نتایج جستجو برای: taxonomic units
تعداد نتایج: 197687 فیلتر نتایج به سال:
[This corrects the article DOI: 10.1186/s40168-015-0081-x.].
Molecular fingerprinting techniques offer great promise for analyzing changes in microbial community structure, especially when dealing with large number of samples. However, a serious limitation has been the lack of quantification offered by such techniques since the relative abundances of the identified operational taxonomic units (OTUs) in the original samples are not measured. A quantitativ...
Although copious qualitative information describes the members of the diverse microbial communities on Earth, statistical approaches for quantifying and comparing the numbers and compositions of lineages in communities are lacking. We present a method that addresses the challenge of assigning sequences to operational taxonomic units (OTUs) based on the genetic distances between sequences. We de...
BACKGROUND Tropical mountain forests are hotspots of biodiversity hosting a huge but little known diversity of insects that is endangered by habitat destruction and climate change. Therefore, rapid assessment approaches of insect diversity are urgently needed to complement slower traditional taxonomic approaches. We empirically compare different DNA-based species delimitation approaches for a r...
BACKGROUND The operational taxonomic unit (OTU) is widely used in microbial ecology. Reproducibility in microbial ecology research depends on the reliability of OTU-based 16S ribosomal subunit RNA (rRNA) analyses. RESULTS Here, we report that many hierarchical and greedy clustering methods produce unstable OTUs, with membership that depends on the number of sequences clustered. If OTUs are re...
بخش سیناروییدس از جنس کوزینیا (تیره کاسنی ( مورد بازنگری تاکسونومیکی قرار می گیرد.تاکسون های زیر به عنوان تاکسونهای جدید شرح داده می شوند. cousinia shiraziana, c. denaensis, c. lurestanica, c. pasagadensis, c. sahandica, c. gaharensis, c. silvanica, c. arakensis, c. kurdestanica, c. ardalensis. تاکسون های زیر یکبار دیگر در مقایسه با آخرین مطالعه گروه به عنوان تاکسون های مستقل شناخته می شوند. c...
In a recent paper Warwick & Clarke (1995: Mar Ecol Prog Ser 129:301-305) introduced 2 new measures of community diversity, A and A' These measures dlffer from more conventional d~ver sity indices by incorporating the taxonomic relatedness of species into their calculation. In this paper we compare temporal trends in A and A' with more conventional diversity measures for the demersal fish commun...
The prokaryotic diversity and respiratory activity of microbial mat communities on the Markham Ice Shelf and Ward Hunt Ice Shelf in the Canadian high Arctic were analysed. All heterotrophic isolates and > 95% of bacterial 16S rRNA gene clone library sequences from both ice shelves grouped within the phyla Bacteroidetes, Proteobacteria and Actinobacteria. Clone library analyses showed that the b...
Recent advances in next-generation sequencing (NGS) technologies spur progress in determining the microbial diversity in various ecosystems by highlighting, for example, the rare biosphere. Currently, high-throughput pyrotag sequencing of PCR-amplified SSU rRNA gene regions is mainly used to characterize bacterial and archaeal communities, and rarely to characterize protist communities. In addi...
Due to human impact, there is extensive degradation and loss of marine habitats, which calls for measures that incorporate taxonomic as well as functional and trophic aspects of biodiversity. Since such data is less easily quantifiable in nature, the use of habitats as surrogates or proxies for biodiversity is on the rise in marine conservation and management. However, there is a critical gap i...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید