Letters in Mathematical Physics 55: 249-250, 2001. Contents of Volume 55 (2001) Volume 55 No.1 January 2001 Publisher’s Note DIMA MOZYRSKY / Exactly Solvable Model of a Two-Level Quantum System Interacting with Spin Environment S. A. ALBEVERIO, P. EXNER and V. A. GEYLER / Geometric Phase Related to Point-Interaction Transport on a Magnetic Lobachevsky Plane PARTHA GUHA / Diff(S') and Adler—Gelfand—Dikii Spaces and Integrable Systems DIDIER ARNAL and NABIHA BEN AMAR / g-Relative Star Products PEKKA LAHTI, MACIEJ MACZYNSKI and KARI YLINEN Unitary and Antiunitary Operators Mapping Vectors to Parallel or to Orthogonal Ones, with Applications to Symmetry Transformations VOLKER BACH and OLIVER MATTE / Exponential Decay of Eigenfunctions of the Bethe—Salpeter Operator M.W.WALSER and C. H. KEITEL / Geometric and Algebraic Approach to Classical Dynamics of a Particle with Spin S. MOGHIMI-ARAGHI, S. ROUHANI and M. SAADAT/ Current Algebra Associated with Logarithmic Conformal Field Theories P. P KULISH and N. MANOJLOVIC / Bethe Vectors of the osp(1| 2) Gaudin Model Volume 55 No.2 February 2001 E. YU. LERNER and M. D. MISSAROV / Singularities of Adelic Feynman Amplitudes FABIEN BESNARD / Number Operator Algebras and Deformations of é-Poisson Algebras ANDRZEJ SITARZ / More Noncommutative 4-Spheres CHRISTIAN HAINZL and ROBERT SEIRINGER / Bounds on One-Dimensional Exchange Energies with Application to Lowest Landau Band Quantum Mechanics 250 LETTERS IN MATHEMATICAL PHYSICS L. A. FERREIRA and A. V. RAZUMOV/ Hopf Solitons and Area-Preserving Diffeomorphisms oft he Sphere 143-148 FRIEDEMANN BRANDT/ Jet Coordinates for Local BRST Cohomology 149-159 HARALD GROSSE and KARL-GEORG SCHLESINGER /A Suggestion for an Integrability Notion for Two-Dimensional Spin Systems 161-167 JEROME GERMONI/On the Classification of Admissible Representations of the Virasoro Algebra 169-177 Volume 55 No.3 March 2001 Special Issue on TOPOLOGICAL AND GEOMETRICAL METHODS Applications in Dynamic Systems, Physics, Chemistry and Biology Edited by J. M. GAMBAUDO and H. R. JAUSLIN Centre de Dynamique des Systemes Complexes, Université de Bourgogne, Dijon, France J. M. GAMBAUDO and H. R. JAUSLIN / Preface 179 MITCHELL A. BERGER / Topological Invariants in Braid Theory 181-192 R. GHRIST / Steady Nonintegrable High-Dimensional Fluids 193-204 VU NGOC SAN / Quantum Monodromy and Bohr—Sommerfeld Rules 205-217 FREDERIC FAURE and BORIS ZHILINSKII / Topologicl Properties of the Born—Oppenheimer Approximation and Implications for the Exact Spectrum AKOS DOBAY, PIERRE-EDOUARD SOTTAS, JACQUES DUBOCHEaTn d ANDREZEJ STASIAK / Predicting Optimal Lengths of Random Knots 239-247