1,720,986 research outputs found
Food habits of two leopard species, competition, climate change and upper treeline: A way to the decrease of an endangered species
Full text linkor carnivore species, spatial avoidance is one of the evolutionary solutions to coexist in an area, especially if food habits overlap and body sizes tend to coincide. We reviewed the diets of two large cats of similar sizes, the endangered snow leopard (Panthera uncia, 16 studies) and the near-threatened common leopard (Panthera pardus, 11 studies), in Asia. These cats share ca 10,000 km2 of their mountainous range, although snow leopards tend to occur at a significantly higher altitude than common leopards, the former being a cold-adapted species of open habitats, whereas the latter is an ecologically flexible one, with a preference for woodland. The spectrum of prey of common leopards was 2.5 times greater than that of snow leopards, with wild prey being the staple for both species. Livestock rarely contributed much to the diet. When the breadth of trophic niches was compared, overlap ranged from 0.83 (weight categories) to one (main food categories). As these leopard species have approximately the same size and comparable food habits, one can predict that competition will arise when they live in sympatry. On mountains, climate change has been elevating the upper forest limit, where both leopard species occur. This means a habitat increase for common leopards and a substantial habitat reduction for snow leopards, whose range is going to be squeezed between the forest and the barren rocky altitudes, with medium-to long-term undesirable effects on the conservation of this endangered cat. © 2013 Dipartimento di Biologia, Università di Firenze, Italia
A 28.3 THz Plasmonic Graphene Arrow-bowtie Nanoantenna for Energy Harvesting
No full textIn this paper, the design of a 28.3 aor1 THz graphene arrow bowtie nanoantenna for IR energy harvesting applications astr is presented. A sensitivity analysis of the resonance frequency in terms of geometric parameters acty number of graphene sheets acny doping, and thickness of the substrate is reported. The simulations are carried out using the CST 2020 3D simulator
ASTER-REP, a Database of Asteraceae Sequences for Structural and Functional Studies of Transposable Elements
Full text linkTransposable elements (TEs) are interspersed repetitive DNA sequences that can move independently within the genome through specific transposition mechanisms. In eukaryotes, TEs are divided into two classes: class I TEs (retrotransposons, REs), which use an RNA intermediate for the transposition, and class II TEs (DNA transposons), which move through DNA excision (Wicker et al. 2007). These classes are grouped into orders and lineages, according to sequence homology and to the ability to encode their own transposition machinery or not.
Traditionally, TEs have been poorly studied also because their identification has been challenging; nevertheless, these sequences have tremendous implications for genome stability and function: first, TEs drive structural variation, as their transposition can cause deletions, inversions (i.e., homologous recombination of TEs with an opposite orientation) and duplications (Cordaux and Batzer 2009), making TEs activity strongly associated with dynamics of genome reduction/expansion. Second, TEs may drastically affect the expression of other genes (Lisch 2013, Fambrini et al. 2018), either by disrupting the coding sequence or by altering the gene regulation when transposing into the upstream region with different effects, such as the disruption of regulatory sites, epigenetic silencing of neighboring regions or providing new regulatory elements (Morgante et al. 2007, Slotkin and Martienssen 2007). Finally, TEs can originate novel genes through exaptation mediating neofunctionalization with a selective advantage to the host (Ventimiglia et al. 2022)
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
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