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At least 19 recordsLinked to original sources
PubMed1992

[The configuration of a video signal digitalizing system used in astronomy for radiological applications].

A digital system of video signals of astronomical use was developed to be applied in the field of radiology. The images were obtained from radiologic films by means of a standard video camera. The minimal specifications of the digital images for use in radiology are as follows: a) 2.5 lpm spatial resolution, b) a digital resolution of 8 bits (256 gray levels). Images (194 by 154 mm in size) can be obtained. The software processing was adapted for treatment of the images in radiology.

Astronomy↗
PubMed1991

From radio-astronomy to medical imaging.

A common thread in much of the medical imaging that has developed over the past 20 years has been the Fourier transform. It was Richard Bates' interest in radio-interferometry, as well as his fascination with problems of medical imaging that prompted an initial interest in applying Fourier techniques to medical imaging in general and to Computed Tomography in particular. This resulted 20 years ago in one of the earliest technical papers advocating Fourier techniques for reconstructing cross-sections from radiographic projections (Bates and Peters, NZ J Science 14:883-896, 1971). Since those early days, medical imaging has explored into a multi-billion dollar industry. The CT scanner has become the workhorse imaging modality in the radiology department, while its more recent relative, the MR scanner, is rapidly gaining ground as a technique of even greater importance. Richard Bates, with his team of "Medical Imagers" was a very significant force in the development of the field of Medical Imaging as we know it today. This paper attempts to chronicle the genesis of this process from the personal perspective of the author.

Diagnostic Imaging↗
PubMedDate not supplied

[Dr. Tadeusz Rakowiecki (July 26, 1878-April 6, 1965), physician, astronomer and writer--on the 25th anniversary of his death].

He decided to study medicine to be self-reliant and helpful for the society though he showed outstanding abilities to exact sciences, in particular mathematics. He was graduated at the Warsaw University in 1903 "cum eximia laude" in medicine. Apart from medicine he had disclosed interest in literature that was realized by many lectures and publications related to the famous and outstanding Polish writer Stefan Zeromski. Since 1930 Dr. Rakowiecki has started as self-taught astronomy studies becoming soon one of seven most eminent Polish astronomers. In the thirties there appeared his two-volume monography entitled "Drogi Planet i Komet" ("Motions of planets and comets") that has become the first fundamental Polish handbook of astronomy actual up to seventies. His scientific achievements based on higher mathematics included 20 important reports on astronomy and several monographs on mathematics. In 1930 he had refused several proposals to head University Chairs of Astronomy, among others in Lwów, due to modesty and his willingness to help and to serve his patients. He had been a demon for work, his rest after admission of patients were astronomy calculations, while when tired with the latters he became occupied with medicine.

Astronomy↗
PubMed1989

Quantitative visual psychophysics during the period of European enlightenment. The studies of the astronomer and mathematician Tobias Mayer (1723-1762) on visual acuity and colour perception.

During the sixth decade of the 18th century, Tobias Mayer, Professor of Astronomy and Applied Mathematics (Economy) at the University of Göttingen, performed two investigations on quantitative visual psychophysics. He deduced a power law for the dependence of visual acuity on the intensity of light by which the stimulus pattern was illuminated. In his measurements he compared visual acuity determined with single black dots and visual acuity measured with gratings or checkerboard patterns; the latter he considered as the "real" measurement of visual acuity. Mayer also developed a three-dimensional hexaedric colour space from the definition of subtractive colour mixtures of three primary pigments (red, yellow, blue). This colour space can be considered as the predecessor of the later colour tables of Ostwald and Munsell. Mayer gave a simple quantitative description of each of the 819 hues in his colour space. Both psychophysical studies developed out of Mayer's interest in practical problems in astronomy and cartography. Mayer's main scientific merits were in the field of astronomy and mathematical geography. His psychophysical studies were performed in the spirit of enlightenment with the a priori assumption that the performance of the human perceptual machinery can be measured quantitatively and that the results are adequately expressed by mathematical rules. Mayer's achievements in the fields of mathematics, physics, astronomy and cartography were recently summarized by the extensive historical research of G.F. Forbes. In the present report a short biographical note precedes the description of Mayer's psychophysical studies.

Astronomy↗
PubMed1991

Extrapolation by proximate inference.

Scientific extrapolation, as in astronomy, is different from legal or regulatory extrapolation, as in arriving at acceptably safe levels of agents. Scientific and technological information is required in the latter process, but scientists fail to contribute when they respond to legal and regulatory questions by attempting purely scientific extrapolation.

Animals↗
PubMed1989

Manifesto of space medicine: the next dermatologic frontier.

