A mechanical model for guided motion of mammalian cells

We introduce a generic, purely mechanical model for environment sensitive motion of mammalian cells that is applicable to chemotaxis, haptotaxis, and durotaxis as modes of motility. It is able to theoretically explain all relevant experimental observations, in particular, the high efficiency of motion, the behavior on inhomogeneous substrates, and the fixation of the lagging pole during motion. Furthermore, our model predicts that efficiency of motion in following a gradient depends on cell geometry (with more elongated cells being more efficient).Comment: 5 pages, 5 figures, 5 pages Supplemental Materia

Environmental control of conodont distribution in the Shawnee Group (Upper Pennsylvanian) of eastern Kansas

124 p., 16 pl., 18 fig.http://paleo.ku.edu/contributions.htm

What's in it for me? Recommendation of Peers in Networked Innovation

Sie R. L. L., Bitter-Rijpkema, M., & Sloep, P. B. (2011). What's in it for me? Recommendation of Peers in Networked Innovation. Journal of Universal Computer Science, 17(12), 1659-1672.Several studies have shown that connecting to people in other networks foster creativity and innovation. However, it is often difficult to tell what the prospective value of such alliances is. Cooperative game theory offers an a priori estimation of the value of future collaborations. We present an agent-based social simulation approach to recommending valuable peers in networked innovation. Results indicate that power as such does not lead to a winning coalition in networked innovation. The recommendation proved to be successful for low-strength agents, which connected to high-strength agents in their network. Future work includes tests in real-life and other recommendation strategies.idSpac

The La Coulée Formation, a new post-Acadian continental clastic unit bearing groundwater calcretes, Gaspé Peninsula, Quebec

A 1 km2 erosional remnant of the La Coulée Formation, a previously unrecognized stratigraphic unit, has been studied in the Percé area of the Gaspé Peninsula. It unconformably overlies folded Cambrian to Devonian rocks and is unconformably overlain by the mid-Carboniferous Bonaventure Formation. The erosional remnant includes the lowest 60 m of this newly identified formation of unknown thickness. Original sedimentary fades are limited to 50 m of breccia debris flows passing stratigraphically upward into 10m of conglomeratic debris flows. Groundwater calcrete formation has partially or completely transformed the lowest 30 m of the sequence. The depositional environment is interpreted as being related to a proximal continental alluvial fan. The nearby presence of a saline body of water is inferred to account for thick and massive groundwater calcrete formation and water-saturated debris flows in a relatively arid climatic context Most of the formation was eroded prior to deposition of the Bonaventure Formation. However, the basal groundwater calcretes were more widely preserved. They underlie the Bonaventure Formation in most of the Percé area and in the Saint-Elzéar area, close to a hundred kilometres to the southwest. Post-sedimentary faulting has affected both the La Coulée and Bonaventure formations. RÉSUMÉ La Formation de La Coulée, une unite stratigraphique nouvellement répertoriée, a été éudiée a I'intérieur d'une masse résiduelle de 1 km2 dans la région de Percé en Gaspésie. La séquence recouvre en discordance des roches plissees du Dévonien Inférieur et elle est recouverte en discordance par la Formation de Bonaventure qui est attribuée au Carbonifere moyen. La masse résiduelle inclue les 60 premiers mètres de cette formation nouvellement identifiée et d'une épaisseur inconnue. Les fades sédimentaires originels sont limités à cinquante mètres de coulees de débris bréchiques, passant à une dizaine de mètres de coulées de débris conglomératiques. La formation d'une calcrete phréatique affecte les premiers 30 mètres de la séquence, lesquels sont en partie ou complètement transformés. L'environnement sédimentaire est interprété comme étant lié à un còne de déjection continental dans sa partie proximale, mais la présence non-lointaine d'un plan d'eau salde est suggerée pour expliquer la formation de calcretes phréatiques épaisses et massives, ainsi que la saturation en eau des coulées de débris dans un contexte climatique relativement aride. La formation a presqu'entierement été érodée avant que ne survienne la sédimentation de la Formation de Bonaventure. Toutefois, la base de calcrete a été plus largement préservée, ce qui fait qu'on la retrouve sous la Formation de Bonaventure preque partout dans la region de Percé ainsi que dans la région de Saint-Elzéar, a presqu'une centaine de kilomètres au sud-ouest. Des failles post-sédimentaires ont affecté à la fois la Formation de La Coulée et la Formation de Bonaventure

