Abstract We examine the technological aspects of political collaborative practices in one of the first studies of participatory constitution writing in the course of its progression. In particular, we examine how digital collaborative and communicative tools can facilitate (or inhibit) the permeation of boundaries, which manifest through the differences in political ideologies and partisan beliefs. Our study is grounded in interviews with 15 members of the Constituent Assembly in the canton of Valais, Switzerland, and its primary contribution is in constructing a fine-grained contextualized understanding of political collaborations, their evolution, and their relationship with collaborative tools. Our findings demonstrate the centrality of versatile and widely available digital tools (such as WhatsApp and Google Docs) in political work. In addition, elected lawmakers prefer tools that allow them to organize their collaborative and communicative actions based on dynamic social boundaries, and their need for asynchronous work practices. We observed a tendency of simultaneously using multiple digital tools to accomplish specific political objectives, and leveraging them in plenary sessions for strategic advantages. On the one hand, collaborative tools enabled strategic advantages by selective permeation of boundaries across political ideologies. On the other hand, lack of awareness about boundaries between ‘private’ and ‘public’ on social networks were considered as privacy blind spots. By focusing on boundaries of different kinds, our paper elucidates how the introduction of digital technologies into political process transforms the long-established categories, distinctions and divisions that are often taken for granted.

Large amounts of medical images are being produced to help physicians in diagnosis and treatment planning. These images are then archived in PACS (Picture Archival and Communication Systems) and usually they are only reused in the context of the same patient during further visits. Medical image retrieval systems allow medical professionals to search for images in institutional archives, the Internet or in the scientific literature. The goal of the search can be in diagnosis but often as well for teaching and research. A large body of research has investigated efficient and effective algorithms to retrieve a set of images to fulfil a specific information need. However, much less research has been done on studying simple and engaging interaction for users of medical image retrieval systems. In this paper we propose an intuitive and engaging web--based interface targeted to be used by a large range of users with gesture control. This interface allows users to retrieve medical images by accessing a system called Parallel Distributed Image Search Engine (ParaDISE), a text-- and content--based image retrieval system. Accepting search with keywords and example images, this interface uses simple gestures to get random example images and mark examples as positive and negative relevance feedback with results being updated after each interaction.

Soft tissue palpation plays an important role in diagnosing various diseases. Palpating skills are tedious to learn due to the difficulty of describing the sense of touch. Because of its interactive nature, a virtual reality (VR) training system embedding with real-time soft-tissue models may be helpful to teach such skills to medical residents. Studies show that such a VR system impacts human perception during palpating at various levels, largely due to the real-time models. Therefore, we propose a formal method for evaluating real-time models considering the human perception. Based upon surface (multi-vertex) contact with 4 force distributions, the evaluation compared a real-time model with a Finite Element Method (FEM) model featuring physical parameters. The comparison consisted of two statistical approaches - ANOVA and Bland and Altman agreement- to assess both visual displacement and force feedback. A case study demonstrated the advantages provided by this evaluation method.

Virtual reality (VR) has been gaining popularity in surgical planning and simulation. Most VR surgical simulation systems provide haptic (pertinent to the sense of touch) and visual information simultaneously using certain alignments between a haptic device and visual display. A critical aspect of such VR surgical systems is to represent both haptic and visual information accurately to avoid perceptual illusions (e.g., to distinguish the softness of organs/tissues). This study compared three different alignments (same-location alignment, vertical alignment, and horizontal alignment) between a haptic device and visual display that are widely used in VR systems. We conducted three experiments to study the influence of each alignment on the perception of object softness. In each experiment, we tested 15 different human subjects with varying availability of haptic and visual information. During each trial, the task of the subject was to discriminate object softness between two deformable balls in different viewing angles. We analyzed the following dependent measurements: subject perception of object softness and objective measurements of maximum force and maximum pressing depth. The analysis results reveal that all three alignments (independent variables) have similar effect on subjective perception of object softness within the interval of viewing angles from -7.5°to +7.5°. The viewing angle does not affect objective measurements. The same-location alignment requires less physical effort compared with the other two alignments. These observations have implications in creating accurate simulation and interaction for VR surgical systems.

A critical issue of virtual reality (VR) surgical systems is to correctly represent both haptic and visual information for distinguishing the softness of organs/tissues. We investigated the relationship between subjective perception of object softness and objective measurements of haptic and visual information. On a co-location VR setup, human subjects pressed deformable balls (simulating organs/tissues) under the conditions of both haptic and visual information available and only haptic (or visual) information available. We recorded and analyzed the subject's selection (subjective perception) of the harder object between two balls and objective measurements of maximum force (haptic) and pressing depth (visual). The results preliminarily indicated that subjective perception behaves differently from objective measurements in perceiving object softness. This has implications for creating accurate simulation in VR surgical systems.