1,720,967 research outputs found
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
Propagation of Two Utah Native Plants: Ceanothus velutinus and Cercocarpus montanus
Get PDFAmong various water conservative approaches, the use of native plants in landscape, such as Ceanothus velutinus (snowbrush ceanothus) and Cercocarpus montanus (alder-leaf mountain mahogany), is attractive. Efficient propagation methods are required to allow these native species to use in water-efficient landscaping. Sexual (seed) and asexual/vegetative (cuttings and micropropagation) propagation methods were evaluated.
Seeds of both C. velutinus and C. montanus were scarified and/or stratified and treated with gibberellic acid (GA3) to break dormancy. The results showed hot water scarification and 2-3 months of stratification effectively broke the dormancy of C. velutinus seeds, and stratification for 2-3 months was needed for C. montanus seeds. Furthermore, GA3 also helped to increase germination of both species.
Terminal cuttings of C. velutinus were collected from May to Sept. 2019 and June to Aug. 2020 from the Tony Grove Lake area, Utah. Terminal and stem cuttings were also collected in Aug. 2019 from the same area. Likewise, different rooting hormones were tested using cuttings collected from greenhouse-grown seedlings. Ceanothus velutinus cuttings collected in July tended to have a better rooting percentage than those collected at other times of the year. Hormodin 2 [3,000 mg·L-1 indole-3-butyric acid (IBA)] tended to be the better rooting hormone. Terminal cuttings were good compared with stem cuttings but were not significantly different in terms of rooting percentage.
Terminal cuttings of C. montanus ‘Coy’ were collected in mid-July and different rooting hormones were tested. Hormodin 2 tended to be the better rooting hormone. A separate experiment was also conducted using terminal and stem cuttings. Stem cuttings tended to be better for C. montanus. In addition, on 11 May, 2020, hardwood stem cuttings were collected and wounding study was performed. Wounding promoted adventitious root formation of C. montanus.
For micropropagation, Murashige and Skoog (MS) and Gamborg’s B-5 (B5) medium supplemented with 1 mg·L-1 benzylaminopurine (BA) were better than other medium for establishment of C. velutinus. In addition, ex vitro rooting study was successful for rooting microshoots of C. velutinus. For C. montanus, MS + 1 mg·L-1 BA tended to be better medium for multiplication stage
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
Evaluating Two Penstemon Species for Salinity Tolerance
Get PDFPenstemons are among the most attractive native flowers of North America with high aesthetic importance in urban landscape. Limited studies have been conducted previously to determine their salt tolerance. In this study, we examined how salinities ranging from the electrical conductivity (EC) of 1.0 to 10.0 dS·m-1 affected the growth and physiology of two penstemons [Penstemon barbatus ‘Blue’ (rock candy series beardtongue) and Penstemon strictus ‘Rocky Mountain’ (Rocky Mountain beardtongue)]. Salinity stress reduced the growth rate and biomass production of penstemon species. Penstemon barbatus had slight foliar salt damage with an averaged visual score of 3.2 (0 = dead, 5 = excellent without foliar salt damage) and P. strictus had minimal foliar salt damage with an averaged visual score of 4.0 when irrigated with treatment solution at an EC of 5.0 dS·m-1. Similarly, when irrigated with treatment solution at an EC of 7.5 dS·m-1, P. barbatus and P. strictus had moderate to severe foliar salt damage with averaged visual score of 1.6 and 2.5, respectively. Penstemons had severe foliar salt damage or were dead when irrigated with treatment solution at an EC of 10.0 dS·m-1. Net photosynthesis (Pn), stomatal conductance (gs) and transpiration (E) rate measured using a CIRAS-3 portable photosynthesis system decreased with increasing salinity levels. Furthermore, sodium (Na+) and chloride (Cl-) contents in the leaves of P. barbatus and P. strictus increased quadratically with the increase in salinity levels of the treatment solution. Therefore, P. barbatus and P. strictus are sensitive to salinity levels at ECs of 7.5 and 10.0 dS·m-1
