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1.
The coming of mathematicians to the United States fleeing the spread of Nazism presented a serious problem to the American mathematical community. The persistence of the Depression had endangered the promising growth of mathematics in the United States. Leading mathematicians were concerned about the career prospects of their students. They (and others) feared that placing large numbers of refugees would exacerbate already present nationalistic and anti-Semitic sentiments. The paper surveys a sequence of events in which the leading mathematicians reacted to the foreign-born and to the spread of Nazism, culminating in the decisions by the American Mathematical Society to found the journal Mathematical reviews and to form a War Preparedness Committee in September 1939. The most obvious consequence of the migration was an enlarged role for applied mathematics.  相似文献   

2.
In 1892, Eliakim Hastings Moore accepted the task of building a mathematics department at the University of Chicago. Working in close conjuction with the other original department members, Oskar Bolza and Heinrich Maschke, Moore established a stimulating mathematical environment not only at the University of Chicago, but also in the Midwest region and in the United States in general. In 1893, he helped organize an international congress of mathematicians. He followed this in 1896 with the organization of the Midwest Section of the New York City-based American Mathematical Society. He became the first editor-in-chief of the Society's Transactions in 1899, and rose to the presidency of the Society in 1901.  相似文献   

3.
基于最新获取的数据,从规模、结构、产业特征和运营特征等多个方面分析了美国科技企业孵化器发展动态及原因。整体上,美国科技企业孵化行业表现出经济紧缩背景下"集约型"发展特征。根据美国的经验和我国科技企业孵化行业发展的现实,本文最后提出了若干启示建议。  相似文献   

4.
Summary Isometric tension was measured in arterial strips from neonatal lambs and adult sheep, after stimulation by angiotensin II. During the early maturation period immediately following birth (3 weeks) there was a progressive increase in sensitivity to the agent.This study was supported by the Golden Empire Chapter of the American Heart Association and the United States Public Health Service, grant No. PHS HL 14780-03.  相似文献   

5.
A national scientific community developed in the United States following the American Revolution. The independent scientific societies, journals and other institutions that formed the basis of this community were, however, centred in the North. An analysis of the work of four leading natural historians of the Southern tidewater (two from before the Revolution and two from after it) suggests that their region participated in this development by shifting scientific ties and allegiances from Europe to the North rather than by creating national or regional scientific institutions.  相似文献   

6.
ABSTRACT

Key figures in the founding years of the United States of America were part of the first American learned agricultural society, known as the Philadelphia Society for Promoting Agriculture (PSPA). Its members were georgic farmers who set out to describe, explore and explain agricultural processes by practical experiences, observations, and theories written in British books. Those theories, however, did not provide any reason for the widespread agricultural practice in Pennsylvania of using plaster as fertilizer, which was German in origin. Although imports were heavily tariffed and later even banned, plaster became, and remained, a top commodity in America. In order to keep agricultural businesses and investments afloat, several members of the PSPA began to scientifically justify the application of plaster fertilization. In so doing, they incorporated chemical theories and methods to both their agricultural practices and investigations. Thus, I argue, they acquired and developed an agrochemical knowledge that was mainly determined by a material history of plaster. Their knowledge was new, unique and more practicable in comparison to the British knowledge in this sector. Eventually, it was through the newly developed knowledge by PSPA members that contributed to the formation of agricultural chemistry as a science in its own respect.  相似文献   

7.
During the 1920s and 1930s, Italian physicists established strong relationships with scientists from other European countries and the United States. The career of Bruno Rossi, a leading personality in the study of cosmic rays and an Italian pioneer of this field of research, provides a prominent example of this kind of international cooperation. Physics underwent major changes during these turbulent years, and the traditional internationalism of physics assumed a more institutionalized character. Against this backdrop, Rossi's early work was crucial in transforming the study of cosmic rays into a branch of modern physics. His friendly relationships with eminent scientists — notably Enrico Fermi, Walther Bothe, Werner Heisenberg, Hans Bethe, and Homi Bhabha — were instrumental both for the exchange of knowledge about experimental practices and theoretical discussions, and for attracting the attention of physicists such as Arthur Compton, Louis Leprince-Ringuet, Pierre Auger and Patrick Blackett to the problem of cosmic rays. Relying on material from different archives in Europe and the United States, this case study aims to provide a glimpse of the intersection between national and international dimensions during the 1930s, at a time when the study of cosmic rays was still very much in its infancy, strongly interlaced with nuclear physics, and full of uncertain, contradictory, and puzzling results. Nevertheless, as a source of high-energy particles it became a proving ground for testing the validity of the laws of quantum electrodynamics, and made a fundamental contribution to the origins of particle physics.  相似文献   

