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Articles 1 - 14 of 14
Full-Text Articles in Physical Sciences and Mathematics
Variation Of Superparamagnetic Properties With Iron Loading In Mammalian Ferritin, Richard B. Frankel, G. C. Papaefthymiou, G. D. Watt
Variation Of Superparamagnetic Properties With Iron Loading In Mammalian Ferritin, Richard B. Frankel, G. C. Papaefthymiou, G. D. Watt
Physics
The average blocking temperatures of ferritin molecules containing differing amounts of iron were determined by Mossbauer spectroscopy. The results imply that the magnetic anisotropy of the ferritin core particles is a function of particle volume. By addition of 57Fe to ferritin core particles it was determined that, at a given temperature within the superpara-magnetic temperature region, the “last-in” ferric ions have average relaxation times that are shorter than those of the bulk ferric ions.
Visual Interaction: A Link Between Perception And Problem Solving, Erika Rogers, Ronald C. Arkin
Visual Interaction: A Link Between Perception And Problem Solving, Erika Rogers, Ronald C. Arkin
Computer Science and Software Engineering
The approach taken in this research is to develop a cognitive model of how a human observer extracts information from a visual display and then uses this perceptual information in a decision-making task. Knowledge about this relationship provides information about the occurrence of perceptual events in the course of problem-solving activities, and suggests that perceptual assistance in the form of image enhancements is a useful supplement to the user’s own abilities. This knowledge is then to be embedded in an intelligent computerized assistant which is designed to facilitate and stimulate the human problem-solving process.
Inorganic Particles Produced By Microorganisms, Richard B. Frankel
Inorganic Particles Produced By Microorganisms, Richard B. Frankel
Physics
The processes by which microorganisms, particularly bacteria, produce inorganic mineral particles are reviewed.
Structure, Morphology And Growth Of Biogenic Greigite (Fe3S4), Brigid R. Heywood, Stephen Mann, Richard B. Frankel
Structure, Morphology And Growth Of Biogenic Greigite (Fe3S4), Brigid R. Heywood, Stephen Mann, Richard B. Frankel
Physics
Several species of aquatic bacteria are known to exploit the earth's geomagnetic field as a means of directing their motion towards suitable habitats. A feature common to these bacteria is the presence of discrete intracellular magnetic inclusions, magnetosomes, aligned in chains along the long axis of the organism. The size and orientation of the individual magnetic particles imparts a permanent magnetic dipole moment to the cell which is, in turn, responsible for the magnetotactic response. In all species examined to date the magnetic particles have been found to be well-ordered, single domain, membrane-bounded crystals with reproducible, species-specific morphologies. Until recently, …
Paper Or Plastic?, Matthew J. Moelter
Visual Interaction In Diagnostic Radiology, Erika Rogers, Ronald C. Arkin, M. Baron
Visual Interaction In Diagnostic Radiology, Erika Rogers, Ronald C. Arkin, M. Baron
Computer Science and Software Engineering
The concept of Visual Interaction is introduced as the process which links perception and problem-solving such that problem-solving is affected by what is seen, and conversely, what is seen and perceived is affected by the current state of the problem-solving process. This paper describes the development of a cognitively-based model of the visual interaction process in diagnostic radiology, and shows how aspects of this model are being incorporated into the design and implementation of an intelligent computer-based radiological assistant. In order to achieve this, it is necessary to extract information about the nature and type of knowledge involved in this …
Method For The Automatic Level Adjustment In A Local Area Network, In Particular For A Multiprocessor Arrangement With A Bus System Of Optical Fibres, For The Purpose Of Collision Detection, Hans Thinschmidt, Franz J. Kurfess
Method For The Automatic Level Adjustment In A Local Area Network, In Particular For A Multiprocessor Arrangement With A Bus System Of Optical Fibres, For The Purpose Of Collision Detection, Hans Thinschmidt, Franz J. Kurfess
Computer Science and Software Engineering
European Patent. Written in German.
Redox Capacity Of Apo Mammalian Ferritin, Gerald D. Watt, Richard B. Frankel
Redox Capacity Of Apo Mammalian Ferritin, Gerald D. Watt, Richard B. Frankel
Physics
No abstract provided.
