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631.
The multicatalytic proteinase (prosome) is ubiquitous from eukaryotes to archaebacteria 总被引:17,自引:0,他引:17
B Dahlmann F Kopp L Kuehn B Niedel G Pfeifer R Hegerl W Baumeister 《FEBS letters》1989,251(1-2):125-131
From the thermoacidophilic archaebacterium, Thermoplasma acidophilum, a proteolytically active particle has been isolated which is almost identical in size and shape with the multicatalytic proteinase (prosome) from rat. This result indicates that prosomes have been developed early in evolution and that they possibly serve functions common to all living cells. 相似文献
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The halobacterial insertion element ISH28. 总被引:1,自引:1,他引:0
636.
U Pfeifer K Aterman 《Virchows Archiv. B, Cell pathology including molecular pathology》1979,29(4):229-243
A liver biopsy specimen from a case of primary amyloidosis was investigated by electron microscopy. The cytoplasmic periphery of the hepatocytes showed degenerativechanges which are interpreted as indicating shedding of peripheral parts of the cytoplasm. Two main variants of this process could be discerned: 1) Protrusion and sequestration of hernia-like blebs of cytoplasm, and 2) shedding of vesicles derived from degenerated endoplasmic reticulum. In the latter case transient defects of the plasma membrane seem to be relevance. Endoplasmic reticulum and cytoplasmic ground substance appeared to be shed preferentially, whereas mitochondria are retained within the cell. As a consequence the fractional volume of the mitochondria in the cytoplasm of atrophic cells is markedly increased. Shedding of peripheral cytoplasm, therefore, seems to be an effective mechanism enabeling the cell to adapt the mass and the composition of its cytoplasm to an unfavourable environment. 相似文献
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Nico Pfeifer Andreas Leinenbach Christian G Huber Oliver Kohlbacher 《BMC bioinformatics》2007,8(1):468
Background
High-throughput peptide and protein identification technologies have benefited tremendously from strategies based on tandem mass spectrometry (MS/MS) in combination with database searching algorithms. A major problem with existing methods lies within the significant number of false positive and false negative annotations. So far, standard algorithms for protein identification do not use the information gained from separation processes usually involved in peptide analysis, such as retention time information, which are readily available from chromatographic separation of the sample. Identification can thus be improved by comparing measured retention times to predicted retention times. Current prediction models are derived from a set of measured test analytes but they usually require large amounts of training data. 相似文献639.
640.
Rebecca Sargent Nicolas J. Deere Philip J.K. McGowan Nils Bunnefeld Marion Pfeifer 《Mammal Review》2022,52(1):39-51
- Globally, large terrestrial carnivores (Carnivora) have suffered precipitous declines in population and range. Today, they must persist in increasingly isolated natural habitat patches within a human-dominated matrix. Effective conservation aimed at supporting carnivores in such landscapes requires species-specific understanding of habitat requirements.
- We present results from a review of the published literature to assess the current state of knowledge regarding habitat preferences of the African lion Panthera leo, with the aim of identifying common drivers of habitat use across contexts.
- Using the Web of Science, we identified 154 usable articles and extracted information relating to study topic, location, habitats described, land-use type, and any documented habitat preferences.
- Only 31 studies documented evidence of habitat use, and collectively, they suggested that preferences for specific habitat types were varied and context-specific. The importance of prey abundance and proximity to water was highlighted in multiple studies. Anthropogenic factors interfered with expected patterns of habitat use. There was evident bias in study locations: 83% of the habitat-use studies were based in only three countries, and 70% were focussed on protected or managed areas.
- Our synthesis suggests that lions demonstrate behavioural plasticity in habitat use in response to anthropogenic pressures. To understand the limits of this plasticity and to manage Africa’s changing landscapes effectively for roaming lions, future research should be focussed on analysis of habitat use outside protected areas, taking into account gradients of distance to water, prey abundance, and anthropogenic risk.