1,720,971 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
Improving weed management and crop productivity in maize systems in Zimbabwe
Full text linkKeywords: Intercropping, narrow planting, precise fertilizer placement, radiation interception, leaf stripping, detasselling, Land Equivalent Ratio, maize, pumpkin, dry beans, reduced herbicide dosagesIn the tropics, weeds cause more crop losses and farmers spend more of their time weeding crops than in any other part of the world. Weeds form a major factor which contributes to the miserable quality of life of smallholder farmers, especially of women and children, in rural areas of sub-SaharanAfrica. The effects of maize-pumpkin and maize-bean intercropping and, narrow row planting and precise basal fertilizer placement in monocrop maize, on crop and weed radiation interception (RI), crop yields, weed emergence, growth and fecundity were investigated in this study. The effects of leaf stripping (removal of the lowest 2-6 leaves) and detasselling maize at anthesis on the radiant environment and crop yields in a maize monocrop and maize-pumpkin and maize-bean intercrops were also studied to determine the impact of these interventions on yield of component crops. The aim of the studies was to generate technologies that could be integrated into the production practices of smallholder farmers to suppress weeds and alleviate the severe weeding burden faced by these farmers while ensuring high crop productivity.Maize-pumpkin and maize-bean intercropping reduced weed biomass by 50-66% when established at a density of 12,300 plants ha-1for pumpkins equivalent to 33% of the maize density (37,000 plants ha-1), and 222,000 plants ha-1for beans. Lower densities of pumpkins than 33% of the maize density failed to reduce weed biomass more than that achieved by sole maize. Sole maize crops were weeded twice or thrice to achieve the same weed biomass as intercrops weeded once showed that intercropping could reduce the weeding requirements of maize by 33 to 67%. Maize grain yield was reduced by 20% in one out of four seasons in the first study on maize-pumpkin intercropping. Maize grain yield was not reduced in three seasons when the maize-pumpkin intercropping treatments were leaf stripped and/or detasselled and the trend of leaf stripping and detasselling alleviating the effects of companion crop competition on maize grain was shown in the maize-bean intercrop experiments as well. Intercrop productivity increased with leaf stripping and detasselling as a result of greater penetration of radiation to the companion crop and their effects of increasing dry matter distributed to the maize cob (indicated by 1000-grain weight, cob weight, and kernel weight cob-1). Leaf stripping maize at anthesis focused on the removal of leaves that were beginning to senesce. If they would remain on the plant they would compete with the cob for assimilates as they senesce further, until necrosis. Detasselling is known to remove apical dominance and to increase radiation penetration to the middle leaves on the maize plant that produce most assimilates destined for the cob. Leaf stripping did not affect the ability of the intercrop to suppress weed growth and seed production. In maize monocrops more weed biomass and weed seeds were produced with leaf stripping and detasselling.Maize grain yield decreased with an increase in maize density from 30,000 plants ha-1to 36,000 and 42,000 plants ha-1and weed growth suppression increased with an increase in maize density in a semi arid location in Zimbabwe. Planting maize using narrow row (60 cm × 45 cm) and (75 cm × 36 cm) spatial arrangements increased radiation interception by maize plants by 16 to 24% and maize grain yields by 15 to 26% compared to wide row (90 cm × 30 cm) spatial arrangement commonly used by smallholder farmers. Weed biomass was reduced by 20 to 80%, dependent on weed species, in narrow row spatial arrangements compared to normal farmer planting patterns. The duration of the weed free period required to attain maximum yield increased from 6 weeks after emergence (WAE) in the 60 cm × 45 cm spatial arrangement to 9 WAE in the wider row spatial arrangements. It is, therefore, risky for smallholder farmers to increase maize density to suppress weeds as this will lead to maize grain yield reductions. The use of narrow rows proved to be a better option.Precise fertilizer placement (banding and spot placement) resulted in higher rates of early growth and by 4 WAE these treatments intercepted 20% more of the incoming radiation than a broadcast placement method. Weed emergence, growth and seed production was higher in the broadcast placement treatment as a result of weeds intercepting more incoming radiation and greater access to applied fertilizer nutrients. High fertilizer rates of 225 kg ha-1of a compound fertilizer (8% N, 14% K 2 O,7% P 2 O 5 ), reduced maize grain yield by 15% compared to 150 kg ha-1in a season characterized by drought. It was hypothesized that high concentrations of fertilizer around the root zone predisposed the maize plants to more severe effects of drought than lower fertilizer application rates.Reduced dosages of atrazine and nicosulfuron (25% of the Label Recommended Dosages, LRDs) protected maize from weeds as well as the full LRDs of each herbicide.The reduced dosages suppressed weed competition during the critical period for weed control in maize. However, the tolerant weed species Eleusine indica (L.)Gaertn.,Setaria verticillata (L.)Beauv.,Setaria homonyma (Stead.)Chiov.foratrazine and E. indica , Galinsoga parviflora Cav. and Portulaca oleracea L. for nicosulfuron, tended to escape the herbicide effects and survive as dosages were reduced. Reduced dosages of these herbicides have to be combined with hoe weeding or ox-cultivation to prevent the inadvertent selection of these species by the reduced dose strategy. Recalcitrant species recovering from tillage were shown to be more vulnerable to reduced herbicide toxicity in a greenhouse experiment.It was concluded that cultural weed management techniques that enhance radiation capture by the crop were effective in suppressing weed growth and seed production and increasing crop yields and should be incorporated into smallholder farmer's production practices in a systematic manner as part of Integrated Weed Management and cropping system design
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
- …
