Microbial systems biology has made enormous advances in relating microbial physiology to the underlying biochemistry and molecular biology. By meticulously studying model microorganisms, in particular Escherichia coli and Saccharomyces cerevisiae, increasingly comprehensive computational models predict metabolic fluxes, protein expression, and growth. The modeling rationale is that cells are constrained by a limited pool of resources that they allocate optimally to maximize fitness. As a consequence, the expression of particular proteins is at the expense of others, causing trade‐offs between cellular objectives (...) such as instantaneous growth, stress tolerance, and capacity to adapt to new environments. While current computational models are remarkably predictive for E. coli and S. cerevisiae when grown in laboratory environments, this may not hold for other growth conditions and other microorganisms. In this contribution, we therefore discuss the relationship between the instantaneous growth rate, limited resources, and long‐term fitness. We discuss uses and limitations of current computational models, in particular for rapidly changing and adverse environments, and propose to classify microbial growth strategies based on Grimes's CSR framework. (shrink)
The introduction of a new analytical method, due fundamentally to François Viète and René Descartes and the later dissemination of their works, resulted in a profound change in the way of thinking and doing mathematics. This change, known as process of algebrization, occurred during the seventeenth and early eighteenth centuries and led to a great transformation in mathematics. Among many other consequences, this process gave rise to the treatment of the results in the classic treatises with the new analytical method, (...) which allowed new visions of such treatises and the obtaining of new results. Among those treatises is the Arithmetic of Diophantus of Alexandria which was written, using the new algebraic language, by the French mathematician Jacques Ozanam, who in addition to profusely increasing the original problems of Diophantus, solved them in a general way, thus obtaining many geometric consequences. The work is handwritten, it has never been published, it has been lost for almost 300 years, and the known references show its importance. We will show that Ozanam’s manuscript was quoted as an important work on several occasions by others mathematicians of the time, among whom G. W. Leibniz stands out. Once the manuscript has been located, our aim in this article is to show and analyze this work of Ozanam, its content, its notation and its structure and how, through the new algebraic method, he not only solved and expanded the questions proposed by Diophantus, but also introduced a connection between the algebraic solutions and what he called geometric determinations by obtaining loci from the solutions. (shrink)
Representation and models have been the focus of considerable interest in philosophy of science for several decades. But the publication in 2008 of Bas van Fraassen’s important book Scientific representation: Paradoxes of perspective gave a novel and strong impetus to the study of their role in the dynamic of scientific knowledge, as attested by the growing quantity of papers and conferences related to representation. In science, knowing necessarily involves representing—phenomena at least and perhaps more for the scientific realist—by means of (...) mathematical structures. Even if these structures are not, as van Fraassen aptly insists, mental ideas, scientific activity is still evolving within the modern Cartesian “épistèmè de la representation” as Michel Foucault famously put it.This book is a welcome collection of exciting papers which grew out of a Workshop on representation and models organized on 11–12 March in Ferrol, at the University of A Coruña . Most papers are devoted to .. (shrink)
After more than a century of research on glycolysis, we have detailed descriptions of its molecular organization, but despite this wealth of knowledge, linking the enzyme properties to metabolic pathway behavior remains challenging. These challenges arise from multi‐layered regulation and the context and time dependence of component functions. However, when viewed as a system that functions according to the principles of supply and demand, a simplifying theoretical framework can be applied to study its regulation logic and to assess the coherence (...) of experimental interpretations. These principles are universally applicable, as they emphasize the common metabolic tasks of glycolysis: the provision of free‐energy carriers, and precursors for biosynthesis and stress‐related compounds. Here we will review the regulation of multi‐tasking by glycolysis and consider how an understanding of this central metabolic pathway can be pursued using general principles, rather than focusing on the biochemical details of constituent components. (shrink)
In this bold addition to Oxford's What Everyone Needs to Know® series, John L. Esposito and Natana DeLong-Bas offer a guide to the often-discussed but seldom-understood concept of Sharia, responding to misunderstandings and distortions, as well as providing answers to questions about the origin, nature, and content of Sharia.