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31.
Zusammenfassung Die indirekten und direkten Flugmuskelfasern der Wanderheuschrecke enthalten parallel und voneinander getrennt verlaufende Myofibrillen. In den interfibrillären Räumen liegen zahlreiche, säulenförmig aneinandergereihte Mitochondrion, ein dichtes endoplasmatisches Retikulum und Tracheolen. In Höhe der A-I-Band-Grenzen befindet sich ein charakteristisches retikuläres System, dessen Queranordnung als Diade zu bezeichnen ist. Die chromatinreichen Kerne liegen peripher dicht unter dem Sarkolemm.Sowohl bei den indirekten als auch bei den direkten Flugmuskelgruppen kommt es im Verlaufe des Dauerfluges zu Transformationen der Mitochondrien, die sich in einer erheblichen Schwellung und in einer Umwandlung der Cristae zu Tubuli äußern. Diese Umwandlung wird als intramitochondriale Kompensation aufgefaßt, um das Verhältnis von Oberfläche der inneren membranösen Phase zum Volumen der inneren wäßrigen Phase — d. h. die spezifische Oberfläche — möglichst konstant zu halten. Eine Vesikulation der Tubuli könnte der morphologische Ausdruck für eine Dekompensation sein, da dann der Zusammenhang der äußeren wäßrigen Phase verlorengeht.Die Mitochondrien verschiedener Muskeln reagieren nicht synchron auf die Dauerbelastung, sondern ausgesprochen belastungs- und funktionsspezifisch: Zunächst transformieren sich die Mitochondrien der indirekten, dann erst die der direkten Flugmuskelgruppen, und der anfängliche Schwirrflug geht während fortschreitenden Dauerfluges in einen Flatterflug über. Die unterschiedlichen Erschöpfungszeitpunkte der indirekten Flugmuskeln werden durch die jeweils spezifische Funktion und die ontogenetische Entwicklung erklärt.  相似文献   
32.
Bruno M. Cormier 《CMAJ》1966,94(6):276-291
A historical and psychological study of genocide is presented in which special emphasis is given to modern manifestations of this phenomenon. The policy of eradication of the Jews by the Hitler regime is considered as an example of genocide in the twentieth century. The psychopathology of genocide and the complex relationships among aggressors, victims and witnesses are elaborated. Inferences are drawn from past and present patterns of genocide that may provide some leads to the future. It is now possible to envisage an all-consuming genocide unless nations can learn to live together, not necessarily in unity but in diversity.  相似文献   
33.
J Bruno  W D Horrocks  R J Zauhar 《Biochemistry》1992,31(31):7016-7026
The effects of minor differences in the amino acid sequences between a vertebrate (bovine testes) and an invertebrate (octopus) calmodulin on metal ion binding were investigated via laser-induced Eu3+ and Tb3+ luminescence. Amino acid substitutions at residues which are coordinated to the metal ion do not produce any detectable changes in the 7F0----5D0 excitation spectrum of the Eu3+ ion bound to octopus calmodulin relative to bovine testes calmodulin; only minor differences in the excited-state lifetime values in D2O solution are observed. The dissociation constants for Eu3+ (1.0 +/- 0.2 microM) and Tb3+ (5 +/- 1 microM) from the weak lanthanide binding sites (III and IV, numbered from the amino terminus) of octopus calmodulin were measured using luminescence techniques. Both values agree well with those reported previously for bovine testes calmodulin [Mulqueen, P. M., Tingey, J. M., & Horrocks, W. D., Jr. (1985) Biochemistry 24, 6639-6645]. The measured dissociation constant of Eu3+ bound in the tight lanthanide binding sites (I and II) is 6 +/- 2 nM for octopus calmodulin and 12 +/- 2 nM for bovine testes calmodulin. The distances between sites I and II (12.4 +/- 0.5 A) and sites III and IV (11.7 +/- 0.8 A) were determined from F?rster-type energy transfer in D2O solutions of octopus calmodulin containing bound Eu3+ donor and Nd3+ acceptor ions. F?rster theory parameters for nonradiative energy transfer between Tyr138 and Tb3+ ions bound at sites III and IV of octopus calmodulin were comprehensively evaluated, including a dynamics simulation of the orientation factor kappa 2. This theory is found to account quantitatively for the observed energy-transfer efficiency as evaluated from the observed sensitized Tb3+ emission.  相似文献   
34.
