1,721,633 research outputs found
Evolutionary concepts can benefit both fundamental research and applied research in toxicology (A comment on brady et al. 2017).
Get PDFAuthor Posting. © John Wiley & Sons, 2019. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Hahn, Mark E. Evolutionary concepts can benefit both fundamental research and applied research in toxicology (A comment on brady et al. 2017). Evolutionary Applications, 12(2), (2019):350-352, doi:10.1111/eva.12695.National Institute of Environmental Health Sciences (NIEHS) through the Boston University Superfund Research Program (P42ES007381) and the Woods Hole Center for Oceans and Human Health (NIH grant P01ES021923 and NSF Grant OCE-1314642)
Hubble Space Telescope Wide Field Planetary Camera 2 Imaging of UGC 12695: A Remarkably Unevolved Galaxy at Low Redshift
Get PDFUtilizing the F814W and F300W filters, short-exposure Hubble Space Telescope Wide Field Planetary Camera 2 images were taken of UGC 12695, a nearby (z ∼ 0.021) low surface brightness disk galaxy. UGC 12695 has an unusual morphology, consisting of a Y-shaped nucleus surrounded by a faint spiral arm with a number of bright H II regions interspersed throughout the galaxy. Surface photometry indicates that the majority of recent star formation in this galaxy occurred in these very localized regions, most of which have a radius of ≲2″. This uneven stellar distribution, combined with the galaxy\u27s overall extremely blue color and low metallicity, indicates that UGC 12695 is an unevolved galaxy. Some of the structural peculiarities of this galaxy arise because a number of background galaxies, previously thought to be morphological components of this galaxy, are showing through both the outer nucleus and spiral arms of UGC 12695. Surface photometry of these galaxies shows them to be fairly small (α \u3c 1″.8) disk galaxies with total magnitudes ranging from 19.6 through 24.2 mag and central surface brightnesses in the range 20.2 mag arcsec-2 ≤ μ(0) ≤ 23.1 mag arcsec-2. When possible, the U, B, V, and I colors of these galaxies were measured using ground-based images, which show the galaxies to be fairly red, indicating that they are likely at redshifts z ≥ 0.5. Inclusion of them in the photometry of UGC 12695 makes the galaxy appear significantly redder. When these galaxies are masked out, the resultant U-I color of UGC 12695 is -0.2 ± 0.1, making it perhaps the bluest galaxy ever measured in this color system and confirming its nature as a very unevolved galaxy at low redshift. Spectroscopy of these background galaxies, through the transparent disk of UGC 12695, may help to clarify its chemical evolution and current heavy-element content
Star Formation and Tidal Encounters with the Low Surface Brightness Galaxy UGC 12695 and Companions
Get PDFWe present VLA H I observations of the low surface brightness (LSB) galaxy UGC 12695 and its two companions, UGC 12687 and a newly discovered dwarf galaxy 2333 + 1234. UGC 12695 shows solid-body rotation but has a very lopsided morphology of the H I disk, with the majority of the H I lying in the southern arm of the galaxy. The H I column density distribution of this very blue LSB galaxy coincides in detail with its light distribution. Comparing the H I column density of UGC 12695 with the empirical (but not well-understood) value of Σc = 1021 atoms cm-2 found in, e.g., Skillman\u27s 1987 paper shows the star formation to be a local affair, occurring only in those regions where the column density is above this star formation threshold. The low surface brightness nature of this galaxy could thus be attributed to an insufficient gas surface density, inhibiting star formation on a more global scale. Significantly, however, the Toomre criterion places a much lower critical density on the galaxy (∼1020 atoms cm-2), which is shown by the galaxy\u27s low star formation rate not to be applicable. Within a projected distance of 300 kpc/30 km s-1 of UGC 12695 lie two companion galaxies - UGC 12687, a high surface brightness barred spiral galaxy, and 2333 + 1234, a dwarf galaxy discovered during this investigation. The close proximity of the three galaxies, combined with UGC 12695\u27s extremely blue color and regions of localized starburst and UGC 12687\u27s UV, excess bring to mind mutually induced star formation through tidal activity
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
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