12 research outputs found
Experimental Study of the Brittle Behavior of Clay shale in Rapid Unconfined Compression
The mechanical behavior of clay shales is of great interest in many branches of geo-engineering, including nuclear waste disposal, underground excavations, and deep well drilling. Observations from test galleries (Mont Terri, Switzerland and Bure, France) in these materials have shown that the rock mass response near the excavation is associated with brittle failure processes combined with bedding parallel shearing. To investigate the brittle failure characteristics of the Opalinus Clay recovered from the Mont Terri Underground Research Laboratory, a series of 19 unconfined uniaxial compression tests were performed utilizing servo-controlled testing procedures. All specimens were tested at their natural water content with loading approximately normal to the bedding. Acoustic emission (AE) measurements were utilized to help quantify stress levels associated with crack initiation and propagation. The unconfined compression strength of the tested specimens averaged 6.9MPa. The crack initiation threshold occurred at approximately 30% of the rupture stress based on analyzing both the acoustic emission measurements and the stress-strain behavior. The crack damage threshold showed large variability and occurred at approximately 70% of the rupture stres
Clouds - Peerbasiertes On-Demand Computing
Der vorliegende Bericht stellt die Ergebnisse des Projekts 538
"Clouds -- Peerbasiertes On-Demand Computing" vor, das am Institut für Roboterforschung der Technischen
Universität Dortmund im Sommersemester 2009 und Wintersemester 2009/2010 stattfand.
Mit dem Beginn der Projektgruppenarbeiten im April 2009 wurden durch Vorträge
während einer Seminarfahrt die grundlegenden Kenntnisse im Bereich der Softwareentwicklung
und spezielle Kenntnisse für das Projektziel, hinsichtlich des aktuellen Stands
der Technik im Bereich der Delokalisierung computerbasierter Datenhaltung und Verarbeitung
und deren Hochverfügbarkeit gescha en.
Neben der Homogenisierung des Wissenstandes der Projektgruppenteilnehmer durch
diese Vorträge konnten auch erste Vorstellungen bezüglich der späteren Realisierung der
Projektgruppenziels gewonnen werden. Die Gliederung der Kapitel des folgenden Endberichts
folgt überwiegend dem klassischen Life-Cycle für Softwareentwicklung, der sich
in der Reihenfolge in die Anforderungsanalyse, Entwurfs-, Modellierungs- und Implementierungsphase
chronologisch subsumieren lässt.
Durch die kritische Diskussion und spätere Qualitätssicherung mit Hilfe von Softwaretests
konnte die Chronologie der genannten Phasen nicht immer eingehalten werden.
Beispielsweise erforderten Schwächen der ersten Entwurfsergebnisse während der folgenden
Modellierungsphase die Rückkehr zur Entwurfsphase.
Um die Lesbarkeit dieser Abhandlung zu wahren wird die beschriebene Reihenfolge
der Entwicklungsphasen strikt eingehalten. Innerhalb der Kapitel werden jedoch die
unterschiedlichen Modelle und Technologieentscheidungen denen sich die Projektgruppe
gegenüber sah ergebnisorientiert diskutiert
The Virtual Space Robotics Testbed : Comprehensive Means for the Development and Evaluation of Components for Robotic Exploration Missions
Enhancing Resilience in Biometric Research: Generation of 3D Synthetic Face Data Using Advanced 3D Character Creation Techniques from High-Fidelity Video Games and Animation
Biometric authentication plays a vital role in various everyday applications with increasing demands for reliability and security. However, the use of real biometric data for research raises privacy concerns and data scarcity issues. A promising approach using synthetic biometric data to address the resulting unbalanced representation and bias, as well as the limited availability of diverse datasets for the development and evaluation of biometric systems, has emerged. Methods for a parameterized generation of highly realistic synthetic data are emerging and the necessary quality metrics to prove that synthetic data can compare to real data are open research tasks. The generation of 3D synthetic face data using game engines’ capabilities of generating varied realistic virtual characters is explored as a possible alternative for generating synthetic face data while maintaining reproducibility and ground truth, as opposed to other creation methods. While synthetic data offer several benefits, including improved resilience against data privacy concerns, the limitations and challenges associated with their usage are addressed. Our work shows concurrent behavior in comparing semi-synthetic data as a digital representation of a real identity with their real datasets. Despite slight asymmetrical performance in comparison with a larger database of real samples, a promising performance in face data authentication is shown, which lays the foundation for further investigations with digital avatars and the creation and analysis of fully synthetic data. Future directions for improving synthetic biometric data generation and their impact on advancing biometrics research are discussed
Evaluation of soluble suppression of tumorigenicity 2 (sST2) as serum marker for liver fibrosis
Background & aims
With the increase in patients at risk of advanced liver disease due to the obesity epidemic, there will be a need for simple screening tools for advanced liver fibrosis. Soluble suppression of tumorigenicity 2 (sST2) is a serum biomarker for fibrotic processes. The aim of this study was to evaluate sST2 as marker for liver fibrosis in patients successfully treated for chronic hepatitis C.
