The Ultraviolet Plume Instrument (UVPI)

The Ultraviolet Plume Instrument (UVPI) was launched aboard the Low-power Atmospheric Compensation Experiment (LACE) satellite on 14 Feb. 1990. Both the spacecraft and the UVPI were sponsored by the Directed Energy Office of the Strategic Defense Initiative Organization. The mission of the UVPI was to obtain radiometrically calibrated images of rocket plumes at high altitude and background image data of the Earth, Earth's limb, and celestial objects in the near- and middle-UV wave bands. The UVPI was designed for nighttime observations, i.e., to acquire and track relatively bright objects against a dark background

Using virtual worlds for online role-play

The paper explores the use of virtual worlds to support online role-play as a collaborative activity. This paper describes some of the challenges involved in building online role-play environments in a virtual world and presents some of the ideas being explored by the project in the role-play applications being developed. Finally we explore how this can be used within the context of immersive education and 3D collaborative environments

Reflections on the use of Project Wonderland as a mixed-reality environment for teaching and learning

This paper reflects on the lessons learnt from MiRTLE?a collaborative research project to create a ?mixed reality teaching and learning environment? that enables teachers and students participating in real-time mixed and online classes to interact with avatar representations of each other. The key hypothesis of the project is that avatar representations of teachers and students can help create a sense of shared presence, engendering a greater sense of community and improving student engagement in online lessons. This paper explores the technology that underpins such environments by presenting work on the use of a massively multi-user game server, based on Sun?s Project Darkstar and Project Wonderland tools, to create a shared teaching environment, illustrating the process by describing the creation of a virtual classroom. It is planned that the MiRTLE platform will be used in several trial applications ? which are described in the paper. These example applications are then used to explore some of the research issues arising from the use of virtual environments within an education environment. The research discussion initially focuses on the plans to assess this within the MiRTLE project. This includes some of the issues of designing virtual environments for teaching and learning, and how supporting pedagogical and social theories can inform this process

The Glue Around Quarks and the Interquark Potential

The quarks of quark models cannot be identified with the quarks of the QCD Lagrangian. We review the restrictions that gauge field theories place on any description of physical (colour) charges. A method to construct charged particles is presented. The solutions are applied to a variety of applications. Their Green's functions are shown to be free of infra-red divergences to all orders in perturbation theory. The interquark potential is analysed and it is shown that the interaction responsible for anti-screening results from the force between two separately gauge invariant constituent quarks. A fundamental limit on the applicability of quark models is identified.Comment: 4 pages, LaTeX, talk given at Montpellier meeting QCD9

Understanding the expression and implications of deceptive affectionate messages

Affectionate messages are important in romantic relationships as they are linked to multiple emotional, physical, and relational benefits (e.g., Floyd, 2006a). When examining affection, it is important to distinguish that feelings of affection and the communication of affection are two unique processes that theorists argue covary. Yet, deception researchers have found that individuals routinely lie to their non-married romantic partners about their feelings (DePaulo & Kasy, 1998; DePaulo, Kashy, Kirkendol, Wyer, & Epstein, 1996). This dissertation, composed of two studies, examined how individuals in non-married romantic relationships communicated deceptive affection and the implications of such messages. Study one used a week long diary method in which participants recorded instances of deceptive affection and rumination. Results indicated that individuals communicated approximately three deceptive affectionate messages (DAMs) to their partners in a week, and the type of DAM was related to rumination. These messages were most often used to conceal negative feelings and expressed for prosocial reasons. Study two was an experiment that examined the emotional (guilt and shame) and physiological (heart rate and blood pressure) implications of expressing DAMs to romantic partners. A writing method was used where participants wrote for 20 minutes about either a DAM, honest affection, or plans with friends (control). Results indicated that the writing method did not result in any physiological changes. Deceptive motives did not influence deceivers\u27 feelings of guilt and shame. Together, deceptive affection appears to be a message that partners routinely communicate to one another resulting in minimal emotional and physiological implications

Leakage Evaluation of Three Endodontic Sealers Used in a Single-cone Technique: A Study Using Bioluminescent Bacteria

Introduction.;After proper chemomechanical disinfection and obturation of a root canal system, the next important goal in endodontic therapy is obtaining an adequate coronal seal. If the coronal seal becomes compromised, it is difficult to decide whether the root canal system should be re-treated. This decision should be made based on the ability of the root canal filling to resist bacterial contamination and on the length of time the seal has been compromised.;The root canal system should be filled in three dimensions, typically with a combination of gutta percha and sealer. One obturation method that has seen a revival in recent years is the single-cone technique. Newly developed sealers claim to create an effective seal through adhesive bonding to the gutta percha and/or dentin. The objective of this study was to evaluate the sealing ability of three currently available endodontic sealers used in a single-cone technique with a bacterial leakage model. A pilot study was also conducted in an attempt to better quantify and localize the bacteria in the obturated experimental teeth.;Materials and Methods.;Fifty extracted human maxillary anterior teeth were decoronated and root length was standardized. Each tooth was instrumented and irrigated. The teeth were randomly divided into three experimental groups (n = 12) and two control groups (5 positive and 5 negative). The final four teeth were used in the pilot study. Obturation of the three experimental groups, EndoSequence BC Sealer, ThermaSeal Plus Ribbon Sealer, or GuttaFlow 2, was performed with a single-cone technique using a ProTaper master cone. A bacterial leakage experimental apparatus was constructed to evaluate the seal created by each of the experimental groups.;For the pilot study, four teeth were obturated with varying levels of gutta percha and evaluated in the same experimental apparatus. A solution of a bioluminescent bacterium, Staphylococcus aureus Xen36, was used to inoculate each tooth. Scans of the teeth were taken with an In Vivo Imaging System (IVIS) at Days 0, 3, 7, and 10 to show whether bacteria could be detected at varying levels in the teeth.;The remaining forty-six apparatuses were evaluated with a more traditional bacterial leakage method, where Difco Purple Broth Base was placed in the lower chamber of the apparatus so that 2 mm of the root end was submerged. A solution of S. aureus Xen36 was used to inoculate the top chamber of the apparatus, and the apparatuses were incubated for up to 50 days. The apparatuses were checked daily to monitor for bacterial contamination.;Results and Conclusion.;The pilot study was unable to provide accurate information on the localization and quantification of bacteria in the four sample teeth. For the traditional bacterial leakage study, each of the experimental groups had a noticeable amount of early leakage, and after one week, all three groups had a survival rate of 58.3%. After 50 days, the ThermaSeal Plus Ribbon Sealer group had a survival rate of 8.3%, while the EndoSequence BC Sealer and GuttaFlow 2 groups had a survival rate of 25.0%. The log-rank test showed no statistically significant differences between the three groups with respect to leakage over time (p = 0.665). The results of the present study showed that in the absence of a coronal seal, the single-cone method of root canal obturation does not provide long-term sealing ability in many teeth. Further studies should be piloted to see if the IVIS could be beneficial for analyzing obturated teeth