Machine Learning and Image Interpretation

The mystery of how migrating animals find their way over unfamiliar terrain has intrigued people for centuries, and has been the focus of productive research in the biological sci- ences for several decades. Whether or not the earth's magnetic field had anything to do with their navigational abilities has sufaced and been dismissed several times, beginning at least in the mid to late 1800s. This topic generally remained out of the mainstream of scientific research for two reasons: (1) The apparent irreproducibility of many of the be- havioral experiments which were supposed to demonstrate the existence of the magnetic sense; and (2) Perceived theoretical difficulties which were encountered when biophysi- cists tried to understand how such a sensory system might operate. However, during the mid to late 1960s as the science of ethology (animal behavior) grew, it became clear from studies on bees and birds that the geomagnetic field is used under a variety of conditions. As more and more organisms were found to have similar abilities, the problem shifted back to the question as to the basis of this perception. Of the various schemes for trans- ducing the geomagnetic field to the nervous system which have been proposed, the hy- pothesis of magnetite-based magnetoreception discussed at length in this volume has per- haps the best potential for explaining a wide range of these effects, even though this link is as yet clear only in the case of magnetotactic bacteria.

Table of Contents:
I. Introduction and Background.- 1 * Iron Biomineralization: A Geobiological Perspective.- 1. Introduction.- 2. Biological Aspects of Iron Mineralization.- 3. Biological Functions of Iron Biomineralization.- 4. Geological Aspects of Biogenic Fe Oxides and Sulfides.- References.- 2 * Ferrimagnetic Properties of Magnetite.- 1. Introduction.- 2. Basic Data.- 3. Bulk Properties.- 4. Magnetic Domain States.- 5. Remanent Magnetizations.- 6. Magnetic Granulometry.- References.- 3 * The Geomagnetic Field: Its Nature, History, and Biological Relevance.- 1. Introduction.- 2. The Main Geomagnetic Field.- 3. The Field of External Origin.- References.- II. Experimental Techniques and Instrumentation.- 4 * An Introduction to the Use of SQUID Magnetometers in Biomagnetism.- 1. Introduction.- 2. Operating Principles of SQUIDs.- 3. Cryogenics.- 4. Instrument Configurations.- 5. Applications of SQUID Magnetometers in Biomagnetism.- 6. Conclusions.- References.- 5 * Detection, Extraction, and Characterization of Biogenic Magnetite.- 1. Introduction.- 2. Magnetometry Studies.- 3. Extraction and Characterization of Biogenic Magnetite.- 4. Discussion.- 5. Summary.- References.- 6 * Studying Mineral Particulates of Biogenic Origin by Transmission Electron Microscopy and Electron Diffraction: Some Guidelines and Suggestions.- 1. Introduction.- 2. Sample Preparation for Electron Microscopy.- 3. Studying the Sample in the Microscope.- 4. Analysis of Electron Diffraction Powder Patterns.- 5. Conclusions.- Selected References.- 7 * The Cellular Localization of Particulate Iron.- 1. Introduction.- 2. Anatomical Techniques.- 3. An Example: The Bumblebee.- 4. Conclusions.- References.- 8 * Large-Volume, Magnetically Shielded Room: A New Design and Material.- 1. Introduction.- 2. General Principles of Electric and Magnetic Shielding.- 3. Practical Techniques for Building Magnetically Shielded Rooms.- 4. Three Specific Examples.- 5. Summary.- References.- III. Magnetoreception: Theoretical Considerations.- 9 * Limits to Induction-Based Magnetoreception.- 1. Introduction.- 2. Noise and General Considerations.- 3. The Induction Magnetoreception Organ.- 4. Conclusion.- 5. Addendum: A Comment on Navigation.- References.- 10 * Energetics and Sensitivity Considerations of Ferromagnetic Magnetoreceptors.- 1. Introduction.- 2. Energy Considerations.- 3. Response Times.- 4. Sensitivity to Field Changes.- 5. Other Types of Receptors.- 6. Tests of the Hypothesis.- References.- 11 * Particle-Size Considerations for Magnetite-Based Magnetoreceptors.- 1. Introduction.- 2. The Thermally Driven Variance Model of Magnetic Intensity Reception.- 3. Discussion.- 4. Summary.- References.- 12 * Are Animal Maps Magnetic?.- 1. Introduction.- 2. The Compass Sense.- 3. The Map Sense.- 4. Problems with Magnetic Maps.- 5. Future Research.- References.- IV. Magnetoreception and Magnetic Minerals in Living Organisms.- 13 * Mossbauer Spectroscopy of Iron Biomineralization Products in Magnetotactic Bacteria.- 1. Introduction to Mossbauer Spectroscopy.- 2. Application of Mossbauer Spectroscopy to Magnetotactic Bacteria.- References.- 14 * Magnetotactic Microorganisms Found in Muds from Rio de Janeiro: A General View.- 1. Introduction.- 2. The Geomagnetic Field.- 3. Results.- 4. Conclusions.- References.- 15 * Structure, Morphology, and Crystal Growth of Bacterial Magnetite.