Personalization on a peer-to-peer television system

We introduce personalization on Tribler, a peer-to-peer (P2P) television system. Personalization allows users to browse programs much more efficiently according to their taste. It also enables to build social networks that can improve the performance of current P2P systems considerably, by increasing content availability, trust and the realization of proper incentives to exchange content. This paper presents a novel scheme, called BuddyCast, that builds such a social network for a user by exchanging user interest profiles using exploitation and exploration principles. Additionally, we show how the interest of a user in TV programs can be predicted from the zapping behavior by the introduced user-item relevance models, thereby avoiding the explicit rating of TV programs. Further, we present how the social network of a user can be used to realize a truly distributed recommendation of TV programs. Finally, we demonstrate a novel user interface for the personalized peer-to-peer television system that encompasses a personalized tag-based navigation to browse the available distributed content. The user interface also visualizes the social network of a user, thereby increasing community feeling which increases trust amongst users and within available content and creates incentives of to exchange content within the community.     

Monitoring the Quality of Perishable Foods: Opportunities for Intelligent Packaging

This review paper discusses opportunities for intelligent packaging for monitoring directly or indirectly quality attributes of perishable packaged foods. The possible roles of intelligent packaging as a tool in supply chain management are discussed as well as the barriers to implement this kind of technology in commercial applications. Cases on pasteurized milk and fresh cod fillets illustrate the application of different intelligent packaging concepts to monitor and estimate quality attributes. Conditions influencing quality (e.g., temperature–time) can be monitored to predict the quality of perishable products when the initial quality is known and rather constant (e.g., pasteurized milk). Products with a highly variable initial quality (e.g., fresh fish) require sensors monitoring compounds correlated with quality.     

Microgravity and bone cell mechanosensitivity: FLOW experiment during the DELTA mission

The catabolic effects of microgravity on mineral metabolism in bone organ cultures might be explained as resulting from an exceptional form of disuse. It is possible that the mechanosensitivity of bone cells is altered under near weightlessness conditions, which likely contributes to disturbed bone metabolism observed in astronauts. In the experiment “FLOW”, we tested whether the production of early signaling molecules that are involved in the mechanical load-induced osteogenic response by bone cells is changed under microgravity conditions. FLOW was one of the Biological experiment entries to the Dutch Soyuz Mission “DELTA” (Dutch Expedition for Life Science, Technology and Atmospheric Research). FLOW was flown by the Soyuz craft, launched on April 19, 2004, on its way to the International Space Station. Primary osteocytes, osteoblasts, and periosteal fibroblasts were incubated in plunger boxes, developed by Centre for Concepts in Mechatronics, using plunger activation events for single pulse fluid shear stress stimulations. Due to unforeseen hardware complications, results from in-flight cultures are considered lost. Ground control experiments showed an accumulative increase of NO in medium for osteocytes (as well as for osteoblasts and periosteal fibroblasts). Data from the online-NO sensor showed that the NO produced in medium by osteocytes increased sharply after pulse shear stress stimulations. COX-2 mRNA expression revealed high levels in osteoblasts compared to the other cell types tested. In conclusion, preparations for the FLOW experiment and preliminary ground results indicate that the FLOW setup is viable for a future flight opportunity.     

Linear models for the analysis and construction of instruments in a facet design.

Describes linear models for the situation wherein a measurement instrument is constructed for all elements of the Cartesian product of several facets when the elements of each facet are not ordered. The structure of the covariance matrix of the instrument is derived from the models. By using covariance structure analysis, the models can be tested, and estimates of the parameters can be obtained. Models for 20 tests were formulated and tested and were constructed from a design with a behavioral and a situational facet measuring social anxiety in children; for 15 tests a model proved to fit the data. It is concluded that covariance structure analysis is useful for the analysis and construction of measurement instruments. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploring ‘Generation Y’ interaction qualities at home and at work

Information technology support of office work has increased rapidly in functionality, but new ways of interacting have evolved more slowly. This paper adds to the design research community’s notion of interaction quality by exploring these new ways of interacting and comparing them in the home and work contexts. We describe and analyze two interview studies conducted with office workers to consider how they perceive, experience and compare interaction qualities. Six interaction qualities (instant, expressive, playful, collaborative, responsive and flexible) were identified that together embody an interaction style that we have labeled ‘Generation Y.’ From learning and comparing these qualities, we found that personal and natural type of interactions were mostly experienced in the more private home context. Formal and subtle type of interactions were mostly experienced in the more public work context. We also found that the office workers scored the interaction qualities in their home context as richer than in their work context. This study resulted in a set of design guidelines, aiming to be used to implement the Generation Y interaction style in future office tools and applications. Designers and researchers will benefit from the result of this study from understanding rich interaction design in the work context.     

The systematic construction of a one-combinator basis for Lambda-Terms

A single closed λ-expression that generates all λ-expressions is constructed. The derivation is carried out with simplicity as driving force. The result is simpler than single-combinator bases known in the literature.     

Influence of Oxygen in the Cultivation of Human Mesenchymal Stem Cells in Simulated Microgravity: An Explorative Study

Previous studies indicated that human Adipose Tissue-derived Mesenchymal Stem Cells (AT-MSCs) cultured in simulated microgravity (sim-μg) in standard laboratory incubators alter their proliferation and differentiation. Recent studies on the stem cell (SC) niches and the influence of oxygen on SC proliferation, senescence, and differentiation point to oxygen level as one of the key regulators of SC fate. Here we present the results of a study that focussed at the evaluation of the influence of oxygen level in the cultivation of AT-MSCs in sim-μg. In detail, cells were cultured for 14 days in sim-μg using the Random Positioning Machine (RPM) and two different oxygen concentrations: 5 % and 20 %. The results were compared with those obtained at 1g in the same conditions. Affymetrix Human Gene 1.0 ST array and Gene Ontology (GO) analysis were performed. The results confirmed that in all of the sim-μg experiments oxygen concentration modulates cell signalling and adhesion, in line with the knowledge that sim-μg affects cell shape and cytoskeletal organization.