Morphological and Physio-Biochemical Responses and Gene Expression Analyses of Landscape Plants Under Salinity Stress
Get PDFSoil salinity is a significant global issue that adversely impacts the growth and development of landscape plants. One of the effective strategies to prevent salinity damage to landscape plants is to cultivate species that are tolerant to the prevailing salinity levels. Salinity tolerance varies among plant species and cultivars. Therefore, this research aimed to investigate the salinity tolerance of nine landscape plants [Albizia julibrissin (mimosa tree), Arctostaphylos uva-ursi (kinnikinnick), Cercocarpus ledifolius (curl-leaf mountain mahogany), Cercocarpus montanus ‘Coy’ (alder-leaf mountain mahogany), Penstemon barbatus ‘Novapenblu’ (rock candy blue® penstemon), Penstemon strictus ‘Rocky Mountain’ (rocky mountain beardtongue), Punica granatum ‘Wonderful’ (pomegranate), Shepherdia ×utahensis ‘Torrey’ (hybrid buffaloberry), and Sophora japonica (Japanese pagoda tree)] and determine their responses to salinity stress. These landscape plants were tested for salinity tolerance in four separate greenhouse experiments. The effects of salinity levels ranging from electrical conductivity (EC) of 1.0 to 10.0 dS·m-1 were investigated. During the 8-week experiments, minimal to no foliar salt damage, such as leaf tip burn, leaf burn, or necrosis, was observed on A. julibrissin, P. granatum ‘Wonderful’, S. japonica, and S. ×utahensis ‘Torrey’. Whereas A. uva-ursi and C. montanus ‘Coy’ were dead when irrigated with saline solution at an EC of 10.0 dS·m-1. Two penstemon species had severe foliar salt damage or were dead when irrigated with saline solution at an EC of 10.0 dS·m-1. Elevated salinity reduced the shoot dry weight and photosynthesis of all plants. Furthermore, sodium (Na+) and chloride (Cl-) contents in plant tissues were affected by the elevated salinity levels. Chloride accumulation was greater in leaves than in stems or roots. However, Na+ accumulation was greater in roots compared to that in stems and leaves. Albizia julibrissin, P. granatum ‘Wonderful’, and S. japonica were able to maintain less Na+ content in their leaf tissue across all treatments. In conclusion, landscape plants exhibited different responses to salinity stress, A. julibrissin, S. japonica, S. ×utahensis ‘Torrey’, and P. granatum ‘Wonderful’ were relatively tolerant, while A. uva-ursi, C. montanus ‘Coy’, and two penstemons were relatively sensitive
Responses of Utah Native Plants to Saline Water Irrigation
Get PDFNative plants are of great value in urban landscape as they are drought, disease, and pest tolerant. Use of native plants also helps to reduce air pollution and promote biodiversity. However, limited information exists for salinity stress responses of native plants. Four Utah native plants [Arctostaphylos uva-ursi (Kinnikinnick), Cercocarpus ledifolius (curl-leaf mountain mahogany), Cercocarpus montanus ‘Coy’ (alder-leaf mountain mahogany), and Shepherdia × utahensis ‘Torrey’ (hybrid buffaloberry)] were evaluated for relative salinity tolerance under greenhouse conditions. Plants were irrigated with a nutrient solution at an electrical conductivity (EC) of 1.2 dS·m-1 (control) or saline solutions at ECs of 5.0 or 10.0 dS·m-1 for 8 weeks. At harvest, A. uva-ursi and C. montanus ‘Coy’ had a visual score of 3.7 (0 = dead, 5 = excellent without foliar salt damage) when irrigated with saline solution at an EC of 5.0 dS·m-1 and were dead at an EC of 10.0 dS·m-1. Similarly, C. ledifolius had slight foliar salt damage with an average visual score of 3.4 when irrigated with saline solution at an EC of 10.0 dS·m-1. However, no foliar salt damage was observed on S. × utahensis ‘Torrey’ during the experimental period. In addition, with elevated salinity levels in the irrigation water leaf area and shoot dry weight of plants were decreased. In conclusion, A. uva-ursi and C. montanus ‘Coy’ were more sensitive to salinity levels tested in this study compared to C. ledifolius and S. × utahensis ‘Torrey’
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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