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Syväoppimisen avulla johdetut histologiset piirteet eturauhassyöpäpotilaiden riskitason arvioinnissa
No full textProstate cancer is a common cancer that varies between patients from mild symptoms and slow progressing to an aggressively spreading and metastatic disease. Thereby, accurate prognosis is particularly important for treatment planning. In the case of an aggressive cancer, an early treatment might prevent the disease from spreading, while unnecessary treatments of slowly progressing prostate cancers should be avoided due to side effects. The prognosis of prostate cancer is based on the Gleason grading system. In the Gleason grading system, prostate biopsies are scored based on histological features, focusing on glandular structures. A low score indicates a slowly progressing disease while a high score refers to a more aggressive cancer. However, for patients with an intermediate Gleason score, determining the prognosis is challenging. In this work, I search for histological features that could supplement the Gleason grading system by assisting the risk stratification of the patients with intermediate Gleason scores. I employ artificial intelligence to extract features from histological image data and compose histological clusters. Secondly, I conduct survival analysis to examine the relationships between the clusters and survival outcomes. I discover clusters with significant effects on survival both on a data set covering several Gleason scores, and on a data set mostly covering only intermediate Gleason scores. Accordingly, the histological clusters are suggested to provide additional information to the Gleason grading system which could be beneficial in evaluating the risk for the patients with intermediate Gleason scores. Finally, I investigate the histological features of the significant clusters, focusing on the size of epithelial nuclei. For this, I first segment and classify the nuclei using an artificial intelligence model. The obtained results reveal that clusters with a protective influence contain small epithelial nuclei in terms of the median area, diameter, and perimeter in comparison to clusters that increase the risk of prostate cancer death.Eturauhassyöpä on yleinen sairaus, jonka taudinkuva vaihtelee potilaiden välillä lieväoireisesta ja hitaasti etenevästä taudista aggressiivisesti leviävään ja etäpesäkkeitä muodostavaan tautiin. Näin ollen täsmällisen ennusteen määrittäminen on erityisen tärkeää sopivan hoitosuunnitelman laatimiseksi. Aggressiivisten syöpätapausten kohdalla nopea hoidon aloitus voi estää taudin leviämisen, kun taas hitaasti etenevien eturauhassyöpien tarpeetonta hoitoa tulisi välttää haittavaikutusten vuoksi. Eturauhassyövän diagnostiikka ja ennusteen arvioiminen perustuvat Gleasonin luokitukseen. Siinä potilaan eturauhasesta otetulle koepalalle määritetään pisteytys histologisten piirteiden perusteella, rauhasrakenteisiin keskittyen. Matala pisteytys viittaa hitaasti etenevään syöpään ja korkea pisteytys aggressiivisempaan tautiin. Monissa tapauksissa pistemäärä on kuitenkin keskitasolla, jolloin ennusteen määrittäminen on haastavampaa. Tämän työn tarkoituksena on etsiä histologisia piirteitä, jotka voisivat täydentää Gleasonin luokitusta tarkentamalla keskitason pistemäärän omaavien potilaiden riskitasoarviointia. Työssä poimin piirteitä histologisesta kuvadatasta ja muodostan niistä histologisia klustereita tekoälyä hyödyntäen. Tämän jälkeen suoritan elinaika-analyysin tutkiakseni klustereiden vaikutuksia potilaiden selviytymiseen. Sekä useita eri Gleason-pisteytyksiä sisältävällä datalla, että pääosin keskitason pisteytyksistä koostuvalla datalla löytyi klustereita, joiden vaikutus selviytym-seen oli merkittävä. Histologisten klusterien voidaan siten arvioida sisältävän Gleasonin luokitukseen sisältymätöntä tietoa, joka voisi olla hyödyksi keskitason Gleason-pistemäärän potilaiden ennusteen arvioimisessa. Lopuksi tarkastelen merkityksellisiksi havaittujen klustereiden sisältämiä histologisia piirteitä, keski-tyen epiteelisolujen tumakokoon. Tätä varten tunnistan ja luokittelen tumat tekoälymallin avulla. Saadut tulokset osoittavat, että klustereissa, joilla on suojaava vaikutus, epiteelitumat ovat pienikokoisia mediaanipinta-alan, -halkaisijan ja -piirin suhteen verrattuna klustereihin, jotka lisäävät syöpäkuoleman riskiä
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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