ECG Multilead QT Interval Estimation Using Support Vector Machines.

This work reports a multilead QT interval measurement algorithm for a high-resolution digital electrocardiograph. The software enables off-line ECG processing including QRS detection as well as an accurate multilead QT interval detection algorithm using support vector machines (SVMs). Two fiducial points (Q ini and T end) are estimated using the SVM algorithm on each incoming beat. This enables segmentation of the current beat for obtaining the P, QRS, and T waves. The QT interval is estimated by updating the QT interval on each lead, considering shifting techniques with respect to a valid beat template. The validation of the QT interval measurement algorithm is attained using the Physionet PTB diagnostic ECG database showing a percent error of 2.60 ± 2.25 msec with respect to the database annotations. The usefulness of this software tool is also tested by considering the analysis of the ECG signals for a group of 60 patients acquired using our digital electrocardiograph. In this case, the validation is performed by comparing the estimated QT interval with respect to the estimation obtained using the Cardiosoft software providing a percent error of 2.49 ± 1.99 msec.

Bioinformatic identification of cassava miRNAs differentially expressed in response to infection by Xanthomonas axonopodis pv. manihotis.

BACKGROUND: microRNAs (miRNAs) are short RNA molecules that control gene expression by silencing complementary mRNA. They play a crucial role in stress response in plants, including biotic stress. Some miRNAs are known to respond to bacterial infection in Arabidopsis thaliana but it is currently unknown whether these responses are conserved in other plants and whether novel species-specific miRNAs could have a role in defense. RESULTS: This work addresses the role of miRNAs in the Manihot esculenta (cassava)-Xanthomonas axonopodis pv. manihotis (Xam) interaction. Next-generation sequencing was used for analyzing small RNA libraries from cassava tissue infected and non-infected with Xam. A full repertoire of cassava miRNAs was characterized, which included 56 conserved families and 12 novel cassava-specific families. Endogenous targets were predicted in the cassava genome for many miRNA families. Some miRNA families' expression was increased in response to bacterial infection, including miRNAs known to mediate defense by targeting auxin-responding factors as well as some cassava-specific miRNAs. Some bacteria-repressed miRNAs included families involved in copper regulation as well as families targeting disease resistance genes. Putative transcription factor binding sites (TFBS) were identified in the MIRNA genes promoter region and compared to promoter regions in miRNA target genes and protein coding genes, revealing differences between MIRNA gene transcriptional regulation and other genes. CONCLUSIONS: Taken together these results suggest that miRNAs in cassava play a role in defense against Xam, and that the mechanism is similar to what's known in Arabidopsis and involves some of the same families.