Videos in Context for Telecommunication and Spatial Browsing

The research presented in this thesis explores the use of videos embedded in panoramic imagery to transmit spatial and temporal information describing remote environments and their dynamics. Virtual environments (VEs) through which users can explore remote locations are rapidly emerging as a popular medium of presence and remote collaboration. However, capturing visual representation of locations to be used in VEs is usually a tedious process that requires either manual modelling of environments or the employment of specific hardware. Capturing environment dynamics is not straightforward either, and it is usually performed through specific tracking hardware. Similarly, browsing large unstructured video-collections with available tools is difficult, as the abundance of spatial and temporal information makes them hard to comprehend. At the same time, on a spectrum between 3D VEs and 2D images, panoramas lie in between, as they offer the same 2D images accessibility while preserving 3D virtual environments surrounding representation. For this reason, panoramas are an attractive basis for videoconferencing and browsing tools as they can relate several videos temporally and spatially. This research explores methods to acquire, fuse, render and stream data coming from heterogeneous cameras, with the help of panoramic imagery. Three distinct but interrelated questions are addressed. First, the thesis considers how spatially localised video can be used to increase the spatial information transmitted during video mediated communication, and if this improves quality of communication. Second, the research asks whether videos in panoramic context can be used to convey spatial and temporal information of a remote place and the dynamics within, and if this improves users' performance in tasks that require spatio-temporal thinking. Finally, the thesis considers whether there is an impact of display type on reasoning about events within videos in panoramic context. These research questions were investigated over three experiments, covering scenarios common to computer-supported cooperative work and video browsing. To support the investigation, two distinct video+context systems were developed. The first telecommunication experiment compared our videos in context interface with fully-panoramic video and conventional webcam video conferencing in an object placement scenario. The second experiment investigated the impact of videos in panoramic context on quality of spatio-temporal thinking during localization tasks. To support the experiment, a novel interface to video-collection in panoramic context was developed and compared with common video-browsing tools. The final experimental study investigated the impact of display type on reasoning about events. The study explored three adaptations of our video-collection interface to three display types. The overall conclusion is that videos in panoramic context offer a valid solution to spatio-temporal exploration of remote locations. Our approach presents a richer visual representation in terms of space and time than standard tools, showing that providing panoramic contexts to video collections makes spatio-temporal tasks easier. To this end, videos in context are suitable alternative to more difficult, and often expensive solutions. These findings are beneficial to many applications, including teleconferencing, virtual tourism and remote assistance

Effect of prophylactic timolol 0.1% gel on intraocular pressure after an intravitreal injection of ranibizumab: a randomized study

Purpose: The purpose of this study is to make a prospective evaluation of the effect of timolol 0.1% eye gel on short-term intraocular pressure (IOP) after an intravitreal injection (IVI) of ranibizumab. Participants and methods: One hundred and fifty eyes of 150 IVI-naïve patients with macular edema caused by various pathological conditions (age-related macular degeneration, central or branch retinal vein occlusion, and diabetic retinopathy) were scheduled to undergo an IVI of ranibizumab (0.5 mg/0.05 cc). The patients were randomly divided into three groups: 50 were not treated with timolol before the IVI (group 1); 50 received an instillation of timolol 0.1% eye gel the evening before the IVI (group 2); and 50 received an instillation of timolol 0.1% eye gel 2 hours before the IVI (group 3). The incidence of clinically significant intraocular hypertensive spikes (>25 mmHg and >40 mmHg) was then assessed. Results: Our findings showed that mean IOP at baseline was significantly higher than at both 5 and 60 minutes after IVI (P25 mmHg were recorded at either time in 27 patients (54%) in group 1, 23 patients (44%) in group 2, and 24 patients (48%) in group 3. None of the between-group differences were significant. Spikes of >40 mmHg (which were only detected 5 minutes after IVI) were recorded in nine (18%), eight (16%), and one patient (2%) in groups 1, 2, and 3, respectively. The only significant difference was between the control and group 3 (P=0.012). Conclusion: An increase in IOP after antivascular endothelial growth factor IVI is a frequent complication. The prophylactic use of timolol 0.1% gel effectively reduced the mean IOP when administered 2 hours before IVI and was also effective in preventing dangerous IOP spikes of >40 mmHg. It is therefore recommended before IVIs as a means of preventing emergency procedures and preserving the health of the optic nerve

