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1.
Summary In an auditory experiment, digits and tonal sequences were presented simultaneously to both ears. In a visual experiment, words and nonsense figures had to be compared in both visual half-fields. The verbal stimuli were better reported from the right ear and right visual half-field. The nonverbal stimuli were reported equally well from both ears and visual half-fields. It appears that the processing of stimuli presented to both input channels depends on the type of the stimuli. These results point to a cerebral mechanism classifying incoming information to the brain and yielding an optimal processing of verbal and nonverbal stimuli by the cerebral hemispheres.This study was supported in part by grants 6.182-0.76 and 6.183-0.76 of the Swiss National Science Foundation to E. Perret.  相似文献   

2.
Late Babylonian astronomical texts contain frequent measurements of the positions of the Moon and planets. These measurements include distances of the Moon or a planet from a reference star and measurements of the position of celestial bodies within a sign of the zodiac. In this paper, I investigate the relationship between these two measurement systems and propose a new understanding of the concepts of celestial longitude and latitude in Babylonian astronomy. I argue that the Babylonians did not define latitude using the ecliptic but instead considered the Moon and each planet to move up or down within its own band as it travelled around the zodiac.  相似文献   

3.
Summary Young birds on their first migration possess innate information on the direction of their migration route. It is present in two forms, using celestial rotation and the geomagnetic field as references. These two systems, together with information provided by factors associated with sunset, interact in a complex way to establish the migratory direction. During ontogeny, celestial rotation appears to be dominant; during migration, however, celestial cues appear to be controlled by the magnetic field. The factors associated with sunset — the view of the setting sun, the characteristic pattern of polarized light — are important secondary cues which seem to derive their directional significance from the magnetic field. Their role appears to be more variable, with possible species-specific differences. During spring migration and later autumn migrations, flying in the migratory direction is complemented by navigational processes which enable the birds to return to a specific home site known from previous stays.  相似文献   

4.
In this paper the astronomical explorations of the southern celestial sky by Dutch navigators at the end of the sixteenth century are investigated. It is shown that the main motivation for this scientific enterprise stemmed from Dutch cartographic tradition and interests, represented first and foremost by Petrus Plancius and the competing globemakers Hondius and Blaeu. It is shown, too, that at the time actually two surveys were carried out. We have investigated the results of the two surveys by analysing the data presented on celestial globes by Hondius and Blaeu, and in the star catalogue published by De Houtman in 1603. It appears that only after the first survey was it recognized that the stars of the well-known Southern Cross constellation could be matched with stars already recorded by Ptolemy.  相似文献   

5.
Summary A 1-step silver-staining technique, requiring only 2 min to perform, is described for the differential staining of nucleolus organizer regions. A protective colloidal developer is used to control the reduction of the silver.This research was supported by the National Science Foundation, grant Nos PCM-76-82828 and DEB-76-84195 to WMH.  相似文献   

6.
The metaphysical commitment to the circle as the essential element in the analysis of celestial motion has long been recognized as the hallmark of classical astronomy. Part I of this paper contains a discussion of how, for Kepler, the circle also functions in geometry to select the basic polygons, in music to select the basic harmonies, and in astrology to select the basic aspects. In Part II, the discussion centres on the question of how the replacement of circular planetary orbits by elliptical orbits in the Astronomia Nova of 1609 affected Kepler's metaphysical commitment to celestial circularity that was made manifest in the derivation of planetary radii in the Mysterium Cosmographicum of 1596. The answer is found in the new and much more accurate derivation of both the planetary radii and their eccentricities in the Harmonice Mundi of 1619. It is the relationship of the diurnal movements of single planets at aphelion and perihelion to specific musical consonances that provides the first step. Then, in the second step, these ratios are ‘tempered’ so that all six planets can provide a heavenly choir. The third and final step employs the ‘mean period’, which is obtained directly from the tempered ratios given by musical theory and diurnal (not annual) motion, in the 3/2 power law to calculate the planetary radii and eccentricities with amazing accuracy. Thus the ellipse is necessary to supply the variation in angular velocities that contain the Creator's archetypal celestial circularity.  相似文献   

