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Kolloquium des ZeSt

geplante Vortragstermine:

Dienstag, 19.10.2021, 12-13 Uhr

Jonas Bauer
Universität Bielefeld

Uncertainty quantification in scRNA-Seq

Scientists today are still puzzled by many diseases that are related to changes on the level of gene expressions, such as cancer. Studying, for instance, blood or tissue samples can help to understand the underlying microbiological mechanism, the progression of a disease itself and finally to deduce appropriate treatments. Therefore it is necessary to quantify gene expressions in a sample, and distinguish healthy from infected cells adequately. However, one cannot observe and count these molecules directly. Instead, several intermediary steps are necessary which lead to millions of duplicated and much shorter RNA sequences. This talk discusses the impact of the single cell RNA-Seq set-up on the estimation accuracy and the various sources of uncertainty that are involved. Four mapping approaches are compared and a Bayesian framework for the data generating process as well as for Hamiltonian-Monte-Carlo-based sampling is presented.

The talk will be held in English.

 

Dienstag, 02.11.2021, 12-13 Uhr - Vortrag über zoom

Prof. Dr. Annika Hoyer
Universität Bielefeld

Methods for the meta-analysis of ROC curves – A statistical challenge

While methods for meta-analysis, i.e. the weighted summary of the results of several studies, are meanwhile widespread in the context of intervention studies, there is still a need for innovative statistical approaches for meta-analysis of diagnostic accuracy studies. This can be attributed to the complex underlying data with an at least bivariate outcome consisting of sensitivity and specificity. Sensitivity and specificity refer to the conditional probabilities of a positive or negative test result in the population of diseased and non-diseased, respectively. A particular challenge arises when individual studies report not only a pair of sensitivity and specificity, but complete receiver operating characteristic (ROC) curves in which sensitivity and specificity are evaluated at several different diagnostic thresholds. One way to appropriately deal with these data is to adapt statistical methods from survival analysis, such as the application of bivariate time-to-event models for interval-censored data. In the talk, newly developed, innovative methods for the complex situation of meta-analysis of diagnostic studies, especially in case of ROC curves, will be presented and discussed.

The talk will be held in English.

 

Dienstag, 16.11.2021, 12-13 Uhr

 

Dienstag, 30.11.2021, 12-13 Uhr

Dr. Annette Möller
TU Clausthal

Titel folgt

The talk will be held in English.

 

Dienstag, 14.12.2021, 12-13 Uhr

 

Dienstag, 11.01.2022, 12-13 Uhr - Vortrag über zoom

Dr. Christian Rudloff
AIT Austrian Institute of Technology GmbH

Titel folgt

 

Dienstag, 25.01.2022, 12-13 Uhr

Aktuelle Forschungsthemen im ZeSt

 


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