262 research outputs found

    Using virtual reality to train infection prevention: what predicts performance and behavioral intention?

    Full text link
    Training medical professionals for hand hygiene is challenging, especially due to the invisibility of microorganisms to the human eye. As the use of virtual reality (VR) in medical training is still novel, this exploratory study investigated how preexisting technology acceptance and in-training engagement predict VR hand hygiene performance scores. The effect of training in the VR environment on the behavioral intention to further use this type of training device (a component of technology acceptance) was also investigated. Participants completed a VR hand hygiene training comprising three levels of the same task with increasing difficulty. We measured technology acceptance, composed of performance expectancy, effort expectancy, and behavioral intention, pre- and post-training, and in-training engagement using adaptations of existing questionnaires. We used linear regression models to determine predictors of performance in level-3 and of behavioral intention to further use VR training. Forty-three medical students participated in this exploratory study. In-training performance significantly increased between level-1 and level-3. Performance in level-3 was predicted by prior performance expectancy and engagement during the training session. Intention to further use VR to learn medical procedures was predicted by both prior effort expectancy and engagement. Our results provide clarification on the relationship between VR training, engagement, and technology acceptance. Future research should assess the long-term effectiveness of hand hygiene VR training and the transferability of VR training to actual patient care in natural settings. A more complete VR training could also be developed, with additional levels including more increased difficulty and additional medical tasks

    Querying Spatio-temporal Patterns in Mobile Phone-Call Databases

    Full text link
    Abstract — Call Detail Record (CDR) databases contain millions of records with information about cell phone calls, including the position of the user when the call was made/received. This huge amount of spatiotemporal data opens the door for the study of human trajectories on a large scale without the bias that other sources (like GPS or WLAN networks) introduce in the population studied. Also, it provides a platform for the development of a wide variety of studies ranging from the spread of diseases to planning of public transport. Nevertheless, previous work on spatiotemporal queries does not provide a framework flexible enough for expressing the complexity of human trajectories. In this paper we present the Spatiotemporal Pattern System (STPS) to query spatiotemporal patterns in very large CDR databases. STPS defines a regular-expression query language that is intuitive and that allows for any combination of spatial and temporal predicates with constraints, including the use of variables. The design of the language took into consideration the layout of the areas being covered by the cellular towers, as well as “areas ” that label places of interested (e.g. neighborhoods, parks, etc) and topological operators. STPS includes an underlying indexing structure and algorithms for query processing using different evaluation strategies. A full implementation of the STPS is currently running with real, very large CDR databases on Telefónica Research Labs. An extensive performance evaluation of the STPS shows that it can efficiently find complex mobility patterns in large CDR databases. I

    Cocaine Selectively Reorganizes Excitatory Inputs to Substantia Nigra Pars Compacta Dopamine Neurons

    Get PDF
    Substantia nigra pars compacta (SNc) dopamine neurons and their targets are involved in addiction and cue-induced relapse. However, afferents onto SNc dopamine neurons themselves appear insensitive to drugs of abuse, such as cocaine, when afferents are collectively stimulated electrically. This contrasts with ventral tegmental area (VTA) dopamine neurons, whose glutamate afferents react robustly to cocaine. We used an optogenetic strategy to isolate identified SNc inputs and determine whether cocaine sensitivity in the mouse SNc circuit is conferred at the level of three glutamate afferents: dorsal raphé nucleus (DR), pedunculopontine nucleus (PPN), and subthalamic nucleus (STN). We found that excitatory afferents to SNc dopamine neurons are sensitive to cocaine in an afferent-specific manner. A single exposure to cocaine in vivo led to PPN-innervated synapses reducing the AMPA-to-NMDA receptor-mediated current ratio. In contrast to work in the VTA, this was due to increased NMDA receptor function with no change in AMPA receptor function. STN synapses showed a decrease in calcium-permeable AMPA receptors after cocaine, but no change in the AMPA-to-NMDA ratio. Cocaine also increased the release probability at DR-innervated and STN-innervated synapses, quantified by decreases in paired-pulse ratios. However, release probability at PPN-innervated synapses remained unaffected. By examining identified inputs, our results demonstrate a functional distribution among excitatory SNc afferent nuclei in response to cocaine, and suggest a compelling architecture for differentiation and separate parsing of inputs within the nigrostriatal system

    Understanding Drivers and Challenges of Multi-actor Collaborations at the Local Level

    Get PDF
    In a world increasingly characterized by complexity and ambiguity, problem solving is often achieved through collaboration among multiple actors in multi-level settings, involving national, state, and local agencies. Yet, our knowledge is limited in terms of the drivers and challenges of collaborations that require both inter-organizational collaboration and collaboration with citizens. Using a case study of the development of a mobile app for emergency preparedness and response, this study explores key drivers and challenges of multi-actor collaboration at the local level. Our results show that local leadership and direct communication are key drivers for both inter-organizational collaboration and collaboration with citizens and that political dynamics are a challenge regarding inter-organizational collaboration. The two types of collaboration become distinct and independent processes while they complement each other to achieve the purpose and goals shared among different actors

    Does Co-Creation Affect the Adoption of IT-Enabled Solutions? The Case of a Mobile Application for Emergency Preparedness

    Get PDF
    Co-creation has been increasingly advocated by both scholars and practitioners in the public sector to enable the development of information technologies driven by citizens’ needs. Despite other potential advantages, it is not clear whether co-creation actually influences the adoption of IT-enabled solutions. The current knowledge about the effects of co-creation processes in the public sector is especially limited in non-urban environments. Based on a case study of the development of a mobile app for emergency preparedness and response in a rural town, the results of this study show that citizens play an important role in co-creation by identifying unique challenges for using the app. Local leadership plays a key role in the recruiting of participants, while professionals’ facilitation and openness are key during the co-designing of the app. Overall, the co-creation process increased citizens’ perceived ease of use and facilitated their adoption of the app

    Sensitivity of Computational Control Problems

    Get PDF
    It is well-known that many factors contribute to the accurate and efficient numerical solution of mathematical problems such as those arising in computational control system design. In simple terms these are the arithmetic of the machine on which the calculations are carried out, sensitivity (or conditioning) of the mathematical model to small changes of the data and the numerical stability of the algorithms. It happens quite often that these concepts are confused. We define these concepts and demonstrate some of the subtleties that often lead to confusion. In particular we demonstrate with several examples what may happen when a problem is modularized, i.e., split into subproblems for which computational modules are available. For three classical problems in computational control, pole placement, linear quadratic control and optimal H∞H_\infty control, we then discuss the conditioning of the problems and point out sources of difficulties. We give some ill-conditioned examples for which even numerically stable methods fail. We also stress the need for condition and error estimators that supplement the numerical algorithm and inform the user about potential or actual difficulties, and we explain what can be done to avoid these difficulties

    SiC/SiC Ceramic Matrix Composites Developed for High-Temperature Space Transportation Applications

    Get PDF
    Researchers at the NASA Glenn Research Center have been developing durable, high-temperature ceramic matrix composites (CMCs) with silicon carbide (SiC) matrices and SiC or carbon fibers for use in advanced reusable launch vehicle propulsion and airframe applications in the Next Generation Launch Technology (NGLT) Program. These CMCs weigh less and are more durable than competing metallic alloys, and they are tougher than silicon-based monolithic ceramics. Because of their high specific strength and durability at high temperatures, CMCs such as C/SiC (carbon- fiber-reinforced silicon carbide) and SiC/SiC (silicon-carbide-fiber-reinforced silicon carbide) may increase vehicle performance and safety significantly and reduce the cost of transporting payloads to orbit
    • 

    corecore