297 research outputs found
An Approach to Detect the Origin and Distribution of Software Defects in an Evolving Cyber-Physical System
Cyber-Physical Systems (CPS) are usually developed by an incremental approach. A changing environment like demanding user requirements or legislation amendments lead often to multiple development paths in an evolving CPS. Hence, software variability plays an increasingly important role adapting the characteristics of such CPS to different contexts. This paper focuses on software variability realized through a Software Product Line (SPL) more specifically. Thereby, variability and evolution are usually managed in different tools. However with respect to software defects, a holistic handling of variability and evolution is necessary to ensure a reliable software defect removal. Particularly, detecting software defects in different evolution stages and derived variants is ordinary, but complex and error-prone. To close the gap between variability and evolution, this paper presents a systematic approach to combine both disciplines. In particular, we apply existing variant management techniques in combination with software configuration management methods to determine a software defect's origin and distribution in an evolving SPL. We apply our approach to a CPS from the automotive domain to show its industrial relevance and usefulness
Synthese S/N-funktionalisierter Dipeptide als Hemmstoffe von Zinkendoproteasen
Eine Reihe potentieller neuer Hemmstoffe der Zinkendoproteasen Thermolysin (TLN) und der Matrixmetalloproteasen (MMPŽs) wurden entwickelt. Einem Substrat-basierten Ansatz folgend wurde ein Dipeptid als Grundgerüst eingesetzt, das mit funktionellen Gruppen verknüpft wurde, die Zink-bindende Eigenschaften erwarten ließen. Diese basierten vorzugsweise auf bisher nicht untersuchten S-/N-funktionellen Strukturen. Als Dipeptid-Grundgerüst dienten vorzugsweise Leu-Phe und Leu-Trp.
Als potentielle Zink-bindende Gruppen wurden neben Hydroxamsäure, Carbonsäure und Thiol, Sulfonamide, Sulfinamide, Sulfinylharnstoffe, Sulfonylharnstoffe, Sulfonimidoylharnstoffe, Sulfodiimide, sowie die Sulfoximidocarbonylgruppe, Sulfodiimidocarbonylgruppe und die N-Sulfamoylgruppe verwendet. Die Umsetzung von verschiedenen Aminosäureestern und Dipeptiden mit
Diphenyl-N-sulfamoyl-iminocarbonat führte zur Einführung der N-Sulfamoyliminophenoxymethylgruppe die weiter zur N-Sulfamoylcarbamimidoylgruppe umgesetzt wurde. Die Reaktion der Dipeptide mit N-Cyaniminokohlensäurediphenylester führte zu Cyaniminophenoxymethyl-N-substituierten Dipeptiden, die weiter zum 3-Amino-1,2,4-triazol, 3-Amino-1-methyl-1,2,4-triazol und 5-Amino-1-oxa-2,4-diazol cyclisiert werden konnten.
Die Hydroxamsäure, Carbonsäure, das Thiol, die N-Tosyl-Dipetide, die Sulfinylharnstoffe und das 3-Amino-1,2,4-triazol hemmten die Matrixmetalloproteasen im mikromolaren Bereich. Ein Sulfonimidoylharnstoff zeigte eine schwache Hemmung im mikromolaren Bereich gegen Thermolysin. Die N-Sulfamoyl-Dipeptide wurden gegen die humanen Carboanhydrasen I und II getestet und zeigten hemmende Eigenschaften im mikromolaren Bereich
TanDEM-X Acquisition Planning and DEM Performance in the Third Year of Operation
TanDEM-X is a spaceborne SAR mission with the goal to derive a global Digital Elevation Model (DEM). The two incorporated satellites fly in a close formation with distances of around 500 m. These small baselines form a single pass bistatic interferometer for accurate DEM acquisitions. The final DEM product will enter a new level of detail and accuracy on a global scale. The absolute height error shall be less than 10 m in a 90% confidence interval at a pixel spacing of 12 m. The vertical height specification for the TanDEM-X mission foresees a 90% point-to-point error of 2 m (4 m) for areas with predominant terrain slopes smaller than 20% (greater than 20%) for a 1° by 1° cell.
