With the knowledge that cells can react to lithographically manufactured nanometer-sized surface objects, our interest concerned whether cells would respond to surface structures of systematically increasing size. Our approach to answer this question was to fabricate surfaces with the same surface chemistry and similar surface roughness but increasing size of structural features. To fabricate large areas of patterned surfaces, required for cell culture studies, we used colloidal lithography utilizing colloidal particles as a template for surface nanostructuring. The fabricated surfaces contained hemispherical nanopillars with diameters ranging from 60 to 170 nm. Changes in cell morphology of a pancreatic epithelial cell line (AR4-2J) were studied by evaluating cell area and cell shape. The latter was studied by applying the cell shape classification method using three shape descriptors. The pancreatic cells responded in a systematic way to the surface nanostructures. The cells spread more and became more nonround when cultured on surfaces with increasing size of the topographic features. Index Terms-Biological cells, image analysis, nanotechnology, shape measurement, surfaces.
The paper analyses the development of newly started bioscience firms in terms of their capabilities and changes in their business models. The study consists of eight retrospective case studies stemming from their foundation over a period of 5-15 years. Empirically the paper finds that all the firms quickly develop a technological capability at the time of their foundation, and over time all firms added distinctly new business capabilities. Seven firms radically changed their business models by identifying and exploiting new opportunities by drawing on their existing business capability combined with a new, different technological capability. The initial technological capability -the firms' 'ticket to entry' -does not seem to be relevant to explain the process of firm development. These initial technological capabilities are surprisingly seldom leveraged within the cumulative process of opening up additional opportunities and business models. The paper concludes by creating a model and discusses some reasons for the findings.
Africa is, paradoxically, a continent rich in resources, and yet, lacking and lagging in overall development. When the wealth of Africa's people is compared with that of other continents a contrasting picture of poverty, stunted growth and famine resulting from inadequate food production is revealed. The agricultural, and food security problems in Africa cannot be solved by applying plant biotechnology alone. Five key factors seem to be necessary for the improvement of crop production such as the use of agrochemicals, irrigation, plant breeding, farm management, and, of course, plant biotechnology. In this context, biotechnology can play a role in commercializing crops, creating new jobs and earning foreign exchange. The goals of national and regional development in Africa are attainable through proper planning and active participation in technical networks involving regional and international scientific cooperation that emphasize the use of plant and microbial genetic resources for economic development and progress.
Growth of Candida famata and Trichosporon cutaneum on uric acid as the sole source of carbon and energy, a hitherto unknown property of yeasts Middelhoven, W.J.; Brink, Jolanda A. van den; Veenhuis, M. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum.
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