Anomaly Detection in Electrocardiogram Readings with Stacked LSTM Networks

Real-world anomaly detection for time series is still a challenging task. This is especially true for periodic or quasi-periodic time series since automated approaches have to learn long-term correlations before they are able to detect anomalies. Electrocardiography (ECG) time series, a prominent real-world example of quasi-periodic signals, are investigated in this work. Anomaly detection algorithms often have the additional goal to identify anomalies in an unsupervised manner. In this paper we present an unsupervised time series anomaly detection algorithm. It learns with recurrent Long Short-Term Memory (LSTM) networks to predict the normal time series behavior. The prediction error on several prediction horizons is used to build a statistical model of normal behavior. We propose new methods that are essential for a successful model-building process and for a high signal-to-noise-ratio. We apply our method to the well-known MIT-BIH ECG data set and present first results. We obtain a good recall of anomalies while having a very low false alarm rate (FPR) in a fully unsupervised procedure. We compare also with other anomaly detectors (NuPic, ADVec) from the state-of-the-art.Algorithms and the Foundations of Software technolog

Inhibition of group B streptococcal growth by IFN gamma-activated human glioblastoma cells.

Group B streptococci are the most important bacteria inducing neonatal septicemia and meningitis. The aim of this study was to assess the role of IFNgamma in the induction of anti-microbial effector mechanisms in human brain tumor cells. Different human glioblastoma/astrocytoma cell lines, stimulated with IFNgamma, restricted the growth of group B streptococci. In addition, we found that TNF alpha is able to enhance the IFNgamma-mediated anti-microbial effect. In contrast to group B streptococci, other bacteria which are also capable of inducing meningitis, like E. coli and all but one of the tested Streptococcus pneumoniae strains, were not influenced by the IFNgamma treated cells. We found that the IFNgamma or the IFNgamma/TNF alpha induced activation of indoleamine 2,3-dioxygenase is responsible for the inhibition of streptococcal growth, since the addition of supplemental L-tryptophan completely blocks the IFNgamma induced bacteriostasis

Role of Indoleamine-2,3-Dioxygenase in Alpha/Beta and Gamma Interferon-Mediated Antiviral Effects against Herpes Simplex Virus Infections

Gamma interferon (IFN-γ)-mediated indoleamine-2,3-dioxygenase (IDO) activity in human astrocytoma cells and in native astrocytes was found to be responsible for the inhibition of herpes simplex virus replication. The effect is abolished in the presence of excess amounts of l-tryptophan. Both IFN-α and IFN-β restricted herpes simplex virus replication in both cell types, but (in contrast to the results seen with IFN-γ) the addition of an excess amount of l-tryptophan did not inhibit the induced antiviral effect