A gamification-based approach on indoor wayfinding research

Indoor environments can be very complex. Due to the challenges in these environments in combination with the absence of mobile wayfinding aids, a great need exists for innovative research on indoor wayfinding. In this explorative study, a game was developed in Unity to investigate whether the concept of gamification could be used in studies on indoor wayfinding so as to provide useful information regarding the link between wayfinding performance, personal characteristics, and building layout. Results show a significant difference between gamers and non-gamers as the complexity of the player movement has an important impact on the navigation velocity in the game. However, further analysis reveals that the architectural layout also has an impact on the navigation velocity and that wrong turns in the game are influenced by the landmarks at the decision points: navigating at deeper decision points in convex spaces is slower and landmarks of the categories pictograms and infrastructural were more effective in this particular building. Therefore, this explorative study, which provides an approach for the use of gamification in indoor wayfinding research, has shown that serious games could be successfully used as a medium for data acquisition related to indoor wayfinding in a virtual environment

Intraspecific variation shapes community-level behavioral responses to urbanization in spiders

International audienceUrban areas are an extreme example of human-changed environments, exposing organisms to multiple and strong selection pressures. Adaptive behavioral responses are thought to play a major role in animals' success or failure in such new environments. Approaches based on functional traits have proven especially valuable to understand how species communities respond to environmental gradients. Until recently, they have, however, often ignored the potential consequences of intraspecific trait variation (ITV). When ITV is prevalent, it may highly impact ecological processes and resilience against stressors. This may be especially relevant in animals, in which behavioral traits can be altered very flexibly at the individual level to track environmental changes. We investigated how species turnover and ITV influenced community-level behavioral responses in a set of 62 sites of varying levels of urbanization, using orb web spiders and their webs as models of foraging behavior. ITV alone explained around one-third of the total trait variation observed among communities. Spider web structure changed according to urbanization, in ways that increase the capture efficiency of webs in a context of smaller urban prey. These trait shifts were partly mediated by species turnover, but ITV increased their magnitude, potentially helping to buffer the effects of environmental changes on communities. The importance of ITV varied depending on traits and on the spatial scale at which urbanization was considered. Despite being neglected from community-level analyses in animals, our results highlight the importance of accounting for intraspecific trait variation to fully understand trait responses to (human-induced) environmental changes and their impact on ecosystem functioning

Urbanization-driven changes in web-building and body size in an orb-web spider

International audience1.In animals, behavioural responses may play an important role in determining population persistence in the face of environmental changes. Body size is a key trait central to many life history traits and behaviours. Correlations with body size may constrain behavioural variation in response to environmental changes, especially when size itself is influenced by environmental conditions. 2.Urbanization is an important human-induced rapid environmental change that imposes multiple selection pressures on both body size and (size-constrained) behaviour. How these combine to shape behavioural responses of urban-dwelling species is unclear. 3.Using web-building, an easily quantifiable behaviour linked to body size, and the garden spider Araneus diadematus as a model, we evaluated direct behavioural responses to urbanization and body size constraints across a network of 63 selected populations differing in urbanization intensity. We additionally studied urbanization at two spatial scales to account for some environmental pressures varying across scales and to obtain first qualitative insights about the role of plasticity and genetic selection. 4.Spiders were smaller in highly urbanized sites (local scale only), in line with expectations based on reduced prey biomass availability and the Urban Heat Island effect. Web surface and mesh width decreased with urbanization at the local scale, while web surface also increased with urbanization at the landscape scale. The latter two responses are expected to compensate, at least in part, for reduced prey biomass availability in cities. The use of multivariate mixed modelling reveals that although web traits and body size are correlated within populations, behavioural responses to urbanization do not appear to be constrained by size there is no evidence of size-web correlations among populations or among landscapes, and web traits appear independent from each other. 5.Our results demonstrate that responses in size-dependent behaviours may be decoupled from size changes, thereby allowing fitness maximisation in novel environments. The spatial scale at which traits respond suggests contributions of both genetic adaptation (for web investment) and plasticity (for mesh width). Although fecundity decreased with local-scale urbanization, Araneus diadematus abundances were similar across urbanization gradients; behavioural responses thus appear overall successful at the population level

