Constructing a gazebo: supporting teamwork in a tightly coupled, distributed task in virtual reality

Many tasks require teamwork. Team members may work concurrently, but there must be some occasions of coming together. Collaborative virtual environments (CVEs) allow distributed teams to come together across distance to share a task. Studies of CVE systems have tended to focus on the sense of presence or copresence with other people. They have avoided studying close interaction between us-ers, such as the shared manipulation of objects, because CVEs suffer from inherent network delays and often have cumbersome user interfaces. Little is known about the ef-fectiveness of collaboration in tasks requiring various forms of object sharing and, in particular, the concurrent manipu-lation of objects. This paper investigates the effectiveness of supporting teamwork among a geographically distributed group in a task that requires the shared manipulation of objects. To complete the task, users must share objects through con-current manipulation of both the same and distinct at-tributes. The effectiveness of teamwork is measured in terms of time taken to achieve each step, as well as the impression of users. The effect of interface is examined by comparing various combinations of walk-in cubic immersive projection technology (IPT) displays and desktop devices

A study of event traffic during the shared manipulation of objects within a collaborative virtual environment

Event management must balance consistency and responsiveness above the requirements of shared object interaction within a Collaborative Virtual Environment (CVE) system. An understanding of the event traffic during collaborative tasks helps in the design of all aspects of a CVE system. The application, user activity, the display interface, and the network resources, all play a part in determining the characteristics of event management. Linked cubic displays lend themselves well to supporting natural social human communication between remote users. To allow users to communicate naturally and subconsciously, continuous and detailed tracking is necessary. This, however, is hard to balance with the real-time consistency constraints of general shared object interaction. This paper aims to explain these issues through a detailed examination of event traffic produced by a typical CVE, using both immersive and desktop displays, while supporting a variety of collaborative activities. We analyze event traffic during a highly collaborative task requiring various forms of shared object manipulation, including the concurrent manipulation of a shared object. Event sources are categorized and the influence of the form of object sharing as well as the display device interface are detailed. With the presented findings the paper wishes to aid the design of future systems

Supporting a Closely Coupled Task between a Distributed Team: Using Immersive Virtual Reality Technology

Collaboration and teamwork is important in many areas of our lives. People come together to share and discuss ideas, split and distribute work or help and support each other. The sharing of information and artefacts is a central part of collaboration. This often involves the manipulation of shared objects, both sequentially as well as concurrently. For coordinating an efficient collaboration, communication between the team members is necessary. This can happen verbally in form of speech or text and non-verbally through gesturing, pointing, gaze or facial expressions and the referencing and manipulation of shared objects. Collaborative Virtual Environments (CVE) allow remote users to come together and interact with each other and virtual objects within a computer simulated environment. Immersive display interfaces, such as a walk-in display (e.g. CAVE), that place a human physically into the synthetic environment, lend themselves well to support a natural manipulation of objects as well a set of natural non-verbal human communication, as they can both capture and display human movement. Communication of tracking data, however, can saturate the network and result in delay or loss of messages vital to the manipulation of shared objects. This paper investigates the reality of shared object manipulation between remote users collaborating through linked walk-in displays and extends our research in [27]. Various forms of shared interaction are examined through a set of structured sub tasks within a representative construction task. We report on extensive user-trials between three walk-in displays in the UK and Austria linked over the Internet using a CVE, and demonstrate such effects on a naive implementation of a benchmark application, the Gazebo building task. We then present and evaluate application-level workarounds and conclude by suggesting solutions that may be implemented within next-generation CVE infrastructures

The endemic gastropod fauna of Lake Titicaca : correlation between molecular evolution and hydrographic history

Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had a complex history that included at least five major hydrological phases during the Pleistocene. It is generally assumed that these physical events helped shape the evolutionary history of the lake´s biota. Herein, we study an endemic species assemblage in Lake Titicaca, composed of members of the microgastropod genus Heleobia, to determine whether the lake has functioned as a reservoir of relic species or the site of local diversification, to evaluate congruence of the regional paleohydrology and the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses indicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital taxa) forms a species flock. A molecular clock analysis suggests that the most recent common ancestor (MRCAs) of the Altiplano taxa evolved 0.53 (0.28–0.80) My ago and the MRCAs of the Altiplano taxa and their extralimital sister group 0.92 (0.46–1.52) My ago. The endemic species of Lake Titicaca are younger than the lake itself, implying primarily intralacustrine speciation. Moreover, the timing of evolutionary branching events and the ages of two precursors of Lake Titicaca, lakes Cabana and Ballivián, is congruent. Although Lake Titicaca appears to have been the principal site of speciation for the regional Heleobia fauna, the contemporary spatial patterns of endemism have been masked by immigration and/or emigration events of local riverine taxa, which we attribute to the unstable hydrographic history of the Altiplano. Thus, a hierarchical distribution of endemism is not evident, but instead there is a single genetic break between two regional clades. We also discuss our findings in relation to studies of other regional biota and suggest that salinity tolerance was the most likely limiting factor in the evolution of Altiplano species flocks

Towards a class library for mission planning

The PASTEL Mission Planning System (MPS) has been developed in C++ using an object-oriented (OO) methodology. While the scope and complexity of this system cannot compare to that of an MPS for a complex mission one of the main considerations of the development was to ensure that we could reuse some of the classes in future MPS. We present here PASTEL MPS classes which could be used in the foundations of a class library for MPS

Berufsschulumfrage 2012. Einflussfaktoren auf die Berufswahl und Verbleibentscheidung von Auszubildenden im Landkreis Mecklenburgische Seenplatte

