1,721,633 research outputs found
Revisión de la distribución geográfica del genero Cyrtograpsus en Argentina
Full text linkEl género Cyrtograpsus, constituye un género exclusivamente marino, el cual se encuentra representado por cuatro especies hasta la fecha endémicas para Sudamérica. Estos cangrejos en su mayoría son de tamaño pequeño a mediano con respecto a otros miembros de la misma familia son de vital importancia en los ecosistemas costeros donde habitan. Este trabajo presenta una revisión del género respecto a su distribución geográfica, su representación en Argentina, caracterización de los hábitat, ecología, etc.Fil: Rojas, Fernando Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin
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
Electrónica analógica
No full text1 archivo PDF (394 páginas). En página legal dice: 2a. edición, 2005"El objetivo de estos apuntes es mostrar cómo funcionan los circuitos básicos que
conforman a los Amplificadores Operacionales y a los Amplificadores de Potencia,
es decir, solo cubren una parte de lo que constituye la Electrónica Analógica.
Estos Apuntes se encuentran divididos en nueve capítulos, los cuales se estructuraron
de la siguiente forma:
• Capítulo 1- Se establecen las convenciones y el modelo electrónico del transistor
que se utilizan en el resto de los capítulos.
• Capítulo 2- Presenta un método de análisis de circuitos desarrollado en la
Universidad Autónoma Metropolitana Azcapotzalco desde el año de 1984, el
cual se ha venido enriqueciendo gracias a la contribución de profesores y alumnos
de la Licenciatura en Ingeniería Electrónica.
Esta es la primera publicación de dicho método de análisis y se emplea mucho
en la mayoría de los capítulos.
• Capítulos 3, 4, 5 y 6- Se presentan y analizan los cuatro circuitos básicos de
acoplamiento directo: Par Darlington, Par Cascodo, Reguladores de Corriente
y Par Diferencial.
• Capítulo 7- Muestra el análisis de circuitos electrónicos desde el punto de
vista de su respuesta en frecuencia, presentando dos métodos de análisis: por
circuitos eléctricos a través del análisis de su Función de Transferencia y
mediante el Método de las Constantes de Tiempo.
• Capítulo 8- Se presenta la Teoría de Retroalimentación aplicada a circuitos
electrónicos, mostrando detalladamente las técnicas de análisis empleadas.
• Capítulo 9- Se estudian los amplificadores de potencia, principalmente el
Amplificador en Simetría Complementaria. Se incluye también un Método Simplificado
de diseño de Amplificadores de Potencia en Simetría Complementaria.
• Apéndices- Se incluyen tres apéndices que contienen el desarrollo del
Modelo Hibrido "PI" en base común, un análisis del circuito de acoplamiento
directo "Par Cascodo" y una serie de ejercicios propuestos sobre los nueve
capítulos anteriores." PALABRAS CLAVE: Electrónica. Acoplamiento directo. Retroalimentación. Respuesta en frecuencia. Amplificación de potencia. Par diferencial. Frequency response (Electrical engineering)
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
Testicular histology of Mustelus schmitti springer, 1939 (Elasmobranchii, triakidae)
Full text linkMustelus schmitti presenta unos testiculos de desarrollo diametrico en la que espermatocistos forma redonda muestran una disposición zonal. Cada zona tiene espermatocistos que contienen células germinales en una sola fase de desarrollo. Los especímenes adultos mostraron seis etapas diferentes que van desde espermatogonias a espermatozoides maduros. Las mismas etapas morfológicas se encuentran en los animales jóvenes, mientras que algunas etapas adultas se han encontrado en animales inmaduros entre las espermatogonias primarias o secundarias. Etapas similares en el desarrollo espermático se encontraron las descritas para M. manazo, M. griseus y otros elasmobranquiosThe testicles of Mustelus schimitti from a temperate estuary in the South Western Atlantic have a diametric development in which round-shaped spermatocysts show a zonal arrangement. Each zone had spermatocysts containing germ cells in a single development phase. Adult specimens showed six different stages from spermatogonia to mature sperm. The same morphological stages were found in young animals, while some adult stages have been found in immature animals among the spermatogonia, whether primary or secondary. Spermatic stages were found in similar sequences as described for M. manazo, M. griseus and other elasmobranchs.Fil: Rojas, Fernando Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentin
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
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