1,720,970 research outputs found
Protection against ultraviolet radiation involves MC1R-mediated non-pigmentary and pigmentary mechanisms in vivo
No full textIndividuals with red hair and fair skin due to MC1R gene variants are at higher risk of cutaneous neoplasia, consistent with MC1R having a role in photoprotection. The exact reasons for greater UVR susceptibility as a result of compromised MC1R function are unclear, but hypotheses include reduced photoprotection due to less eumelanin, pheomelanin-induced phototoxicity, and lower protection by “non-pigmentary” MC1R effects. To determine how MC1R photoprotects, an in vivo hairless MC1R model containing Mc1r?/? albino, MC1R+Mc1r?/? albino, Mc1r?/? pigmented, and MC1R+Mc1r?/? pigmented mice was generated. After single doses of UVR, no significant differences in epidermal cyclobutane pyrimidine dimers or sunburn cell (SBC) formation were observed between pigmented and albino groups. However, after repeated UVR exposure, the number of p53 clones in albino skin was significantly elevated when this was null for MC1R. Furthermore, in the absence of functional MC1R, fewer p53 clones were observed in pigmented than in albino skin. The results indicate that MC1R protects by a combination of pigmentary and non-pigmentary effects in vivo and that when MC1R function is compromised the melanin type in skin is still protective against UVR
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
The mutation burden of narrowband ultraviolet B phototherapy (NB-UVB) in human skin; relevance to NB-UVB lifetime exposures and skin cancer surveillance
No full textBackground: ultraviolet radiation (UVR) is used as treatment for psoriasis and other skin diseases, but UVR can induce DNA mutations which may lead to skin cancer development. While skin cancers have been documented in patients treated with phototherapy, a limited number of epidemiological studies have examined skin cancer incidence in people receiving narrowband ultraviolet B (NB-UVB) treatment. Information on mutagenicity of NB-UVB would help inform about the potential skin cancer risks of this treatment.Objectives: to determine the mutation burden in human skin resulting from a NB-UVB treatment course and use this data to estimate the total number of NB-UVB exposures whereupon skin cancer surveillance should commence.Methods: biopsies of normal skin were obtained before and after a course of NB-UVB from 16 patients with psoriasis. Epidermal DNA was sequenced using nanorate sequencing (NanoSeq) to determine the mutational signatures and mutation burden from NB-UVB.Results: the NB-UVB treatment course increased the number of mutations in skin. Median increase in mutation burden was 0.55 substitutions/Mb in infrequently sun-exposed (buttock) and 0.89 substitutions/Mb in frequently sun-exposed (forearm) skin, P= 0.0001, n=14 patients and P=0.0098, n=10 patients respectively. Change in mutation burden due to NB-UVB ranged from 1.16 to 10.5-fold in buttock skin and 0.93 to 2.33-fold in forearm skin. This increase was mainly attributable to UVR-exposure linked mutational signatures, SBS7a and SBS7b, with some evidence that mutational burden related to genetic background of the individual. Modelling the change in mutation burden from NB-UVB relative to minimal erythema dose (MED) in comparison with average mutation burden in keratinocyte skin cancers allowed estimation of total lifetime exposures at which patients are likely to require skin cancer surveillance; for patients with MED equal to 2 standard erythemal doses (SEDs), skin cancer surveillance should be offered at 422, 165 and 58 NB-UVB exposures for those receiving low, typical, and high levels of sun exposure, respectively.Conclusions: a treatment course of NB-UVB causes UVR-induced mutations in normal skin of patients with psoriasis. Relating mutation burden to MED and sun behaviour habits allows estimation of when to commence skin cancer surveillance according to total lifetime NB-UVB exposures
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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