This presentation gives an overview about the planning and the actual status of the global DEM acquisition. This includes the acquisition plan after the first two years of operation, i. e. two global coverages, including the acquisitions of the Antarctica and difficult terrain. Also, the actual performance status in terms of absolute and relative height error and the narrow relation between the DEM acquisition planning and the performance evaluation is presented
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Examination of universal microhardness of liard reaction layers resulting from reactions of organic polymers with container glass surfaces and their use for low-friction protective layers
Clear, highly alkaline and wear-resistant hard reaction layers are formed by direct alkaline coupling of organic polymers with functional groups, particularly high-molecular polyols, to siliceous glass surfaces having container glass compositions. As compared with untreated glass these are characterized by an increased universal hardness and an excellent scratch resistance. Formation of these layers requires a highly alkahne reaction medium, e.g. 2% NaOH, 85°C, according to the conditions of the alkaline washing process of returnable beverage bottles in the bottling plants. It can be assumed that the formation of the reaction layer is associated with the formation of highly molecular ionic polymers with 5-coordinated silicon. Results of universal microhardness measurements of the hard reaction layers which were formed with aqueous polymer dispersions (epoxy resin microdispersion; low-molecular oxidized polyethylene) are presented. The increase of plastic universal hardness in comparison with untreated glass demonstrates the enhanced wear resistance of these layers. So far layer thicknesses up to 0.3 µm could be achieved. These results suggest new approaches to develop highly efficient low-friction protective layers for returnable bottles, and after increasing the thickness of the hard reaction layer up to several micrometers, they could possibly be applied also to lightweight bottles under enhanced internal pressure as used for carbonated beverages. Universal microhardness measurements are a very useful tool in the development and most effective improvement of such novel low-friction protective coatings for container glass
Silicon Promotes Exodermal Casparian Band Formation in Si-Accumulating and Si-Excluding Species by Forming Phenol Complexes
We studied the effect of Silicon (Si) on Casparian band (CB) development, chemical composition of the exodermal CB and Si deposition across the root in the Si accumulators rice and maize and the Si non-accumulator onion. Plants were cultivated in nutrient solution with and without Si supply. The CB development was determined in stained root cross-sections. The outer part of the roots containing the exodermis was isolated after enzymatic treatment. The exodermal suberin was transesterified with MeOH/BF3 and the chemical composition was measured using gas chromatography-mass spectroscopy (GC-MS) and flame ionization detector (GC-FID). Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) was used to determine the Si deposition across root cross sections. Si promoted CB formation in the roots of Si-accumulator and Si non-accumulator species. The exodermal suberin was decreased in rice and maize due to decreased amounts of aromatic suberin fractions. Si did not affect the concentration of lignin and lignin-like polymers in the outer part of rice, maize and onion roots. The highest Si depositions were found in the tissues containing CB. These data along with literature were used to suggest a mechanism how Si promotes the CB development by forming complexes with phenols.DFG/SCHR 506/12-
Funktionsbedarf nutzergerechter Interaktionssysteme: Befragungsergebnisse aus dem Verbundprojekt HÜMNOS
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Tuning the properties of magnetic thin films by interaction with periodic nanostructures
The most important limitation for a significant increase of the areal storage density in magnetic recording is the superparamagnetic effect. Below a critical grain size of the used CoCrPt exchange-decoupled granular films the information cannot be stored for a reasonable time (typically ten years) due to thermal fluctuations arbitrary flipping of the magnetization direction. An alternative approach that may provide higher storage densities is the use of so-called percolated media, in which defect structures are imprinted in an exchange-coupled magnetic film. Such percolated magnetic films are investigated in the present work. We employ preparation routes that are based on (i) self-assembly of Au nanoparticles and (ii) homogeneous size-reduction of self-assembled polystyrene particles. On such non-close-packed nanostructures thin Fe films or Co/Pt multilayers are grown with in-plane and out-of-plane easy axis of magnetization. The impact of the particles on the magnetic switching behavior is measured by both integral magnetometry and magnetic microscopy techniques. We observe enhanced coercive fields while the switching field distribution is broadened compared to thin-film reference samples. It appears possible to tailor the magnetic domain sizes down to the width of an unperturbed domain wall in a continuous film, and moreover, we observe pinning and nucleation at or close to the imprinted defect structures
NCBP3 positively impacts mRNA biogenesis
The nuclear Cap-Binding Complex (CBC), consisting of Nuclear Cap-Binding Protein 1 (NCBP1) and 2 (NCBP2), associates with the nascent 5' cap of RNA polymerase II transcripts and impacts RNA fate decisions. Recently, the C17orf85 protein, also called NCBP3, was suggested to form an alternative CBC by replacing NCBP2. However, applying protein-protein interaction screening of NCBP1, 2 and 3, we find that the interaction profile of NCBP3 is distinct. Whereas NCBP1 and 2 identify known CBC interactors, NCBP3 primarily interacts with components of the Exon Junction Complex (EJC) and the TRanscription and EXport (TREX) complex. NCBP3-EJC association in vitro and in vivo requires EJC core integrity and the in vivo RNA binding profiles of EJC and NCBP3 overlap. We further show that NCBP3 competes with the RNA degradation factor ZC3H18 for binding CBC-bound transcripts, and that NCBP3 positively impacts the nuclear export of polyadenylated RNAs and the expression of large multi-exonic transcripts. Collectively, our results place NCBP3 with the EJC and TREX complexes in supporting mRNA expression
Rationale and design of the MULTISTARS AMI Trial: a randomized comparison of immediate versus staged complete revascularization in patients with ST-segment elevation myocardial infarction and multivessel disease
Background:
About half of patients with acute ST-segment elevation myocardial infarction (STEMI) present with multivessel coronary artery disease (MVD). Recent evidence supports complete revascularization in these patients. However, optimal timing of non-culprit lesion revascularization in STEMI patients is unknown because dedicated randomized trials on this topic are lacking.
Study design:
The MULTISTARS AMI trial is a prospective, international, multicenter, randomized, two-arm, open-label study planning to enroll at least 840 patients. It is designed to investigate whether immediate complete revascularization is non-inferior to staged (within 19-45 days) complete revascularization in patients in stable hemodynamic conditions presenting with STEMI and MVD and undergoing primary percutaneous coronary intervention (PCI). After successful primary PCI of the culprit artery, patients are randomized in a 1:1 ratio to immediate or staged complete revascularization. The primary endpoint is a composite of all-cause death, non-fatal myocardial infarction, ischemia-driven revascularization, hospitalization for heart failure, and stroke at 1 year.
Conclusions:
The MULTISTARS AMI trial tests the hypothesis that immediate complete revascularization is non-inferior to staged complete revascularization in stable patients with STEMI and MVD
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