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1.
In the formative period of London's scientific instrument industry membership of a guild was a necessary step towards owning a business in the City. Through the guilds' formal system of apprenticeship, boys received first-class training in a skilled trade, and learned essential marketing and managerial techniques. By analysing the guilds' records of apprenticeship and subsequent guild life it is possible to determine chains of masters and apprentices by which the knowledge passed from generation to generation. At the same time, dates can be established for the training and subsequent working life of many known makers. The chains of knowledge reveal new and often important masters who were previously unknown because, by chance, their instruments or advertisements have not survived to the present day. Two guilds have been used to illustrate the chains: Broderers' Company and Joiners' Company.  相似文献   

2.
Summary Following lens removal from the eye of adultEurycea bislineata, the northern (USA) 2-lined salamander, it was found that this salamander has the capacity for lens regeneration. Its widespread distribution and high percentage of regenerative success suggests it as a suitable organism for the study of this differentiative phenomenon.This research was supported by N.I.H. grant EY-02534 from the National Eye Institute. We thank S.M. DiRienzo for excellent technical assistance.  相似文献   

3.
Summary A non-cannabinoid phenol (4,4,dihydroxy-5-methoxybibenzyl) increased uterine weight in prepubescent female rats, suggesting non-cannabinoids contribute to the estrogenic effects ofCannabis.Acknowledgments. This research was supported by Contract 271-78-3527 from the National Institute on Drug Abuse and by the Research Institute of Pharmaceutical Sciences, University of Mississippi. The authors are grateful to Karen S. Tomaszewski for technical assistance.  相似文献   

4.
Summary Drosophila melanogaster adults were collected for several years in various localities of Italy. The frequencies of thePgm electrophoretic alleles were determined and the similarity of the configuration of allelic frequencies observed. It was concluded that the PGM electrophoretic polymorphism could be maintained by random genetic drift in the natural populations studied only if the effective breeding size (N e ) during the bottle-neck period is about 5000.I am grateful to Prof. D. Sperlich and Prof. W. Seyffert for their kind hospitality during my sojourn as Research Fellow of the Alexander von Humboldt Foundation in the Institute of Biology II at the University of Tübingen (FRG) where the final version of this paper has been done. The technical assistance of Mr A. Micheli is also acknowledged.  相似文献   

5.
Summary A competitive enzyme linked immunosorbent assay was developed for the quantification of a large lipoprotein, namely the yolk protein vitellogenin, in the haemolymph of cockroaches (Nauphoeta cinerea). This assay was found to be specific, reproducible and it has a high sensitivity (approximately 10 ng).Acknowledgments. We would like to express our thanks to Prof. H. Fey and Ms H. Pfister, Veterinary Bacteriological Institute, University of Berne, for introducing us into the ELISA methodology, to P. Beyeler for technical assistance and to M. Kaltenrieder for drawing the graphs. We also thank the Sandoz Foundation for a fellowship to M. Dumas and the Swiss National Science Foundation (grant No. 3. 188-0.77) for financial support.  相似文献   

6.
Mining education was one of the areas of technical savoir transformed during the eighteenth century. Mining academies arose and spread through Europe in the second half of that century. This happened first in the German states and the Austrian dominions, due to the cameralistic system, and soon developed elsewhere through a transfer of the German model to France (Ecole des mines) as well as to other francophone and Spanish-speaking areas (Belgium and Piedmont-Savoy, Spain and America). The mining academies may rightly be considered among the prototypes of technical high schools (Polytechniques and Technische Hochschulen) established during the nineteenth century. In the course of exploring some of the details of this development, the present paper aims at suggesting outlines to be followed in pursuing a comparative analysis of special schools for the training of technicians and mining officers (Bergschulen and Bergakademien). A second aim is to examine more closely the Italian case as a typical example of adaptation, although on a smaller scale, of French and German experiences. This can provide a framework within which to place further microanalyses and case-studies.  相似文献   

