1,720,971 research outputs found
¿Quién depreda a los grandes roedores de Colombia?: un análisis mediante redes de interacción y áreas de distribución
No full textTablas, figurasLos roedores (Rodentia) representan el orden más diverso en términos de número de especies entre los mamíferos a nivel mundial. Esta alta riqueza se refleja en adaptaciones a diversos ambientes y cambios en su forma y áreas de distribución diferenciales. Los roedores son, además, componentes importantes en las dinámicas ecológicas. A nivel Neotropical, los roedores incluidos dentro del suborden Hystricomorpha incluyen especies de talla grande agrupadas en seis familias con especies que cuentan con hábitos terrestres,arborícolas, semiacuáticos, y distribuciones contrastantes. Aunque son un grupo particularmente llamativo, aún existen vacíos en temas como la ecología de la mayoría de las especies presentes en Colombia. Por esta razón, el presente trabajo busca explorar las interacciones entre los grandes roedores presentes en Colombia y sus depredadores en las diferentes regiones naturales del país mediante redes de interacción. Además, busca explorar si el tamaño del roedor y su área de distribución se relaciona con el número de depredadores que puede llegar a tener. Para ello, se empleó información disponible en la literatura para dar respuesta a dos hipótesis planteadas a priori: 1. Una especie de roedor con distribución amplia tendrá un mayor número de depredadores. 2. Independiente del tamaño del área de distribución, el número de depredadores es igual para los roedores de gran tamaño y lo que influye en el número de depredadores es el tamaño del roedor. Los resultados muestran que, a nivel nacional, el número de investigaciones sobre grandes roedores como presas es bajo (n = 10 estudios). El mayor número de datos de depredación documentados son para Cuniculus Paca (n= 11 estudios). Los depredadores con mayor número de presas son Puma concolor y Leopardus pardalis (6 especies de roedores histricomorfos). Los resultados de las nueve regresiones lineales realizadas para comparar las relaciones entre las variables “área de distribución/número de depredadores” y “tamaño de roedor/número de depredadores” no mostraron significancia estadística para los nueve modelos realizados, aunque no se tiene un 100 % de confiabilidad de que el rechazo de las hipótesis sea por la insignificancia estadística y no por la carencia de datos. Por último la red de interacción tiene un índice de robustez alto, esto representa una comunidad bien estructurada, que puede resistir a diferentes cambios y presiones, como pérdida de biodiversidad, extinciones o competencia, resaltando la importancia de los roedores histricomorfos y de los depredadores del neotrópico y de ahí la necesidad de realizar más estudios sobre este tema.Rodents (Rodentia) represent the most diverse order in terms of number of species among mammals worldwide. This high richness is reflected in adaptations to diverse environments and changes in their shape and differential ranges. Rodents are also important components of ecological dynamics. At the Neotropical level, rodents within the suborder Hystricomorpha include large-sized species grouped in six families with species with terrestrial, arboreal, or semi-aquatic habits, and contrasting distributions. Although they are a particularly striking group, there are still gaps in topics such as the ecology of most of the species distributed in Colombia. For this reason, the present work seeks to explore the interaction networks between the large rodents present in Colombia and their predators in the different natural regions of the country. In addition, to explore whether the size of the rodent and its distribution area is related to the number of predators it may have. For this purpose, interaction networks between large rodent species and their predators documented in the literature were generated. It is expected to answer two a priori hypotheses: 1. A rodent species with a wide distribution will have a greater number of predators. 2. Regardless of the distribution area size, the number of predators is the same for large rodents and the number of predators is influenced by the size of the rodent. The results show that, nationally, the number of investigations of large rodents as prey is low (n = 10 studies). The highest number of documented predation is for Cuniculus paca (n= 11 studies). The predators with the highest number of prey are Puma concolor and Leopardus pardalis (6 species of hystricomorph rodents). The results of the nine linear regressions carried out to compare the relationships between the variables “distribution area/number of predators” and “rodent size/number of predators'' didn't show statistical significance for the nine models carried out, although there isn't a 100% reliability that the hypotheses rejection was due to statistical insignificance and not due to lack of data. Finally, the interaction network has a high robustness index value, which represents a well-structured community that can resist different changes and pressures, such as biodiversity loss, extinctions or competition, highlighting the importance of the hystricomorph rodents and the predators of the Neotropics and thus the need for further studies on this topic.INTRODUCCIÓN/MATERIALES Y MÉTODOS/Depredación de roedores histricomorfos/Redes de interacción entre roedores histricomorfos y sus depredadores/Evaluación del tamaño del roedor, su área de distribución y su relación con el número de depredadores/RESULTADOS/Depredación de roedores histricomorfos/Redes de interacción entre roedores histricomorfos y sus depredadores/Evaluación del tamaño del roedor, su área de distribución y su relación con el número de depredadores/DISCUSIÓN/Redes de interacción entre roedores histricomorfos y sus depredadores/Área vs tamaño del roedor/CONCLUSIONES Y RECOMENDACIONES/REFERENCIASUniversitarioBiólogo(a
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
Evolutionary developmental biology of the mammalian middle ear: using virtual reconstruction to integrate development and biomechanics
No full textThe Bat Lands, a project that seeks to explore potential areas of bat-mediated zoonotic outbreaks
No full textDiseño y estandarización de un formato de etograma en el Bioparque Ukumarí, Pereira, Colombia
No full textIlustracionesSpa:El comportamiento animal es estudiado por su gran relevancia en el conocimiento de la biología de las especies. Actualmente los esfuerzos de los zoológicos están destinados principalmente a la conservación, investigación y bienestar animal de las especies que albergan. Una de las estrategias para la conservación y bienestar de una especie es el seguimiento conductual. A raíz de lo expuesto, se realizó un formato de etograma base para estudios etológicos rutinarios de los animales bajo cuidado humano del Bioparque Ukumarí, Pereira, Colombia. Se observaron y describieron 60 comportamientos agrupados en 12 categorías: locomoción, manipulación e inspección de objetos, eliminación, interacción externa, descanso, alimentación, actividad social, juego, comportamiento agonístico, cuidado del cuerpo, comportamiento sexual y otros. La elaboración de etogramas parciales es uno de los primeros pasos en el estudio del comportamiento, ya que permiten llevar a cabo análisis cualitativos y cuantitativos, otorgando la posibilidad de ampliar los conocimientos en el manejo, detectar conductas anormales y aplicar tratamientos con enriquecimientos que puedan mejorar las condiciones de las especies bajo cuidado humano.Eng:Animal behavior is studied for its great relevance in the knowledge of the biology of the species. Currently, efforts of zoos are mainly aimed at the conservation, research and animal welfare of the species they house. One of the strategies for the conservation and welfare of a species is behavioral monitoring. As a result of this, a base ethogram format was made for routine ethological studies of the animals under human care at the Bioparque Ukumarí, Pereira, Colombia. 60 behaviors grouped into 12 categories were observed and described: locomotion, manipulation and inspection of objects, elimination, external interaction, rest, feeding, social activity, play, agonistic behavior, body care, sexual behavior and others. The elaboration of partial ethograms is one of the first steps in the study of behavior, since they allow to carry out qualitative and quantitative analysis, giving the possibility of expanding knowledge in management, detecting abnormal behaviors and applying treatments with enrichments that can improve the conditions of the species under human care.UniversitarioEl documento no podrá ser publicado hasta una próxima revisión por parte del Bioparque Ukumarí.Biólogo(a
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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