101 research outputs found
Full Body Acting Rehearsal in a Networked Virtual Environment-A Case Study
No full textIn order to rehearse for a play or a scene from a movie, it is generally required that the actors are physically present at the same time in the same place. In this paper we present an example and experience of a full body motion shared virtual environment (SVE) for rehearsal. The system allows actors and directors to meet in an SVE in order to rehearse scenes for a play or a movie, that is, to perform some dialogue and blocking (positions, movements, and displacements of actors in the scene) rehearsal through a full body interactive virtual reality (VR) system. The system combines immersive VR rendering techniques as well as network capabilities together with full body tracking. Two actors and a director rehearsed from separate locations. One actor and the director were in London (located in separate rooms) while the second actor was in Barcelona. The Barcelona actor used a wide field-of-view head-tracked head-mounted display, and wore a body suit for real-time motion capture and display. The London actor was in a Cave system, with head and partial body tracking. Each actor was presented to the other as an avatar in the shared virtual environment, and the director could see the whole scenario on a desktop display, and intervene by voice commands. A video stream in a window displayed in the virtual environment also represented the director. The London participant was a professional actor, who afterward commented on the utility of the system for acting rehearsal. It was concluded that full body tracking and corresponding real-time display of all the actors' movements would be a critical requirement, and that blocking was possible down to the level of detail of gestures. Details of the implementation, actors, and director experiences are provided
D-2473: 245 West 500 North, Logan, Utah, William M. and Vivian P. Swapp residence. Block 37 Plat A
No full textD-2473: 245 West 500 North, Logan, Utah, William M. and Vivian P. Swapp residence. Block 37 Plat
Corrigendum: Action Sounds Modulate Arm Reaching Movements
No full textA corrigendum on:
Action Sounds Modulate Arm Reaching Movements
by Tajadura-Jiménez, A., Marquardt, T., Swapp, D., Kitagawa, N., and Bianchi-Berthouze, N. (2016).
Front. Psychol. 7:1391. doi: 10.3389/fpsyg.2016.0139
Energetics of the Charge-Coupled Substitution Si4+ Na++ T3+ in the-Glasses NaTO2–SiO2 (T = Al, Fe, Ga, B)
No full textHeats of solution in molten 2PbO·B2O3 at 973 K are reported for glasses xNaT3+O2–(1 –x)SiO2 for T = Fe, Ga. These measurements, combined with previous data for T = Al, B, give a relative measure of the enthalpy of the charge-coupled substitution Si4+→ Na++ T3+. The heats of solution become more endothermic with increasing x for x→ 0.5 and exhibit a maximum near x= 0.5. This indicates an exothermic enthalpy for the substitution and an overall stabilization of the glasses. The degree to which the glasses are stabilized decreases in the order Al > Ga > Fe > B. On the basis of molecular orbital calculations, X-ray scattering, and Raman spectroscopy, it is argued that this trend is primarily due to a decrease in the range of energetically favorable T–O–T bond angles as Al, Ga, Fe, and B are substituted for Si
Transgenic BACE expression in mouse neurons accelerates amyloid plaque pathology
No full textThe cleavage of APP by BACE initiates the amyloidogenic process in Alzheimer's disease (AD). We have generated transgenic mice expressing BACE and double transgenic mice expressing BACE and the Swedish mutations of APP (SwAPP) in neurons. BACE transgenic mice did not develop beta-amyloid plaques by age of 14 months, but showed intracellular beta-amyloid immunoreactivity that was co-localized with transgenic BACE in neurons. Abeta levels were increased and AD-like pathology was accelerated in double transgenic mice expressing both BACE and SwAPP. At two months of age, early signs of extracellular Abeta deposition and reactive astrocytes were found in double transgenic, but not in single transgenic mice. Furthermore, at four months, well defined beta-amyloid deposits surrounded by activated astrocytes could be detected in the double transgenic mice. We suggest that BACE overexpression is not sufficient to produce beta-amyloid plaques, but simultaneous expression of BACE and its substrate (SwAPP) leads to an accelerated amyloid plaque formation
The role of phospholipase D2 in Alzheimer's disease
No full textTese de doutoramento em Ciências da Saúde (ramo do conhecimento em Medicina)Growing evidence implicates aberrant lipid signaling in Alzheimer‟s disease (AD). While phospholipases
A2 and C have been recently shown to mediate key actions of amyloid β-peptide (Aβ) through a
dysregulation of arachidonic acid and phosphatidylinositol-4,5-bisphosphate metabolism, respectively,
the role of phospholipase D (PLD) has so far remained elusive. PLD produces phosphatidic acid (PA), a
bioactive lipid involved in multiple aspects of cell physiology, including signaling and membrane
trafficking processes. Here we show that oligomeric Aβ enhances PLD activity in cultured neurons and
that this stimulatory effect does not occur upon ablation of PLD2 via gene targeting. Aβ fails to
suppress long-term potentiation in PLD2-deficient hippocampal slices, suggesting that PLD2 is required
for the synaptotoxic action of this peptide. In vivo PLD activity, as assessed by detection of
phosphatidylethanol levels using mass spectrometry (MS) following ethanol injection, is also increased
in the brain of a transgenic mouse model of AD (SwAPP). Furthermore, Pld2 ablation rescues memory
deficits and confers synaptic protection in SwAPP mice despite a significant Aβ load. MS-based lipid
analysis of Pld2 mutant brains in the presence or absence of the SwAPP transgene unmasks striking
crosstalks between different PA species. This lipid analysis shows an exquisite acyl chain specificity and
plasticity in the perturbation of PA metabolism, with the notable elevation in SwAPP brains of a pool of
PA previously linked to degeneration. Collectively, our results point to specific molecular species of PA
as key modulators of AD pathogenesis and identify PLD2 as a novel potential target for therapeutics.
