1,720,968 research outputs found
Molecular Advances in Abiotic Stress Signaling in Plants
No full textPlant reactions to abiotic stresses are extraordinarily complex. They take place at various levels of plant organization, starting from changes in biochemical processes, such as respiration, photosynthesis, and transpiration, and ending during morphological and anatomical changes in plant organs. However, these above-mentioned changes are preceded by the activation of efficient molecular signaling machinery, which ensures that plants tune in to external abiotic stimuli
Biochemical mechanisms of neurotoxicity caused by cadmium
No full textCadmium (Cd), which belongs to the heavy metals, is one of the major polluting component of human and animal environment. Exposure to cadmium can lead to absorption of the compounds to the organism and consequently, the toxic effects in the nervous system. The paper presents various views on the biochemical mechanisms of neurotoxicity caused by cadmium. This paper describes the disturbances in the cellular antioxidant system, generation of reactive oxygen and nitrogen species, changes in energy production in the metabolic pathways, changes in the metabolism of biogenic amines, neurotransmitter amino acids and calcium ions and inhibition of enzymatic proteins.Mateusz Labudd
Lipid Peroxidation as a Biochemical Marker for Oxidative Stress During Drought. An Effective Tool for Plant Breeding
Full text linkOxidative stress can be induced by a wide range of environmental factors, including drought. One of the main cellular components susceptible to damage by reactive oxygen species are lipids (by peroxidation of unsaturated fatty acids in biological membranes). The assay of Thiobarbituric Acid Reactive Substances (TBARS) is a well–established method for monitoring lipid peroxidation. This relatively simple analytical protocol facilitates extensive screening research in plant breeding.Mateusz Labudd
Biochemical changes in the brain of rats with different resistance to hypoxia exposed to cadmium toxicity
Full text linkThe goal of the study was to estimate the effect of cadmium (II) chloride intoxication, on the activity of some metabolic enzymes (alanine transaminase ALT, aspartate transaminase AST, lactate dehydrogenase LDH and succinate dehydrogenase SDH), and the levels of lipid and protein oxidation processes in the brain of male rats with different resistance to hypoxia.Mateusz Labudd
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
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