Suhteelliseen ilmaantuvuuteen perustuvan kovarianssirakenteen bayesiläinen MCMC-estimointi valikoituneessa perheaineistossa

Tässä tutkielmassa rintasyövän ja ruoansulatuselinten syöpien perheittäistä kertymistä ja perimäosuutta estimoitiin lapsena tai nuorena syövän sairastaneiden suomalaisten perheaineistoissa. Perheet poimittiin siten, että jokaisessa perheessä on vähintään yksi alle 40-vuotiaana diagnosoitu syöpätapaus vuosina 1970-2012. Rintasyöpäaineisto koostui 4921 perheestä, joissa oli kaikkiaan 26 259 henkilöä. Ruoansulatuselinten aineisto puolestaan koostui 3328 perheestä ja 22 441 henkilöstä. Syövän perimäosuuden suhteellista ilmaantuvuutta mallinnettiin hierarkkisella bayesiläisellä Poisson-regressio sekamallilla, jossa sairastumisalttiuden vaihtelu jaettiin ympäristön, perimän ja ylihajonnan komponentteihin. Parametrien yhteisposteriorijakaumaa arvioitiin MCMC-otannan avulla JAGS-ohjelmalla. Lisäksi syöpien kertymistä tarkasteltiin estimoimalla sukulaisuussuhteiden mukaan ositettuja suhteellisia syöpäilmaantuvuuksia. Simulaatiotutkimuksella arvioitiin tilastollisen mallin satunnaiskomponenttien estimoituminen ja tarkasteltiin harhan korjauksen vaikutusta tutkimusasetelmaan. Rintasyöpäaineistossa nuorten syöpäpotilaiden perheenjäsenillä havaittiin 739 syöpää ja perheenjäsenten keskimääräinen syöpäriski oli 81% (95%:n todennäköisyysväli 68-94%) suurempi kuin vastaavalla väestöllä. Rintasyövän perimäosuus oli 26% (0-57%). Ruoansulatuselinten syöpiä havaittiin perheenjäsenillä 574 ja perheenjäsenten syöpäriski oli 60% (48-73%) suurempi kuin väestöllä ja sen perimäosuudeksi estimoitiin 63% (37-88%). Tutkielman tulosten mukaan ympäristötekijöiden merkitys rintasyöpäaineistossa on suuri. Vastaavasti ruoansulatuselinten syövissä ympäristötekijöiden merkitys on pienempi ja perimän osuus selvästi suurempi.Siirretty Doriast

Maximal Ancestral Graph Structure Learning via Exact Search

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Learning Chordal Markov Networks via Branch and Bound

We present a new algorithmic approach for the task of finding a chordal Markov network structure that maximizes a given scoring function. The algorithm is based on branch and bound and integrates dynamic programming for both domain pruning and for obtaining strong bounds for search-space pruning. Empirically, we show that the approach dominates in terms of running times a recent integer programming approach (and thereby also a recent constraint optimization approach) for the problem. Furthermore, our algorithm scales at times further with respect to the number of variables than a state-of-the-art dynamic programming algorithm for the problem, with the potential of reaching 20 variables and at the same time circumventing the tight exponential lower bounds on memory consumption of the pure dynamic programming approach.Peer reviewe

Learning Chordal Markov Networks via Stochastic Local Search

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User Influence in E-Service Evolution: A Case Study of E-Banking

In this interpretive case study we examine the processes and the related information systems (IS) fostering user influence in a large scale e-banking case. Our focus is user involvement in the IS evolution by enhancing and utilizing unsolicited feedback and initiatives. As a result, we develop a new conceptualization of feedback and initiative management. Organizations may utilize this model and the related patterns of action and interaction for organizing their congruent processes. Our case is an international financial organization which has one of the first e-banks and largest user bases of these systems in the world. E-banking is one of the advanced strategic web application areas where there is already a long history of use by a high number of external, heterogeneous users. Hence, we believe that these results may be applicable to other web-based information systems as well

The 'Incel' Phenomenon in the Digital Era--How Echo Chambers have Fueled the Incel Movement

The “incel” phenomenon began after 2010 when like-minded young – mostly straight white – men started to share similar thoughts and worldviews on certain digital platforms and online forums leading to an exclusive community. The phenomenon is characterized by misogynism, racism and homophobia. The most extreme forms of the phenomenon have led to violent hate crimes. The aim of this paper is to understand this phenomenon and analyze it by applying the echo chamber theory

Learning Optimal Causal Graphs with Exact Search

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Changes In Higher Education Communication Practices And Tools - Through The Pandemic Towards New Communication Models

The COVID-19 pandemic has significantly impacted traditional modes of communication in higher education institutions, leading to a shift towards remote communication and digital tools. This scientific paper examines the changes in higher education communication practices and tools resulting from the pandemic. The paper analyzes the challenges and opportunities presented by this shift and the ways in which teachers have applied communication models familiar from contact teaching to distance education. A previous review of published literature on adaptations in higher education institutions identified key factors for a successful transition to novel distance education communication practices and tools. These factors included effective use of digital platforms, skillful faculty with additional training and support available, and consistent efforts to maintain engagement and community building in the online environment. To determine how teachers have been able to adapt their communication practices and tool use at both the course and curriculum levels in response to the pandemic and whether they see these changes as welcome and lasting, a questionnaire survey was conducted at Tampere University. The results of the survey demonstrated how local experiences reflected the broader changes and contribute to the ongoing discussion about teachers adopting new communication models. However, some teachers expressed a desire to return to pre-COVID-19 practices, as they perceived contact learning as more engaging and effective. Therefore, the authors propose the creation of communication models by teaching staff for their own contexts as a tool for discussing and designing teaching-related communications.Peer reviewe