1,720,965 research outputs found
Fig. 1. Aspidoras albater, MZUSP 95905, about 25.0 in Differentiating cave Aspidoras catfish from a karst area of Central Brazil, upper rio Tocantins basin (Siluriformes: Callichthyidae)
No full textFig. 1. Aspidoras albater, MZUSP 95905, about 25.0 mm SL, from Anésio III cave, Goiás, Brazil. Specimen kept in aquarium. Photo Alexandre Lopes Camargo.Published as part of Secutti, Sandro, Reis, Roberto E. & Trajano, Eleonora, 2011, Differentiating cave Aspidoras catfish from a karst area of Central Brazil, upper rio Tocantins basin (Siluriformes: Callichthyidae), pp. 689-695 in Neotropical Ichthyology 9 (4) on page 691, DOI: 10.1590/S1679-62252011005000045, http://zenodo.org/record/542318
Fig. 1 in Scientific Note A cave population of Isbrueckerichthys alipionis (Gosline, 1947) in the Upper Ribeira karst area, southeastern Brazil (Siluriformes: Loricariidae)
No full textFig. 1. Slightly depigmented specimen of Isbrueckerichthys alipionis from the riacho Taqueupa, inside Santana Cave in southern São Paulo, Brazil.Published as part of Trajano, Eleonora, Secutti, Sandro, Pereira, Edson H. L. & Reis, Roberto E., 2008, Scientific Note A cave population of Isbrueckerichthys alipionis (Gosline, 1947) in the Upper Ribeira karst area, southeastern Brazil (Siluriformes: Loricariidae), pp. 679-682 in Neotropical Ichthyology 6 (4) on page 680, DOI: 10.1590/S1679-62252008000400017, http://zenodo.org/record/542018
Fig. 2 in Scientific Note A cave population of Isbrueckerichthys alipionis (Gosline, 1947) in the Upper Ribeira karst area, southeastern Brazil (Siluriformes: Loricariidae)
No full textFig. 2. Plots of factor scores of principal component analysis of Isbrueckerichthys alipionis. Above: head measurements only; Below: all measurements. Dot: epigean population; circle: hypogean population. H = holotype.Published as part of Trajano, Eleonora, Secutti, Sandro, Pereira, Edson H. L. & Reis, Roberto E., 2008, Scientific Note A cave population of Isbrueckerichthys alipionis (Gosline, 1947) in the Upper Ribeira karst area, southeastern Brazil (Siluriformes: Loricariidae), pp. 679-682 in Neotropical Ichthyology 6 (4) on page 680, DOI: 10.1590/S1679-62252008000400017, http://zenodo.org/record/542018
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
Reproductive behavior, development and eye regression in the cave armored catfish, Ancistrus cryptophthalmus Reis, 1987 (Siluriformes: Loricariidae), breed in laboratory
Full text linkThe troglobitic armored catfish, Ancistrus cryptophthalmus (Loricariidae, Ancistrinae) is known from four caves in the São Domingos karst area, upper rio Tocantins basin, Central Brazil. These populations differ in general body shape and degree of reduction of eyes and of pigmentation. The small Passa Três population (around 1,000 individuals) presents the most reduced eyes, which are not externally visible in adults. A small group of Passa Três catfish, one male and three females, reproduced spontaneously thrice in laboratory, at the end of summertime in 2000, 2003 and 2004. Herein we describe the reproductive behavior during the 2003 event, as well as the early development of the 2003 and 2004 offsprings, with focus on body growth and ontogenetic regression of eyes. The parental care by the male, which includes defense of the rock shelter where the egg clutch is laid, cleaning and oxygenation of eggs, is typical of many loricariids. On the other hand, the slow development, including delayed eye degeneration, low body growth rates and high estimated longevity (15 years or more) are characteristic of precocial, or K-selected, life cycles. In the absence of comparable data for close epigean relatives (Ancistrus spp.), it is not possible to establish whether these features are an autapomorphic specialization of the troglobitic A. cryptophthalmus or a plesiomorphic trait already present in the epigean ancestor, possibly favoring the adoption of the life in the food-poor cave environment. We briefly discuss the current hypotheses on eye regression in troglobitic vertebrates.O cascudo troglóbio (exclusivamente subterrâneo), Ancistrus cryptophthalmus (Loricariidae, Ancistrinae) é conhecido de quatro cavernas na área cárstica de São Domingos, bacia do alto rio Tocantins, Goiás. Estas populações diferem quanto ao formato geral do corpo e grau de redução dos olhos e da pigmentação cutânea. A pequena população encontrada na caverna Passa Três (aproximadamente 1.000 indivíduos) é a que apresenta os olhos mais reduzidos, não visíveis externamente nos adultos. Um grupo de um macho e três fêmeas provenientes dessa caverna reproduziu-se espontaneamente três vezes em laboratório, no fim do verão, em 2000, 2003 e 2004. Descrevemos aqui o comportamento reprodutivo observado em 2003, assim como o desenvolvimento das proles de 2003 e 2004, com foco no crescimento corporal e regressão ontogenética dos olhos. O cuidado parental pelo macho, que inclui defesa do abrigo rochoso onde os ovos eram aderidos e limpeza e oxigenação destes, segue o padrão típico de loricariídeos. Por outro lado, o desenvolvimento relativamente lento, incluindo a regressão tardia dos olhos (iniciando aos 12 meses de idade), as baixas taxas de crescimento corporal e a alta longevidade estimada (mais de 15 anos) são característicos de ciclos de vida do tipo "precoce", ou K-selecionados. Na ausência de dados comparáveis para os aparentados epígeos próximos, não é possível estabelecer com exatidão se tais características se tratam de adaptações autapomórficas da espécie cavernícola ou de pré-adaptações (exaptações) dos ancestrais epígeos, as quais poderiam ter favorecido a colonização do meio subterrâneo. Finalmente, apresentamos uma breve discussão sobre as hipóteses correntes acerca da regressão dos olhos em vertebrados troglóbios.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
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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