Change Detection im städtischen Umfeld von Graz/Österreich mit sehr hoch auflösenden UltraCamDaten

Dieser Beitrag befasst sich mit der Analyse von Landnutzungsänderungen mittels hochauflösender UltraCam-Daten in einer städtischen Umgebung. Das Hauptziel ist es, herauszufinden, ob die Daten geeignet sind, um Landnutzungs- bzw. Landschaftsveränderungen in Städten, die sich durch hohe Heterogenität und rasche Veränderung auszeichnen, halbautomatisch zu erkennen. Die theoretischen Ansätze und Fernerkundungsänderungserfassungsprinzipien werden im ersten Teil des Beitrages behandelt. Die Anzahl der Änderungserkennungsmethoden ist enorm und daher wird ein "Stand der Technik" präsentiert. Der zweite Hauptteil widmet sich der Entwicklung einer Änderungserkennungsmethode für Testgebiete der Stadt Graz und deren Anwendung auf das gesamt Stadtgebiet. Dabei wird ein objektbasiertes, wissensbasiertes Hybridänderungs-Erkennungsverfahren, bzw. die Integration von „image differencing, image rationing and principle component analysis“ angwandt. Die Umwelteinflüsse und Dateneigenschaften, die einen großen Einfluss auf die Genauigkeit des Änderungserfassungsergebnisses haben, werden sowohl für die Befliegungszeiträume (September 2007, Juni 2011 und März/April 2015) dokumentiert und erörtert. Der letzte Teil dieses Aufsatzes beschäftigt sich mit der Diskussion der Ergebnisse der Change Detection Analysen und der Eignung der erreichten Methodik für die Anwendungen in der städtischen Planung durch das Magistrat Graz

Change of Microhardness in Stoichiometric CuAu

Microhardness of stoichiometric CuAu was measured during isochronal heating starting from the disordered and the ordered state as well as for isochronal cooling from the disordered state. It is shown that a continuous increase of long-range order connected with similar hardness behaviour was observed in all cases of thermal treatment and pre-treatment. In correspondence with earlier resistometric experiments during isochronal temperature variation no hysteresis between heating and cooling was observed

Die Literaturrundschau

Die Literaturrundschau dieser Ausgabe von Communicatio Socialis

Effective hydrogen gas sensor based on palladium nanoparticles dispersed on graphene sheets by spin coating technique

A room-temperature hydrogen gas (H2) sensor was successfully fabricated by dispersion of palladium nanoparticles (Pd NPs) on graphene sheets (GRs) (hereafter referred to as “Pd NPs/GRs”). GRs and Pd NPs were synthesized by chemical vapor deposition technique and by polyol process, respectively. A colloidal solution of Pd NPs with an average diameter of 11 nm was then dispersed onto the GRs by spin coating technique. The density of dispersed Pd NPs on GRs was controlled by varying the volume of the dispersed solution within the range of 50 – 150 μL. The fabricated Pd NPs/GRs sensors exhibited a high sensitivity for H2 gas with a concentration of 1500 – 6000 ppm at room temperature. Upon H2 exposure, the Pd NPs/GRs sensors showed an increase in electrical resistance, which could easily be measured. The relationship between sensor response and H2 concentration is in correspondence with the Langmuir adsorption model. The H2 detection limit is estimated to be 1 ppm. The results demonstrate that the Pd NPs/GRs sensor is an easily fabricated, but very effective means for room-temperature detection of H2at ppm level

Clustering molecular dynamics conformations of the CC’-loop of the PD-1 immuno-checkpoint receptor

Molecular mechanisms within the checkpoint receptor PD-1 are essential for its activation by PD-L1 as well as for blocking such an activation via checkpoint inhibitors. We use molecular dynamics to scrutinize patterns of atomic motion in PD-1 without a ligand. Molecular dynamics is performed for the whole extracellular domain of PD-1, and the analysis focuses on its CC’-loop and some adjacent Cα-atoms. We extend previous work by applying common nearest neighbor clustering (Cnn) and compare the performance of this method with Daura clustering as well as UMAP dimension reduction and subsequent agglomerative linkage clustering. As compared to Daura clustering, we found Cnn less sensitive to cutoff selection and better able to return representative clusters for sets of different 3D atomic conformations. Interestingly, Cnn yields results quite similar to UMAP plus linkage clustering

DataSheet1_Molecular dynamics identifies semi-rigid domains in the PD-1 checkpoint receptor bound to its natural ligand PD-L1.ZIP

Cells in danger of being erroneously attacked by leucocytes express PD-L1 on their surface. These cells activate PD-1 on attacking leucocytes and send them to death, thus curbing erroneous, autoimmune attack. Unfortunately, cancer cells exploit this mechanism: By expressing PD-L1, they guard themselves against leucocyte attack and thereby evade immune clearance. Checkpoint inhibitors are drugs which re-enable immune clearance of cancer cells by blocking the binding of PD-L1 to PD-1 receptors. It is therefore of utmost interest to investigate these binding mechanisms. We use three 600 ns all-atom molecular dynamics simulations to scrutinize molecular motions of PD-1 with its binding partner, the natural ligand PD-L1. Usually, atomic motion patterns are evaluated against whole molecules as a reference, disregarding that such a reference is a dynamic entity by itself, thus degrading stability of the reference. As a remedy, we identify semi-rigid domains, lending themselves as more stable and reliable reference frames against which even minute differences in molecular motion can be quantified precisely. We propose an unsupervised three-step procedure. In previous work of our group and others, minute differences in motion patterns proved decisive for differences in function. Here, several highly reliable frames of reference are established for future investigations based on molecular motion.</p

On the role of morphological richness in the early development of noun and verb inflection

This study proposes a new methodology for determining the relationship between child-directed speech and child speech in early acquisition. It illustrates the use of this methodology in investigating the relationship between the morphological richness of child-directed speech and the speed of morphological development in child speech. Both variables are defined in terms of mean size of paradigm (MSP) and estimated in a set of longitudinal spontaneous speech corpora of nine children and their caretakers. The children are aged 1;3-3;0, acquiring nine different languages that vary in terms of morphological richness. The main result is that the degree of morphological richness in child-directed speech is positively related to the speed of development of noun and verb paradigms in child speech