Lightweight Interaction Modeling in Evolutionary Prototyping

The paper discusses a systematic integration of evolutionary and exploratory prototyping of interactive systems by a lightweight use of formal methods. Formal models guide the development of the underdesigned evolutionary prototype. In combination with techniques from Design Rationale, they implement theexploration and assessment of possible solutions to open design questions. Models and corresponding tool support are used to express design options and to make them more accessible to a broader audience by the creation of parallel model-guided throwaway extensions of the current evolutionary prototype. They are also used to describe design constraints (for example, in terms of tasks or in terms of actions on artifacts) and to assess design options against these criteria. The suggested approach is demonstrated through an example design scenario that shows an intertwining of different design activities and discusses the role of formal models. In particular, the scenario describes a coupling of HOPS models, QOC diagrams, and Java prototypes

A semi-formal framework for describing interaction design spaces

Interactive system design is typically more successful if it is an iterative process involving collaboration between multi-disciplinary teams with different viewpoints. While some sub-teams may focus on the creative aspects of the user interface design and other sub-groups on the implementation of required functionality, all must ensure that they are working towards the same goal. They must also satisfy the requirements and needs of all stakeholders. Although many suggestions have been made as to how such design might be supported in a more formal way (such as by using a model-driven process), less focus has been given to managing the co-ordination of design sub-teams following a creative process. In this paper we propose a semi-formal framework to describe and to compare design spaces, and the external design representations within those spaces. The framework is based on ideas from interaction design and on formal refinement approaches. It suggests a distinction of design options into alternatives and variants to describe and guide processes of idea generation and convergence within, and between, different design sub-spaces and sub-groups. We provide a small example to illustrate our approach and to show how it can be implemented by using standard formal approaches alongside less formal design notations and human-computer interaction processes

Formal Definitions for Design Spaces and Traces

Within the domain of interactive system development and design, particularly for safety-critical systems, there is an inherent tension between formalisms used for software engineering methodologies and the creative aspects of design. In this paper we consider how we might better unify these by way of a framework for design spaces and design artefacts. We present formal definitions for simple and complex design spaces and then describe how they are incorporated into traces. We then discuss how these can be used to reason about considerations such as preservation of requirements and iterative changes throughout the design process and provide some small examples of this

Task models as basis for requirements engineering and software execution

ABSTRACT In this paper we discuss an approach linking GUI specifications to abstract dialog models. Both specifications are based on task models describing behavioral features. It will be shown how first prototypes of interactive systems, which are generated from user interface models, can help to capture requirements. Users can interactively play with prototypes. Tool support is also provided for co-operative work of different users, which starts with abstract canonical prototypes that can evolve to concrete GUI specifications

Statin-induced myopathic changes in primary human muscle cells and reversal by a prostaglandin F2 alpha analogue

Statin-related muscle side effects are a constant healthcare problem since patient compliance is dependent on side effects. Statins reduce plasma cholesterol levels and can prevent secondary cardiovascular diseases. Although statin-induced muscle damage has been studied, preventive or curative therapies are yet to be reported. We exposed primary human muscle cell populations (n = 22) to a lipophilic (simvastatin) and a hydrophilic (rosuvastatin) statin and analyzed their expressome. Data and pathway analyses included GOrilla, Reactome and DAVID. We measured mevalonate intracellularly and analyzed eicosanoid profiles secreted by human muscle cells. Functional assays included proliferation and differentiation quantification. More than 1800 transcripts and 900 proteins were differentially expressed after exposure to statins. Simvastatin had a stronger effect on the expressome than rosuvastatin, but both statins influenced cholesterol biosynthesis, fatty acid metabolism, eicosanoid synthesis, proliferation, and differentiation of human muscle cells. Cultured human muscle cells secreted ω-3 and ω-6 derived eicosanoids and prostaglandins. The ω-6 derived metabolites were found at higher levels secreted from simvastatin-treated primary human muscle cells. Eicosanoids rescued muscle cell differentiation. Our data suggest a new aspect on the role of skeletal muscle in cholesterol metabolism. For clinical practice, the addition of omega-n fatty acids might be suitable to prevent or treat statin-myopathy

