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In the ongoing discussions about the qualities of Germany regarding economic activities and especially industrial production in a unifying Europe and with respect to worldwide economic competition, it is important to carefully consider the conditions for innovative and competitive scientific research. Germany as a site for science is dependent not only on the resources of public research institutes, on available research funds and on industrial R&D investment, but just as decisively on the existing framework of conditions for scientific-technological progress. Thus, the whole educational system is of utmost importance since it must form and develop the coming generations of researchers. Their knowledge and their attitudes, as acquired in this educational process, determine not only their future scientific productivity, but also the public acceptance of high-tech production in Germany.  相似文献   
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 We isolated 6×6 hemocyanin, dissociated it into subunits, and examined it by electron microscopy. The subunits were separated by native polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate PAGE, and crossed immunoelectrophoresis. Single subunits were isolated by gel cutting from native PAGE and identified as hemocyanin by measuring their ultraviolet spectrum. A total of four distinct hemocyanin subunits were identified, and the subunit pattern of the three electrophoresis systems assigned to each other. The relative proportion of subunits a:b:c:d were 2 : 2 :>: 1 as determined by densitometry. Presumably, c and d act as linkers between hexamers. Received: 9 November 1998 / Accepted in revised form: 14 April 1999  相似文献   
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Summary This paper analyzes the flexibility of maternal care in wild house mice (Mus domesticus) under different reproductive conditions in the laboratory. All maternal activities were both qualitatively and quantitatively analyzed over a period of 28 days after birth of a litter. The standard behavior of a lactating house mouse with 7–8 young can be described as follows: During days 1–16 the offspring fully depend on the mother for nutrition. Due to rapid growth of the litter, the energetic demands of lactation reach a peak for the female during days 13–16. During days 17–22, the weaning period, the young begin to eat solid food. This period is characterized by behaviors that indicate different interests of the mother and offspring, and thus the existence of a parent-offspring conflict sensu Trivers (1974). Resting alone and remaining far from the litter indicate the female's interest in avoiding the offspring's demands, which are expressed in frequent attempts to initiate sucking. There is no aggression towards the young during weaning. House mice are weaned at 23 days. The relationship between mother and young appears free of conflict after weaning. Nursing is replaced by resting with body contact, but the offspring do not try to suck. The following results suggest that during the weaning period the offspring do not get more milk than corresponds to the maternal optimum—despite their frequent sucking attempts:(a) When the mother is simultaneously lactating and pregnant, offspring are smaller at weaning than under standard conditions. (b) Small litters are weaned earlier than large ones. Despite a longer nursing period, offspring from large litters are lighter at weaning than those from small ones. (c) Under high energy demand, as after postpartum mating and with large litters, females wean their young at a body weight which corresponds to the earliest physiologically possible state of independence.Parity of the female has no effect on maternal activities, nor has the presence of the father. In the latter case, however, offspring are less often left alone and unprotected.Females seem to adjust their investment according to the body weight of the progeny by delaying or advancing the date of weaning (Table 2). This behavior allows the production of the largest possible number of offspring that can be raised to a minimal physiological threshold corresponding to a body weight of approximately 9 g. Such flexibility in parental care may enhance maternal fitness under different and unpredictable environmental conditions.  相似文献   
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