Untwinned

Mobile Genetic Elements introduces the nonspecialist to the biology and genetics of mobile elements. It attempts to make the biochemistry of DNA rearrangements more accessible to embryologists and evolutionists, and to illuminate the related developmental cycles to the biochemist. The book also shows how natural the activity of mobile elements can be in diverse biological situations. The chapters describe several well-studied cases in which genetic determinants—often identified as specific nucleic acid sequences—repeatedly change their positions within or between cellular genomes. Because their genomic positions are not fixed, these determinants may conveniently be classed together under the rubric of mobile genetic elements. The book begins with a discussion of maize controlling elements. This is followed by separate chapters on the bacteriophages ? and Mu; nonviral mobile elements in bacteria; transposable Ty elements in brewer's yeast; Drosophila transposable element; and hybrid dysgenesis. Subsequent chapters cover vertebrate retroviruses; Agrobacterium oncogenesis in plants; flagellar phase variation in Salmonella; yeast mating type; and surface antigenic variation in trypanosomes.

With the advent of High Temperature Superconductivity and the increasing reliability of fabrication techniques, superconductor technology has moved firmly into the mainstream of academic and industrial research. There is currently no single source of practical information giving guidance on which technique to use for any particular category of superconductor. An increasing number of materials scientists and electrical engineers require easy access to practical information, sensible advice and guidance on 'best-practice' and reliable, proven fabrication and characterisation techniques.The Handbook will be the definitive collection of material describing techniques for the fabrication and analysis of superconducting materials. In addition to the descriptions of techniques, authoritative discussions written by leading researchers will give guidance on the most appropriate technique for a particular situation.Characterisation and measurement techniques will form an important part of the Handbook, providing researchers with a standard reference for experimental techniques. The tutorial style description of these techniques makes the Handbook particularly suitable for use by graduate students.The Handbook will be supported by a comprehensive web site which will be updated with new data as it emerges.The Handbook has six main sections: -- Fundamentals of Superconductivity - characteristic properties, elementary theory, critical current of type II superconductors-- Processing - bulk materials, wires and tapes, thick and think films, contact techniques-- Characterisation Techniques - structure/microstructure, measurement and interpretation of electromagnetic properties,measurement of physics properties-- Materials - characteristic properties of low and high Tc materials-- Applications - high current applications, trapped flux devices, high frequency devices, josephson junction devic

The 12th International Symposium on Superconductivity was held in Morioka, Japan, October 17-19, 1999. Convened annually since 1988, the symposium covers the whole field of superconductivity from fundamental physics and chemistry to a variety of applications. At the 12th Symposium, a mini-symposium focusing on the two-dimensionality of high-temperature superconductors, or the c-axis transport, and a session on vortex physics were organized. There were also many reports on the recent developments of YBCO-based coated conductors both in the United States and in Japan, AC losses of wires and tapes, developments of bulk materials with strong flux pinning, the recent progress in thin film and junction technologies, and the demonstration of various electronics applications using SQUIDs, microwave devices, and single-flux-quantum (SFQ) digital devices. This volume is a valuable resource for all those working in the field of superconductivity.

Scientists have long speculated on the impact of extreme natural catastrophes on human societies. Archeology and Volcanism in Central America provides dramatic evidence of the effects of several volcanic disasters on a major civilization of the Western Hemisphere, that of the Maya. During the past 2,000 years, four volcanic eruptions have taken place in the Zapotitán Valley of southern El Salvador. One, the devastating eruption of Ilopango around A.D. 300, forced a major migration, pushing the Mayan people north to the Yucatán Peninsula. Although later eruptions did not have long-range implications for cultural change, one of the subsequent eruptions preserved the Cerén site—a Mesoamerican Pompeii where the bodies of the villagers, the palm-thatched roofs of their houses, the pots of food in their pantries, even the corn plants in their fields were preserved with remarkable fidelity. Throughout 1978, a multidisciplinary team of anthropologists, archeologists, geologists, biologists, and others sponsored by the University of Colorado's Protoclassic Project researched and excavated the results of volcanism in the Zapotitan Valley—a key Mesoamerican site that contemporary political strife has since rendered inaccessible. The result is an outstanding contribution to our understanding of the impact of volcanic eruptions on early Mayan civilization. These investigations clearly demonstrate that the Maya inhabited this volcanically hazardous valley in order to reap the short-term benefits that the volcanic ash produced—fertile soil, fine clays, and obsidian deposits.

Proceedings of the NATO Advanced Study Institute on Reading Provenance from Arenites, Cetraro, Cosenza, Italy, June 3-11, 1984