBMEC.

*<p>Ratio to Diazepam is calculated by average PE_cell data of the investigated NSAID and the corresponding diazepam value.</p><p>Summary of permeability data of the group study with NSAIDs piroxicam, ibuprofen, meloxicam, tenoxicam and diclofenac across the RBMEC cell layers (n = 3, data are presented as means ± SD).</p

Characterization of the BBB model based on primary rat brain microvascular endothelial cells (RBMEC) and astrocytes.

<p>RBMECs grow in endothelial cell typical spindle-like morphology proven by light and scanning electron microscopy (SEM). Transmission electron microscopic (TEM) images confirmed that RBMEC grow as a monolayer. The enlarged part of the image shows two RBMECs connected to each other directly over a pore of the Transwell insert membrane (A). mRNA expressions of tight junction proteins ZO-1, occludin, claudin-3, claudin-5 and claudin-12, and of adhesion molecules PECAM-1, VCAM, ICAM-1 and CD44. All data were related to endogenous control GAPDH which was set to 1000 (B). Immunofluorescence images of PECAM-1, ZO-1, occludin, claudin-3 and claudin-5 confirmed the protein’s presence and localization in RBMEC layers (C). Transport studies with paracellular marker APTS-dextran ladder confirmed functionality of the barrier. RBMEC layers were able to differentiate between the different dextran fractions in a molecular size-dependent manner. Comparison of the permeability coefficients for APTS-dextran across PBMEC/C1-2, ECV304 and RBMEC layers is presented in the table on the right side (D).</p

RayPortals: a light transport editing framework

International audiencePhysically based rendering, using path-space formulation of global illumination, has become a standard technique for high-quality computer-generated imagery. Nonetheless, being able to control and edit the resulting picture so that it corresponds to the artist vision is still a tedious trial-and-error process. We show how the manipulation of light transport translates into the path-space integral formulation of the rendering equation. We introduce portals as a path-space manipulation tool to edit and control renderings and show how our editing tool unifies and extends previous work on lighting editing. Portals allow the artist to precisely control the final aspect of the image without modifying neither scene geometry nor lighting setup. According to the setup of two geometric handles and a simple path selection filter, portals capture specific lightpaths and teleport them through 3D space. We implement portals in major path-based algorithms (Photon Mapping, Progressive Photon Mapping and Bi-directional Path Tracing) and demonstrate the wide range of control this technique allows on various lighting effects, from low-frequency color bleeding to high-frequency caustics as well as view-dependent reflections

Rankings of the group transport studies with NSAIDs across PBMEC/C1-2 layers.

<p>Permeability coefficient of each substance was normalized to the corresponding permeability coefficient of internal standard diazepam of the same experiment. <b>A):</b> Variant substance compositions - results of the group study with all investigated substances (diazepam, piroxicam, ibuprofen, meloxicam, tenoxicam, diclofenac, celecoxib, carboxyfluorescein = CF) were compared to the study without celecoxib (w/o CC), without celecoxib accomplished in serum-free C6 medium (serum-free), without celecoxib accomplished in PBMEC-Fib medium (GCM  =  glioma conditioned medium) and without celecoxib and carboxyfluorescein (w/o CF). <b>B):</b> Different transport study conditions - results of the group study with all investigated substances (diazepam, piroxicam, ibuprofen, meloxicam, tenoxicam, diclofenac, celecoxib, carboxyfluorescein = CF) were compared to the study without meloxicam (w/o MEL), without meloxicam and with probenecid (with Probenecid) and without meloxicam and with verapamil (with Verapamil). To calculate the statistical significances between the groups, which differed in the substance compositions, a one-way ANOVA was used, to compare the groups with same substance compositions under different experimental transport conditions (in A: w/o CC, serum-free medium, GCM; in B: w/o MEL, with Probenecid, with Verapamil) a two-way ANOVA was accomplished followed by an all pairwise multiple comparison procedure (Holm-Sidak method) with an overall significance level of 0.05. Statistical significance (p<0.05) for each substance is indicated in the figure by * (all vs. w/o CC, all vs. w/o MEL), by # (w/o CC vs. serum-free or GCM; w/o MEL vs. with Probenecid or with Verapamil), by § (serum-free vs. GCM; with Probenecid vs. with Verapamil) or by $ (w/o CC vs. w/o CF). Data are presented as means ± SD (n = 3).</p