1,720,954 research outputs found
Development of a potential distribution model for the Hyacinth Macaw (Anodorhynchus hyacinthinus)
Full text linkThis study aimed to model the potential distribution of the Hyacinth Macaw (Anodorhynchus hyacinthinus) across its vast range in central and eastern South America, addressing the urgent problem of habitat loss and insufficient protected areas that threaten the species' survival. By employing advanced species distribution models that integrate multi-temporal occurrence records and land use/cover data, it is possible to assess changes in suitable habitat over the past 25 years and identified key environmental predictors influencing macaw distribution. The results revealed that while the overall modelled range of the Hyacinth Macaw expanded by approximately 75,000 km², only 8–10 % of this habitat currently falls within protected areas, and more than 20,500 km² of protected land has been degazetted in recent decades. The most influential factors explaining habitat suitability were the distribution of key palm and tree species, forest cover, and recent changes in land use, particularly the expansion of agriculture and pasture. These findings highlight the dynamic and regionally variable response of the species to land cover change, with expansion in the Amazon, stability in the Pantanal, and fragmentation in the Cerrado. The distinctive feature of this research is the use of multi-temporal modelling, which allowed to capture spatiotemporal patterns and identify priority areas for conservation and restoration, even in data-poor and remote regions. The models developed here can be practically applied to guide conservation planning, inform protected area designation, and support community-based monitoring initiatives across the Hyacinth Macaw’s rang
O que Dinâmica Não Linear pode nos ensinar sobre Comunidades Planctônicas?
No full textToda a nossa ciência moderna se desenvolveu basicamente sobre um paradigma de mundo que pode ser denominado de paradigma linear de acordo com a definição de paradigma de Thomas Kuhn (1962). Dentro deste paradigma os efeitos são sempre proporcionais às causas, de maneira tal que causas de intensidade pequena geram efeitos finais pequenos. A grande maioria das teorias e modelos construídos em toda a biologia foi estruturada sob esta ótica. A partir do surgimento e crescimento do poder computacional nos últimos 50 anos surgiu um novo paradigma, denominado paradigma não linear ou ciência não linear. Dentro desta nova ótica, efeitos não são proporcionais à intensidade das causas, e prevalece na maioria dos casos uma dinâmica de não equilíbrio regendo os fenômenos. O presente artigo tem por foco questões de dinâmica de comunidades planctônicas que ganharam novas formas de entendimento a partir deste paradigma, sem fazer uso de uma matemática mais densa e elaborada na exposição das questões, buscando torná-las assim mais acessíveis em sua essência. Questões como o paradoxo do plâncton de Hutchinson (1961), que pareciam insolúveis dentro de um paradigma de mundo linear, tornam-se melhor tratáveis a partir de métodos não lineares, que apontam também novas formas de manejar e se entender comunidades planctônicas de elevada riqueza e o fenômeno de blooms algais. Em decorrência das questões referidas, aborda-se no presente artigo três “lições” oriundas deste novo paradigma, possivelmente bastante úteis para o entendimento e manejo de comunidades planctônicas.Palavras Chave: Caos; Manejo; Comunidades Planctônicas; Não Linearidade; Blooms Algais.ABSTRACTWhat Nonlinear Dynamics can teach us about plankton communities?All our modern science has developed largely on world paradigm that can be called linear paradigm, according to the definition of Thomas Kuhn (1962). Within this paradigm the effects are always proportional to the causes, in a manner that small intensity causes generate small end effects. The vast majority of theories and models built in biology has been structured under this point of view. From the emergence and growth of computing power in the last fifty years has emerged a new paradigm called nonlinear paradigm or nonlinear science. Within this new perspective, effects are not proportional to the intensity of the causes, and prevails in most cases a non-equilibrium dynamics governing the phenomena. This article focuses on questions about planktonic communities that have gained new ways of understanding from this paradigm, without using a dense and elaborated mathematics for the exposition of the issues, trying to make them more accessible in their essence. Questions such as the plankton paradox of Hutchinson (1961), which seemed insoluble within a linear world paradigm, ones become better treatable from nonlinear methods that also suggest new ways to manage and to understand high species richness planktonic communities and the phenomenon of algal blooms. As a result of the above issues, three experiences arising out this new paradigm will be explored, which can be quite useful for the understanding and management of real planktonic communities.Key Words: Chaos; Management; Planktonic communities; Non Linearity; Algal Blooms
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