The ubiquitous grapevine-associated octopine/cucumopine Ti plasmids of biotype III Agrobacterium tumefaciens strains carry two T regions, TA and TB, with a complex oncogene arrangement. Within the octopine/cucumopine group, two main strain types were identified: large TA strains with a TA region resembling the TL region of the biotype I octopine strain Ach5 and small TA strains with a similar T region organization as the large TA strains but with a large internal TA deletion. Structural and functional studies of the representative large TA strain Tm4 revealed six oncogenes. Each oncogene was inserted in a disarmed vector and tested for biological activity using the corresponding oncogenes of Ach5 as standards. Five Tm4 oncogenes, TA-iaaM, T-ipt, T-6b, TB-iaaH and TB-iaaM, were shown to be active, the IS-interrupted TA-iaaH gene was inactive. To study the role of each gene in the pTiTm4 context, several single and multiple pTiTm4 mutations were constructed. It was shown that whereas TA-iaaM and TB-iaaH are essential for tumour formation on grapevine, T-ipt, T-6b and TB-iaaM are not. The avirulence of the TA-iaaM - mutant was shown to be due to an inhibitory effect of the T-ipt gene, since a TA-iaaM - /T-ipt - double mutant was fully virulent. We conclude that the TA-iaaM gene of large TA strains is specifically required to counteract the tumour growth inhibiting activity of the T-ipt gene. Both TA-iaaM and T-ipt are absent from the small TA strains. A model on the roles and interactions of the different oncogenes in large TA and small TA strains is presented.  相似文献   
35.
In laboratory dual-choice assays females of the cabbage root fly, Delia radicum, prefer for oviposition plants with roots damaged by conspecific larvae to undamaged controls. Cauliflower and kale plants were inoculated with root fly eggs (25 per plant) and the hatching larvae were allowed to feed on the roots for various periods of time (1–17 days). After 4 (cauliflower) or 5 (kale) days of larval feeding the oviposition preference was most pronounced and flies laid between 64% and 68% of their eggs near plants with damaged roots. Later, with increasing damage but fewer surviving, and thus actively feeding, larvae, the magnitude of the preference declined. The preference for plants already damaged by conspecific larvae may contribute to the previously observed aggregated distribution of D. radicum eggs in Brassica crop fields.Further experiments revealed that the sensory cues inducing this oviposition preference originate from the complex consisting of the damaged roots, the surrounding substrate (soil) and associated microbes, rather than from the aerial plant parts. In choice assays using the root-substrate complex of damaged and control plants (aerial parts removed), the observed preference for damaged roots was similar to that found for the entire plant but was more pronounced. The damaged roots alone, compared to control roots, received up to 72% (cauliflower) and 75% (kale) of the eggs. By contrast, surrogate leaves sprayed with methanolic leaf surface extracts from the most preferred plants which had been damaged were not discriminated from surrogate leaved sprayed with extracts of the respective control plants. Analysis of glucosinolate levels in methanolic leaf surface extracts revealed that root damage resulted in enhanced concentrations of indole-glucosinolates on the leaf surface in kale but not in cauliflower. Although indole-glucosinolates are oviposition stimulants for the cabbage root fly, the induced changes were apparently too small to influence oviposition behaviour.  相似文献   
36.
37.
The hemochromatosis gene (HFE) maps to 6p21.3, in close linkage with the HLA Class I genes. Linkage disequilibrium (LD) studies were designed to narrow down the most likely candidate region for HFE, as an alternative to traditional linkage analysis. However, both the HLA-A and D6S105 subregions, which are situated 2–3 cM and approximately 3 Mb apart, have been suggested to contain HFE. The present report extends our previous study based upon the analysis of a large number of HFE and normal chromosomes from 66families of Breton ancestry. In addition to the previously used RFLP markers spanning the 400-kb surrounding HLA-A, we examined three microsatellites: D6S510, HLA-F, and D6S105. Our combined data not only confirm a peak of LD at D6S105, but also reveal a complex pattern of LD over the i82 to D6S105 interval. Within our ethnically well-defined population of Brittany, the association of HFE with D6S105 is as great as that with HLA-A, while the internal markers display a lower LD. Fine haplotype analysis enabled us to identify two categories of haplotypes segregating with HFE. In contrast to the vast majority of normal haplotypes, 50% of HFE haplotypes are completely conserved over the HLA-A to D6S105 interval. These haplotypes could have been conserved through recombination suppression, selective forces and/or other evolutionary factors. This particular haplotypic configuration might account for the apparent inconsistencies between genetic linkage and LD data, and additionally greatly complicates positional cloning of HFE through disequilibrium mapping.The authors contributed equally to this work  相似文献   
38.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination. Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient to determine the key allergenic thresholds in the studied area.  相似文献   
39.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination. Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient to determine the key allergenic thresholds in the studied area.  相似文献   
40.
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