7.
The contents of Scala Graduum Caloris are described, supplemented by unpublished material. Both temperature measurements by his linseed oil thermometer and those based upon his law of cooling are shown to be reasonably accurate to 300°C, but above that value they are much too low. The apparent agreement and the deviation are explained by the differences between the assumptions that Newton made in deriving his law of cooling and the conditions in which he used it. Newton's attempts to link terrestrial and celestial science in applications in the Principia are shown to fail from his confounding the concepts of temperature, heat and radiant intensity and his ignorance of most factors affecting the temperature rise of irradiated materials. Other comments on varied aspects of heat, mainly published in the Queries, are set out and analysed. His originality is assessed.  相似文献   

8.
吴家沟尾矿库初期坝包括下部天然岩土体初期坝和上部土石混填初期坝两部分。在分析初期坝基本特征的基础上,把初期坝视作重力式档土墙结构,采用极限平衡法计算堆积坝对初期坝的静止土压力和主动土压力,应用抗剪强度公式分析上部初期坝与基岩之间坝基面的抗滑稳定性,得到无水和有水工况下静止土压力和主动土压力作用下坝基面抗滑稳定安全系数,其安全系数值明显大于规范规定的安全系数。采用ABAQUS有限元软件对初期坝应力特征进行分析,初期坝(包括天然坝体和堆石坝体)的最大剪应力及最大竖向应力分别小于坝体的抗剪强度和抗压强度,初期坝是稳定的。  相似文献   

9.
Summary C- and G-banding patterns ofOrycteropus afer are described on the basis of fibroblast cultures obtained from a female individual.This work was supported in part by a research grant DEB 76-10580 from the National Science Foundation.  相似文献   

10.
An unusual silver celestial planisphere is held in the collection of the Whipple Museum of the History of Science (Wh.1762); little information about this object is recorded in the museum’s documentation. A comparison of this silver example with celestial planispheres printed on paper, coupled with the consideration of other aspects of the lives and work of the cartographers and instrument-makers involved in producing such objects, suggests some possibilities regarding its production. Through this individual case study, I aim to demonstrate that the careful examination of an individual instrument, coupled with an understanding of the class of instruments to which it belongs and the milieu in which it was produced, can result in a deeper understanding of any given artefact, its circumstances of design and manufacture, and its intended use and users.  相似文献   

11.
Summary Oviducts of the guinea-pig, mouse and immature baboon show prominent electrical slow waves. In the guinea-pig oviduct they are 40–50 mV in amplitude and have a duration of 1.5 sec in the isthmus. Slow waves in these tissues propagate at a speed of 1–13 mm/sec.Decreased 6th December 1977.Supported by NIH-09339-02 and Rockefeller Foundation. A. T. was a Rockefeller Foundation Fellow. Correspondence to B. J. Hodgson, Dept. Obstetrics and Gynecology, UTHSCSA, San Antonio, Texas 78284.  相似文献   

12.
Summary A net reabsorption of fluid was observed in isolated ferret trachea under control conditions. Cholinergic stimulation resulted in net secretion of fluid while atropine blocked this response without any effect on the basal process of fluid reabsorption.Supported by research grants from the Cystic Fibrosis Foundation and the University of Florida (GML) and by a Pediatric Pulmonary Center award (A 2018) from the Division of Maternal and Child Health of the Department of Health and Human Services and Whitehall Foundation grant (No. 78-156 ck-1).  相似文献   

13.
Ecological causes and consequences of bird orientation   总被引:6,自引:0,他引:6  
Summary An advanced orientation capability offers possibilities for birds to optimize movement patterns in a wide variety of ecological situations. The adaptive significance of different patterns of angular dispersion and of orientation responses to topography and sociality are elucidated. The orientation capacity is characterized by flexibility, exemplified by reorientation promoting safety and restoration of fat reserves during migration. There are also limitations to the orientation process, leading to costs of migration through mis- or disorientation, and to constraints on the evolution of routes and timing of migratory flights. Young migrants may acquire an erroneous compass sense, and misorient several thousands of kilometers off their normal course. Widespread and dense fog of long duration causes disorientation and mortality among land birds migrating over the sea. Orientational constraints in the evolution of migration routes may be most easily disclosed at high geographic and magnetic latitudes. Here the birds are faced with special difficulties in using their celestial as well as their magnetic compasses. The sun compass could be used for great circle orientation, but observed spring flight trajectories of high arctic shorebirds and geese seem to conform with rhumbline routes.  相似文献   

