An analytical solution for diffusion and nonlinear uptake of oxygen in a spherical cell

We develop a new analytical solution for a reactive transport model that describes the steady-state distribution of oxygen subject to diffusive transport and nonlinear uptake in a sphere. This model was originally reported by Lin (Journal of Theoretical Biology, 1976 v60, pp449–457) to represent the distribution of oxygen inside a cell and has since been studied extensively by both the numerical analysis and formal analysis communities. Here we extend these previous studies by deriving an analytical solution to a generalized reaction-diffusion equation that encompasses Lin’s model as a particular case. We evaluate the solution for the parameter combinations presented by Lin and show that the new solutions are identical to a grid-independent numerical approximation

A Review on Possible Approaches for Detecting Early Warning Signs in Projects

In this paper, we attempt to provide an overview of the full extent of early warning detection approaches, which are directly or indirectly addressed in the literature. These approaches can aid project managers in taking corrective actions timely enough for preventing failures. The study is based on a review of the current literature within the field of early warning in project management and our own experiences gained from practice. An analysis of the strengths and weaknesses of each approach and their applications in different contexts are also performed. We conclude that the choice of the most effective approach is arguably dependent on the type of project, organizational culture, and the project environment

The glass menagerie of urban governance and social cohesion: concepts and stakes/concepts as stakes

Social goals and social action are increasingly framed by a host of ambiguously egalitarian notions. The ambiguity of notions like 'social cohesion' originates principally in the tentative accommodation of competition and social Justice that former radical approaches considered in fundamental contradiction. The social cohesion terminology has become part of political realism and the question is whether such notions are or could be fuelling practices that promote social justice, overcoming the ambiguity/contradiction of the different/competing interpretations nebulously juxtaposed in their fluid definition. This article comments on interrelated ambiguities in the content of social cohesion, governance and tolerance starting with a reformulated goal (social cohesion) which necessitates new means of implementation ('new governance') that entail the dominance of non-conflictual social relations (tolerance). Social cohesion, governance and tolerance are Janus-faced concepts, full of restrictions and contradictions but also full of possibilities related to the mobilizing potential of their inherently positive meaning. Social cohesion and governance would become real stakes if radical discourse and politics tried to invest them with content and meaning that would effectively transgress their legitimating function of conservative social regulation, and create massive demand for more social justice both in terms of redistributive Justice and of democracy