Biophysical Effects of Steady Magnetic Fields

7 Les Houches The purpose of this workshop was to bring together, for the first time, active scientists from very different fields, such as physics, chemistry, physiology and the behavioural sciences, all having a common interest: The interac tion of static magnetic fields with biological and macromolecular matter. As physicists, biologists and medical scientists naturally have different scientific competences, attitudes and abilities, this appeared to be an enterprise of un certain issue. However, it turned out that all participants tried to find (and many succeeded in reaching) a mutual basis of understanding. Thanks to a fair number of outstanding, comprehensive talks and to very active discus sions, most of us, we believe, have substantially enlarged our insight into the actual hard facts within a research area that was considered for a long time - and still remains in many aspects - somewhat controversial. The perhaps most striking and useful reaction to magnetic fields at the supermolecular level is the alignment of biopolymers, proteins, viruses, large assemblies such as retinal rods and membranes when suspended in a solvent, usually water. The ease of alignment depends on the anisotropy of the dia magnetic susceptibility of the constituent groups and bonds and, in addition, on the extent of their mutual orientational order inside a macromolecular assembly. Here very strong fields above I-lOT appear to be necessary, in general, to achieve measurable alignment.

Autorentext
Dr. Nino Boccara is Professor Emeritus of Physics at the University of Illinois at Chicago, Professor Emeritus of Mathematics at the Ecole Supérieure de Physique et Chimie de la Ville de Paris, and Former Director of Research in Theoretical Physics at the CNRS.

Inhalt
I Diamagnetic Orientation of Macromolecules and Membranes.- Magnetic Birefringence in Polymers and Polyelectrolytes.- Propagation and Generation of High-Frequency Ultrasonic Waves in Magnetically Oriented Lyotropic Liquid Crystals.- Liquid Crystals and Virus Solutions in Strong Magnetic Fields.- Magnetic Damping of Orientational Fluctuations in Nematics with Negative Diamagnetic Anisotropy.- Magnetic Birefringence Study of Fibrin Formation and Chylomicron Behaviour in Human Blood Plasma.- Diamagnetic Anisotropy of Proteins and Magnetic Orientation of Biological Membranes and Protein Assemblies.- Superdiamagnetism in Lipid Monolayers.- Magnetic Field Effect on the Gel-Liquid Crystal Phase Transition of Phospholipid Membranes.- Membrane Responses to Magnetic and Electromagnetic Fields.- II Ferrofluids.- Wetting of Solids by Ferrofluids.- Ionic Ferrofluids: Physico-Chemical Aspects.- Ferrofluids in Lyotropic Nematic Liquid Crystals.- III Biological and Chemical Photoreactions.- Magnetic Field Effect on Photosynthetic Reactions.- Polymethylene-Linked Radical Ion Pairs in Magnetic Fields.- Study of Polymer Dynamics by Magnetic Field-Dependent Biradical Reactions.- Model for a Physiological Magnetic Compass.- Retinal Response to Variations of the Earth's Magnetic Field.- Influence of Geomagnetic Field Alterations on Electric Retinal Potentials and Dark Adaptation in Humans.- Effects of Earth-Strength Magnetic Stimuli on the Pineal Gland and Central Nervous Neurons. A Short Review.- IV Physiological Effects and Animal Development.- Static Magnetic Fields Influence the Evoked Potentials of Man.- The Influence of Static Magnetic Fields on Skin Temperature and Blood Flow in Man.- Magnetic Field-Induced Blood Flow Changes in Frogs and Red-Green Vision of Man AfterNMR-Tomography.- Magnetic Field Driven Thermal Convection in Air: A Mechanism for Field-Induced Skin Temperature Changes in Animals.- Embryonic Development of the Quail in Strong Magnetic Fields.- V Animal Orientation and Magnetoreception.- A Review of Magnetic Effects on Homing Pigeon Orientation.- A Further Analysis of the Orientation Behavior of Homing Pigeons Released Within Magnetic Anomalies.- Pigeon Homing: The Use of Magnetic Information in Position Finding.- Homing Experiments with Pigeons at the Magnetic Equator.- Magnetic Orientation and Magnetically Sensitive Material in Migratory Birds.- Magnetite and Magnetotaxis in Bacteria and Algae.- Biogenic Magnetite in Higher Organisms and the Current Status of the Hypothesis of Ferrimagnetic Magnetoreception.- The Effect of Ultrahigh Magnetic Fields on the Initial Orientation of Homing Pigeons.- Experimental and Correlational Studies of Responses to Magnetic Field Stimuli by Different Species.- The Cetacean Geomagnetic Travel Strategy.- A Mathematical Model for Magnetic Navigation by Animals.- VI Applications in NMR and Medecine.- Magnets for NMR Imaging and Spectroscopy.- In Vivo NMR Spectroscopy of Mammalian Nervous Systems.- The Cytoplasmic pH of the Green Alga Chlorella fusca, Measured by 31-P-NMR Spectroscopy.- Magnetic Mapping of the Human Thorax Using a SQUID Magnetometer.- Index of Contributors.