1,721,170 research outputs found
A Case Study in Desertified Area: Soybean Growth Responses to Soil Structure and Biochar Addition Integrating Ridge Regression Models
Full text linkDesertified land covers one-fourth of the world’s total land area. Meeting the high food demands in areas affected by desertification is a major problem. This case study provided fundamental information to demonstrate the potential for utilizing the desertified land. The soybean trial was established in two sandy clay loam soils (desertified land) and one silty clay loam soil. Two types of biochar were applied as treatments. We aimed to investigate the response of soybean plants to soil structure, soil nutrient condition, and biochar amendment in the two types of soil. In addition, ridge regression was employed to model the plant growth indicators by soil structure, soil nutrients condition, soil water content, and biochar amendment. We conclude that (1) overall soil productivity in sandy clay loam soil is lower than in silty clay loam soil. The sandy clay loam soil may have high efficacy for crop production due to its higher harvest index. (2) Aggregate size 0.5–1 mm, 1–2 mm, and 2–3 mm indicated more important in plant biomass formation in silty clay loam soil. The low aggregate stability of sandy clay loam soil made the field more vulnerable to wind erosion in the semi-arid monsoon climate. (3) Cob biochar and wood biochar increased soybean shoot biomass by 48.7% and 45.0% in silty clay loam soil. (4) The higher N-fixing ability of nodules in sandy clay loam soil indicates an advantage to reduce the use of N-fertilizers in desertified areas. (5) Exponential polynomial regression ameliorated the accuracy of prediction of plant growth indicators in comparison to linear regression
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
Functional impact of Fungus-growing termites on tropical soil functioning and hydraulic properties
No full textL’étude de l'impact des ingénieurs écologiques du sol est nécessaire à la définition de pratiques agricoles durables, en particulier sous les tropiques. Cette thèse pose la question de l’influence des termites champignonnistes sur les dynamiques du sol et de l’eau le long d’un gradient pédoclimatique allant du Sud de l’Inde au Nord du Vietnam. Ce travail de thèse confirme dans un premier temps l’impact positif des termites sur l’infiltration de l’eau dans le sol. Bien que l’importance de cet effet varie selon les conditions pédoclimatiques et selon la biodiversité des autres espèces ingénieures (termites vs. coléoptères et vers de terre), les résultats obtenus nous ont permis de démontrer que la stimulation de l’activité des termites est également possible à condition d’utiliser des substrats organiques spécifiques. Dans une seconde partie, ce travail de thèse a porté sur l’architecture porale et la stabilité des galeries grâce à des reconstructions 3D à partir d’images obtenues par tomographie à rayons X. Les galeries de termites ont été comparées avec celle des scarabées et des vers de terre dépendamment des milieux considérés et leurs conséquences sur les transferts d’eau ont été étudiées. L’application de ces méthodes nous a permis de mieux décrire le réseau poral mais aussi de démontrer l’importance de prendre en compte la dynamique des galeries pour mieux appréhender de la dynamique de l’eau dans les sols.The definition of sustainable agricultural practices calls for the study of the ecological impact of soil ecological engineers, especially in the tropics. This thesis raises the question of the influence of fungus-growing termites on soil and water dynamics along a pedoclimatic gradient from southern India to northern Vietnam. First, this thesis work confirms the positive impact of termites on soil water infiltration. Although the extent of this effect varies according to pedoclimatic conditions and to the biodiversity of soil engineers (termites vs. beetles and earthworms). The results obtained have enabled us to demonstrate that stimulation of termite activity is possible if specific organic substrates are used. In a second chapter, this thesis focused on the architecture and stability of galleries through the use of 3D image analyses obtained from computer assisted tomography. Termite galleries were compared with those of beetles and earthworms and their effects on water transfers were studied. The application of these methods have enabled us to better describe the poral network, as well as to demonstrate the importance of taking into account the dynamic of the galleries for a better understanding water dynamic in soil
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
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