Acting rehearsal in collaborative multimodal mixed reality environments

This paper presents the use of our multimodal mixed reality telecommunication system to support remote acting rehearsal. The rehearsals involved two actors, located in London and Barcelona, and a director in another location in London. This triadic audiovisual telecommunication was performed in a spatial and multimodal collaborative mixed reality environment based on the 'destination-visitor' paradigm, which we define and put into use. We detail our heterogeneous system architecture, which spans the three distributed and technologically asymmetric sites, and features a range of capture, display, and transmission technologies. The actors' and director's experience of rehearsing a scene via the system are then discussed, exploring successes and failures of this heterogeneous form of telecollaboration. Overall, the common spatial frame of reference presented by the system to all parties was highly conducive to theatrical acting and directing, allowing blocking, gross gesture, and unambiguous instruction to be issued. The relative inexpressivity of the actors' embodiments was identified as the central limitation of the telecommunication, meaning that moments relying on performing and reacting to consequential facial expression and subtle gesture were less successful

Efficacy of Overground Robotic Gait Training on Balance in Stroke Survivors: A Systematic Review and Meta-Analysis

Strokes often lead to a deficit in motor control that contributes to a reduced balance function. Impairments in the balance function severely limit the activities of daily living (ADL) in stroke survivors. The present systematic review and meta-analysis primarily aims to explore the efficacy of overground robot-assisted gait training (o-RAGT) on balance recovery in individuals with stroke. In addition, the efficacy on ADL is also investigated. This systematic review identified nine articles investigating the effects of o-RAGT on balance, four of which also assessed ADL. The results of the meta-analysis suggest that o-RAGT does not increase balance and ADL outcomes more than conventional therapy in individuals after stroke. The data should not be overestimated due to the low number of studies included in the meta-analysis and the wide confidence intervals. Subgroup analyses to investigate the influence of participant’s characteristics and training dosage were not performed due to lack of data availability. Further well-designed randomized controlled trials are needed to investigate the efficacy of o-RAGT on balance in individuals with stroke

Prep1 (pKnox1) transcription factor contributes to pubertal mammary gland branching morphogenesis

Prep1 (pKnox1) is a homeodomain transcription factor essential for in utero and post-natal development and an oncosuppressor gene in human and adult mice. We have analyzed its role in the development of the mouse mammary gland. We used Prep1i/i hypomorphic and Prep1F/F-Ker5CRE crosses to analyze the role of Prep1 in vivo in adult mouse mammary gland development. We also cultured mammary gland stem/progenitor cells in mammospheres to perform biochemical studies. Prep1 was expressed in mammary gland progenitors and fully differentiated mammary gland cells. Using different Prep1-deficient mouse models we show that in vivo Prep1 contributes to mammary gland branching since the branching efficiency of the mammary gland in Prep1-deleted or Prep1 hypomorphic mice was largely reduced. In-vitro, Prep1 sustained functions of the mammary stem/progenitor compartment. Prep1-deficient mammary stem/progenitor cells showed reduced ability to form mammospheres; they were not able to branch in a 3D assay, and exhibited reduced expression of Snail1, Snail2 and vimentin. The branching phenotype associated with increased Tp53-dependent apoptosis and inability to properly activate signals involved in branching morphogenesis. Finally, Prep1 formed complexes with Snail2, a transcription factor essential in branching morphogenesis, and its absence destabilizes and promotes Snail2 proteasome-mediated degradation. We conclude that Prep1 is required for normal adult mammary gland development, in particular at its branching morphogenesis step. By binding Snail2, Prep1 protects it from the proteasomal degradation

po 466 pi3k c2a regulates mitotic spindle assembly and chemotherapy response in breast cancer

