1,721,554 research outputs found
The subspecific characters and distribution of the New World Skimmers - Rynchops nigra The subspecific characters and distribution of the New World Skimmers - Rynchops nigra
Full text linkThe distribution of the forms of the New World rayador, or skimmer, Rynchops nigra, and the characters that mark the geographic races, have been matters of interest to me for a number of years, an interest heightened by recent discussions in current literature of the identity of the birds found on the Pacific coast of Mexico, and far to the south in Chile. Investigation into these matters with the material available in the National Museum not being conclusive, specimens from Mexico and the West Indies southward to Argentina and Chile in other large collections in the United states have been assembled through the courtesy of Dr. Robert Cushman Murphy of the American Museum of Natural History, James l.. Peters of the Museum of Comparative Zoology,W. E. C. Todd of the Carnegie Museum, and Dr. Karl P. Schmidt of the Field Museum of Natural History. I have also to thank Dr. Alden H. Miller for the use of one specimen from Chubut in the Museum of Vertebrate Zoology, and Dean Amadon for certain notes on this group of birds that he had assembled.The distribution of the forms of the New World rayador, or skimmer, Rynchops nigra, and the characters that mark the geographic races, have been matters of interest to me for a number of years, an interest heightened by recent discussions in current literature of the identity of the birds found on the Pacific coast of Mexico, and far to the south in Chile. Investigation into these matters with the material available in the National Museum not being conclusive, specimens from Mexico and the West Indies southward to Argentina and Chile in other large collections in the United states have been assembled through the courtesy of Dr. Robert Cushman Murphy of the American Museum of Natural History, James l.. Peters of the Museum of Comparative Zoology,W. E. C. Todd of the Carnegie Museum, and Dr. Karl P. Schmidt of the Field Museum of Natural History. I have also to thank Dr. Alden H. Miller for the use of one specimen from Chubut in the Museum of Vertebrate Zoology, and Dean Amadon for certain notes on this group of birds that he had assembled.</p
A new species of duck from central colombia
Full text linkFor a number of years there has been persistent report of "black ducks" from the mountain lakes of central Colombia, with the supposition on the part of hunters that these were the well-known species of that name of eastern North America. The senior author made some inquiry into the matter especially following a note published in CALDASIA N,o.9, Jan. 6, 1944, p. 407, where Mr. F. C. Lehmann gave a brief summary of what was known of these birds. His account indicates that dark-colored ducks are of common occurrence in various part of Colombia, especially in the Bogotá Savanna where they are called "pico de oro" or "picodioro". He recorded others near Cali in the Cauca Valley where they are known as "pato amarillo". The matter is of especial interest since the black duck of North America, Anas rubripes, while migratory in the northern part of its range is not known to pass south of the southern United states except for two or three casual records from the West Indies. Shortly before this, on September 17, 1943, Brother Nicéforo Maria of the Instituto de La Salle in Bogotá wrote that he has forwarding to the U. S. National Museum as a gift a small collection of birds taken principally by himself for which he desired identifications. When these arrived in due time there was among them a strange duck somewhat resembling Anas spinicauda, but differing in form and especially in much darker color. There was some supposition that it might be a hybrid, but this seemed hardly probable, so that the question of the "black ducks" reported from this area came immediately to mind.For a number of years there has been persistent report of "black ducks" from the mountain lakes of central Colombia, with the supposition on the part of hunters that these were the well-known species of that name of eastern North America. The senior author made some inquiry into the matter especially following a note published in CALDASIA N,o.9, Jan. 6, 1944, p. 407, where Mr. F. C. Lehmann gave a brief summary of what was known of these birds. His account indicates that dark-colored ducks are of common occurrence in various part of Colombia, especially in the Bogotá Savanna where they are called "pico de oro" or "picodioro". He recorded others near Cali in the Cauca Valley where they are known as "pato amarillo". The matter is of especial interest since the black duck of North America, Anas rubripes, while migratory in the northern part of its range is not known to pass south of the southern United states except for two or three casual records from the West Indies. Shortly before this, on September 17, 1943, Brother Nicéforo Maria of the Instituto de La Salle in Bogotá wrote that he has forwarding to the U. S. National Museum as a gift a small collection of birds taken principally by himself for which he desired identifications. When these arrived in due time there was among them a strange duck somewhat resembling Anas spinicauda, but differing in form and especially in much darker color. There was some supposition that it might be a hybrid, but this seemed hardly probable, so that the question of the "black ducks" reported from this area came immediately to mind
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
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