1,721,322 research outputs found
A search for clustering around Herbig Ae/Be stars
No full textWe present the results of new near-infrared observations of the fields around a sample of 19 Herbig Ae/Be stars. The observations reveal the population of young stars that accompanies the formation of intermediate-mass stars. The richness of the detected star clusters is investigated. We find a clear dependence of the richness of the cluster on the spectral type of the Herbig Ae/Be star, confirming that the mode of formation of intermediate-mass stars represents the transition between the high-mass and the low-mass modes. In particular, we find that the cluster nature of star formation appears at a significant (i.e. detectable) level for stars of B7 spectral type or earlier
The active source in the region of the Herbig star BD+40 4124
No full textWe present new near-infrared, millimeter and radio observations of the region associated with BD+40 4124, a Herbig Be star located in the direction of the Cygnus arm. BD+40 4124 is the optically brightest member of a small group of young emission line stars, including V 1318 Cygni and V 1686 Cygni. Near-IR broad-band imaging of V 1318 Cygni reveals the presence of two distinct stellar components oriented north-south, a result recently reported by Aspin et al. (1994). On a larger scale, the near-IR images also indicate the presence of many highly embedded sources concentrated in the vicinity of the bright visible stars. In the central part of the cluster, the near-IR sources outnumber the optically visible ones by a factor of three. The distribution of the high density molecular gas traced by the CS J=5->4 emission is highly concentrated around V1318 and V1686 Cygni, while the total column density of gas traced by the C^18^O J=2->1 shows a ridge morphology centered on these sources. The Herbig star BD+40 4124lies at the edge of both structures. From the otpically thin C^18^O emission, we derive a total molecular mass of M_core_=280Msun_. A molecular outflow has been detected in CO J=2->1. The high velocity gas is confined to a compact region of size =~20", corresponding to a physical length of 0.1pc. The outflow is not well resolved, or collimated, on the observed scales. We have also detected H_2_O maser emission at 22.2GHz at a position coincident with the center of the bipolar outflow. Both the maser and the outflow are located at the position of the southern source V1318 S which we identify as the source responsible for the activity observed in the BD+40 region
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
BD+40 Degrees 4124: Water maser, CO outflow and young stars
No full textWe present multiwavelength observations of the region associated with the Herbig Be star BD+40 Degrees 4124. The main results are the detections of water maser emission at 22 GHz and of a CO outflow, both displaced from the position of the Herbig star. Dense molecular gas observed in C18O and CS also peaks at the position of the maser. Finally, near infrared images reveal the presence of a conspicuous group of heavily embedded stars
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
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