1,720,960 research outputs found
Preferential solute transport under variably saturated conditions in a silty loam soil: Is the shallow water table a driving factor?
No full textA shallow water table might enhance preferential solute movement by modifying both the water flow and solute
dynamics. In this study, we estimated soil hydraulic and solute transport parameters through a tracer experiment
in lysimeters comparing different water table levels. In a set-up of 12 lysimeters, the bottom boundary condition
was set as a water table depth of 120 cm, or 60 cm, or as free drainage. A tracer solution of bromide (250 mg l 1,
40 mm) was added to each lysimeter and soil water was sampled with suction cups at different depths for the
following 174 days. Soil water content and matric potential were monitored using TDR probes and electronic
tensiometers at the same depths. Soil hydraulic and solute transport parameters in different soil layers were
estimated by inverse modeling using HYDRUS 1D. Soil hydraulic parameters were estimated from the Mualemvan
Genuchten equations, while both the advection–dispersion (ADE) and physical non-equilibrium mobileimmobile
water (MIM) models were used to describe the solute transport. Moreover, the soil pore network was
analyzed by means of 3D X-ray microtomography. Results showed different solute dynamics between contrasting
water table managements. With free drainage, solute in the immobile domain was negligible, and its transport
was fully associated with the mobile water flow. In contrast, a shallow water table affected the tracer transport,
by modifying a) the soil pore network, with an increase of the macropores and a reduction of the pore connectivity;
b) the flow field, with an increase of immobile water and a reduction of αMIM, indicating slow exchange
between mobile and immobile regions, in turn promoting preferential pathways. Hence, groundwater pollution
might be worsened by preferential solute transport of agrochemicals occurring with shallow water table
conditions
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
Influence of conservation agriculture and shallow water table on glyphosate transport through the soil profile.
No full textIdentifying NH3 emission mitigation techniques from farm to field using a Bayesian network
Full text linkThis study addresses the challenge of reducing ammonia (NH3) emissions from agriculture by evaluating various mitigation techniques. The research utilized a Bayesian Belief Network (BBN) to integrate quantitative data on NH3 volatilization reduction with qualitative stakeholder perceptions, aiming to identify the best available techniques (BATs) that balance environmental, economic, and socio-cultural factors for farmers in the Veneto region of Italy. The BBN framework established probabilistic dependencies between variables related to livestock, crop type, manure storage, fertilization management, and pedo-climatic conditions. Stakeholder opinions were quantified through a value elicitation process and combined with the BBN to create an integrated Influence Diagram (ID). Results indicated that effective NH3 reduction requires a comprehensive approach across the entire agri-livestock supply chain. Based on the results obtained, no single technique clearly emerged as the primary focus, rather various areas would require improvement across the agri-livestock supply chain. However, if prioritizing techniques were necessary, efforts should concentrate on stable management of infirmary animals (HCInf), overcrowding reduction by decreasing the number of animals on densely populated farms (OC-Animal), and optimization of protein in animal ration (FDProt). These measures should be combined with effective manure application through slurry injection (INJSlu) in the field. Stakeholders showed reluctance towards more expensive or innovative methods, indicating that socio-cultural perceptions and economic feasibility can heavily influence the adoption of new technologies although they proved to be among the most environmentally effective. The primary insight from applying the BBNs was that selecting effective techniques necessitates a multi-perspective approach to foster consensus among stakeholders throughout the agri-livestock supply chain
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
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