Methods
424 patients from the Swiss Hepatitis C Cohort Study were screened for inclusion in this post-hoc cohort study. Inclusion criteria were sustained virological response (SVR), available elastography (VCTE) and serum samples for biomarker analysis before and after treatment. For the validation of sST2, values were compared to VCTE, FIB-4 and APRI using Spearman’s correlation and AUROC analyses.
Results
Data of 164 subjects were finally analyzed. Median sST2 values slightly increased with VCTE-derived fibrosis stages and remained stable after reaching SVR within the respective fibrosis stage, suggesting that sST2 is not influenced by liver inflammation. However, correlation of sST2 pre- and post-treatment with VCTE was fair (Spearman’s rho = 0.39 and rho = 0.36). The area under the curve (AUROC) for sST2 in detecting VCTE-defined F4 fibrosis (vs. F0-F3) before therapy was 0.74 (95%CI 0.65–0.83), and 0.67(95%CI 0.56–0.78) for the discrimination of F3/F4 fibrosis vs. F0-F2. Adding sST2 to either APRI or FIB-4, respectively, increased diagnostic performance of both tests.
Conclusions
sST2 can potentially identify patients with advanced fibrosis as a single serum marker and in combination with APRI and FIB-4
Transcriptome and Parasitome Analysis of Beet Cyst Nematode Heterodera schachtii
Beet cyst nematodes depend on a set of secretory proteins (effectors) for the induction and maintenance of their syncytial feeding sites in plant roots. In order to understand the relationship between the beet cyst nematode H. schachtii and its host, identification of H. schachtii effectors is crucial and to this end, we sequenced a whole animal pre-infective J2-stage transcriptome in addition to pre- and post-infective J2 gland cell transcriptome using Next Generation Sequencing (NGS) and identified a subset of sequences representing putative effectors. Comparison between the transcriptome of H. schachtii and previously reported related cyst nematodes and root-knot nematodes revealed a subset of esophageal gland related sequences and putative effectors in common across the tested species. Structural and functional annotation of H. schachtii transcriptome led to the identification of nearly 200 putative effectors. Six putative effector expressions were quantified using qPCR and three of them were functionally analyzed using RNAi. Phenotyping of the RNAi nematodes indicated that all tested genes decrease the level of nematodes pathogenicity and/or the average female size, thereby regulating cyst nematode parasitism. These discoveries contribute to further understanding of the cyst nematode parasitism
Transcriptome and Parasitome Analysis of Beet Cyst Nematode Heterodera schachtii
Beet cyst nematodes depend on a set of secretory proteins (effectors) for the induction and maintenance of their syncytial feeding sites in plant roots. In order to understand the relationship between the beet cyst nematode H. schachtii and its host, identification of H. schachtii effectors is crucial and to this end, we sequenced a whole animal pre-infective J2-stage transcriptome in addition to pre- and post-infective J2 gland cell transcriptome using Next Generation Sequencing (NGS) and identified a subset of sequences representing putative effectors. Comparison between the transcriptome of H. schachtii and previously reported related cyst nematodes and root-knot nematodes revealed a subset of esophageal gland related sequences and putative effectors in common across the tested species. Structural and functional annotation of H. schachtii transcriptome led to the identification of nearly 200 putative effectors. Six putative effector expressions were quantified using qPCR and three of them were functionally analyzed using RNAi. Phenotyping of the RNAi nematodes indicated that all tested genes decrease the level of nematodes pathogenicity and/or the average female size, thereby regulating cyst nematode parasitism. These discoveries contribute to further understanding of the cyst nematode parasitism.This article is published as Elashry, Abdelnaser M., Samer S. Habash, Paramasivan Vijayapalani, Nahal Brocke-Ahmadinejad, Roman Blümel, Arun Seetharam, Heiko Schoof, and Florian MW Grundler. "Transcriptome and Parasitome Analysis of Beet Cyst Nematode Heterodera schachtii." Scientific Reports 10 (2020): 3315. DOI: 10.1038/s41598-020-60186-0. Posted with permission.</p