1,720,960 research outputs found
Uptake and metabolism of four isomers of dinitrotoluene in A. thaliana and their sequestration in feeding aphids: a phytoremediation perspective
Full text linkPlants, being sessile, have wide variety of metabolic pathways to detoxify hazardous compounds therefore ensuring the success of phytoremediation of a wide variety of xenobiotics. One such a compound is dinitrotoluene (DNT) that is available as a mixture of six different isomers. Phytoremediation of DNTs is a cost effective, eco friendly and preferable approach compared to commercially available chemical and physical remediation systems. DNTs are toxic to plants at higher concentrations, however lower concentrations are tolerable. The present study considers the uptake of DNTs in the model plant Arabidopsis thaliana to observe the potential of phytoremediation and considers the metabolites during different phases of detoxification. Further it evaluates the possible propagation of DNT and its metabolites in ecosystem through a model system of plant-aphid interaction.
The first step in the study included establishment of the toxicity of four different available isomers of DNT (2,6-DNT, 2,3-DNT, 3,4-DNT and 2,4-DNT) in A. thaliana. This was achieved by root growth analysis in Phytagel (axenic) and hydroponic media (non axenic), root and shoot ratio in Phytagel and hydroponic media and finally a time course reduction in root length in hydroponic media. The results obtained from the study showed that all isomers of DNT have different toxicities (EC50 for 2,6-DNT, 2,4-DNT, 3,4-DNT and 2,3-DNT was 13.3 mg /L ,0.33 mg /L 0.23 mg /L and 0.13 mg /L of Phytagel media). At lower concentrations these DNTs were tolerable but at higher concentration they induced biomass inhibition.
The uptake and metabolism of different DNT isomers was analysed by GC-MS in A. thaliana cultivated in Phytagel and hydroponic media amended with different concentrations of DNT isomers. The analysis of metabolites showed that the major metabolites of DNT were aminonitrotoluenes (ANTs), the concentration of which varied with the concentration of DNTs in the media (ranged from 0.54-5.2 μg /g dry tissue wt. of A. thaliana for 2A6NT; 20.03 to 280.3 ng /g dry tissue wt. of A. thaliana for 2A4NT and 11.34 to 508.39 ng /g dry tissue wt. of A. thaliana for 4A2NT; 32.8 to 675.22 ng/g dry tissue wt. of A. thaliana for 2A3NT; 41.23 to 564.32 ng /g dry tissue wt. of A. thaliana for 3A4NT).
The qualitative and quantitative analysis of possible DNT based conjugates was carried out by LC-MS/MS analysis for A. thaliana cultivated in liquid MS media (axenic). The quantitative analysis of DNT based conjugates indicated ten significant conjugates with higher concentrations of O- and C- glucosides, mostly with hydroxylaminonitrotoluene. The abundant metabolites of DNT (aminonitrotoluene) have been observed to have lesser conjugation. The concentration of DNT based conjugates were observed to be indirectly related to the concentration of metabolites (increase with the decrease in the concentration of metabolites) and their concentrations were 102 times higher than aminonitrotoluenes. The concentration of conjugates varied with the type of isomer in the media.
The effect of DNT treatment to herbivore feeders was evaluated through analysis of survival, fecundity and growth of Brevicoryne brassicae (specialist) and Myzus persicae (generalist) aphids on DNT treated A. thaliana at different concentrations. The DNT based metabolites were evaluated in the feeding aphid species to observe the possible propagation. Finally, the aphids were observed to tolerate lower concentrations of DNT treatments and their survival, fecundity and growth was highly compromised with high concentrations of DNT in the medium with B. brassicae showed higher sensitivity than M. persicae (in M. persicae LC50 for 2,6-DNT, 2,4-DNT, 3,4-DNT and 2,3-DNT was 13.9 mg /L , 0.34 mg /L , 0.138 mg /L and 0.14 mg /L of Phytagel media and in B. brassicae LC50 for 2,6-DNT , 2,4-DNT, 3,4-DNT and 2,3-DNT was 11.48 mg /L , 0.24 mg /L , 0.1 mg /L and 0.08 mg /L of Phytagel media). Both aminonitrotoluenes and glucosyl conjugates were present in both aphid species and their concentrations were directly related with the concentration of metabolites in the plants on which they were reared. GC-MS analysis showed that B. brassicae managed to accumulate more metabolites than M. persicae. LC-MS analysis showed that the type of conjugates varied with the type of isomer. Therefore this study shows that if Phytoremediation of DNTs is considered then plants convert the toxic DNTs to their polar (less toxic) reduced metabolites and glucosides which could potentially be transported to the feeding aphids.Open acces
Comparative Genomic Hybridization (CGH) in Genotoxicology: From the Basics to Modern Approaches.
No full textOver the past two decades, comparative genomic hybridization (CGH) and array CGH have become essential tools in clinical diagnostics, oncology, and toxicological risk assessment. Initially developed to identify chromosomal imbalances like copy number variations (CNVs) in tumor cells, these technologies have expanded into genotoxicology and toxicogenomics, exploring gene responses to toxic agents and their molecular mechanisms. As of 2024, new developments include integrating array CGH with next-generation sequencing (NGS), machine learning, and CRISPR-Cas9 genome editing, greatly improving precision. High-density CGH arrays now offer single-cell resolution, enabling the detection of cellular heterogeneity in toxic responses, while long-read sequencing facilitates the identification of complex genomic rearrangements. Recent innovations include combining CGH and toxicogenomics with organ-on-chip models for real-time, tissue-specific toxicological assessment. This has significantly improved the relevance of toxicological data for human health. However, while these advances are promising, array CGH remains costly and requires substantial data processing, driving the need for advanced bioinformatics tools. AI-driven predictive toxicology models are also gaining traction, correlating toxicogenomic profiles with clinical outcomes. Despite these advancements, the field still faces challenges, such as evolving regulatory guidelines and complex data interpretation, which hinder broader adoption and the full realization of CGH's potential in toxicology and risk assessment. [Abstract copyright: © 2026. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.
Isolation and Biochemical Characterization of Chromium Reducing Bacteria from Hudiara Drain Sludge
No full textAbstract In the past few decades, the environmental pollution of toxic heavy metals is the major issue throughout the world since industrial evolution
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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