共查询到20条相似文献,搜索用时 15 毫秒
1.
First British Mesozoic Spider, From Cretaceous Amber Of The Isle Of Wight, Southern England 总被引:1,自引:0,他引:1
Paul A. Selden 《Palaeontology》2002,45(5):973-983
Cretamygale chasei , a new genus and species of spider, is described from a single specimen preserved in amber of early Barremian age from the Isle of Wight. This is the oldest (and second Cretaceous) amber spider to be described, and the first record of a Mesozoic spider from Britain. It belongs to the group Bipectina of the infraorder Mygalomorphae, and is tentatively referred to the family Nemesiidae. It is the oldest bipectinate, extending the record by around 90 myr, the only known fossil nemesiid, and the second oldest fossil mygalomorph. 相似文献
2.
Anubhav P. S. Narula 《化学与生物多样性》2014,11(10):1629-1638
There is a constant need for developing new fragrance ingredients in the flavor and fragrance industry, as it allows perfumers to create unique and differentiating perfumes for fine as well as functional products. Among all the categories of notes used in perfume creation, amber notes are indispensible and ubiquitous in their presence in all perfumes. Not only amber notes impart high performance and substantivity to fragrances, but they are paramount in the development of classic and legendary fragrances. This article is based on the plenary lecture delivered at the flavor & fragrance 2013 conference of the German Chemical Society in Leipzig, Germany. The strategy, rationale, and the various synthetic approaches that led to the discovery of two new very powerful, woody, amber materials, Amber Xtreme® ( 1 ) and Trisamber® ( 2 ), are delineated. 相似文献
3.
F. W. Stahl 《Genetics》1995,141(2):439-442
4.
《Revista iberoamericana de micología》2021,38(3):125-131
BackgroundThe fungi present in the decaying remains enable a better understanding of the processes of decomposition after death. There are not many studies about fungi on decaying bodies and it is not known which fungal sampling methods are effective.AimsThe main objective of this study was to find the best method for sampling fungi in carcasses, prove the effectiveness of this method and identify the fungal colonies in animal carcasses from experimental burials.MethodsSamples from 13 carcasses of Sus scrofa domestica, from the experimental project Taphos-m, were taken with different materials: spatula, sterile swabs and RODAC contact plates.ResultsRODAC contact plates with the RBA culture medium showed higher proliferation of fungal colonies. Thirty genera of fungi were isolated from different substrates (bone, tissue, lime). Most of the fungi genera or groups identified have been described before in the literature, but the substrates they came from were different in some cases.ConclusionsSampling with RODAC contact plates was found to be the most effective method, as it provides a nutritional culture medium that may allow growth since the moment of sampling. Fungi colonies grew better in RBA culture medium because bacterial growth is inhibited. Most of the observed fungi are related to the environment but some others have been found related to decomposing bodies for the first time. 相似文献
5.
Paleontological Journal - Two new genera and species of gall midges are described from Lower-Middle Miocene amber, based on males, which have binodose flagellomeres possessing long looplike... 相似文献
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7.
Genetic properties of amber uvrA and uvrB mutants of Escherichia coli K-12 are described. The isolation of three amber uvrA and two amber uvrB mutants indicates that the products of these genes are proteins. 相似文献
8.
Hayova V. P. Tykhonenko Yu. Ya. Sukhomlyn M. M. Martynova K. V. Vasilenko D. V. 《Paleontological Journal》2019,53(10):1104-1110
Paleontological Journal - The first record of fruit bodies of a microscopic fungus on the leaf of an unidentified dicotyledonous plant in amber is reported. The fungus is represented by numerous... 相似文献
9.
《Current biology : CB》2019,29(14):2396-2401.e2
10.
Paleontological Journal - So far 107 families of chelicerates are known from the Rovno amber, which is comparable with those known from the Baltic amber (144 families) and three times more than in... 相似文献
11.
T. P. Scoffin 《Coral reefs (Online)》1992,11(2):57-77
This review summarises the major factors that affect the post-mortem history of skeletons in a coral reef environment. Skeletal material is traced from life, through death, breakdown, transport, burial and diagenesis to its final fossil form. The fact that most reef sediments are of skeletal composition poses problems of concentration or dilution of individual grain types in taphonomic analysis of reefs. Rates of supply of grains vary, not only with organism abundance and skeletal growth rates, but also with rates of physical and biological breakdown to transportable sediment. Physical and organic processes affect sedimentary structures and textures by mixing or segregating skeletal grains, though biogenic processes normally dominate in the protected setting of reef lagoons. The soft and hard substrates associated with reefs present different media for calcium carbonate accumulation and post-depositional disturbance, for example, loose sediments suffer bioturbation and rocks surfaces suffer bioerosion. The wide range of durability of skeletons and their susceptibility to diagenesis contribute further to the complexities of the preservation of coral reefs. 相似文献
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13.
Isolation and Genetic Analysis of a Strain of Escherichia coli K-12 with an Amber recA Mutation 总被引:11,自引:5,他引:6 下载免费PDF全文
David W. Mount 《Journal of bacteriology》1971,107(1):388-389
The isolation, properties, and genetic analysis of a strain of Escherichia coli K-12 with an amber recA mutation are described. The experiments demonstrate that the recA product is a protein that is probably not essential for growth. 相似文献
14.