Introduction Proper organisation of the mitotic spindle is key to genetic stability but the molecular components of inter-microtubule (MT) bridges that crosslink kinetochore fibres (K-fibres) are still largely unknown. Here, we identify class II phosphoinositide 3-OH kinase a (PI3K-C2α) as a limiting scaffold protein organising the clathrin and TACC3 complex crosslinking K-fibres. Material and methods Pik3c2a+/- mice were intercrossed with a transgenic strain expressing the activated HER-2/Neu oncogene in the mammary gland. Mice were weekly followed for survival, tumour appearance and growth. Primary Murine Mammary Epithelial Tumour (MMET) cells were derived from early and late stage tumours. Truncating PI3KC2α mutants were generated and interaction with TACC3 was tested. Levels of PI3K-C2α expression were assessed by IHC in breast cancer tissue microarrays (TMA) and correlated with response to chemotherapy. Results and discussions Loss of PI3K-C2α expression is a frequent occurrence in breast cancer patients (48%) and correlates with local recurrence and metastatic disease. The heterozygous loss of PI3K-C2α initially delays tumour onset but, on the long run, leads to the convergent evolution of aggressive clones with mitotic checkpoint defects. In line with this, downregulation of PI3K-C2α promotes spindle alterations and aneuploidy, indicating that PI3K-C2α expression is a key determinant of genomic stability. As a consequence of the altered spindle, reduction of PI3K-C2α expression increases the sensitivity to anti-MT drugs, such as paclitaxel, in pre-clinical models and in breast cancer patients. Conclusion Loss of PI3K-C2α expression is a frequent occurrence in breast cancer patients (48%) and correlates with local recurrence and metastatic disease. The heterozygous loss of PI3K-C2α initially delays tumour onset but, on the long run, leads to the convergent evolution of aggressive clones with mitotic checkpoint defects. In line with this, downregulation of PI3K-C2α promotes spindle alterations and aneuploidy, indicating that PI3K-C2α expression is a key determinant of genomic stability. As a consequence of the altered spindle, reduction of PI3K-C2α expression increases the sensitivity to anti-MT drugs, such as paclitaxel, in pre-clinical models and in breast cancer patients

IRSp53 controls plasma membrane shape and polarized transport at the nascent lumen in epithelial tubules

It is unclear whether the establishment of apical\u2013basal cell polarity during the generation of epithelial lumens requires molecules acting at the plasma membrane/actin interface. Here, we show that the I-BAR-containing IRSp53 protein controls lumen formation and the positioning of the polarity determinants aPKC and podocalyxin. Molecularly, IRSp53 acts by regulating the localization and activity of the small GTPase RAB35, and by interacting with the actin capping protein EPS8. Using correlative light and electron microscopy, we further show that IRSp53 ensures the shape and continuity of the opposing plasma membrane of two daughter cells, leading to the formation of a single apical lumen. Genetic removal of IRSp53 results in abnormal renal tubulogenesis, with altered tubular polarity and architectural organization. Thus, IRSp53 acts as a membrane curvature-sensing platform for the assembly of multi-protein complexes that control the trafficking of apical determinants and the integrity of the luminal plasma membrane

IRSp53 controls plasma membrane shape and polarized transport at the nascent lumen in epithelial tubules

It is unclear whether the establishment of apical–basal cell polarity during the generation of epithelial lumens requires molecules acting at the plasma membrane/actin interface. Here, we show that the I-BAR-containing IRSp53 protein controls lumen formation and the positioning of the polarity determinants aPKC and podocalyxin. Molecularly, IRSp53 acts by regulating the localization and activity of the small GTPase RAB35, and by interacting with the actin capping protein EPS8. Using correlative light and electron microscopy, we further show that IRSp53 ensures the shape and continuity of the opposing plasma membrane of two daughter cells, leading to the formation of a single apical lumen. Genetic removal of IRSp53 results in abnormal renal tubulogenesis, with altered tubular polarity and architectural organization. Thus, IRSp53 acts as a membrane curvature-sensing platform for the assembly of multi-protein complexes that control the trafficking of apical determinants and the integrity of the luminal plasma membrane