Landscape-level urbanization

This file contains levels of urbanization for all 3 by 3 km landscapes included in the Journal of Animal Ecology paper. See README for details

Data from: Urbanization-driven changes in web-building and body size in an orb-web spider

1. In animals, behavioural responses may play an important role in determining population persistence in the face of environmental changes. Body size is a key trait central to many life history traits and behaviours. Correlations with body size may constrain behavioural variation in response to environmental changes, especially when size itself is influenced by environmental conditions. 2. Urbanization is an important human-induced rapid environmental change that imposes multiple selection pressures on both body size and (size-constrained) behaviour. How these combine to shape behavioural responses of urban-dwelling species is unclear. 3. Using web-building, an easily quantifiable behaviour linked to body size, and the garden spider Araneus diadematus as a model, we evaluated direct behavioural responses to urbanization and body size constraints across a network of 63 selected populations differing in urbanization intensity. We additionally studied urbanization at two spatial scales to account for some environmental pressures varying across scales and to obtain first qualitative insights about the role of plasticity and genetic selection. 4. Spiders were smaller in highly urbanized sites (local scale only), in line with expectations based on reduced prey biomass availability and the Urban Heat Island effect. Web surface and mesh width decreased with urbanization at the local scale, while web surface also increased with urbanization at the landscape scale. The latter two responses are expected to compensate, at least in part, for reduced prey biomass availability in cities. The use of multivariate mixed modelling reveals that although web traits and body size are correlated within populations, behavioural responses to urbanization do not appear to be constrained by size: there is no evidence of size-web correlations among populations or among landscapes, and web traits appear independent from each other. 5. Our results demonstrate that responses in size-dependent behaviours may be decoupled from size changes, thereby allowing fitness maximisation in novel environments. The spatial scale at which traits respond suggests contributions of both genetic adaptation (for web investment) and plasticity (for mesh width). Although fecundity decreased with local-scale urbanization, Araneus diadematus abundances were similar across urbanization gradients; behavioural responses thus appear overall successful at the population level

Spider web and body size information

This file contains trait information for all spiders included in the Journal of Animal Ecology paper. See README for details

R Script to reproduce analyses

This file allows to reproduce analyses presented in the paper using the three datasets made available alongside it

Spider population density

This file contains spider population density (females caught per 200*200 m site) for all sites included in the Journal of Animal Ecology paper. See README for details

Development of 3D IVOCT Imaging and Co-Registration of IVOCT and Angiography in the Catheterization Laboratory

© 2014, Springer Science+Business Media New York. Intravascular optical coherence tomography (IVOCT) has become the imaging modality of choice for the evaluation of coronary artery disease and percutaneous coronary intervention (PCI). Both for clinical practice and research, there is a growing interest in 3-dimensional (3D) visualization, as this gives a more comprehensive and intuitively easier to understand representation, compared with 2-dimensional, cross-sectional images. Integrating 3D-IVOCT with classic X-ray angiographic images offers additional advantages and the prospect of integrating IVOCT in fluoroscopic guidance during PCI. Different vendors of IVOCT technology already provide integrated 3D rendering software in their consoles, making 3D images available at the ‘push-of-a-button’. In this review, we will discuss (1) the basic principles and elaboration of 3D-IVOCT in recent years, (2) the feasibility and potential advantages of co-registration with X-ray angiography, (3) the currently available solutions for 3D imaging and their potential clinical applications, and (4) the ongoing development of applications for advanced 3D visualization.status: publishe

Threat Modelling for Security Tokens in Web Applications

In the last couple of years, several European countries have started projects which intend to provide their citizens with electronic identity cards, driven by the European Directive on Electronic Signatures. One can expect that within a few years, these smart cards will be used in a wide variety of applications. In this paper, we describe the common threats that can be identified when using security tokens such as smart cards in web applications. We illustrate each of these threats with a few attack scenarios. This paper is part of a series of papers, written by several academic teams. Each paper focuses on one particular technological building block for web applications. © 2005 by International Federation for Information Processing.status: publishe