1,721,018 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
The Role of Large-Scale Land-Use Change on the Global Climate - Response and Sensitivity to Amazon Deforestation
Get PDFThis work was embargoed by the author and will not be publicly available until November 2015.Large-scale land-use change, such as Amazon deforestation, can have a significant local effect on the climate and has the potential to impact the global climate system. Previous modeling studies have shown non-local responses due to Amazon deforestation. However, a common flaw in these studies is using prescribed ocean conditions, which can dampen the global response. This study uses a set of fully coupled modeling simulations to determine the responses and sensitivities to Amazon deforestation, both locally and globally. In addition, a set of realistic tropical crop vegetation types are developed for the Community Land Model version 4.5. The local increase in surface temperature and decrease in precipitation from this study are consistent with previous modeling studies. After deforestation, it was determined that stronger regions of land-atmospheric coupling are found in the formerly densely forested regions, while areas that receive irrigation become less coupled. This study highlights large-scale changes to the zonal and meridional circulation that are found to have impacts in remote regions throughout the tropics. Lastly, using a set of partial deforestation simulations, areas of non-linear responses to deforestation are found. A metric to quantify the degree of non-linearity over the spatial domain was developed; Amazon deforestation is found to have a tipping point effect for the climate system with less than half of the impacts within the spatial domain of influence being provided by 50% deforestation
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
An Investigation of a Subseasonal Forecast Model’s Ability to Represent Land-Atmosphere Interactions
Get PDFA reanalysis of atmospheric and land-surface states is investigated to understand the water cycle, energy cycle and the role of the planetary boundary layer (PBL) in land-atmosphere interactions, and is used as validation for model forecast data. Subseasonal to seasonal (S2S) forecasts from an operational forecast model are examined to determine if they can replicate the relationships observed when using the reanalysis data. The ability of the S2S models to properly show relationships that indicate land-atmosphere interactions are crucial for forecasting extreme events, and understanding the conditions that allow for the intensification and persistence of these events. Daily noontime values of temperature, humidity, and surface fluxes were taken from the reanalysis dataset, as well as morning values of soil moisture over the contiguous United States. Potential evaporation and boundary layer properties are calculated and correlation analyses are carried out to determine the significance of these relationships to one another and to state variables. A similar investigation is carried out using daily averaged data from the S2S forecast model. The reanalysis reinforces previous knowledge on the role of soil moisture and the boundary layer in land-atmosphere interaction over the continental US. Correlations (or anticorrelations) among terms involved in land-atmosphere interactions are strong in the summer months (June, July, and August) with gradients from either north to south, or west to east. The western US typically show that soil moisture and evaporation plays a role in the land-atmosphere interactions. The forecast model was inconclusive, with values of surface fluxes over the western and north-central US showing the possibility of issues in the way this model behaves. Overall, further studies need to be carried out on the forecast model to determine better ways to determine these relationships, or improve on the data products from the model
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
Nonlinearity and Regimes in global Soil Moisture-surface Heat Flux Coupling
Get PDFFeedbacks on the atmosphere induced by soil moisture variability are recognized as an essential component of the Earth system. Coupling between SM and surface heat fluxes, especially the latent heat flux (LE), is the foundation of these feedbacks as it exchanges water and energy between the interface of land and atmosphere. Building upon that, this dissertation aims to understand land-atmosphere interactions by exploring the nonlinearity, multivariable dependency, and regime characteristics in the SM:LE coupling at a global scale. I show that LE is significantly affected by both SM and net radiation not only linearly but also nonlinearly and synergistically. Then, I determine active and inactive regimes in SM:LE sensitivity and confirm spatial patterns of SM:LE dependency during active regimes are consistent among observations and climate models. Nevertheless, the spatial patterns of the existence of local coupling regimes reflecting hydroclimate are diverse. I further find that, under global warming, the locally dominant regime may change, and projected SM variability tends to span more regimes. These changes in the dominant regime are decomposed into contributions from moisture processes and energy processes using a novel framework. Results show moisture processes result in a more moisture-limited world while the energy effect is also significant, but its impact is inconsistent among climate models. The global patterns computed in this research not only shed new light on aspects of land-atmosphere interactions but also raise several follow-up topics worthy of further study
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