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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
Modelling the Impact of Biochar and Fertilizer on Maize Production in Kenya Using the FAO AquaCrop Model
Get PDFAfrika sør for Sahara står overfor en rekke utfordringer knyttet til klimaendringer, som alle påvirker matsikkerheten. Det er et akutt behov for bærekraftige løsninger som kan bidra til å øke matproduksjonen og styrke robustheten i landbrukssystemene. Denne oppgaven undersøker effekten av å bruke biokull i kombinasjon med mineralgjødsel på maisproduksjon i Embu, Kenya, ved bruk av vekstmodellen AquaCrop, utviklet av FNs organisasjon for ernæring og landbruk (FAO). Som en del av BICEPS-prosjektet undersøker studien om denne integrerte strategien for jordforbedring kan øke avlingsnivået og motstandskraften mot klimarelaterte stressfaktorer, innenfor rammen av bevaringsjordbruk (CA). Studien fant at det var næringstilførselen (fra gjødsel) som var hoveddriveren bak økt avling, snarere enn biokullets effekt på jordas vannlagringsevne. To behandlinger ble analysert: én med 3 tonn biokull per hektar og gjødsel (BC3F), og en kontroll uten noen tilførsel. Feltdata ble samlet inn og deretter brukt til å kalibrere simuleringer i AquaCrop for å vurdere avlingsutvikling, vannbalanse i jorda og effekten av endret såtid.
Modellen, etter kalibrering, klarte å gjenskape observert biomasse for begge behandlinger. BC3F- simuleringen viste betydelig høyere biomasse (7,48 t/ha) og kornavling (3,26 t/ha) sammenlignet med kontrollen (2,60 t/ha og 1,15 t/ha), noe som understreker viktigheten av næringstilgang. Disse resultatene samsvarte tett med observert biomasse på henholdsvis 7,27 t/ha for BC3F og 2,37 t/ha for kontrollen. Modellen hadde imidlertid utfordringer med å reprodusere observerte verdier for bladdekke, særlig under næringsstress. Dette skyldes trolig AquaCrops forenklede tilnærming til fertilitetsstress og mulig avvik mellom feltmålt bladdekke og modellens interne definisjon. Statistiske analyser av jordas vannretensjon viste ingen signifikante forskjeller mellom behandlingene, noe som indikerer at biokull ikke hadde noen målbar effekt på jordas vannlagringsevne i dette forsøket. Mangelen på en ren biokull-behandling gjorde det vanskelig å isolere biokullets uavhengige effekt på avling. En hypotetisk AquaCrop-simulering uten gjødsel ble forsøkt for å undersøke dette, men modellen klarte ikke å generere realistiske resultater på grunn av kalibreringsutfordringer og fravær av feltdata til validering. Simuleringer med alternative sådatoer viste at tidligere såing kunne forbedre avling og redusere vannstress under vekstsesongen 2024.
Disse resultatene tyder på at agronomiske tiltak som integrert næringsbruk og tilpasning av såtid kan bidra til bedre maisproduksjon i småskala systemer. Samtidig viste simuleringene begrensninger ved AquaCrop-modellen når det gjelder å fange opp interaksjoner mellom biokull, jord og planter, særlig under næringsmangel. Oppsummert viste studien at biokull alene ikke forbedret jordas vannretensjon, men at kombinasjonen med gjødsel hadde en positiv effekt på avlingene. Funnene understøtter at forbedret næringstilgang er avgjørende for å øke maisproduksjonen, og støtter bruken av integrert jordfruktbarhetsforvaltning som en strategi for klimarobust landbruk. Fremtidig forskning bør inkludere mer detaljert modellering av næringsstoffer, flerårig feltvalidering og scenario-baserte AquaCrop-simuleringer for å undersøke biokullets effekt under ulike innsatsnivå, for å kunne vurdere dets rolle som bærekraftig landbruksstrategi i Afrika sør for Sahara.Sub-Saharan Africa is facing a number of challenges due to climate change, that all affect food security. There is an urgent need for sustainable solutions that can help increase crop production and support resilient agricultural systems. This thesis explores the impact of applying biochar in combination with mineral fertilizer on maize production in Embu, Kenya, using the crop growth model AquaCrop, developed by the United Nation’s FAO. As part of the BICEPS project, the study investigates whether this integrated soil amendment strategy can enhance crop productivity and increase resilience to climate-related stress as a conservation agriculture (CA) practice. The study found that added nutrients (from fertilizer) were the primary driver of yield improvements, rather than biochar’s effect on soil water retention. Two treatments were analyzed: one with 3 tons of biochar per hectare and fertilizer (BC3F), and a control with no inputs. Field data were collected and used to calibrate simulations in AquaCrop to evaluate yield development, soil water balance, and the effects of sowing date variation.
The model, after calibration, reproduced observed biomass values for both treatments. The BC3F simulated significantly higher biomass (7.48 t/ha) and grain yield (3.26 t/ha) compared to the Control (2.60 t/ha and 1.15 t/ha), underlining the importance of nutrient supply. This matched very closely with the observed biomass of 7.27 ton/ha for BC3F and 2.37 for the Control. However, the model had difficulty reproducing observed canopy cover, especially under stressed conditions. This was likely due to AquaCrop’s simplified fertility stress approach and potentially a mis-match between field-measured canopy cover and the internal definition in AquaCrop. Statistical analysis of the soil water retention data showed no significant difference between treatments, indicating that biochar had no measurable effect on water-holding capacity in this experiment. The lack of a biochar-only treatment limited the ability to isolate biochar’s independent effect on yield. A hypothetical AquaCrop simulation without fertilizer inputs was attempted to explore this scenario, but the model could not produce realistic results due to calibration challenges and the absence of observed data for validation. Simulation of alternative sowing dates indicated that earlier planting may improve yield and reduce water stress during the 2024 season’s weather.
These results suggest that agronomic management strategies such as integrated nutrient use and sowing date adjustments could enhance maize performance in smallholder systems. Nonetheless, the simulations also revealed AquaCrop’s limitations in fully capturing biochar-soil-plant interactions, particularly under nutrient stress. In conclusion, while biochar alone did not improve soil water retention, its combination with fertilizer proved effective for yield enhancement. These findings support that boosting nutrient availability is key to increase maize production, supporting the use of integrated soil fertility management in climate-resilient maize production. Future work should include more detailed nutrient modeling, multi-year field validation, and scenario-based AquaCrop simulations to explore biochar’s effects under varying input conditions, in order to better assess its role in sustainable intensification strategies in sub-Saharan Africa
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
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
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
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