7.
Tycho Brahe's lunar theory, mostly the work of his assistant Christian Longomontanus, published in the Progymnasmata (1602), was the most advanced and accurate lunar theory yet developed. Its principal innovations are: the introduction of equant motion for the first inequality in order to separate the determination of direction and distance; a more accurate limit for the second inequality although requiring a more complex calculation; additional inequalities of the variation and, in place of the annual inequality in Tycho's earlier theory, a reduction in the equation of time; in the latitude theory a variation of the inclination of the orbital plane and an inequality of the motion of the nodes; a reduction in the range of variation of distance, parallax, and apparent diameter. Some of these were already present in Tycho's earlier lunar theory (1599), but all were changed in notable ways. Twenty years later Longomontanus published a modified version of the lunar theory in Astronomia Danica (1622), for the purpose of facilitating the calculation through new correction tables, and also explained his reasons for parts of the theory in the Progymnasmata. This paper is a technical study of both lunar theories.  相似文献   

8.
Isocardenolides     
Zusammenfassung Ein einfacher Weg zur Synthese eines von zwei möglichen isomeren Cardenoliden wurde entwickelt und die Reaktionsfolge an Hand der Überführung von Pregnenolon in Isocardenolide V gezeigt.

Steroids and Related Natural Products XXI. For the previous contribution refer to:G. R. Pettit andP. Hofer, Helv. chim. Acta46, 2142 (1963).

A preliminary account of this study was presented (December 1963) at the VI. Pan-American Congress of Pharmacy and Biochemistry, Mexico City (Mexico).

This investigation was supported by PHS Research Grants CY-4074 (C3) to CA-04074-06 from the National Cancer Institute, Public Health Service.  相似文献   

9.
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   

10.
This paper analyzes the Spanish appropriation of one of the great French eighteenth-century best-sellers, the Spectacle de la Nature (1732--1750) by the abbé Antoine Nöel Pluche. In eight volumes, the abbé discussed current issues in natural philosophy, such as Newtonianism, the origin of fossils, artisan techniques, natural history, machines, gardening or insect-collection in a polite-conversation format. It was translated into English (1735), Dutch (1737), Italian (1737), German (1746) and Spanish (1753). But the four Spanish editions were very different from their European counterparts. In Spain, it was delivered in 16 carefully printed and extensively commented volumes. In Pluche's original, there was a concern for the young gentleman's education, new pedagogical methods and an enthusiastic defence of experimental knowledge. However, Le Spectacle in Spain was conceived as a useful tool for modernizing the country, it served political and propagandist goals, defended Spanish culture and science (in particular with respect to American flora, fauna and geography) and the Jesuit contribution to science and aimed to harmonize experimental knowledge and scholastic tradition. The analysis of the more than 1500 footnotes, prefaces, some readers’ comments and other questions related to the format gives insight on how it was appropriated.  相似文献   

11.
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   

12.
Cold tolerance of two Antarctic terrestrial arthropods   总被引:2,自引:0,他引:2  
Summary Two Antarctic arthropods,Alaskozetes antarcticus (Acari) andCryptopygus antarcticus (Collembola) possess the ability to supercool to –30°C, but the realisation of this potential is dependent on starvation. The mite contains glycerol in a concentration of about 1% fresh weight.Acknowledgments. We thank the British Antarctic Survey, Cambridge and the Zoological Institute. University of Oslo for support and reasearch facilities, and the Natural Environment Research Council for a research grant (GR. 3/2797). We are grateful to Ms I. Tambs-Lyche for technical assistance.  相似文献   

13.
Summary Analysis by GC-EAG indicates that abdominal tip extracts of femalePrays oleae contain a tetradecenal. Synthetic (Z)-7-tetradecenal elicits a strong EAG respones from maleP. oleae and field tests it to be comparable in attractancy with the virgin female moth. (Z)-9-Tetradecenal also produces a strong EAG response but it is not an attractant and, when added to (Z)-7-tetradecenal, markedly reduces trap catches.Acknowledgments. The authors are indebted to Mr N. Psylakis, Agricultural Research Centre, Chania, Crete, and to Dr D. Vassilopoulos, Benaki Phytopathological Institute, for providing facilities for this work. They thank the Commonwealth Institute of Entomology, London, for moth species confirmation.  相似文献   

14.
Three problems in book I of Diophantus’ Arithmetica contain the adjective plasmatikon, that appears to qualify an implicit reference to some theorems in Elements, book II. The translation and meaning of the adjective sparked a long-lasting controversy that has become a nonnegligible aspect of the debate about the possibility of interpreting Diophantus’ approach and, more generally, Greek mathematics in algebraic terms. The correct interpretation of the word, a technical term in the Greek rhetorical tradition that perfectly fits the context in which it is inserted in the Arithmetica, entails that Diophantus’ text contained no (implicit) reference to Euclid’s Elements. The clause containing the adjective turns out to be a later interpolation, that cannot be used to support any algebraic interpretation of the Arithmetica.  相似文献   

