1,720,962 research outputs found
Synthetic torpor protects rats from exposure to accelerated heavy ions
No full textHibernation or torpor is considered a possible tool to protect astronauts from the deleterious effects of space radiation that contains high-energy heavy ions. We induced synthetic torpor in rats by injecting adenosine 5′-monophosphate monohydrate (5′-AMP) i.p. and maintaining in low ambient temperature room (+ 16 °C) for 6 h immediately after total body irradiation (TBI) with accelerated carbon ions (C-ions). The 5′-AMP treatment in combination with low ambient temperature reduced skin temperature and increased survival following 8 Gy C-ion irradiation compared to saline-injected animals. Analysis of the histology of the brain, liver and lungs showed that 5′-AMP treatment following 2 Gy TBI reduced activated microglia, Iba1 positive cells in the brain, apoptotic cells in the liver, and damage to the lungs, suggesting that synthetic torpor spares tissues from energetic ion radiation. The application of 5′-AMP in combination with either hypoxia or low temperature environment for six hours following irradiation of rat retinal pigment epithelial cells delays DNA repair and suppresses the radiation-induced mitotic catastrophe compared to control cells. We conclude that synthetic torpor protects animals from cosmic ray-simulated radiation and the mechanism involves both hypothermia and hypoxia
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
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
FLASH with carbon ions: Tumor control, normal tissue sparing, and distal metastasis in a mouse osteosarcoma model
No full textBackground and purpose: The FLASH effect is a potential breakthrough in radiotherapy because ultra-high
dose-rate irradiation can substantially widen the therapeutic window. While the normal tissue sparing at
high doses and short irradiation times has been demonstrated with electrons, photons, and protons, so far
evidence with heavy ions is limited to in vitro cell experiments. Here we present the first in vivo results
with high-energy 12C-ions delivered at an ultra-high dose rate.
Materials and methods: LM8 osteosarcoma cells were subcutaneously injected in the posterior limb of
female C3H/He mice 7 days before radiation exposure. Both hind limbs of the animals were irradiated
with 240 MeV/n 12C-ions at ultra-high (18 Gy in 150 ms) or conventional dose rate (18 Gy/min).
Tumor size was measured until 28 days post-exposure, when animals were sacrificed and lungs, limb
muscles, and tumors were collected for further histological analysis.
Results: Irradiation with carbon ions was able to control the tumour both at conventional and ultra-high
dose rate. FLASH decreases normal tissue toxicity as demonstrated by the reduced structural changes in
muscle compared to conventional dose-rate irradiation. Carbon ion irradiation in FLASH conditions sig-
nificantly reduced lung metastasis compared to conventional dose-rate irradiation and sham-irradiated
animals.
Conclusions: We demonstrated the FLASH effect in vivo with high-energy carbon ions. In addition to nor-
mal tissue sparing, we observed tumor control and a substantial reduction of lung metastasis in an
osteosarcoma mouse mode
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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