Driven Polymer Translocation Through a Narrow Pore

Motivated by experiments in which a polynucleotide is driven through a proteinaceous pore by an electric field, we study the diffusive motion of a polymer threaded through a narrow channel with which it may have strong interactions. We show that there is a range of polymer lengths in which the system is approximately translationally invariant, and we develop a coarse-grained description of this regime. From this description, general features of the distribution of times for the polymer to pass through the pore may be deduced. We also introduce a more microscopic model. This model provides a physically reasonable scenario in which, as in experiments, the polymer's speed depends sensitively on its chemical composition, and even on its orientation in the channel. Finally, we point out that the experimental distribution of times for the polymer to pass through the pore is much broader than expected from simple estimates, and speculate on why this might be.Comment: 16 pages, 8 figures, RevTex and harvard citation style, submitted to Biophysical Journa

When Languages Die: The Extinction Of The World\u27s Languages And The Erosion Of Human Knowledge

In When Languages Die, K. David Harrison illustrates the individual face of language loss, as well as its global scale. Languages are the accretion of thousands of years of a people\u27s science and art - from observations of ecological patterns to creation myths. The author shows that the disappearance of a language is a loss not only for the community of speakers itself but also for our common human knowledge of mathematics, biology, geography, philosophy, agriculture, and linguistics. In this century, we face a massive erosion of the human knowledge base. The global abandonment of indigenous languages will bring a massive loss of accumulated knowledge and culture - this book argues for the irreplaceable nature of these unique knowledge systems and the urgency of documenting them before they are lost forever

[Review of] Mongane Serote. To Every Birth Its Blood

Mongane Serote is a poet of considerable merit; this I should have discovered from reading his novel, To Every Birth Its Blood, even had I not heard and seen him read his poetry to an African Literature Association Conference in 1975. The novel, however, is not obtrusively poetic; rather, its physical and psychological insights are apt and genuine parts of an integral whole, not ends in and of themselves. Yet a careful reader will respond most positively to such expression

[Review of] Sterling Plumpp, ed. Somehow We Survive: An Anthology of South African Writing

Somehow We Survive takes its title from an included poem by Dennis Brutus and is a collection of poems written in English by non-white South Africans. It is not a new book, having been published in 1982, but it still is worth the attention of Western readers, particularly of those who have not already become students of South Africa\u27s shameful history of apartheid and the growing resistance of black and colored persons, both in direct action and literary activity. As the book is now available in paperback, at a modest price, it is worth having, in spite of its limitations

Editorial: The pre-history of Chaos—An Interdisciplinary Journal of Nonlinear Science

Published versio