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81.
This paper discusses the development of research in business ethics and recent directions taken by scholars in the field. We also analyze ethical considerations in systems theory and speculate on the possibilities of examining business ethics from a systemic perspective.  相似文献   
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Zusammenfassung 7-Hydroxy- 6-tetrahydrocannabinol (7-Hydroxy- 6-THC), ein psychotomimetisch aktiver Metabolit des 6-THC, wird von Kaninchen in inaktive 6-THC-7 Säure metabolisiert. Die Synthese dieser Säure wird beschrieben.

The work in Jerusalem was supported by the US National Institute of Mental Health and in Stockholm by the Swedish Medical Research Council.  相似文献   
85.
Zusammenfassung Nach Injektion (Mesenterialarterie) einer Mischung zweier Blutproben — die eine mit Methämoglobin, die andere mit Sauerstoff markiert — erscheint der Sauerstoff 1–2 sec früher in der Mesenterialvene als die mit Methämoglobin markierten Erythrozyten. Die Existenz eines Gegenstromaustausches in den Darmzotten der Katze scheint damit bewiesen zu sein.

This study was supported by grants from the Medical Faculty University of Göteborg, from the Air Force School of Aerospace Medicine under Contract No. AF 61(052)-732 through the European Office of Aerospace Research (OAR), United States Air Force and from the U.S. Public Health Service No. HE-0575-04-05.  相似文献   
86.
Elements in the alkali metal series are regarded as unlikely superconductors because of their monovalent character. A superconducting transition temperature as high as 20 K, recently found in compressed lithium (the lightest alkali element), probably arises from pressure-induced changes in the conduction-electron band structure. Superconductivity at ambient pressure in lithium has hitherto remained unresolved, both theoretically and experimentally. Here we demonstrate that lithium is a superconductor at ambient pressure with a transition temperature of 0.4 mK. As lithium has a particularly simple conduction electron system, it represents an important case for any attempts to classify superconductors and transition temperatures, especially to determine if any non-magnetic configuration can exclude superconductivity down to zero temperature. Furthermore, the combination of extremely weak superconductivity and relatively strong nuclear magnetism in lithium would clearly lead to mutual competition between these two ordering phenomena under suitably prepared conditions.  相似文献   
87.
In the first clear mathematical treatment of natural selection, Müller proposed that a shared warning signal (mimicry) would benefit defended prey species by sharing out the per capita mortality incurred during predator education. Although mimicry is a mainstay of adaptationist thinking, there has been repeated debate on whether there is a mutualistic or a parasitic relationship between unequally defended co-mimic species. Here we show that the relationship between unequally defended species is mutualistic. We examined this in a 'novel world' of artificial prey with wild predators (great tit, Parus major). We kept the abundance of a highly defended prey ('model') constant and increased the density of a moderately defended prey ('defended mimic') of either perfect or imperfect mimetic resemblance to the model. Both model and defended mimic showed a net benefit from a density-dependent decrease in their per capita mortality. Even when the effect of dilution through density was controlled for, defended mimics did not induce additional attacks on the model, but we found selection for accurate signal mimicry. In comparison, the addition of fully edible (batesian) mimics did increase additional attacks on the model, but as a result of dilution this resulted in no overall increase in per capita mortality. By ignoring the effects of density, current theories may have overestimated the parasitic costs imposed by less defended mimics on highly defended models.  相似文献   
88.
Braun-Munzinger P  Stachel J 《Nature》2007,448(7151):302-309
High-energy collisions between heavy nuclei have in the past 20 years provided multiple indications of a deconfined phase of matter that exists at phenomenally high temperatures and pressures. This 'quark-gluon plasma' is thought to have permeated the first microseconds of the Universe. Experiments at the Large Hadron Collider should consolidate the evidence for this exotic medium's existence, and allow its properties to be characterized.  相似文献   
89.
The c-Myc oncoprotein promotes proliferation and apoptosis, such that mutations that disable apoptotic programmes often cooperate with MYC during tumorigenesis. Here we report that two common mutant MYC alleles derived from human Burkitt's lymphoma uncouple proliferation from apoptosis and, as a result, are more effective than wild-type MYC at promoting B cell lymphomagenesis in mice. Mutant MYC proteins retain their ability to stimulate proliferation and activate p53, but are defective at promoting apoptosis due to a failure to induce the BH3-only protein Bim (a member of the B cell lymphoma 2 (Bcl2) family) and effectively inhibit Bcl2. Disruption of apoptosis through enforced expression of Bcl2, or loss of either Bim or p53 function, enables wild-type MYC to produce lymphomas as efficiently as mutant MYC. These data show how parallel apoptotic pathways act together to suppress MYC-induced transformation, and how mutant MYC proteins, by selectively disabling a p53-independent pathway, enable tumour cells to evade p53 action during lymphomagenesis.  相似文献   
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