8.
Forecasts for the seven major industrial countries, Canada, France, Germany, Italy, Japan, the United Kingdom and the United States, are published on a regular basis in the OECD's Economic Outlook. This paper analyses the accuracy of the OECD annual forecasts of output and price changes and of the current balance in the balance of payments. As a reference basis, the forecasts are compared with those generated by a naive model, a random walk process. The measures of forecasting accuracy used are the mean-absolute error, the root-mean-square error, the median-absolute error, and Theil's inequality coefficient. The OECD forecasts of real GNP changes are significantly superior to those generated by the random walk process; however, the OECD price and current balance forecasts are not significantly more accurate than those obtained from the naive model. The OECD's forecasting performance has neither improved nor deteriorated over time.  相似文献   

9.
Summary Stingless bees (Trigona jaty) routinely visit the flowers ofTheobroma cacao (Sterculiaceae) in the Atlantic lowlands of Costa Rica. The bees collect pollen and behave as pollen thieves in flowers well exposed to direct sunlight in cacao plantations, and avoid flowers in heavy shade. Pollination rates are maximized, however, in heavy shade due to the high abundance of the small-bodied pollinating midges (Ceratopogonidae and Cecidomyiidae) found in such places. Pollen-thieving by stingless bees, therefore, may only impact on fruit set in cacao trees in direct sunlight, with only minimal to no impact in areas of cacao where natural pollinator activity is high.This research was funded by grants from The American Cocoa Research Institute of the United States of America. I thank T. Noeske for statistical assistance.  相似文献   

10.
Summary Our results indicate that pig lymphocytes in culture complete their 1st division at 24 h. At 36 h there are 9% of cells in 2nd division. 3rd mitosis appears at 48 h; and at 72 h there are cells engaged in the 4th division.This work was supported by grants from the International Atomic Energy Agency, the Organization of American States and the Consejo Nacional de Investigaciones Científicas y Técnicas.We wish to thank for the technical assistance of Mr J. Serraïno.  相似文献   

11.
12.
Zusammenfassung Es wurden ein- und dreipaarige elektrolytische Läsionen in den ventromedialen Kernen von Ratten gesetzt, wobei es zu einer Erhöhung von Triglyceriden und Cholesterin kam. Dieses Hypothalamus-Gebiet enthält Regulationszentren des Serumlipidspiegels.

This investigation was supported in part by Grants from the United States Public Health Service No. HD 03331, from the American Heart Association and the Mid-Hudson Heart Association.

Acknowledgments. The authors express their gratitude to Mrs.B. Stone, MissD. Hojnicki and Mr.P. Stanley for their excellent technical assistance.  相似文献   

13.
The nineteenth-century American scientist, philosopher and teacher Joseph LeConte (1823–1901) is well-known for his writings on geology and the reconciliation of evolutionary theory and religion, but he has not been properly recognized for his contributions to the physiology and psychology of vision. This study explores and assesses his work in the latter field, showing the nature of his original investigations into human vision and the influence of his book Sight: an exposition of the principles of monocular and binocular vision, which served as the major textbook on the subject in the United States from its publication in 1881 until after the turn of the century. Grounded in neo-Lamarckian evolutionary theory, LeConte's publications on vision had a strong impact upon subsequent studies of the phenomenon of human sight.  相似文献   

14.
Summary A radioimmunoassay for serum vitamin A is described which can detect as little as 1 ng of retinol. The statistical characteristics of this assay are presented and its use in a nutritional experiment is discussed.This work was supported by United States Public Health Service grant 2 RO1 AM19716.  相似文献   

