Affordances in activity theory and cognitive systems engineering

For the last decade, the Gibsonian concept of affordances has at- tracted much attention within Human-Machine Interaction (HMI) and related research communities. The application of Gibson's ideas in HMI has lead to the notion of direct manipulation of interface objects. Previously, the focus has been on design for low level interaction modalities. To incorporate the concept of affordances in the design of human computer interaction it is necessary to systematically unravel affordances that support human action possibilities. Furthermore, it is a necessity that Gibson's theory of affordances is supplemented by careful analyses of other human modalities and activities than visual perception. Within HMI two well established perspectives on HMI, Activity Theory (AT) and Cognitive Systems Engineering (CSE), have discussed such analyses and design of action possibilities focusing on providing computer support for work situations. Within these perspectives, the primary unit of analysis in HMI is human work activity and the socio-cultural context in which this activity is carried out. Thus, they emphasise the actors' purposeful activity as the most important design rationale. According to previous views in HMI, notably those that have been put forward by Norman and Gaver, affordances are in the foreground, whereas the system or work area is in the background. AT and CSE share the view that the actors' perception of foreground and background shifts dynamically according to the actors' situational context in purposeful activity. AT and CSE follow the original notion by Gibson on the actor's dynamic shifting between foreground and background of the environment. Furthermore, their work- and actor-centred approach to analysis and design of information sys..

Proteomic maps of breast cancer subtypes

Systems-wide profiling of breast cancer has almost always entailed RNA and DNA analysis by microarray and sequencing techniques. Marked developments in proteomic technologies now enable very deep profiling of clinical samples, with high identification and quantification accuracy. We analysed 40 oestrogen receptor positive (luminal), Her2 positive and triple negative breast tumours and reached a quantitative depth of >10,000 proteins. These proteomic profiles identified functional differences between breast cancer subtypes, related to energy metabolism, cell growth, mRNA translation and cell-cell communication. Furthermore, we derived a signature of 19 proteins, which differ between the breast cancer subtypes, through support vector machine (SVM)-based classification and feature selection. Remarkably, only three proteins of the signature were associated with gene copy number variations and eleven were also reflected on the mRNA level. These breast cancer features revealed by our work provide novel insights that may ultimately translate to development of subtype-specific therapeutics

Petri Dish-ELISA, a Simple and Economic Technique for Detecting Plant Viruses

A large number of microtiter plates are needed for mass testing of planting material for viruses in seed certification and plant quarantine. In the case of poorly equipped laboratories, problems with availability of microtiter plates have economic implications for the broad acceptance of enzyme-linked immunosorbent assay (ELISA) for e.g. seed health testing in developing countries. In this experiment the potential of an alternative, cheaper technique was investigated. A conventional indirect ELISA procedure was followed for comparison between the polystyrene solid phases of plastic Petri dishes and microtiter plates for detection of three viruses belonging to the Tobamovirus, Comovirus and Potyvirus genera. A wax pen was used to divide the inner surface of a polystyrene Petri dish into many circles or squares. The hydrophobic boundaries thus provided were effective in separating 50 µl-drops throughout the ELISA procedure. In comparative assays of serial dilutions of the three viruses, the ELISA in Petri dishes resulted in similar or higher A405 values than the ELISA carried out in microtiter plates, suggesting a similar or better protein binding capacity of Petri dishes. The perspectives of this alternative method are briefly discussed