225 research outputs found
Digitale Bildsignalverarbeitung : Grundlagen, Verfahren, Beispiele
Mit dem vorliegenden Buch soll eine Einführung in die digitale Bildverarbeitung gegeben werden. Hierbei werden gemäß der allgemeinen Themenstellung der vorliegenden Buchreihe insbesondere die signalorientierten Aspekte der Bildverarbeitung in den Vordergrund gestellt. Den besonderen Reiz der Bildverarbeitung sehe ich in dem interessanten Zusammenwirken von intuitiven und theoretischen Lösungsansätzen, die jeweils durch ”anschauliche” Experimente evaluierbar sind. Entsprechend wird in der vorliegenden Darstellung versucht, insbesondere anhand von zahlreichen Simulationsbeispielen ein Verständnis dieses jungen, an Bedeutung zunehmenden Gebietes beim Leser zu erreichen. Zum Verständnis des Buches sind außer Kenntnissen der Mathematik, wie sie etwa in ingenieurswissenschaftlichen Studiengängen vermittelt werden, Grundkenntnisse der linearen Systemtheorie bzw. Signalverarbeitung und Grundkenntnisse der Wahrscheinlichkeitsrechnung vorteilhaft
Automatic decomposition of planned assembly sequences into skill primitives
Abstract-This paper presents a new method to decompose complex sequences of assembly operations into skill primitives. This can be realized by analyzing hyperarcs of the underlying AND/ORgraphs representing automatically generated assembly plans. Features like local depart spaces, symbolic spatial relations, and the necessary tools classify the type of assembly operation (peg in hole, placements, alignments, etc.). Skill primitives are robot movements or commands for grippers and tools. The unified modeling language (UML) is used to model the robot tasks and skill primitives. A robot control system uses the skill primitives as input to select the desired control scheme (position, force, or hybrid). In addition to this, we use an algorithm to identify assembly process states considering static friction under uniform gravity to execute skill primitives. This enables a robot to select and modify its motion strategies adequately according to the state of the assembly operation
Molecular insights into antibiotic resistance - how a binding protein traps albicidin
The worldwide emergence of antibiotic resistance poses a serious threat to human health. A molecular understanding of resistance strategies employed by bacteria is obligatory to generate less-susceptible antibiotics. Albicidin is a highly potent antibacterial compound synthesized by the plant-pathogenic bacterium Xanthomonas albilineans. The drug-binding protein AlbA confers albicidin resistance to Klebsiella oxytoca. Here we show that AlbA binds albicidin with low nanomolar affinity resulting in full inhibition of its antibacterial activity. We report on the crystal structure of the drug-binding domain of AlbA (AlbAS) in complex with albicidin. Both α-helical repeat domains of AlbAS are required to cooperatively clamp albicidin, which is unusual for drug-binding proteins of the MerR family. Structure-guided NMR binding studies employing synthetic albicidin derivatives give valuable information about ligand promiscuity of AlbAS. Our findings thus expand the general understanding of antibiotic resistance mechanisms and support current drug-design efforts directed at more effective albicidin analogs
XtremRisK – Integrated Flood Risk Analysis for Extreme Storm Surges at Open Coasts and in Estuaries: Key Results and Lessons Learned
XtremRisK – Integrierte Hochwasserrisikoanalyse für extreme Sturmfluten an offenen Küsten und in Ästuaren: Wichtigste Ergebnisse und Lehren
Metabolite ratios as potential biomarkers for type 2 diabetes:a DIRECT study
Aims/hypothesis
Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes.
Methods
We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case–control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders.
Results
There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p
Conclusion/interpretation
In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors.</p
Assessment of cardiac ischaemia and viability: role of cardiovascular magnetic resonance
Over the past years, cardiovascular magnetic resonance (CMR) has proven its efficacy in large clinical trials, and consequently, the assessment of function, viability, and ischaemia by CMR is now an integrated part of the diagnostic armamentarium in cardiology. By combining these CMR applications, coronary artery disease (CAD) can be detected in its early stages and this allows for interventions with the goal to reduce complications of CAD such as infarcts and subsequently chronic heart failure (CHF). As the CMR examinations are robust and reproducible and do not expose patients to radiation, they are ideally suited for repetitive studies without harm to the patients. Since CAD is a chronic disease, the option to monitor CAD regularly by CMR over many decades is highly valuable. Cardiovascular magnetic resonance also progressed recently in the setting of acute coronary syndromes. In this situation, CMR allows for important differential diagnoses. Cardiovascular magnetic resonance also delineates precisely the different tissue components in acute myocardial infarction such as necrosis, microvascular obstruction (MVO), haemorrhage, and oedema, i.e. area at risk. With these features, CMR might also become the preferred tool to investigate novel treatment strategies in clinical research. Finally, in CHF patients, the versatility of CMR to assess function, flow, perfusion, and viability and to characterize tissue is helpful to narrow the differential diagnosis and to monitor treatment
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