15.
国内外运载火箭POGO抑制技术研究进展   总被引:2,自引:0,他引:2  
本文描述了美国、前苏联、欧洲、日本和中国等国内外运载火箭跷振(POGO)抑制技术研究的发展历程及进展,并总结出国内外火箭POGO抑制技术的特点,以及在小POGO和气蚀动力学等方面带来的启示.美国的POGO抑制技术研究经历了大力神2——土星V——航天飞机——具体问题具体分析等4个阶段的发展历程,中国的POGO抑制技术研究也类似经历了331工程——载人航天工程——新一代火箭——40 Hz问题等4个阶段.由此可知,POGO振动抑制呈现出"事前理论预示难度大、事后危害后果严重、解决过程漫长曲折"的特点,必须在重大航天工程实施前开展研究.  相似文献   

16.
The objective of this study is to discuss the potential impact of a global warming on various aspects of human health. Changes in heat-related mortality are estimated for four countries: the United States, Canada, the People's Republic of China and Egypt. In addition, the potential confounding impact of increased air pollution is considered. Finally, a framework to analyze two vector-borne diseases, onchocerciasis and malaria, which may spread if temperatures increase, is discussed. Our findings suggest that heat-related mortality is estimated to rise significantly in all four countries if the earth warms, with the greatest impacts in China and Egypt. The most sensitive areas are those with intense but irregular heat waves. In the United States, air pollution does not appear to impact daily mortality significantly when severe weather is present, although it seems to have a slight influence when weather conditions are not stressful.  相似文献   

17.
Summary Aortic coarctation induces a large increase in poly ADP-R synthetase activity in non-cardiocyte nuclei, and in cardiocyte nuclei inhibition occures, suggesting a differentiation dependent regulation of polymer metabolism. In noncardiocyte nuclei DNA and poly ADP-R (polyadenosine diphosphoribose) synthesis exhibit positive correlation.Ackowledgment. This work was supported in part by the United States Air Force Office of Scientific Research (F-49620-81-C-007) and in part by a Program Project Grant of the United States Public Health Service (HL-24056). G. Jackowski is the recipient of a Postdoctoral Scholarship of the Canadian Heart Association and E. Kun is a Research Career Awardee of the United State Public Health Service.  相似文献   

18.
United States: The Visiting Program of the National Institutes of Health: Stipends for 1990  相似文献   

19.
Changes in mortality rates have an impact on the life insurance industry, the financial sector (as a significant proportion of the financial markets is driven by pension funds), governmental agencies, and decision makers and policymakers. Thus the pricing of financial, pension and insurance products that are contingent upon survival or death and which is related to the accuracy of central mortality rates is of key importance. Recently, a temperature‐related mortality (TRM) model was proposed by Seklecka et al. (Journal of Forecasting, 2017, 36(7), 824–841), and it has shown evidence of outperformance compared with the Lee and Carter (Journal of the American Statistical Association, 1992, 87, 659–671) model and several others of its extensions, when mortality‐experience data from the UK are used. There is a need for awareness, when fitting the TRM model, of model risk when assessing longevity‐related liabilities, especially when pricing long‐term annuities and pensions. In this paper, the impact of uncertainty on the various parameters involved in the model is examined. We demonstrate a number of ways to quantify model risk in the estimation of the temperature‐related parameters, the choice of the forecasting methodology, the structures of actuarial products chosen (e.g., annuity, endowment and life insurance), and the actuarial reserve. Finally, several tables and figures illustrate the main findings of this paper.  相似文献   

20.
Summary The synthetic estrogen diethylstilbestrol at a subinhibitory level of 1.75 g/ml diminished the production of staphylococcal alpha toxin, coagulase, deoxyribonuclease and penicillinase. Thus, the reported host beneficial effects of diethylstilbestrol may be partially related to its retardive action of certain toxins, or enzymes of S. aureus.Acknowledgments. This work was supported by United States Public Health Service, grant AI 06618, a grant in aid from Loyola University, United States Public Health Service, grant GRSG PRO 5368, and grants from Eli Lilly, Upjohn, Syntex, and G. D. Searle drug companies.  相似文献   

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