14.
This article by Curtis Wilson is an account of the origin of Hansen’s powerful systematic method for finding contributions of higher order perturbations in celestial mechanics. Hansen’s method was developed in the course of improving on Laplace’s treatment of the mutual perturbations of Jupiter and Saturn. This method, an entirely new way of doing celestial mechanics when it first appeared, later made possible the successful treatment of the complicated motions of our moon (see Wilson 2010). In this paper Wilson gives a brief historical introduction followed by an account of relevant technical details of the Laplacian background, an account illustrating technical details in Hansen’s initial development in his Disquisitions of 1829, and a treatment illustrating details contributing to the achievement of Hansen’s more refined development in his Untersuchung of 1831. These details include conditional equations Hansen provides for checking the accuracy of calculations. Wilson also includes a detailed assessment showing the extraordinary improvement in empirical accuracy of Hansen’s treatment over the best earlier treatment of the Jupiter-Saturn  interactions.  相似文献   

15.
Summary Immunoadsorbent and oxamate-Sepharose chromatography were used to isolate electrophoretically homogeneous LDH-X from human testes with a final specific activity of 125 IU/mg and good yields: other applications of this approach are discussed.This work was supported by the Rockefeller Foundation.  相似文献   

16.
Summary The induction of avidin in chick tissues was found in septicEscherichia coli infection. Avidin concentrations in the plasma roughly corresponded to those in the other tissues studied which suggests that avidin in chicks is a secretory protein.Acknowledgments. We thank Mrs O. Kurronen, Miss T.-M. Mattila and Mr C. Hartmann for technical assistance and Dr M.S. Kulomaa for the performance of radioimmunoassay. We are very much obliged to Dr T. Metsä-Ketelä for valuable criticism. The work was supported by grants from the Ford Foundation (No 760-0526) and the Scientific Foundation of the Tampere City.  相似文献   

17.
Summary Scavenging studies are supporting the notion that triplet radical cations are formed during the binding of the carcinogen N-acetoxy-2-acetylamino-fluorene to native DNA in vitro.This work was supported by Grant No.3305.78 of the Swiss National Science Foundation and by a grant from The Roche Research Foundation.  相似文献   

18.
Summary Methods are presented for qualifying clinical reference intervals, for individuals as well as peer groups, according to circadian and other rhythms, using chronobiologically-defined single samples or time series.Supported by the Hoechst Italia Foundation, US Environmental Protection Agency (R804512-01-0), US Public Health Service (5-K6-GM-13, 981), National Cancer Institute (1R01-CA-14446-01), Cancer Supplement (CA-14445-01S1), National Institute of Aging (A6-00158) and National Institute of Occupational Safety and Health (OH 00631).  相似文献   

19.
Summary Histoincompatible skin grafts in rabbits treated with cyclosporine can permanently engraft but show a transient mononuclear cellular infiltrate. This transient cyclosporine-resistant infiltrate consists of cells which are sensitive to steroids, radiation and cryopreservation. They have the same ACM-1 phenotype and the same characteristics as cyclosporine-sensitive cells.9 January 1987Supported by the Swiss National Research Foundation, Grant No. 3.908-0.83.  相似文献   

20.
Summary Nitrate reductase was protected from inactivation in wheat leaf extracts by NADH, while NADPH was less effective. NAD, NADP or adenylates did not affect nitrate reductase inactivation in vitro. Glutamine synthetase was more stable than nitrate reductase and was protected from inactivation by ATP. ADP, AMP or pyridine nucleotides had no or only a minor effect on the decrease of glutamine synthetase activity in extracts. The caseolytic activity extracted from senescing leaves was slightly decreased by NADH and NADPH but this effect was not sufficient to explain the stabilization of nitrate reductase by NADH. Oxidized pyridine nucleotides and adenylates had no major effect on the caseolytic activity under the conditions used.This work was supported by grant 3.067-0.81 from the Swiss National Science Foundation. Author for correspondence: U.F.  相似文献   

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