To whom and why should I connect? Co-author Recommendation based on Powerful and Similar Peers

Sie, R. L. L., Drachsler, H., Bitter-Rijpkema, M., & Sloep, P. B. (2012). To whom and why should I connect? Co-author Recommendation based on Powerful and Similar Peers. International Journal of Technology Enhanced Learning (IJTEL), 4(1), 121-137. doi:10.1504/IJTEL.2012.048314The present article offers preliminary outcomes of a user study that investigated the acceptance of a recommender system that suggests future co- authors for scientific article writing. The recommendation approach is twofold: network information (betweenness centrality) and author (keyword) similarity are used to compute the utility of peers in a network of co-authors. Two sets of recommendations were provided to the participants: Set one focused on all candidate authors, including co-authors of a target user to strengthen current bonds and strive for acceptance of a certain research topic. Set two focused on solely new co-authors of a target user to foster creativity, excluding current co- authors. A small-scale evaluation suggests that the utility-based recommendation approach is promising, but to maximize outcome, we need to 1) compensate for researchers’ interests that change over time, and 2) account for multi-person co-authored papers

Factors that influence cooperation in networks for innovation and learning

Networked cooperation fails if the available partnerships remain opaque. A literature review and Delphi study uncovered the elements of a fruitful partnership. They relate to personality, diversity, cooperation, and management. Innovation networks and learning networks share the same cooperative intention, but they too often fail as members of the network do not know which partnerships are valuable. If one plans to build a support service that provides insight into the value of future cooperation, one first needs to know what contributes to effective and efficient cooperation. In addition to carrying out a literature review, we invoked the eDelphi method to answer this question. eDelphi is a method to solicit knowledge from experts anonymously and without geographical constraints. Observations from two eDelphi rounds are reported in this article. The first round focused on factor generation and determined which factors influence cooperation networks; it was conducted with two groups of six representative experts. Experts list open communication, a positive attitude, trust, keeping appointments, and personality as influential factors for cooperation networks. A team of four moderators categorised the factors in a second round, resulting in four core clusters: personal characteristics, diversity, effective cooperation, and managerial aspects. Interestingly the experts failed to list some factors that are mentioned in the literature. This finding is discussed

A new approach to collaborative creativity support of new product designers

Bitter-Rijpkema, M., Sloep, P. B., Sie, R., Van Rosmalen, P., Retalis, S., & Katsamani, M. (2011). A new approach to collaborative creativity support of new product designers. International Journal of Web Based Communities, 7(4), 478-492. DOI: 10.1504/IJWBC.2011.042992Effective collaborative creativity is crucial to contemporary professionals who have to continuously produce innovative products and services. The technological nature and complexity of the innovations require team work, among specialists from different disciplines. Often these teams work in a distributed fashion, across boundaries of time and place. Therefore they need electronic “spaces” that support (‘afford’) their creative collaboration. Co-creativity support is not only a matter of making appropriate groupware spaces available but also of providing concurrent support in all these dimensions. These considerations inspired the development of the idSpace platform. idSpace is a collaboration platform integrating a variety of creativity tools with pedagogy-based guidance. It aims to optimize both the use of creativity techniques themselves and of the supporting processes of team collaboration and knowledge creation. In this paper we zoom in on Knowledge-sharing Strategies for Collaborative Creativity (KS4CC). We show how collaborative creativity can be enhanced via integration of pattern-based pedagogical flow support, including suggestions of optimal use of creativity techniques. The KS4CC strategies consist of a merger of learning and collaboration flow patterns with support for the application of creative techniques

Question-answering – Connecting and Supporting the Learner

Van Rosmalen, P., Sloep, P., Brouns, F., Kester, L., Koné, M., & Koper, R. (2007). In F. Wild, M. Kalz, J. van Bruggen & R. Koper (Eds.). Proceedings of the First European Workshop on Latent Semantic Analysis in Technology-Enhanced Learning (pp. 1-2). March, 29-30, 2007, Heerlen, The Netherlands: Open University of the Netherlands.Tutors have only limited time to support the learning process. In this paper, we introduce a model that helps answering the questions of students. The model invokes the knowledge and skills of fellow students by bringing them together based on the combination of question posed and their study progress and supports them with text fragments selected from the material studied. We will explain how we used LSA to select and support these peers; examine the calibration of the LSA-parameters and conclude with a small practical simulation to show that the results of our model are fit for use in experiments with students.The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org