共查询到20条相似文献,搜索用时 765 毫秒
1.
Tom N. Ligthart Ruud H. Jongbloed Jacqueline E. Tamis 《The International Journal of Life Cycle Assessment》2010,15(8):745-756
Background, aim and scope
The environmental impact of building products made from heavy metals has been a topic of discussion for some years. This was fuelled by results of life cycle assessments (LCAs), where the emission of heavy metals strongly effected the results. An issue was that the characterisation factors of the Centre for Environmental Studies (CML) 2000 life cycle impact assessment (LCIA) methodology put too much emphasis on the impact of metal emissions. We adjusted Zn characterisation factors according to the most recent insights in the ecotoxicity of zinc and applied them in an LCA using zinc gutters and downpipes as an example. 相似文献2.
V.F. Bondici J.R. Lawrence N.H. Khan J.E. Hill E. Yergeau G.M. Wolfaardt J. Warner D.R. Korber 《Journal of applied microbiology》2013,114(6):1671-1686
Aims
To describe the diversity and metabolic potential of microbial communities in uranium mine tailings characterized by high pH, high metal concentration and low permeability.Methods and Results
To assess microbial diversity and their potential to influence the geochemistry of uranium mine tailings using aerobic and anaerobic culture‐based methods, in conjunction with next generation sequencing and clone library sequencing targeting two universal bacterial markers (the 16S rRNA and cpn60 genes). Growth assays revealed that 69% of the 59 distinct culturable isolates evaluated were multiple‐metal resistant, with 15% exhibiting dual‐metal hypertolerance. There was a moderately positive correlation coefficient (R = 0·43, P < 0·05) between multiple‐metal resistance of the isolates and their enzyme expression profile. Of the isolates tested, 17 reduced amorphous iron, 22 reduced molybdate and seven oxidized arsenite. Based on next generation sequencing, tailings depth was shown to influence bacterial community composition, with the difference in the microbial diversity of the upper (0–20 m) and middle (20–40 m) tailings zones being highly significant (P < 0·01) from the lower zone (40–60 m) and the difference in diversity of the upper and middle tailings zone being significant (P < 0·05). Phylotypes closely related to well‐known sulfate‐reducing and iron‐reducing bacteria were identified with low abundance, yet relatively high diversity.Conclusions
The presence of a population of metabolically‐diverse, metal‐resistant micro‐organisms within the tailings environment, along with their demonstrated capacity for transforming metal elements, suggests that these organisms have the potential to influence the long‐term geochemistry of the tailings.Significance and Impact of the study
This study is the first investigation of the diversity and functional potential of micro‐organisms present in low permeability, high pH uranium mine tailings. 相似文献3.
Background
Searching for proteins that contain similar substructures is an important task in structural biology. The exact solution of most formulations of this problem, including a recently published method based on tableaux, is too slow for practical use in scanning a large database. 相似文献4.
5.
Background
The recognition of functional binding sites in genomic DNA remains one of the fundamental challenges of genome research. During the last decades, a plethora of different and well-adapted models has been developed, but only little attention has been payed to the development of different and similarly well-adapted learning principles. Only recently it was noticed that discriminative learning principles can be superior over generative ones in diverse bioinformatics applications, too. 相似文献6.
Daigo Yamamoto Masanori Yamada Homa Okugawa Kanji Tanaka 《World journal of surgical oncology》2004,2(1):8
Background
With the increased use of mammography for breast cancer screening, the diagnosis of ductal carcinoma in situ (DCIS) too has increased. This study was carried out to identify clinical and radiological factors that may predict the presence of invasive disease within mammographically detected microcalcifcation. 相似文献7.
8.
Role of microRNAs in plant responses to nutrient stress 总被引:1,自引:0,他引:1
Houqing Zeng Guoping Wang Xiaoyan Hu Huizhong Wang Liqun Du Yiyong Zhu 《Plant and Soil》2014,374(1-2):1005-1021
9.
Background
Influenza A viruses exhibit complex epidemiological patterns in a number of mammalian and avian hosts. Understanding transmission of these viruses necessitates taking into account their evolution, which represents a challenge for developing mathematical models. This is because the phrasing of multi-strain systems in terms of traditional compartmental ODE models either requires simplifying assumptions to be made that overlook important evolutionary processes, or leads to complex dynamical systems that are too cumbersome to analyse. 相似文献10.
