1,720,984 research outputs found
Interference of Heavy Metal Toxicity with Auxin Physiology
No full textAuxins are important phytohormones involved in the coordination of plant growth and defence. In this chapter, we summarize auxin functions in plant biology and identify interactions with heavy metal toxicity. Cadmium induces the formation of reactive oxygen species, which in turn activate auxin oxidases. Auxin oxidases lead to an increased degradation of auxin and thereby are likely to decrease the activities of many genes involved in growth processes. Evidence supporting this hypothetic signalling cascade from heavy metals to eventual growth reductions comes from auxin feeding experiments that ameliorate Cd toxicity, positive effects of auxin producing endophytes on Cd tolerance and by monitoring endogenous auxin physiology with auxin reporter lines of Arabidopsis thaliana and Populus × canescens. Available data for essential micronutrients suggest that they interact with auxin physiology in a manner similar to Cd when present in excess
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
Radionuclide Uptake by Plants: Soil-to-Plant Transfer Factors, Kinetics of Absorption, and Internal Radionuclide Distribution of 137Cs and 40K in South American Species
No full textSoil-to-plant transfer factors (F v ) are commonly used as a key link to estimate the transference of radionuclides along the human food chain. The use of F v assumes that the radionuclide concentration in plant is linearly related with the radionuclide concentration in soil. However, for different ecosystems and even considering similar soil type and plant species, a large variability in F v values has been reported, showing that other variables in addition to radionuclide soil concentration have influence on the radionuclide uptake by plants. Another possible source of uncertainty in F v could come from the heterogeneous distribution of the radionuclide in the plant. In this chapter, we analyze two situations: (a) the root uptake of Cs+ and K+ using electrophysiological techniques, for three grass species that grow in seminatural grassland of central Argentina and (b) the incorporation of 137Cs and 40K by tropical plants and their translocation to fruits. In both cases, we have considered components that are incorporated into the human food chain and, consequently, there is a need of adjusting their dosimetric contribution on the population.Fil: Velasco, Ricardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Meigikos Dos Anjos, Roberto. Universidade Federal Fluminense; BrasilFil: Juri Ayub, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentin
Exploring potential of using phytoremediation for co-contaminated soils
No full textContaminated soils often contain mixtures of different organic and inorganic compounds which require a more complex remediation process. This chapter reviews the use of phytoremediation for removal of organic and inorganic contaminants with consideration as to whether phytoremediation technique can be used for the treatment of co-contaminated soils. Literature suggests that plants can be successfully used for remediation of co-contaminated soils however; the interactions between plants and the microbial communities in the contaminated soil could be a major factor.</p
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
Remediation of areas contaminated by caesium: basic mechanisms behind remedial options and experience in application
No full textThere are many areas around the world contaminated with radiocaesium to different extents due to global fallout from nuclear weapons testing, radiation accidents or inadequate waste disposal practices. In recent decades, a wide range of options for remediation of these areas have been developed, tested and implemented to mitigate the potential doses in such areas. A large amount of data on the effectiveness of remediation options has been generated, together with information on ancillary factors such as technical feasibility and side effects. The chapter aims to provide information on available options for remediation of terrestrial and freshwater ecosystems contaminated with radiocaesium. An associated objective is to provide scientific information on the basic mechanisms which impact on effectiveness of the described remedial options
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
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