Plant diversity enhances production and downward transport of biodegradable dissolved organic matter

1. Plant diversity is an important driver of belowground ecosystem functions, such as root growth, soil organic matter (SOM) storage, and microbial metabolism, mainly by influencing the interactions between plant roots and soil. Dissolved organic matter (DOM), as the most mobile form of SOM, plays a crucial role for a multitude of soil processes that are central for ecosystem functioning. Thus, DOM is likely to be an important mediator of plant diversity effects on soil processes. However, the relationships between plant diversity and DOM have not been studied so far. 2. We investigated the mechanisms underlying plant diversity effects on concentrations of DOM using continuous soil water sampling across 6 years and 62 plant communities in a long‐term grassland biodiversity experiment in Jena, Germany. Furthermore, we investigated plant diversity effects on the molecular properties of DOM in a subset of the samples. 3. Although DOM concentrations were highly variable over the course of the year with highest concentrations in summer and autumn, we found that DOM concentrations consistently increased with plant diversity across seasons. The positive plant diversity effect on DOM concentrations was mainly mediated by increased microbial activity and newly sequestered carbon in topsoil. However, the effect of soil microbial activity on DOM concentrations differed between seasons, indicating DOM consumption in winter and spring, and DOM production in summer and autumn. Furthermore, we found increased contents of small and easily decomposable DOM molecules reaching deeper soil layers with high plant diversity. 4. Synthesis. Our findings suggest that plant diversity enhances the continuous downward transport of DOM in multiple ways. On the one hand, higher plant diversity results in higher DOM concentrations, on the other hand, this DOM is less degraded. The present study indicates, for the first time, that higher plant diversity enhances the downward transport of dissolved molecules that likely stimulate soil development in deeper layers and therefore increase soil fertility

Toward a General Model for the Evolutionary Dynamics of Gene Duplicates

Gene duplication is an important process in the functional divergence of genes and genomes. Several processes have been described that lead to duplicate gene retention over different timescales after both smaller-scale events and whole-genome duplication, including neofunctionalization, subfunctionalization, and dosage balance. Two common modes of duplicate gene loss include nonfunctionalization and loss due to population dynamics (failed fixation). Previous work has characterized expectations of duplicate gene retention under the neofunctionalization and subfunctionalization models. Here, that work is extended to dosage balance using simulations. A general model for duplicate gene loss/retention is then presented that is capable of fitting expectations under the different models, is defined at t = 0, and decays to an orthologous asymptotic rate rather than zero, based upon a modified Weibull hazard function. The model in a maximum likelihood framework shows the property of identifiability, recovering the evolutionary mechanism and parameters of simulation. This model is also capable of recovering the evolutionary mechanism of simulation from data generated using an unrelated network population genetic model. Lastly, the general model is applied as part of a mixture model to recent gene duplicates from the Oikopleura dioica genome, suggesting that neofunctionalization may be an important process leading to duplicate gene retention in that organism

Identification of Ischemic Regions in a Rat Model of Stroke

Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia.Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed.TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study

Selective Modeling to Support Task Migratability of Interactive Artifacts

Part 1: Long and Short PapersInternational audienceSelective modeling is suggested as a technique that encourages designers to mix exploratory, analytical, and empirical design activities in interaction design. The co-development of models and prototypes of interactive systems is proposed to support a better balance between formal and explorative design approaches. Models serve to inform design decisions but also to analyze emerging alternatives of prototypical implementations.Task migratability is a usability design principle that describes how control for task execution is transferred between system and user. Refined flexible task allocation is rarely achievable through pure top-down decomposition as used in many model-based approaches. The paper shows at the example of HOPS models how selective modeling can be applied to develop prototypes in a deliberated evolutionary way by using models to express different viewpoints and to explore design options at different levels of granularity

Understanding active non-use through the framework of complex design spaces

Interest in studying non-use has increased in the HCI field. However, most approaches which explain non-use are solely based on the notion of the user. This paper suggests understanding non-use in terms of the user and the complementary notion of designer. The framework of complex design spaces is used to revisit non-use and these underlying notions