Berufswahlsentscheidung und die Frage nach dem Gehen oder Bleiben ist nicht nur für viele junge Menschen in ländlichen Regionen eine wichtige Frage, sondern auch für die im Übergang Schule-Beruf arbeitenden Menschen und Akteure der jeweiligen Kommune. Vor dem Hintergrund der Abwanderungstendenzen und der Optimierung der Übergänge Schule-Beruf hat die Stabsstelle Bildung des Landkreises Mecklenburgische Seenplatte repräsentativ 2800 Auszubildende des Landkreises befragt über die Einflussfaktoren für ihre Berufswahl und über ihre Entscheidung hier zu bleiben oder gehen befragt. Die z.T. überraschenden Ergebnisse werden in dieser Studie zusammen mit Handlungsempfehlungen dargestellt. (DIPF/Autor

Detecting the neuropathic pain component in the clinical setting: a study protocol for validation of screening instruments for the presence of a neuropathic pain component

BACKGROUND The presence of nerve damage plays a key role in the development and prognosis of chronic pain states. Assessment of the presence and severity of a neuropathic pain component (NePC) is key in diagnosing chronic pain patients. Low back pain (LBP) and neck and shoulder pain (NSP) are highly prevalent and clinically important medical and societal problems in which a NePC is frequently present. The more severe the NePC, the worse the course of the pain, its prognosis and the results of treatment. Reliable and standardised diagnosis of the NePC remains difficult to achieve. Standardized and validated screening tools may help to reliably identify the NePC in individual chronic pain patients. The aim of this study is to validate the Dutch language versions of the PainDETECT Questionnaire (PDQ-Dlv) and the 'Douleur Neuropathique 4 Questions' (DN4-Dlv) for use in primary and specialist medical care settings to screen for a NePC in patients with chronic pain due to (1) LBP, (2) NSP or (3) known peripheral nerve damage (PND). METHODS/DESIGN The study design is cross-sectional to assess the validity of the PDQ-Dlv and the DN4-Dlv with 2 weeks follow-up for test-retest reliability and 3 months follow-up for monitoring and prognosis. 438 patients with chronic pain due to (1) LBP, (2) NSP or (3) PND. will be included in this study. Based on the IASP definition of neuropathic pain, two physicians will independently assess whether the patient has a NEPC or not. This result will be compared with the outcome of the PDQ-Dlv & DN4-Dlv, the grading system for neuropathic pain, bed side examination and quantitative sensory testing. This study will further collect data regarding prevalence of NePC, general health status, mental health status, functioning, pain attribution and quality of life. DISCUSSION The rationale for this study is to provide detailed information on the clinimetric quality of the PDQ-Dlv and DN4-Dlv in Dutch speaking countries. Our innovative multi-factorial approach should help achieve more reliable diagnosis and quantification of a NePC in patients with chronic pain. TRIAL REGISTRATION The Netherlands National Trial Register (NTR3030).This project is supported by an unrestricted grant from Pfizer

Spinaxinus (Bivalvia: Thyasiroidea) from sulfide biogenerators in the Gulf of Mexico and hydrothermal vents in the Fiji Back Arc: Chemosymbiosis and Taxonomy

Two new species of the thyasirid genus Spinaxinus (S. emicatus Oliver n. sp. and S. phrixicus Oliver n. sp.) are described from the Gulf of Mexico and the southwest Pacific, respectively. Both are compared with the type species of the genus, the eastern Atlantic S. sentosus Oliver and Holmes, 2006. Living specimens from the Gulf of Mexico were retrieved from artificial sulfide bio-generators on the upper Louisiana Slope. Gill morphology and molecular markers from the symbiotic bacteria confirm that Spinaxinus is chemosynthetic and that the chemoautotrophic bacteria are related to sulfide oxidizing Gammaproteobacteria. Living specimens from the southwest Pacific were retrieved from hydrothermal vent sites in the Fiji and Lau Back Arc Basins. In the Atlantic Spinaxinus is now recorded from two anthropogenic situations and appears to be generally absent from natural cold seep sites and not yet recorded at any hydrothermal sites. The primarily anthropogenic distribution of Spinaxinus in the Atlantic is discussed with reference to the natural hydrothermal vent habitat of the Pacific S. phrixicus.Spinaxinus (Bivalvia: Thyasiroidea) de bio-generadores artificiales de sulfuro situados en el Golfo de Méjico y en fuentes hidrotermales de las Islas Fiji: quimiosimbiosis y taxonomía. – En este trabajo se describen dos especies nuevas de tisárido del género Spinaxinus (S. emcatus Oliver n. sp. y S. phrixicus Oliver n. sp.) encontradas res- pectivamente en el Golfo de Méjico y en el sureste del Pacífico. Se comparan estas dos especies nuevas con la especie tipo del género, S. sentous Oliver y Holmes, 2006 descrita en el Este del Atlántico. Para describir estas dos especies, se observaron ejemplares vivos recolectados sobre bio-generadores artificiales de sulfuro situados en la parte alta de la plataforma conti- nental de Louisiana, en el Golfo de Méjico. Las observaciones realizadas de las branquias de Spinaxinus y la caracterización genética de las bacterias simbiontes en estos ejemplares confirmaron que Spinaxinus es un género quimiosintético que con- tiene bacterias quimioautótrofas cercanas a las Gammaproteobacterias responsables de la oxidación del sulfuro. También se recolectaron ejemplares vivos de fuentes hidrotermales situadas en las Islas Fiji y en ‘Lau Back Arc Basins’ ambas localiza- das en el Pacífico suroccidental. La especie atlántica de Spinaxinus se encontró en dos tipos de sustratos artificiales mientras que parece que esta especie no se encuentra en ambientes naturales equivalentes como serían las surgencias frías y las fuentes hidrotermales. La distribución aparentemente limitada de la especie atlántica se discute en relación con la distribución de S. phrixicus en las fuentes hidrotermales del Pacífico