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Fifty-three clusters of blowfly eggs of the genus Calliphora vicina were observed in the laboratory up to the hatching stage under reproducible and virtually field-like conditions. Rearing the larvae was then continued up to pupation, the larval growth in length being recorded several times a day. As the object was to study the dependence of the larvae increase in length on the temperature conditions in vitro, the substratal humidity and food supply were kept unchanged during the entire study. The temperature ranged from 6.5 degrees C to 35 degrees C, with the temperature for the individual cluster kept constant during the entire developmental process. Data on about 5500 measured larvae were statistically evaluated. The basic result established was that in the case of the blowfly of the genus Calliphora vicina in vivo, all developmental stages relevant to the entomologic determination of the time of death depend on the temperature conditions: (1) the duration of the egg stage increases with decreasing temperature; (2) the speed of larval growth is slower at lower temperatures; (3) the maximal larval length is reached earlier at higher temperatures; (4) the mean value of maximal length decreases with increasing temperature; (5) larvae under all temperature conditions decrease in size after having reached their maximal length, the decrease in length being more rapid at higher temperatures; (6) constant temperatures over 30 degrees C lead to "stunted forms" which do not pupate and die; (7) constant temperatures under approximately 16 degrees C after the peak of growth has been reached inhibit the readiness to pupate, which causes the larvae to fall into a stationary state of rest, which will be interrupted only when the temperature is raised and resumption of the metamorphosis is thus induced. To allow rapid reconstruction of the larval age in general practice, the established growth data were set out in the form of a diagram designated isomegalendiagram, which permits temperature-fluctuation-related entomologic determination of the time of death with a maximum degree of accuracy.  相似文献   
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The purposes of this essay are to describe how federal research and development policy has altered authority relationships and to suggest a new concept of legitimacy in accord with the changed conditions. Research and development (R and D) creates an indeterminate future. Thus, the politics of research and development incorporates an apparent contradiction : political leadership demands that jobs be done which require creative and unpredictable actions on the part of private organizations, while it also demands that contractors be held responsible for fulfilling goals efficiently, avoiding deleterious secondary consequences, and refraining from abuses of power. The paradox can be resolved by creating norms of responsibility that allow for judgments on how a job is done rather than what is to be done. New institutions for technological assessment to check on unintended consequences of projects and citizen review boards to estimate the quality of life engendered by projects may provide such norms of responsibility.  相似文献   
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