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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
Bivariate landslide susceptibility analysis in the Lorestan Arc (Zagros Mountains, Iran)
No full textLandslide susceptibility analysis based on the assessment of a quantitative relationship between multiple controlling factors and landslide occurrence is a consolidated approach for land-use planning in risk mitigation. The Zagros Mountain range (Iran) is one of the most spectacular examples of a landscape whose evolution has been controlled by the erosion of rock outcrops and the growth of thrust-fold structures (predisposing factors for gravity-driven deformations). This paper covers a preliminary study on the landslide susceptibility of the Lorestan region of the Zagros Mountains. Use was made of a bivariate Frequency Ratio, computed on a 30 m pixel size Shuttle Radar Topography Mission Digital Elevation Model. In particular, reliance was made on an unpublished inventory of landslides in the Lorestan Arc. Landslide susceptibility was assessed in the “Falls” (323) and “Slides” (297) categories, the numbers of which (unlike those of other categories) were regarded as suitable for robust modelling. A multi-parametric analysis was carried out to determine the susceptibility of each type of landslide to a set of contributing factors. These factors, most of which are commonly used in the literature, can be grouped in two main categories: a) static, including morphological, hydraulic, and geological factors, and b) pseudo-dynamic, including distance from active faults and steepness index (ksn), a morphometric tectonic uplift proxy computed along stream networks. The latter were considered as potentially landslide-triggering factors in the medium-long term, combining both the effects of transient tectonic forces of individual seismic events and morphotectonic effects on the slope-valley system. The statistical significance of these pseudo-dynamic factors was initially demonstrated via a univariate logistic regression with a randomly generated set of “stable” and “unstable” points. Then, models were built, and the importance of each conditioning factor was assessed by calculating the contribution of the factors in determining the mean landslide susceptibility index value in actual landslides, and the percentage
of landslide cases in which the frequency ratio relative to each variable was above 1. With regard to the “Falls” category, the model showed (with a high reliability) that susceptible areas were those with a slope angle greater than 38°, associated with a 5000 m radius relief energy of about 1100-1550 m and a median fault distance of about 10 km. Conversely, the susceptibility model obtained for the “Slides” category showed that highly susceptible areas were those with slope angle values of 18°-35° and featuring outcrops of the most resistant lithotypes, such as limestone and marly limestone, especially close to flatiron landforms. The resulting model accuracy (validated with the prediction rate curve method on a sample dataset not used in the susceptibility analysis), was equal to 0.94 for “Falls” and 0.77 for “Slides”, indicating a good prediction accuracy
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
Fluvial inverse modeling for inferring the timing of Quaternary uplift in the Simbruini range (Central Apennines, Italy)
Get PDFThe timing of Quaternary uplift evolution of the Simbruini range (Central Apennines, Italy) is poorly known due to the lack of reliable chronological constraints of the post-orogenic continental clastic units, deposited after the upper Messinian thrust-top facies, and tectonic events. In this regard, we identified the main geomorphic markers, including several levels of continental units, whose plano-altimetric projection along the river longitudinal profile has been correlated with the main non-lithological knickpoints. Furthermore, we inferred the uplift history of the range by applying the inverse modeling of the river longitudinal profiles. Assuming a block uplift model, the drainage network cutting the Simbruini range recorded 2.4 ± 0.5 Ma of tectonic history, characterized by variable base-level fall rates (corresponding to variable uplift rates)
Morphoevolution of the Seymareh landslide-dam lake system (Zagros Mountains, Iran): Implications for Holocene climate and environmental changes
No full textThe Seymareh landslide is the largest rock slope failure (44 Gm3) ever recorded on the exposed Earth surface. It detached at ∼10 ka from the northeastern flank of the Kabir-Kuh anticline (Zagros Mountains, Iran) creating a natural dam responsible for the formation of a lake system that persisted for ∼3 kyr during the early and mid-Holocene before its emptying phase caused by overflow. The chronology of its demise and connection to the Holocene climate variations have been barely studied. To reconstruct the influence of local vs. regional environmental changes upon the lake history and unravel their contribution on the lake overflowing phase, we analyzed 13 samples extracted from a 30-m-thick lacustrine succession belonging to Seymareh Lake. We performed grain size analysis, carbon and oxygen stable isotopes of carbonate-bearing sediments, and X-ray diffraction analysis of clay minerals, in addition to the geomorphological analysis to reconstruct the lake system morphoevolution. Main results highlight that the lake infilling phase was characterized by a first period (from 9.73 ± 0.13 to 7.37 ± 0.73 ka) with a median sedimentation rate of ~2 cm yr−1 and a second period (from 7.37 ± 0.73 to 6.98 ± 0.39 ka) marked by an increased sedimentation rate up to ~10 cm yr−1. The age of 6.98 ± 0.39 ka is here considered as the termination of lacustrine sedimentation and the beginning of lake emptying and new valley entrenchment. Stable isotope and X-ray diffraction analyses confirm a stable humid interval after the early-mid Holocene arid to humid transition, consistent with other regions of the Middle East. During this transition, rainfall seasonality and its inter-annual irregularity may have prevented the development of a widespread vegetation cover that likely favored the increase of denudation rates on hillslopes and sediment supply along connected channels network. Therefore, the sedimentation rate increased within the downstream lake basin. However, in the late infilling phase from ~7.6–7.32 ka, local high energy hydroclimatic events, characterized by high sand content and low δ18O concentration, were recorded more frequently. This could justify a sudden increase in the tributaries' discharge that culminated at ~7.3 ka because of the complete overflow of Jaidar Lake into Seymareh Lake likely causing the overflowing of the entire Seymareh landslide-dam lake syste
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
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