Martin Sturm Michael Hackenberg David Langenberger Dmitrij Frishman 《BMC bioinformatics》2010,11(1):292
Background
Virtually all currently available microRNA target site prediction algorithms require the presence of a (conserved) seed match to the 5' end of the microRNA. Recently however, it has been shown that this requirement might be too stringent, leading to a substantial number of missed target sites. 相似文献11.
Dynamics of plant metal uptake and metal changes in whole soil and soil particle fractions during repeated phytoextraction 总被引:2,自引:0,他引:2
Aims
Phytoextration of metal polluted soils using hyperaccumulators is a promising technology but requires long term successive cropping. This study investigated the dynamics of plant metal uptake and changes in soil metals over a long remediation time.Methods
A soil slightly polluted with metals (S1) was mixed with highly polluted soil (S4) to give two intermediate pollution levels (S2, S3). The four resulting soils were repeatedly phyto-extracted using nine successive crops of Cd/Zn-hyperaccumulator Sedum plumbizincicola over a period of 4 years.Results
Shoot Cd concentration decreased with harvest time in all soils but shoot Zn declined in S1 only. Similar shoot Zn concentrations were found in S2, S3 and S4 although these soils differed markedly in metal availability, and their available metals decreased during phytoextraction. A possible explanation is that plant active acquisition ability served to maintain plant metal uptake. Plant uptake resulted in the largest decrease in the acid-soluble metal fraction followed by reducible metals. Oxidisable and residual fractions were less available to plants. The coarse soil particle fractions made the major contribution to metal decline overall than the fine fractions.Conclusion
Sedum plumbizincicola maintained long term metal uptake and the coarse soil particles played the most important role in phytoextraction. 相似文献12.
Birte Vester Lykke H Hansen Lars Bo Lundberg B Ravindra Babu Mads D Sørensen Jesper Wengel Stephen Douthwaite 《BMC molecular biology》2006,7(1):19-9
Background
DNAzymes cleave at predetermined sequences within RNA. A prerequisite for cleavage is that the DNAzyme can gain access to its target, and thus the DNAzyme must be capable of unfolding higher-order structures that are present in the RNA substrate. However, in many cases the RNA target sequence is hidden in a region that is too tightly structured to be accessed under physiological conditions by DNAzymes. 相似文献13.
Background
The alignment of multiple protein sequences is a fundamental step in the analysis of biological data. It has traditionally been applied to analyzing protein families for conserved motifs, phylogeny, structural properties, and to improve sensitivity in homology searching. The availability of complete genome sequences has increased the demands on multiple sequence alignment (MSA) programs. Current MSA methods suffer from being either too inaccurate or too computationally expensive to be applied effectively in large-scale comparative genomics. 相似文献14.
David Bass Thomas A Richards Lena Matthai Victoria Marsh Thomas Cavalier-Smith 《BMC evolutionary biology》2007,7(1):162
Background
It is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. The ubiquitous dispersal hypothesis states that microbes are so numerous and so easily dispersed worldwide that all should be globally distributed and found wherever growing conditions suit them. This has been broadly upheld for protists (microbial eukaryotes) by most morphological and some molecular analyses. However, morphology and most previously used evolutionary markers evolve too slowly to test this important hypothesis adequately. 相似文献15.
Background
Contrary to other areas of sequence analysis, a measure of statistical significance of a putative gene has not been devised to help in discriminating real genes from the masses of random Open Reading Frames (ORFs) in prokaryotic genomes. Therefore, many genomes have too many short ORFs annotated as genes. 相似文献16.
17.
Emanuela Taioli Annie Im Xia Xu Timothy D Veenstra Gretchen Ahrendt Seymour Garte 《Reproductive biology and endocrinology : RB&E》2010,8(1):93
Background
An important aspect of the link between estrogen and breast cancer is whether urinary estrogen levels are representative of the intra-tissue levels of bioavailable estrogens. 相似文献18.
Laurence Loewe 《BMC systems biology》2009,3(1):27-34
Background
Many difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often simple to predict. Current systems biology has accumulated much data on mutations with large effects and can predict the properties of knockout mutants in some systems. However experimental methods are too insensitive to observe small effects. 相似文献19.
20.
Turgut Isitmangil Gulbu Isitmangil Yasemin Budak Recep Aydilek Mehmet Kutlu Celenk 《BMC pulmonary medicine》2001,1(1):4-5