- 1. Introduction.- 2. Instrumentation: High-Resolution Transmission Electron Microscopy.- 3. Materials and Methods.- 4. Results.- 5. Discussion: Bioprecipitation of Bacterial Magnetite.- 6. Conclusions.- References.- 16 * Biomineralization Processes of the Radula Teeth of Chitons.- 1. Introduction.- 2. Materials and Methods.- 3. Anatomy and Operation of the Radula Apparatus.- 4. Anatomy of the Radula Sac.- 5. Blood Chemistry.- 6. The Ultrastructure of the Mineralization Zone.- 7. Concluding Remarks.- References.- 17 * Magnetic Remanence and Response to Magnetic Fields in Crustacea.- 1. Introduction.- 2. Experimental Studies.- 3. Discussion.- 4. Summary.- References.- 18 * Magnetic Field Sensitivity in Honeybees.- 1. Introduction.- 2. Magnetic Fields Cause Misdirection in the Waggle Dance.- 3. Magnetically Oriented Horizontal Dances.- 4. Magnetic Orientation of Comb-Building.- 5. Magnetic Fields and Orientation in Time.- 6. The Magnetic Receptor System.- 7. Summary and Conclusions.- References.- 19 * Magnetic Butterflies: A Case Study of the Monarch (Lepidoptera, Danaidae).- 1. Introduction.- 2. Natural History of the Monarch Butterfly.- 3. Materials and Methods.- 4. Induced Magnetization.- 5. Ontogeny of Magnetic Mineralization.- 6. Intraspecific and Interspecific Variation.- 7. Attempts to Characterize the Magnetic Mineralogy.- 8. Summary and Conclusions.- References.- 20 * Magnetoreception and Biomineralization of Magnetite: Fish.- 1. Introduction.- 2. Magnetic Sensitivity in Yellowfin Tuna.- 3. Detection of Magnetic Material in Fish.- 4. Characterization of the Magnetic Material.- 5. Identification and Analysis of the Magnetic Material.- 6. Discussion.- References.- 21 * Magnetoreception and Biomineralization of Magnetite in Amphibians and Reptiles.- 1. Introduction.- 2. Amphibians.- 3. Reptiles.- 4. Conclusion.- References.- 22 * Avian Navigation, Geomagnetic Field Sensitivity, and Biogenic Magnetite.- 1. The Sensory Basis of Bird Navigation.- 2. Orientation Experiments with Homing Pigeons.- 3. Orientation Experiments with Migratory Birds.- 4. Effects of Small Magnetic Field Changes on Navigation: The Possibility of a Geomagnetic Map.- 5. Laboratory Attempts to Measure Avian Magnetic Field Sensitivity.- 6. Magnetite in Birds and Possible Mechanisms of Magnetic Field Sensitivity.- References.- 23 * Magnetic Remanence in Bats.- 1. Introduction.- 2. Methods.- 3. Results.- 4. Discussion.- References.- 24 * Magnetoreception and Biomineralization of Magnetite in Cetaceans.- 1. Introduction.- 2. Behavioral Studies.- 3. Anatomical Studies.- 4. Conclusion.- References.- 25 * Magnetoreception and the Search for Magnetic Material in Rodents.- 1. Introduction.- 2. Influence of Magnetic Fields on Physiology.- 3. Magnetoreception.- 4. The Search for the Magnetoreceptor.- 5. Summary.- References.- V. Human Magnetoreception: An Editorial Introduction.- 26 * Magnetoreception by Man and Other Primates.- 1. Introduction.- 2. Physiological Responses to Changes in the Ambient Magnetic Field.- 3. Magnetoreception.- 4. Magnetoreceptors?.- 5. Discussion.- 6. Summary.- References.- 27 * Statistical and Methodological Critique of Baker's Chapter.- 1. Statistics in General.- 2. "Chair" Experiments Results Section.- 3. Princeton Data Do Not Support Baker.- 4. Magnets vs. Controls for Baker's Experiments.- 5. Magnets vs. Controls for K-6.- 6. Physiology of Magnetoreceptors.- 7. Summary.- References.- 28 * Human Navigation: Attempts to Replicate Baker's Displacement Experiment.- 29 * Human Homing Orientation: Critique and Alternative Hypotheses.- 1. Introduction.- 2. Bus Tests Conducted at Ithaca, New York.- 3. Oriented Distributions from "Random" Data.- References.- Notes.- Reply to Baker.- 30 * Absence of Human Homing Ability as Measured by Displacement Experiments.- 31 * A Study of the Homeward Orientation of Visually Handicapped Humans.- 1. Introduction.- 2. Methods.- 3. Results.- 4. Discussion.- References.- 32 * An Attempt to Replicate the Spinning Chair Experiment.- 33 * A Cautionary Note on Magnetoreception in Dowsers.- 34 * Human Navigation: A Summary of American Data and Interpretation.- 1. The American Data.- 2. The American Criticisms.- 3. Concluding Remarks.- References.- VI. Biogenic Magnetite in the Fossil Record.- 35 * A Search for Bacterial Magnetite in the Sediments of Eel Marsh, Woods Hole, Massachusetts.- 1. Introduction.- 2. Bacterial Magnetite.- 3. Methods.- 4. Results.- 5. Discussion.- Appendix 1: Eel Marsh NRM and Saturation Magnetization Data.- Appendix 2: Description of Computer Procedure Used to Make Stability Field Diagram 8a.- References.- 36 * Possible Biogenic Magnetite Fossils from the Late Miocene Potamida Clays of Crete.- 1. Introduction.- 2. Samples.- 3. Laboratory Extraction of Magnetite.- 4. Magnetic Studies.- 5. Size and Shape Distribution of Magnetite.- 6. Origin of Magnetite.- 7. Conclusion and Applications.- References.