1,720,953 research outputs found
RESEARCHING PRIMATES IN EASTERN COLOMBIA: THIRTY-FIVE YEARS OF A PRIMATOLOGICAL LIFE
No full textSe relata algunos detalles de la historia de las investigaciones del autor en el oriente de Colombia durante 27 años de trabajo en Vichada, Vaupés, Amazonas y más recientemente en el Meta, desde 1977 hasta el presente. Se hace comentarios sobre cada investigación, ubicándola en el contexto de la primatología y se destacan algunas hipótesis e ideas del autor en cuanto a la naturaleza de las especies, las poblaciones de primates y otros grupos de mamíferos en el país. Especialmente se discute aspectos de los primates Cebus albifrons y su relación con Sapajus (=Cebus) apella (nuevo cambio taxonómico) , y los primates Callicebus lugens, Alouatta seniculus, Lagothrix lagothricha, Cacajao melanocephalus, Callicebus caquetensis y Callicebus ornatus.Some details of the history of the author's investigations in eastern Colombia are recounted during 27 years of work in Vichada, Vaupés, Amazonas and more recently in Meta, from 1977 to the present. Comments are made on each investigation, placing it in the context of primatology and some hypotheses and ideas of the author regarding the nature of the species, populations of primates and other groups of mammals in the country are highlighted. Especially aspects of the primates Cebus albifrons and their relationship with Sapajus (=Cebus) apella (new taxonomic change), and the primates Callicebus lugens, Alouatta seniculus, Lagothrix lagothricha, Cacajao melanocephalus, Callicebus caquetensis and Callicebus ornatus are discussed
Análisis del ciclo estral y evaluación de factores sociales y ecológicos que lo afectan en un grupo de Ateles hybridus en el corregimiento de Carare (Cimitarra, Santander)
Get PDFEn los últimos años se ha incrementado el uso de heces como fuente de Estrogenos y progestágenos; pero son escasos los estudios de campo. Sin embargo son de suma importancia para entender la dinámica poblacional. Por esta razón, se estudio un grupo de Ateles hybridus en el Magdalena medio colombiano, en un remanente de bosque húmedo tropical de 66 hectáreas. El grupo se eligió como modelo para evaluar el comportamiento reproductivo y los ciclos ovulatorios de Ateles hybridus, y ver la influencia de la dieta y las condiciones ambientales. Se utilizó el método de animal focal para caracterizar la dieta, el patrón de actividades, el comportamiento reproductivo. Y se empleó material fecal para hacer seguimientos de perfiles hormonales, tomando en cuenta solo las muestras recolectadas entre las 6 am y las 12 m. Posteriormente en la estación de investigación se realizó una purificación de las muestras. En el laboratorio se cuantificaron las hormonas 17β- estradiol y progesterona, por medio de una prueba Elisa empleando un kit comercial de radio inmuno-ensayo. Se encontraron diferencias significativas entre los niveles hormonales de las hembras lactantes, con ciclo, y preñadas; los niveles máximos presentados para estradiol respectivamente fueron 439.9pg/ml, 1990.4pg/ml, 4203pg/ml , mientras los valores máximos de progesterona fueron 5ng/ml, 14.9ng/ml, 23.8ng/ml. La duración del ciclo ovulatorio osciló entre 16-19 días. Las concentraciones de progesterona alcanzan el pico máximo en el periodo periovulatorio; estos valores descienden rápidamente y se estabilizan en la fase lútea. El grupo de Ateles hybridus consumió 48 especies vegetales, invirtiendo el 30.78% del tiempo en el consumo de hojas y el 62.05% en consumo de frutos, en este sitio se incrementa el consumo de hojas comparado con lo reportado por otros autores posiblemente por efectos de la fragmentación. Se reportaron 20 copulas y 9 nacimientos de los cuales tres fueron durante los meses de muestreo. No se encontraron diferencias entre las agresiones presentadas a hembras preñadas y hembras ciclando, en su gran mayoría el comportamiento de grooming se presento hacia hembras ciclando.Abstract. In recent years it has increased the use of faeces as a source of estrogens and progestins, but there are few field studies. However they are of paramount importance in understanding population dynamics. For this reason, we study a group of Ateles hybridus in Colombian Middle Magdalena, a remnant of tropical rain forest of 66 hectares. The group was chosen as a model to assess the reproductive behavior and ovulatory cycles of Ateles hybridus, and see the influence of diet and environmental conditions. Method was used to characterize focal animal diet, activity patterns, reproductive behavior. And fecal material was used for monitoring hormonal profiles, taking into account only the samples collected between 6 am and 12 m. Later research station in a purification was performed of the samples. In the laboratory were quantified hormones 17β-estradiol and progesterone, using an ELISA test using a commercial kit radio immunoassay. Significant differences were found between hormone levels of female infants, with cycle and pregnant, the maximum levels for estradiol respectively were presented 439.9pg/ml, 1990.4pg/ml, 4203pg/ml, while the maximum values of progesterone were 5 ng / ml, 14.9ng/ml, 23.8ng/ml. Ovulatory cycle length ranged between 16-19 days. Progesterone concentrations reached the peak in the periovulatory period, these values fall rapidly and stabilized in the luteal phase. Ateles hybridus group consumed 48 plant species, reversing the 30.78% of the time feeding on leaves and 62.05% for fruit consumption at this site increases the consumption of leaves compared with those reported by other authors, possibly for purposes of fragmentation. 20 copulations were reported and 9 births of which three were during the months of sampling. No differences were found between the attacks presented to pregnant females and females cycling, the vast majority of grooming behavior was presented to cycling females.Maestrí
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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