Iron Biominerals: An Overview, Richard B. Frankel
Biomineralization Of Iron Sulfides In Magnetotactic Bacteria From Sulfidic Environments, Dennis A. Bazylinski, Richard B. Frankel, Anthony J. Garratt-Reed, Stephen Mann
Biomineralization Of Iron Sulfides In Magnetotactic Bacteria From Sulfidic Environments, Dennis A. Bazylinski, Richard B. Frankel, Anthony J. Garratt-Reed, Stephen Mann
Physics
No abstract provided.
Intercellular Junctions, Motility, And Magnetosome Structure In A Multicellular Magnetotactic Prokaryote, Frank G. Rodgers, Richard P. Blakemore, Nancy A. Blakemore, Richard B. Frankel, Dennis A. Bazylinski, Denise Maratea, Christine Rodgers
Intercellular Junctions, Motility, And Magnetosome Structure In A Multicellular Magnetotactic Prokaryote, Frank G. Rodgers, Richard P. Blakemore, Nancy A. Blakemore, Richard B. Frankel, Dennis A. Bazylinski, Denise Maratea, Christine Rodgers
Physics
A many-celled, magnetotactic, prokaryote obtained from brackish water possessed intercellular connections at points of contact between the outer membranes of constituent cells. These connections structurally resembled the "gap junctions" found in eukaryotes. Each aggregate organism consisted of 10 to 30 individual gram-negative cells containing material with the appearance of poly-𝛽-hydroxybutyrate and magnetosomes of unusual arrangement, structure and composition. The aggregate, which possessed prokaryotic-type flagella arranged at the outward surfaces of each cell, showed motility indicative of coordination between individual component cells. These results suggest that this organism is a multicellular prokaryote.
Electronic Properties Of Monocapped Prismane And Basket Iron-Sulphur Clusters, B. S. Snyder, M. S. Reynolds, R. H. Holm, G. C. Papaefthymiou, R. B. Frankel
Electronic Properties Of Monocapped Prismane And Basket Iron-Sulphur Clusters, B. S. Snyder, M. S. Reynolds, R. H. Holm, G. C. Papaefthymiou, R. B. Frankel
Physics
The ground state electronic properties of the mixed-valence clusters Fe7S6 (PEt3)4Cl3 (1), Fe6S6(PEt3)4L2 [L = Cl− (2), Br− (4), I− (5) and PhS− (6)], Fe6Se6 (PEt3)4Cl2 (3) and [Fe6S6(PEt)6]1− (9), have been investigated by magnetic susceptibility, magnetization and Mössbauer spectroscopic measurements. Cluster 1 has a (idealized C3v) monocapped prismane structure and clusters 2–6 and 9 adopt the C2v “basket” configuration based on the [Fe6 …
Magnetic Fine Particles In Biological Systems, Dominic P.E. Dickson, Richard B. Frankel
Magnetic Fine Particles In Biological Systems, Dominic P.E. Dickson, Richard B. Frankel
Physics
Two examples of biological magnetic fine particles are considered: iron-storage proteins and magnetotactic bacteria. These cover many aspects of this field, including the use of well-defined biological systems for testing theoretical models, using magnetic properties to distinguish between different biological materials, producing magnetic materials by biological processes, and using optimised biological magnetic systems as a guide to the production of synthetic magnetic materials.
Minimax-Optimal Stop Rules And Distributions In Secretary Problems, Theodore P. Hill, Ulrich Krengel
Minimax-Optimal Stop Rules And Distributions In Secretary Problems, Theodore P. Hill, Ulrich Krengel
Research Scholars in Residence
For the secretary (or best-choice) problem with an unknown number N of objects, minimax-optimal stop rules and (worst-case) distributions are derived, under the assumption that $N$ is a random variable with unknown distribution, but known upper bound n. Asymptotically, the probability of selecting the best object in this situation is of order of (log n)-1. For example, even if the only information available is that there are somewhere between 1 and 100 objects, there is still a strategy which will select the best item about one time in five.