1,720,987 research outputs found
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
Effects of chemotherapy on metabolism of glioblastoma stem and differentiated cells
No full textGlioblastom je možganski tumor s slabo prognozo preživetja. Matične celice glioblastoma (GSC) igrajo pomembno vlogo pri odpornosti na terapijo zaradi sposobnosti diferenciacije in zagotavljanjem heterogenosti. Ohranjanje teh lastnosti je povezano z njihovimi interakcijami s tumorskim mikrookoljem (TMO). V okviru naloge smo želeli razumeti razliko v metabolni aktivnosti GSC in diferenciranih celicah glioblastoma (dGB), samih in v mediju z metaboliti endotelijskih celic, ki predstavlja del TMO, pred in po izpostavitvi celic s temozolomidom (TMZ). V nalogi smo primerjali spremembo celične metabolne viabilnosti in ultrastrukturne značilnosti mitohondrijev z uporabo testa, ki temelji na metabolni viabilnosti in s pomočjo transmisijske elektronske mikroskopije. Ugotovili smo, da se ultrastruktura mitohondrijev in s tem najverjetneje tudi metabolizem dGB in GSC razlikuje. Izpostavitev celic glioblastoma TMZ povzroči spremembe metabolne viabilnosti in ultrastrukture mitohondrijev. Ultrastrukturne spremembe nakazujejo na znižanje stopnje oksidativne fosforilacije (OXPHOS) v dGB, medtem ko pri GSC kažejo na povišanje delovanja OXPHOS. Dodajanje signalnih molekul endotelijskih celic povzroči spremembe metabolne viabilnosti in spremembe v ultrastrukturi mitohondrijev. Na podlagi ultrastrukturnih sprememb pride do znižanja stopnje OXPHOS pri dGB in GSC. Ob skupnem delovanju TMO in TMZ sprememba ultrastrukture mitohondrijev v dGB kaže na znižanje stopnje OXPHOS. Na GSC pa TMZ ob dodanem TMO nima vpliva. Ugotovili smo da odziv GSC lahko nakazuje na njihovo odpornost na TMZ, ki igra veliko vlogo pri ponovnem pojavu tumorja. Ker na področju metabolnega stanja dGB in GSC še ni veliko znanega, naši podatki pomembno prispevajo k boljšemu razumevanju odpornosti glioblastoma na TMZ.Glioblastoma is a brain tumor with a poor survival prognosis. Glioblastoma stem cells (GSC) with their ability to differentiate and providing heterogeneity play an important role in resistance to therapy. The maintenance of these properties is related to their interactions with the tumor microenvironment (TMO). As part of the study, we wanted to understand the difference in the metabolic activity of GSC and differentiated glioblastoma cells (dGB) themselves and in the medium with metabolites of endothelial cells, which is part of the TMO, before and after therapy with temozolomide (TMZ). In this study, we compared the change in cellular metabolic viability and the ultrastructural characteristics of mitochondria using a cell viability test, based on metabolic viability, and transmission electron microscopy. We found that the ultrastructure of mitochondria in dGB and GSC and thus likely also their metabolism differs. Treatment of glioblastoma cells with TMZ cause changes in cell viability and mitochondrial ultrastructure which indicate a decrease in oxidative phosphorylation (OXPHOS) level in dGB, and an increase in OXPHOS activity in GSC. Addition of the endothelial part of the TMO cause changes in cell viability and mitochondrial ultrastructure which indicate that the activity of OXPHOS is reduced in dGB and GSC. With the joint action of TMO and TMZ, changes in cell viability and mitochondrial ultrastructure also point to decreased OXPHOS state in dGB. On the other hand, TMZ has no effect on the GSC with the addition of TMO. We found that the response of GSC can indicate their resistance to therapy, which plays a major role in tumor recurrence. Since not much is known about the metabolic state of dGB and GSC, our data significantly contribute to a better understanding of glioblastoma gained resistance upon therapy
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
3D Glioblastoma Cell Culture within Alginate Microfibers for Long-Term Evaluation of Drug Effects
No full textIn our study, we aimed to develop a long-term three-dimensional (3D) model for glioblastoma cell culture to facilitate more reliable drug response studies. We cultured human U87 glioblastoma cells in alginate microfibers for a period of 28 days. Throughout this time, we monitored cell growth, viability, morphology, and aggregation in the 3D culture using fluorescent and confocal microscopy. Calcein-AM/propidium iodide staining was performed every seven days.
We validated the glioblastoma 3D model by subjecting the cells to temozolomide (TMZ) treatments for three consecutive days, starting from the 7th day of culturing cells in alginate microfibers. After a recovery period of 18 days, we evaluated cell viability using MTT assays and assessed the expression of resistance-related genes (MGMT and ABCB1) using qPCR. We also applied the same TMZ treatment schedule to cells cultured in a two-dimensional (2D) setting for comparison purposes.
Our results showed that within the long-term 3D model system in alginate fibers, the U87 cells remained viable for the entire 28-day period. Furthermore, on day 7, we observed that the cells formed visible aggregates oriented towards the periphery of the microfibers. Upon TMZ treatment, we observed a reduction in cell growth, as well as an increase in the expression of drug resistance-related genes. This effect was more pronounced in the 3D culture compared to the 2D culture.
In conclusion, we established a novel glioblastoma 3D model system, which could be particularly valuable for conducting long-term drug testing and optimizing treatment strategies.Breznik B, Novak M, editors. Book of Abstracts: 1st Net4Brain Annual Meeting: Closing the translational gap in brain cancer treatment; 2024 Sep 4-6; Ljubljana, Slovenia. Ljubljana: National Institute of Biology; 2024. p. 28
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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