The subject of low-energy excitations has evolved since two-level-tunneling systems were first proposed ~50 years ago. Initially they were used to explain the common anomalous properties of oxide glasses and polymers; now the subject includes a wide range of other materials containing disorder: amorphous semiconductors and metals, doped- mixed- and quasi-crystals, surface adsorbates, ... and topics such as dephasing of quantum states and interferometer noise. A fairly simple empirical description using a remarkably small range of parameters serves well to describe the effect of these excitations, but the structures causing these effects are known in only a few materials and the reasons for their similarity across disparate materials has only been qualitatively addressed.This book provides a unified, comprehensive description of tunneling systems in disordered solids suitable for graduate students/researchers wishing an introduction to the field. Its focus is on the tunneling systems intrinsic to glassy solids. It describes the experimental observations of 'glassy' properties, develops the basic empirical tunneling model, and discusses the dynamics changes on cooling to temperatures where direct excitation interactions become important and on heating to where tunneling gives way to thermal activation. Finally, it discusses how theories of glass formation can help us understand the ubiquity of these excitations.The Development of the basic tunneling model is the core of the book and is worked out in considerable detail. To keep the total within bounds of our expertise and the readers' patience, many related experimental and theoretical developments are only sketched out here; the text is heavily cited to allow readers to follow their specific interests in much more depth.

Central Asia consists of five newly independent states situated between Russia, China, and Iran halfway around the world from the United States. For the last eight years, the Central Asian States (CAS) have been the object of considerable attention from the United States. The focus of this research is to identify what national interests the United States has in Central Asia, how national interests link to U.S. foreign policy, and explain the benefits and implications of the U.S. pursuing engagement and development in the region. Although the political, economic, and military costs of U.S. engagement in Central Asia are high, so are the benefits.

This widely-adopted casebook provides detailed information on federal income taxation, with specific assignments to the Internal Revenue Code, selected cases, and regulations and rulings from the Internal Revenue Service. The revised and updated Twentieth Edition marks the 50th anniversary of the casebook's first publication, and in this edition Professor Heather M. Field (University of California, Hastings) joins the casebook as an author. This new edition retains the book's long standing format and much of its prior materials, but it is updated to reflect recent events including legislative, judicial, and regulatory developments. The new edition contains expanded materials on tax policy, including discussions of (1) the fundamentals of tax policy, (2) a comparison of the definition of income under the Internal Revenue Code and under Haig-Simons, (3) the realization requirement for gains and losses, (4) the argument for and against the stepped-up basis in Section 1014, (5) a critique of tax expenditures, and (6) the preferential treatment of capital gains. Other significant changes in the casebook include new or revised coverage, sometimes with problems, of: (1) judicial review of Treasury regulations, (2) taxation of virtual currencies, (3) the exclusion for discharge of student loans, (4) the Section 274 limitation on the deductibility of entertainment and meal expenditures, (5) the Section 280A limitation on the deductibility of expenses in connection with the business use of a home, (6) the Section 280E limitation on the deductibility of expenditures in connection with sales of illegal drugs, (7) the concepts of adjusted gross income and miscellaneous itemized deductions, (8) the tax benefit doctrine, (9) net operating losses, (10) Special Opportunity Zones, and (11) the definition of "real property" under Section 1031.