As the fields of astronomy, cosmology, and space travel move rapidly forward, so must space medicine. The manned space program and medical knowledge and support have developed in tandem. Dermatology will play a fundamental role in survival during space flight. This paper reviews past, present, and future accomplishments of the space program as they relate to medicine and characterizes some of dermatology's multiple roles in the future. It further explores the immunologic alterations noted during space flight and the attendant implications for health and well-being both in flight and on return to Earth, or to an Earthlike environment.

Aerospace Medicine↗
PubMed1992

Blind deconvolution of quantum-limited incoherent imagery: maximum-likelihood approach.

Previous research presented by the author and others into maximum-likelihood image restoration for incoherent imagery is extended to consider problems of blind deconvolution in which the impulse response of the system is assumed to be unknown. Potential applications that motivate this study are wide-field and confocal fluorescence microscopy, although applications in astronomy and infrared imaging are foreseen as well. The methodology incorporates the iterative expectation-maximization algorithm. Although the precise impulse response is assumed to be unknown, some prior knowledge about characteristics of the impulse response is used. In preliminary simulation studies that are presented, the circular symmetry and the band-limited nature of the impulse response are used as such. These simulations demonstrate the potential utility and present limitations of these methods.

Algorithms↗
PubMed1992

Concurrent phenomena of science and history in the 17th century and their essential interdependence.

The explanation for the explosion of science in the 17th century lies in history and medical historiography. Without this approach, it becomes fantasy, accidents, or success stories. Sigerist grasped the essential interdependence of science and history, and had no need for devised reasons or speculation. He realized that once the dark night of the Middle Ages was over, the sciences arose with undreamt of force and accelerated development. The advances in astronomy, mathematics, mechanics, and experimental science benefitted a society developing in seafaring, manufacture, and trade in the 17th century. Sigerist's views make the scientific explosion understandable in human and social terms. He did not overlook the capabilities of some extraordinary individuals, such as Paracelsus (1493-1541), to shape the course of medicine, nor the importance of the mechanistic philosophy in the 17th century. Man makes history and science; hence, we find concurrent phenomena of history and science essentially interdependent. The spirit of experimental science of 17th century England was inspired by the new needs of commercial enterprise for more means of transportation and communication. Likewise, the interest in the mechanics of the pump for waterworks and for the drainage of swamps led Harvey to think of the heart as a pump, and to explain the circulation of the blood in terms of its functioning.

England↗
PubMed1991

Assessing the scientific strength of Chile.

We use analysis of co-citation and relative citation rates to assess the scientific strength of Chile as compared with other developing countries and to evaluate the potential for increased international collaboration between Chile and the United States in science and engineering. Co-citation is the citation of two scientific papers by a third paper. By examining frequency and patterns of co-citation, the intellectual structure and evolution of scientific disciplines and research specialties can be traced. Chile is especially "strong", as defined by the co-citation model we employ, in biomedicine and clinical medicine, and in astronomy. A relative citation rate is the ratio of the number of citations a paper receives to the average number of citations for all papers published in the same journal over time. Analysis of relative citation rates of papers published by authors with Chilean addresses show that Chilean physics, including earth and space sciences, is of unusually high quality, considerably higher than any other developing country and comparable to several industrialized countries. We conclude that Chile's scientific capacity is advanced enough to absorb and benefit significantly from strategic additions to the country's resources and capabilities for research. These would include increases in: exchanges of researchers in specific fields with U.S. and other Latin American academic, industrial, and government scientists and engineers; training at outstanding U.S. and Latin American institutions; laboratory equipment, computer time, communications links, and library materials; and funding from U.S. and international organizations. It is also apparent that Chile is strong enough in certain fields to cooperate with the U.S. in mutually beneficial international efforts.

Authorship↗
PubMed1976

The impetus to scientific psychology: a recurrent pattern.

In the nineteenth century, the personal equation, which concerned individual differences in the accuracy of astronomical observations, provided an impetus to the development of experimental psychology. During the first decade of Wundt's laboratory, the measurement of the duration of mental acts received more experimental attention than any other subject. Twentieth century developments in the theoretical physics have stimulated interest in the nature of mental operations and conceptual transformations, a topic which is currently receiving increased attention in psychology. It is suggested that the history of psychology may provide a useful data source for additional work in this area.

Astronomy↗
PubMed1976

General constraints on the Viking biology investigation.

The Viking biological investigation will be conducted in the face of a number of constraints. Problems are created because of the inherent engineering of the instrument, communication constraints and other factors.

Astronomical Phenomena↗
PubMed1977

The origin of the planetesimal theory.

T. C. Chamberlin suggested in 1897, on the basis of geological and climatological arguments, that the planets were formed by accretion of cold solid partices. With F. R. Moulton he developed convincing arguments against the Laplace nebular hypothesis and published a comprehensive 'planetesimal theory' of the origin of the solar system in 1905. The Chamberlin-Moulton theory has current as well as historical interest.

Astronomy↗