1,720,965 research outputs found
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
Kiwifruit plant physiological behavior to different levels of soil water depletion under semi-arid environmental conditions
Full text linkKiwifruit crop is known to be extremely sensitive to unbalanced soil water content, both excess and deficit, and irrigation is therefore a key factor to be properly managed. A field experiment was conducted in a commercial kiwifruit orchard (Actinidia chinensis var. chinensis ‘Zesy 002’) located in Metaponto (southern Italy) to evaluate the variation of vine water status, leaf transpiration and stomatal conductance under different water deficit levels, by increasing depletion of soil water content in the top soil layers (0-35 cm). Reduced soil water availability was achieved gradually, by imposing an irrigation treatment of water restriction (7 0 % of full crop requirements, ETc) for a limited period of the growing season (15 days), which was monitored by multi-profile soil moisture probes. Stem water potential (Ψ), leaf transpiration (E) and stomatal conductance (gsw) were evaluated during the water stress phase and the subsequent recovery phase (7 days) and compared to the control, in which irrigation supply was aimed at ensuring the soil water content in the volume of soil affected by irrigation remained between the field capacity (FC) and the lower readily available water (RAW) level. Leaf transpiration and gsw decreased during the water stress phase, reaching minimum values at midday approximately 60 and 7 0 % lower compared to control. Stem water potential became more negative due to the reduction in the soil water content, showing midday values of -14 bars at the end of the water stress phase. The prompt decline in E in response to Ψ lowering, occurring in the first days after the change in irrigation volumes, confirms a high sensitivity of kiwifruit vines to water deficit. During the recovery phase, a quick re-establishment of Ψ and a slow restoration of leaf activity and functionality were observed, making these parameters important indicators of the vine physiological status
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
Adoption of nature-based solutions and orchard sustainable management to face kiwifruit vine decline syndrome (KVDS)
No full textItaly, the third largest producers of kiwifruit in the world, lost 10% of its production in recent years because of the spread of the kiwifruit vine decline syndrome (KVDS) (Bardi, 2020). Although the etiology of KVDS is still not clear, it is often associated with water excess and stagnation. We hypothesize that soil compaction and hypoxia could have a priming effect in the emergence of KVDS. To investigate the causal factors and potential solutions to counter KVDS, a multi-disciplinary experimental trial was undertaken in a kiwifruit orchard (Actinidia chinensis var. chinensis ‘Zesy002’) affected by KVDS in Latina (Italy). Soils from two areas were sampled: a) vines showing severe symptoms of KVDS, and b) healthy vines as control (CTRL). Soils showed different levels of compaction, clay/silt content and water content, with higher values in KVDS field, compared to CTRL. The topsoil (0-30 cm) redox potential was significantly lower in KVDS field than in the CTRL (256 vs 327 mV), so indicating low soil oxygen content. Higher soil CO2 and CH4, two greenhouse gases that also are indicators of hypoxic conditions, were found in KVDS field (Sofo et al., 2022). The analysis of topsoil (0-30 cm) thin sections showed KVDS soils had fewer macropores than CTRL (8.5 vs 11.5%, v/v). Macroscopically, the roots affected by KVDS were rotting, showing a loss of rhizodermis and cortical parenchyma. Microscope analysis revealed damage to the root system, with tissue breakdown and decomposition (D'Ippolito et al., 2022). Genomic analysis identified some abundant fungal species in KVDS roots (Ilyonectria vredenhoekensis, Fusarium oxysporum and Paraphaeosphaeria michotii), but further investigation is required to determine the eventual role of these fungi in KVDS emergence. A metagenomic/metatranscriptomic analysis of rhizosphere-associated microorganisms was carried out for detecting a) eventual beneficial microorganisms and biocontrol microbial agents for KVDS control isolated from healthy plants, and b) the hypothetical role of pathogenic microorganisms detected in KVDS plants, able to compromise roots functionality. Nature-based solutions were applied, such as planting decompacting crops (e.g., Rafanus spp.) for increasing water permeability and agroecosystem diversification, the application of compost and bio-fertilizers containing plant-growth-promoting microorganisms and mycorrhiza (Saccharomyces cerevisiae, Bacillus megaterium, Bacillus pumilus, Pseudomonas striata, Azospirillum brasilense, Candida tropicalis, Glomus intraradices, and Trichoderma harzianum), the amelioration of water drainage into the soil, and root pruning for improving root regeneration. Implementing novel management strategies can improve kiwifruit growth and vine productivity, also reducing KVDS symptoms in impacted vineyards, contributing to the socio-economic sustainability of farms, and increasing the ecosystem services, according to a sustainable, modern and multifactorial concept of agriculture
Fate of selected contaminants of emerging concern (CECs) in an olive tree soil-plant system irrigated with treated municipal wastewater
No full textThe global emergency of ever-increasing demand for water and the scarcity of this resource bring attention back to the potential use of wastewater. Unfortunately, water reuse presents some risks for human and ecosystem health related to the presence of waterborne contaminants. In this study, preliminary data on contaminants of emerging concern (CECs) dynamics of uptake, distribution and accumulation by olive trees (Olea europaea L.) within a plant-soil system were reported. The trial was conducted on olives grown in pots and irrigated with freshwater (control) and treated municipal wastewater. The treated municipal wastewater used for irrigation was spiked with four CECs (Carbamazepine, Fluconazole, Clarithromycin and Metoprolol) at a concentration of approximately 200 μg L-1 (1×). The fate of these CECs in this soil-plant system was then investigated. The irrigation volume applied per plant in one season was approximately 150 L, adding approximately 30 mg of each compound per plant. Translocation and accumulation of CECs in plants can be explained by their physico-chemical properties, mainly their hydrophobicity/hydrophilicity, chemical structure and charge. QuEChERS method was used to extract CECs from soil and plants and samples were analysed using high resolution mass spectrometry coupled with liquid chromatography (LC-HRMS/MS). The data obtained from the trial showed that two of the four CECs evaluated, Carbamazepine and Fluconazole accumulated in soil (approximately 80 and 86%) and plant (approximately 5 and 6%), respectively, with lower degradation rates (15 and 7%). The other two CECs (Metoprolol and Clarithromycin) accumulated only in soil and plant below ground parts, with degradation of the applied compound exceeding 90%. These preliminary results show different accumulation pathways for each compound. Further research is needed to better investigate the fate of CECs from wastewater used for irrigation in soil-plant ecosystems aiming to ensure food safety through the definition of appropriate irrigation strategies
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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