Interaction is increasingly a public affair, taking place in our theatres, galleries, museums, exhibitions and on the city streets. This raises a new design challenge for HCIhow should spectators experience a performer's interaction with a computer? We classify public interfaces (including examples from art, performance and exhibition design) according to the extent to which a performer's manipulations of an interface and their resulting effects are hidden, partially revealed, fully revealed or even amplified for spectators. Our taxonomy uncovers four broad design strategies: 'secretive,' where manipulations and effects are largely hidden; 'expressive,' where they tend to be revealed enabling the spectator to fully appreciate the performer's interaction; 'magical,' where effects are revealed but the manipulations that caused them are hidden; and finally 'suspenseful,' where manipulations are apparent but effects are only revealed as the spectator takes their turn. ACM ClassificationH1.2 User/Machine Systems; H5. Information Interfaces and Presentation.

Voice User Interfaces (VUIs) are becoming ubiquitously available, being embedded both into everyday mobility via smartphones, and into the life of the home via 'assistant' devices. Yet, exactly how users of such devices practically thread that use into their everyday social interactions remains underexplored. By collecting and studying audio data from month-long deployments of the Amazon Echo in participants' homes-informed by ethnomethodology and conversation analysis-our study documents the methodical practices of VUI users, and how that use is accomplished in the complex social life of the home. Data we present shows how the device is made accountable to and embedded into conversational settings like family dinners where various simultaneous activities are being achieved. We discuss how the VUI is finely coordinated with the sequential organisation of talk. Finally, we locate implications for the accountability of VUI interaction, request and response design, and raise conceptual challenges to the notion of designing 'conversational' interfaces.

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EpiCor, derived from Saccharomyces cerevisiae, has been shown to have immunomodulating properties in human clinical trials and in vitro. However, the underlying mechanisms behind its immune protection via the gut remain largely unknown. Therefore, the aim of this study was to use an integrated in vitro approach to evaluate the metabolism of EpiCor by the intestinal microflora, its modulating effect on the gut microbiota, and its anti-inflammatory activity on human-derived cell lines. Using the SHIME model, in combination with a mucus adhesion assay, has shown that low doses of EpiCor have a prebiotic-like modulatory effect on the luminal- and mucosa-associated microbiota. These include gradual changes in general community structure, reduction of potential pathogens, quantitative increase in lactobacilli, and qualitative modulation of bifidobacteria. Moreover, by combination of the SHIME with Caco-2 cells and Caco-2/THP1 cocultures, a significant decrease in pro-inflammatory cytokines was observed at the end of the treatment period.

Visions of the future are a common feature of discourse within ubiquitous computing and, more broadly, HCI. 'Envisioning', a characteristic future-oriented technique for design thinking, often features as significant part of our research processes in the field. This paper compares, contrasts and critiques the varied ways in which envisionings have been used within ubiquitous computing and traces their relationships to other, different envisionings, such as those of virtual reality. In unpacking envisioning, it argues primarily that envisioning should be foregrounded as a significant concern and interest within HCI. Foregrounding envisioning's frequent mix of fiction, forecasting and extrapolation, the paper recommends changes in the way we read, interpret and use envisionings through taking into account issues such as context and intended audience.

No abstract

The addition of a yeast culture food supplement (DVAqua from Diamond V. Mills, Cedar Rapids, IA, USA) was evaluated during feeding of McConaughy strain rainbow trout Oncorhynchus mykiss. Two trials were run consecutively, starting with initial feeding, and were replicated over 2 years. The yeast culture was added to commercial trout starter at levels of 0.125 and 0.25 g kg−1. The number of rainbow trout that died during the first 4 weeks of rearing was significantly reduced in the tanks receiving either of the yeast culture‐supplemented diets compared with the tanks receiving a control starter diet. Ending tank weights and gain were significantly and consistently greater in the tanks fed the 0.25 g kg−1 yeast culture diet. Individual fish weights were also significantly heavier in the fish‐fed yeast culture containing diets in each year of the study at the end of 27 days. In the trials from 4 to 8 weeks postinitial feeding, mortality rates were significantly less only in the tanks receiving 0.25 g kg−1 yeast culture supplementation. Individual fish lengths and weights at the end of the second trial were significantly greater in the tanks receiving either level of yeast culture compared with the control diet only in 1 year. Total tank weights and feed conversion were not significantly different between any of the treatments. The inclusion of DVAqua yeast culture provided significant increases in trout survival and growth through the first 4 weeks of feeding, with continued benefits for the next 4 weeks.

Field trials of experimental systems 'in the wild' have developed into a standard method within HCI -testing new systems with groups of users in relatively unconstrained settings outside of the laboratory. In this paper we discuss methodological challenges in running user trials. Using a 'trial of trials' we examined the practices of investigators and participants -documenting 'demand characteristics', where users adjust their behaviour to fit the expectations of those running the trial, the interdependence of how trials are run and the result they produce, and how trial results can be dependent on the insights of a subset of trial participants. We develop three strategies that researchers can use to leverage these challenges to run better trials.