1,721,049 research outputs found
The emergence of scale-free fires in Australia
Full text linkBetween 2019 and 2020, during the country's hottest and driest year on
record, Australia experienced a dramatic bushfire season, with catastrophic
ecological and environmental consequences. Several studies highlighted how such
abrupt changes in fire regimes may have been in large part a consequence of
climate change and other anthropogenic transformations. Here, we analyze the
monthly evolution of the burned area in Australia from 2000 to 2020, obtained
via satellite imaging through the MODIS platform. We find that the 2019-2020
peak is associated with signatures typically found near critical points. We
introduce a modeling framework based on forest-fire models to study the
properties of these emergent fire outbreaks, showing that the behavior observed
during the 2019-2020 fire season matches the one of a percolation transition,
where system-size outbreaks appear. Our model also highlights the existence of
an absorbing phase transition that might be eventually crossed, after which the
vegetation cannot recover
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
Genetic variability of earthworm populations in soils with different perturbation levels
Full text linkDensity and genetic variability of both soil macro- and meso-fauna are disturbed by productive practices. This study aimed to analyze the genetic diversity and genetic structure of populations of the earthworm Aporrectodea caliginosa caliginosa (Briones, 1996) in two sites of the Argentine Pampa under different levels of disturbance: i) grassland, ii) livestock-raising plot, iii) agricultural-livestock raising plots and iv) agricultural plot (the most disturbed). The genetic diversity of the earthworm population was determined based on the allele number, polymorphism percentage and Similarity Index. Allele number and polymorphism percentage were lower in populations from one of the soils under agricultural-livestock practices, but differed significantly only from the values of the other agricultural-livestock raising plot and the livestock-raising plot. Population structure was low although significant. This study shows that allele number and polymorphism are very useful metrics to provide historical and functional information of soils. However, the genetic differences here recorded probably depend on multiple historical and recent causes. The stability of environmental conditions along with the degree of disturbance must be considered to understand their impact on population genetic structure.Fil: Rionda, Macarena. Universidad Nacional de General Sarmiento; ArgentinaFil: Diaz Porres, Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable; ArgentinaFil: Momo, Fernando Roberto. Universidad Nacional de General Sarmiento; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable; ArgentinaFil: Fernandez Iriarte, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
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
Fundamentos de Ecología y Ambiente
No full textFil: Malacalza, Leonardo. Universidad Nacional de Luján; Argentina.Fil: Momo, Fernando R. Universidad Nacional de Luján; Argentina.Fil: Coviella, Carlos Eduardo. Universidad Nacional de Luján; Argentina.Este libro fue escrito para quienes comienzan estudios terciarios y también para todos los que estén interesados en iniciarse en el conocimiento de temas de ecología y ambiente.
Los autores son docentes investigadores en la Universidad Nacional de Luján.
Los contenidos del libro son los de la asignatura Ecología General que se puede cursar en esta Universidad y están divididos en dos partes; en la primera se presentan algunas bases de conocimientos biológicos y los fundamentos de la teoría ecológica; en la segunda se describen y analizan grandes temas directamente relacionados con el ambiente en que vivimos. Sobre estos temas muchos investigadores de esta y otras universidades han escrito breves ensayos que pueden encontrarse en una edición electrónica anterior gratuita de este libro y que aquí aparecen citados en el capítulo correspondiente.
Aspiramos a que este texto contribuya no solo a conocer cómo funcionan los ecosistemas, sino que también al leerlo se ejercite, recupere o adquiera la capacidad para observar la naturaleza con espíritu inquisitivo. Quizá logremos que se despierten vocaciones para seguir indagando en alguno de los muchos campos de la ecología y el medio ambiente.
También esperamos que, conociendo el enorme tiempo transcurrido desde el comienzo de la vida en nuestro planeta, y la diversidad y complejidad de los organismos vivientes que la habitan, se incremente nuestra comprensión y aceptación de las diferencias; son estas las que posibilitan y enriquecen la vida en el mundo que conocemos
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
- …