15.
Summary The lipid fraction ofP. acnes was submitted to stepwise purification followed by bioassay in order to localize the prostaglandin-like material. GC-MS analysis revealed the occurrence of substances having a part but not a total molecule in common with the prostaglandin family, suggesting that prostaglandin-like substances represent a new group of prostaglandin compounds.The competent technical assistance of Mr N. Engström and Mr G.A. de Vogel is gratefully acknowledged.  相似文献   

16.
This paper compares the forecasts of recession and recovery made by five non-government U.K. teams modelling the economy (Cambridge Econometrics, the London Business School, the National Institute of Economic and Social Research, the Cambridge Economic Policy Group and the Liverpool Research Group). The paper concentrates on annual ex ante projections as published over the period 1978-1982, i.e. forecasts made, before the event, of the onset, length, depth and character of the economic recession in the U.K. which began in 1979. The comparison is in terms of year by year changes in production, unemployment, prices and other variables. It concludes that no group was systematically better or worse than other groups (confirming U.S. experience) and that the groups tended to perform better in their chosen areas of specialization, e.g. medium-term groups did better at forecasting the medium-term outcome.  相似文献   

17.
Summary A spermatozoid-attracting substance of the hermaphrodite brown algae,Pelvetia wrightii andFucus evanescens, was identified as 1, trans-3, cis-5-octatriene, respectively, by1H-NMR and13C-NMR data and biological activities.Acknowledgments. The authors would like to express their thanks to Mr A. Nishikawa for technical assistance, to Dr M. Abe (Yamagata Univ.) for valuable discussion on biological work and to Prof. Y. Sakai (Hokkaido Univ. Director of the Institute of Algological Research, Muroran) for the facilities during the investigation ofP. wrightii andF. evanescens. Financial support from the Ministry of Education Science, and Culture (Grant-in Aid for Scientific Research No. 556092) is gratefully acknowledged.  相似文献   

18.
Summary Spherical structures in the test cells that surround the embryos of the ascidianCiona intestinalis L. (Tunicata, phylum Chordata) were studied by both light and electron microscope. Our data support the view that these structures are microorganism-like cells living in symbiosis with the test cells. Their possible role is discussed.Acknowledgment. The authors are indebted to the Institute of Comparative Anatomy of Palermo for the use of the Zeiss EM 9 Electron Microscope. Particular thanks to Mr Salvatore Bucculeri for his technical assistance.  相似文献   

19.
Summary A cell line of the spruce budworm (FPMI-CF1) consists of a mixed population of cells that possess variable sensitivity to -endotoxin from crystals ofBacillus thuringiensis. A cell strain was selected from FPMI-CF1 which was resistant to the entomocidal protein extracted fromB. thuringiensis crystals. The resistant character was unstable, however, and could not be maintained in the absence of toxin during growth.The author wishes to thank S.S. Sohi (Forest Pest Management Institute, Canadian Forestry Service, Sault Ste. Marie, Ontario, Canada) for theC.fumiferana cell line, and L.I. Davidson (USDA) for his able technical assistance.  相似文献   

20.
Summary The structures of 2 new polyhydroxylated cannabinoids, (±)9, 10-dihydroxy- 6a(10a)-tetrahydorcannabinol and (±)8, 9-dihydroxy- 6a(10a)-tetrahydrocannabinol, obtained from a hexane extract of an IndianCannabis variant were determined by spectral means and correlation with cannabinol.Acknowledgments. Supported by contract No. HSM-42-70-109 from the National Institute on Drug Abuse and the Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi. The authors are grateful to Mrs Glenda Lewis (Research Institute) for running the gas chromatographic analyses and to Mr C. Versluis (Analytical Chemistry Laboratory, University Of Utrecht, The Netherlands) for recording an element list of both compounds.Cannabis Herbarium specimens are stored in the herbarium, Department of Pharmacology, School of Pharmacy, University of Mississippi, University, MS 38677, USA.  相似文献   

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