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This paper seeks to increase understanding of the role the environment in the emergence of business opportunities, and how opportunities change as industries evolves. It explores the dynamics of entrepreneurial opportunity in the British steamship industry. It suggests niches are created when environmental thresholds are reached. Entrepreneurs who act before thresholds are reached fail. A complex relationship between inventors, innovators/entrepreneurs and higher order opportunities is revealed illustrating the difficulty of identifying 'higher order opportunities. Over time, variations in environmental forces changed niche size and carrying capacity. Causes of new niche formation were both exogenous and endogenous supporting both Kirzner and Schumpeter. Inertial forces inhibited the ability of existing players to seize opening niches and expanded opportunities for new comers.

Stem cells are characterized by their dual ability to self-renew and differentiate, yielding essentially unlimited numbers of progeny that can replenish tissues with either high turnover such as blood and skin or contribute to the regeneration of organs with less frequent remodeling such as muscle. In contrast to their embryonic counterparts, adult stem cells can only preserve their unique functions if they are in intimate contact with an instructive microenvironment, termed niche. Stem cells integrate a complex array of niche signals that regulate their fate, keeping them in a relatively quiescent state during homeostasis, or controlling their numbers via symmetric or asymmetric divisions in response to the regenerative demands of a tissue. This chapter provides an overview of the current state of knowledge of structural and functional hallmarks of mammalian stem cell niches and offers a perspective on how bioengineering principles could be used to deconstruct the niche and providing novel insights into the role of its specific components in the regulation of stem cell fate. Such "artificial niches" constitute powerful tools for elucidating stem cell regulatory mechanisms that should fuel the development of novel therapeutic strategies for tissue regeneration.