Moreover we expanded our MS analysis of the Pld2/SwAPP mice to other lipid groups, other than PA.
We found that overexpression of the SwAPP transgene leads to significant increase in the ganglioside,
GM3. Remarkably, Pld2 ablation leads to a decrease in GM3 in the non-transgenic background and to a
rescue to normals in the SwAPP background. This lipidomic analysis uncovered interesting lipid
signaling crosstalks that are modulated by PLD2 in the context of AD models.Trabalhos anteriores indicam que distúrbios no metabolismo dos lípidos estão relacionados com a
doença de Alzheimer (AD). Enquanto que as fosfolipases A2 e C foram demonstradas como
mediadoras das acções do péptido, amilóide beta (Aβ), através da desregulação do metabolismo do
ácido araquidónico e fosfoinositol-4,5-bifosfato, respectivamente, o papel da fosfolipase D (PLD)
permanence por esclarecer. A PLD produz ácido fosfatídico (PA), um lípido envolvido em múltiplos
aspectos da fisiologia cellular, como vias de sinalização e tráfico membranar. Neste trabalho,
mostramos que oligómeros de Aβ levam a um aumento da actividade da PLD em culturas primárias
de neurónios e que esse efeito estimulatório não ocorre após a delecção genética da PLD2.
A Aβ perde o seu efeito suppressor de potenciação de longo termo em fatias de hipocampo de
ratinhos Pld2--/-, sugerindo que a PLD2 é necessária para o efeito sinaptotóxico deste péptido. A
actividade da PLD in vivo, medida através da detecção dos níveis de fosfatidiletanol, por espectrometria
de massa (MS) após injecção de etanol, também está aumentada no cérebro de um modelo
transgénico de AD (SwAPP). Para além disso a ablação da Pld2 recupera os défices de memória e leva
a uma protecção sináptica em ratinhos SwAPP, apesar dos altos níveis de Aβ. Análise de lípidos por
MS de cérebros de ratinhos mutantes para a Pld2 na presença ou ausência do transgene SwAPP
revela haver uma intensa intraregulação nas espécies de PA. Esta análise lipídica mostra uma
especificidade e plasticidade no modo como o metabolismo do PA está alterado, com uma marcada
elevação nos cérebros SwAPP de uma espécie de PA previamente ligado a processos
neurodegenerativos. Em suma, os nossos resultados apontam para espécies específicas de PA como
moduladores da patogénese da AD e identificam a PLD2 como um novo alvo potencial terapêutico.
Além disso, expandimos a nossa análise por MS para outros lípidos, para além de PA. Observámos
que a sobreexpressão do transgene SwAPP leva a um aumento do gangliosídeo, GM3. A ablação
genética de Pld2 leva a um decréscimo de GM3 nos animais não-transgénicos e a uma renormalização dos valores nos animais SwAPP. Em conclusão, esta análise lipidómica revelou ligações mecanísticas
interessantes reguladas pela PLD2, no contexto da AD
Docking Haptics: Extending the Reach of Haptics by Dynamic Combinations of Grounded and Worn Devices
No full textGrounded haptic devices can provide a variety of forces but have limited working volumes. Wearable haptic devices operate over a large volume but are relatively restricted in the types of stimuli they can generate. We propose the concept of docking haptics, in which different types of haptic devices are dynamically docked at run time. This creates a hybrid system, where the potential feedback depends on the user's location. We show a prototype docking haptic workspace, combining a grounded six degree-of-freedom force feedback arm with a hand exoskeleton. We are able to create the sensation of weight on the hand when it is within reach of the grounded device, but away from the grounded device, hand-referenced force feedback is still available. A user study demonstrates that users can successfully discriminate weight when using docking haptics, but not with the exoskeleton alone. Such hybrid systems would be able to change configuration further, for example docking two grounded devices to a hand in order to deliver twice the force, or extend the working volume. We suggest that the docking haptics concept can thus extend the practical utility of haptics in user interfaces
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