SHANNON LEE DAWDY 《American anthropologist》2006,108(4):719-730
Using observations from recent participation in post-Katrina recovery efforts in New Orleans, I make the case in this article that taphonomic processes such as trash removal, deposition, earthmoving, and demolition are a primary medium through which individuals and communities reconstitute themselves following a disaster. Taphonomy, or the formation of the archaeological record, does not simply reflect social processes, it is a social process. The taphonomic processes currently underway through the clean-up and rebuilding efforts in New Orleans dramatically illustrate this point. I recommend that both ethnographers and archaeologists undertake a fine-grained ethnoarchaeology of disaster. I engage with the literature of disaster to illustrate the potentials I see for this type of study, particularly as it pertains to the culture–nature nexus, perceptions of vulnerability, and the revelatory power of disasters. 相似文献
15.
Amber mutants and chain termination in vitro 总被引:17,自引:0,他引:17
16.
R A Warren 《Journal of bacteriology》1979,137(2):1053-1055
Almost 50% of the clones of Pseudomonas acidovorans(pLM2) selected for resistance to tetracycline supported the growth of an amber mutant of bacteriophage PRD1. 相似文献
17.
Nonsense suppressors were obtained in a haploid yeast strain containing eight nutritional mutations, that are assumed to be amber or ochre, and the cyc1-179 amber mutation that has a UAG codon corresponding to position 9 in iso-1-cytochrome c. Previous studies established that the biosynthesis and function of iso-1-cytochrome c is compatible with replacements at position 9 of amino acids having widely different structures (Stewart and Sherman 1972). UV-induced revertants, selected on media requiring the reversion of one or two of the amber nutritional markers, were presumed to contain a suppressor if there was the unselected reversion of at least one other marker. The 1088 suppressors that were isolated could be divided into 78 phenotypic classes. Only 43 suppressors of three classes caused the production of more than 50% of the normal amount of iso-1-cytochrome c in the cyc1-179 strain. Genetic analyses indicated that all of these highly efficient amber suppressors are allelic to one or another of the eight suppressors which cause the insertion of tyrosine at ochre (UAA) codons (Gilmore, Stewart and Sherman 1971). Furthermore, only tyrosine has been identified at position 9 in iso-1-cytochrome c in cyc1-179 strains suppressed with these efficient amber suppressors. 相似文献
18.
As an approach to inducible suppression of nonsense mutations in mammalian cells, we described recently an amber suppression system in mammalian cells dependent on coexpression of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) along with the E. coli glutamine-inserting amber suppressor tRNA. Here, we report on tetracycline-regulated expression of the E. coli GlnRS gene and, thereby, tetracycline-regulated suppression of amber codons in mammalian HeLa and COS-1 cells. The E. coli GlnRS coding sequence attached to a minimal mammalian cell promoter was placed downstream of seven tandem tetracycline operator sequences. Cotransfection of HeLa cell lines expressing a tetracycline transactivator protein, carrying a tetracycline repressor domain linked to part of a herpesvirus VP16 activation domain, with the E. coli GlnRS gene and the E. coli glutamine-inserting amber suppressor tRNA gene resulted in suppression of the amber codon in a reporter chloramphenicol acetyltransferase gene. The tetracycline transactivator-mediated expression of E. coli GlnRS was essentially completely blocked in HeLa or COS-1 cells grown in the presence of tetracycline. Concomitantly, both aminoacylation of the suppressor tRNA and suppression of the amber codon were reduced significantly in the presence of tetracycline. 相似文献
19.
C.L. Greenblatt A. Davis B.G. Clement C.L. Kitts T. Cox R.J. Cano 《Microbial ecology》1999,38(1):58-68
Abstract
Claims that organisms can be cultured from amber, if substantiated, would be significant contributions to our understanding
of the evolution, tenacity, and potential spread of life. Three reports on the isolation of organisms from amber have been
published. Cano and Borucki recently reported the isolation of Bacillus sphaericus and Lambert et al. have described a new species designated Staphylococcus succinus from 25–40 million year old Dominican amber. These characterized organisms were phylogenetically distant from extant relatives
and the Staphylococcus sp. sufficiently far removed from other extant staphylococci to be considered a new species. Here we report the culture of
bacteria from Dominican and previously untested 120 million year old Israeli (Lebanese lode) amber. Twenty-seven isolates
from the amber matrix have been characterized by fatty-acid profiles (FAME) and/or 16S rRNA sequencing. We also performed
a terminal restriction fragment pattern (TRF) analysis of the original amber before prolonged culture by consensus primer
amplification of the 16S rRNA followed by restriction enzyme digestion of the amplicons. Sample TRFs were consistent with
a sparse bacterial assemblage and included at least five of the isolated organisms. Finally, we microscopically mapped the
internal topography of an amber slice.
Received: 14 December 1998; Accepted: 16 March 1999 相似文献
20.
Strains of the yeast Saccharomyces cerevisiae that contain highly efficient amber (UAG) suppressors grow poorly on nutrient medium, while normal or nearly normal growth rates are observed when these strains lose the supressors or when the suppressors are mutated to lower efficiencies. The different growth rates account for the accumulation of mutants with lowered efficiencies in cultures of strains with highly efficient amber suppressors. Genetic analyses indicate that one of the mutations with a lowered efficiency of suppression is caused by an intragenic mutation of the amber supressor. The inhibition of growth caused by excessive suppression is expected to be exacerbated when appropriate suppressors are combined together in haploid cells if two suppressors act with a greater efficiency than a single suppressor. Such retardation of growth is observed with combinations of two UAA (ochre) suppressors (Gilmore 1967) and with combinations of two UAG suppressors when the efficiencies of each of the suppressors are within a critical range. In contrast, combinations of a UAA suppressor and a UAG suppressor do not affect growth rate. Apparently while either excessive UAA or excessive UAG suppression is deleterious to yeast, a moderate level of simultaneous UAA and UAG suppression is not. 相似文献