19 research outputs found

    A Structured Approach for Designing Collaboration Experiences for Virtual Worlds

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    While 3D virtual worlds are more frequently being used as interactive environments for collaboration, there is still no structured approach developed specifically for the combined design of 3D virtual environments and the collaborative activities in them. We argue that formalizing both the structural elements of virtual worlds and aspects of collaborative work or collaborative learning helps to develop fruitful collaborative work and learning experiences. As such, we present the avatar-based collaboration framework (ABC framework). Based on semiotics theory, the framework puts the collaborating groups into the center of the design and emphasizes the use of distinct features of 3D virtual worlds for use in collaborative learning environments and activities. In developing the framework, we have drawn from best practices in instructional design and game design, research in HCI, and findings and observations from our own empirical research that investigates collaboration patterns in virtual worlds. Along with the framework, we present a case study of its first application for a global collaborative learning project. This paper particularly addresses virtual world designers, educators, meeting facilitators, and other practitioners by thoroughly describing the process of creating rich collaboration and collaborative learning experiences for virtual worlds with the ABC framework

    Fabrication of Massive Sheets of Single Layer Patterned Arrays Using Lipid Directed Reengineered Phi29 Motor Dodecamer

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    The bottom-up assembly of patterned arrays is an exciting and important area in current nanotechnology. Arrays can be engineered to serve as components in chips for a virtually inexhaustible list of applications ranging from disease diagnosis to ultra-high-density data storage. Phi29 motor dodecamer has been reported to form elegant multilayer tetragonal arrays. However, multilayer protein arrays are of limited use for nanotechnological applications which demand nanoreplica or coating technologies. The ability to produce a single layer array of biological structures with high replication fidelity represents a significant advance in the area of nanomimetics. In this paper, we report on the assembly of single layer sheets of reengineered phi29 motor dodecamer. A thin lipid monolayer was used to direct the assembly of massive sheets of single layer patterned arrays of the reengineered motor dodecamer. Uniform, clean and highly ordered arrays were constructed as shown by both transmission electron microscopy and atomic force microscopy imaging

    A framework for the design of avatar-based collaboration

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    Anatomy of the female pelvic nerves: a macroscopic study of the hypogastric plexus and their relations and variations.

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    The autonomic nerves of the lesser pelvis are particularly prone to iatrogenic lesions due to their exposed position during manifold surgical interventions. Nevertheless, the cause of rectal and urinary incontinence or sexual dysfunctions, for example after rectal cancer resection or hysterectomy, remains largely understudied, particularly with regard to the female pelvic autonomic plexuses. This study focused on the macroscopic description of the superior hypogastric plexus, hypogastric nerves, inferior hypogastric plexus, the parasympathetic pelvic splanchnic nerves and the sympathetic fibres. Their arrangement is described in relation to commonly used surgical landmarks such as the sacral promontory, ureters, uterosacral ligaments, uterine and rectal blood vessels. Thirty-one embalmed female pelvises from 20 formalin-fixed and 11 Thiel-fixed cadavers were prepared. In all cases explored, the superior hypogastric plexus was situated anterior to the bifurcation of the abdominal aorta. In 60% of specimens, it reached the sacral promontory, whereas in 40% of specimens, it continued across the pelvic brim until S1. In about 25% of the subjects, we detected an accessory hypogastric nerve, which has not been systematically described so far. It originated medially from the inferior margin of the superior hypogastric plexus and continued medially into the presacral space. The existence of an accessory hypogastric nerve was confirmed during laparoscopy and by histological examination. The inferior hypogastric plexuses formed fan-shaped plexiform structures at the end of both hypogastric nerves, exactly at the junction of the ureter and the posterior wall of the uterine artery at the uterosacral ligament. In addition to the pelvic splanchnic nerves from S2-S4, which joined the inferior hypogastric plexus, 18% of the specimens in the present study revealed an additional pelvic splanchnic nerve originating from the S1 sacral root. In general, form, breadth and alignment of the autonomic nerves displayed large individual variations, which could also have a clinical impact on the postoperative function of the pelvic organs. The study serves as a basis for future investigations on the autonomic innervation of the female pelvic organs
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