1,720,963 research outputs found
Integration of metabolomics, transcriptomica and DNA barcoding data to describe the diversity of iridoids within the genus Nepeta (Nepetoidae, fam. Lamiaceae)
No full textAim: The chemical richness of iridoids in the genus Nepeta, the exclusive representative of the subfamily Nepetoidae (Lamiaceae) that produces iridoids, has complex roles in nature, facilitating interactions with insects, phytopathogens, and other co-occurring plants. On the other hand, Nepeta species are used widely by humans as medicines, flavour additives, fragrances, as well as toys for cats, and their bioactivities are usually assigned to nepetalactones. Data on the distribution and diversity of iridoids across the genus Nepeta are quite fragmental and only rarely, the two subgroups, iridoid glycosides (IGs) and iridoid aglycones (IAs), are simultaneously analysed. Our aim was to develop and adopt non-targeted metabolomics methods to comprehensively acquire, analyse and interpret the overall diversity of iridoids in selected phylodiverse Nepeta taxa, and thus facilitate reconstruction of this diversity at the molecular level.
Material and methods: Metabolomics data were acquired adopting UHPLC/Orbitrap MS, UHPLC/QToF MS, and GC/MS. Leaves of phylodiverse/chemodiverse Nepeta taxa were subjected to RNA-Seq. DNA barcoding analysis was performed using chloroplast markers (matK, rbcL, trnL-trnF) and nuclear ribosomal ITS marker.
Main results: Nepeta taxa were robustly grouped into three major chemotypes: (1) producers of both IGs and IAs; (2) taxa exclusively producing IGs; and (3) taxa lacking iridoids. Chemotype A clade was further roughly classified into several sub-chemotypes based on the stereochemistry of the major compound nepetalactone. Phylogenetic relations between the analysed taxa were reconstructed adopting a selected set of DNA barcoding markers. Transcriptomes of leaves of the distinguished Nepeta chemotypes were searched for transcripts of iridoid-related biosynthetic genes to facilitate the assessment of factors responsible for the presence/absence of IAs and IGs in these plants.
Conclusion: Integration of metabolomics, transcriptomics and DNA barcoding data revealed no clear regularities between chemotype affiliation and phylogenetic relatedness in analysed Nepeta taxa and pointed to several key genes in the iridoid’s biosynthetic pathway as significant determinants of the their diversity within the genus.Chankova S, Parvanova P, editors. Program and Abstracts: International Seminar of Ecology - 2023: Cutting Edge Research of Ecology; 2023 Sep 28-29; Sofia, Bulgaria. Farrago; 2023. p. 77
Ecological status of the Danube river (Serbian stretch) based on macroinvertebrate assemblages
No full textAim: This study was carried out to assess the ecological status of the Danube throughout Serbia based on
the macroinvertebrate assemblages.
Materials and Methods: The research was performed in April and September 2011 at 11 sampling sites.
Samples were collected with the Van Veen type of grab. The total number of taxa, Diversity Index,
Saprobic lndex, BMWP and ASPT Scores were used for the ecological status assessnment. All indexes
were calculated using the ASTERICS software package.
Results: A total of 69 taxa were recorded. Chironomidae with 24 identified taxa, followed by Mollusca
(18) and Oligochaeta (16) were found to be the dominant groups. Ledinci was the site with the number highest of taxa both in April (25) and in September (19). The highest diversity was recorded at Ram (2.67 April) and at Ledinci (2.46 September). The values of the saprobic index varied from 2.25 (Tekija. April: Kladovo - September) to 3.21 (Kusjak April: Tekija - September). The BMWP Score varied from
3 at Kusjak (most downstream site) to 37 at Ledinci (the most upstream site) during April, while the
ASPT value ranged from 1.5 at Kusjak to 4.83 at Novi Sad.
Conclusion: The ecological status in the year 2011 varied from good (class I) at most upstream sites to generally poor (class IV) in Iron Gate stretch. The higher diversity and abundance of macroinvertebrates
were recorded in April (high water level) in comparisson to September (low water level).Chankova S, Parvanova P, Danova K, editors. Program/Abstracts: Seminar of Ecology - 2016 with international participation; 2016 Apr 21-22; Sofia, Bulgaria. Sofia: Institute of biodiversity and ecosystem research - BAS; 2016. p. 29
Diversity of freshwater gastropods in the Danube wetland area Dubovački rit, (1082 - 1085 river km).
No full textAim: This study provides data about the freshwater gastropods of the Danube wetland area Dubova
ki
Rit (1082 1085 river km), aiming to contribute to the knowledge of this taxa group, its assemblage
composition and species abundances.
Materials and Methods: The study of freshwater gastropods was performed in the Dubova
ki Rit at the
left bank of the Danube River. Sampling was performed in 2010, 201l and 2014, four times per year
using benthological hand net and a Van Veen type of grab. The yotal number of taxa, species
composition and abundance were calculated using the ASTERICS software package.
Results: During the research a total of 12 species were recorded, all belonging to the Planorbidae family.
The most abundant species were Segmentina nitida (M., 1774)- 16 specimens, Physella acuta (D., 1805)
- 12 specimens, Hippeutis complanatus (, 1758) 11 specimens, Ferrissia fragilis (T., 1863) - 10
specimens and Anisus vortex (L., 1758) - 9 specimens. Other species were represented with less than 5
specimens (Gyraulus albus, G. erista, Bathyomphalus contortus, Planorbarius cormeus, Planorbis
planorbis, Acroloxus lacustris and Lymnaea stagnalis). Two species (P. acuta and F. fragilis) are nonnative
to the Danube River. At the site inavasive macrophyte Paspalum paspaloides (Michx.) forms
underwater meadows.
Conclusion: The majority of the observed species are phytophilowus taxa. Seasonal differences in
macrophyte density and community composition additionally contribute to the habitat complexity. On this
specific the habitat dominated by invasive P. paspaloides two alien species of snails were recorded.Chankova S, Parvanova P, Danova K, editors. Program/Abstracts: Seminar of Ecology - 2016 with international participation; 2016 Apr 21-22; Sofia, Bulgaria. Sofia: Institute of biodiversity and ecosystem research - BAS; 2016. p. 30
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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