Post-growth perspectives in Economic Geography

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Hierarchical Salient Object Detection for Assisted Grasping

Visual scene decomposition into semantic entities is one of the major challenges when creating a reliable object grasping system. Recently, we introduced a bottom-up hierarchical clustering approach which is able to segment objects and parts in a scene. In this paper, we introduce a transform from such a segmentation into a corresponding, hierarchical saliency function. In comprehensive experiments we demonstrate its ability to detect salient objects in a scene. Furthermore, this hierarchical saliency defines a most salient corresponding region (scale) for every point in an image. Based on this, an easy-to-use pick and place manipulation system was developed and tested exemplarily.Comment: Accepted for ICRA 201

High-resolution neutron depolarization microscopy of the ferromagnetic transitions in Ni3_3Al and HgCr2_2Se4_4 under pressure

We performed neutron imaging of ferromagnetic transitions in Ni$_3$Al and HgCr$_2$Se$_4$ crystals. These neutron depolarization measurements revealed bulk magnetic inhomogeneities in the ferromagnetic transition temperature with spatial resolution of about 100~$\mu$m. To obtain such spatial resolution, we employed a novel neutron microscope equipped with Wolter mirrors as a neutron image-forming lens and a focusing neutron guide as a neutron condenser lens. The images of Ni$_3$Al show that the sample does not homogeneously go through the ferromagnetic transition; the improved resolution allowed us to identify a distribution of small grains with slightly off-stoichiometric composition. Additionally, neutron depolarization imaging experiments on the chrome spinel, HgCr$_2$Se$_4$, under pressures up to 15~kbar highlight the advantages of the new technique especially for small samples or sample environments with restricted sample space. The improved spatial resolution enables one to observe domain formation in the sample while decreasing the acquisition time despite having a bulky pressure cell in the beam

Entwicklung eines Qualitätssicherungssystems für Öko-Futtermittel

Gesamtziel des Vorhabens war die Beschreibung eines Qualitätssicherungssystems für Öko-Futtermittel, verknüpft mit dem Ziel, die Produktsicherheit für die Hersteller und Anwender von Öko-Futtermitteln zu erhöhen. Der im Rahmen dieses Projektes erarbeitete Leitfaden "Qualitätssicherung Öko-Futtermittel" ist ein umfassendes Kompendium, welches alle notwendigen Schritte zu einer systematischen Qualitätssicherung von Öko-Futtermitteln beschreibt. Moderne Prinzipien der Qualitätssicherung, nämlich Eigenkontrolle und Risikoorientierung, finden ausdrücklich Berücksichtigung. Die strenge Orientierung an der EU-Öko-Futtermittelverordnung stellt für den Leitfadennutzer sicher, dass die Anforderungen des Gesetzgebers mit Hilfe dieses Handbuchs erfüllt werden können. Die Betrachtung bezog sich dabei auf den gesamten Herstellungsprozess, von der Rohstoffbereitstellung über die Verarbeitung bis zum eigentlichen Anwender. Mit der Entwicklung einer „Guten Kontrollpraxis“ für Öko-Futtermittel wurde den Verbänden, Behörden und Kontrollorganisationen des Ökologischen Landbaus darüber hinaus eine fundierte Arbeitsgrundlage zur Verfügung gestellt, die den Anstoß für eine harmonisierte Auslegung der „EU-Öko-Futtermittelverordnung“ gibt. Möglicherweise kritische Punkte bei der Herstellung von Futtermitteln für die Ökologische Tierhaltung wurden im Zuge dieses Projektes sorgfältig analysiert. Eigenkontrolle und Risikoorientierung bedeuten allerdings, dass die Analyse von Kritischen Kontrollpunkten letztendlich unter den Produktionsbedingungen im Unternehmen selbst zu erfolgen hat. Die dargelegte „Übersicht über typische Gefahren bei der Herstellung von Öko-Futtermitteln“ bietet jedem Unternehmen den notwendigen systematischen Einstieg in die Risikoanalyse und benennt bewährte Maßnahmen, die zur Beherrschung dieser Gefahren geeignet sind. Dies hat sich durch begleitende Erhebungen und Recherchen in der Praxis erwiesen und wurde während der zwei durchgeführten Workshops von den Betroffenen bestätigt. Die lösungs- und anwendungsorientierte, zum Teil sehr ausführliche Beschreibung qualitätssichernder Maßnahmen berücksichtigt den derzeitigen Stand der Qualitätssicherung bei den Herstellern, Händlern und dem Erfassungshandel für Öko-Futtermittel

Factors influencing vegetation cover change in Mediterranean Central Chile (1975-2008)

Las figuras y apéndices que contiene el documento se localizan al final del mismo.Questions: Which are the factors that influence forest and shrubland loss and regeneration and their underlying drivers?\ud \ud Location: Central Chile, a world biodiversity hotspot.\ud \ud Methods: Using land-cover data from the years 1975, 1985, 1999 and 2008, we fitted classification trees and multiple logistic regression models to account for the relationship between different trajectories of vegetation change and a range of biophysical and socio-economic factors.\ud \ud Results: The variables that most consistently showed significant effects on vegetation change across all time-intervals were slope and distance to primary roads. We found that forest and shrubland loss on one side and regeneration on the other often displayed opposite patterns in relation to the different explanatory variables. Deforestation was positively related to distance to primary roads and to distance within forest edges and was favoured by a low insolation and a low slope. In turn, forest regeneration was negatively related to the distance to primary roads and positively to the distance to the nearest forest patch, insolation and slope. Shrubland loss was positively influenced by slope and distance to cities and primary roads and negatively influenced by distance to rivers. Conversely, shrubland regeneration was negatively related to slope, distance to cities and distance to primary roads and positively related to distance from existing forest patches and distance to rivers.\ud \ud Conclusions: This article reveals how biophysical and socioeconomic factors influence vegetation cover change and the underlying social, political and economical drivers. This assessment provides a basis for management decisions, considering the crucial role of perennial vegetation cover for sustaining biodiversity and ecosystem services.This work was financed by the REFORLAN Project, INCO Contract CT2006-032132 (European Commission), with additional input from projects CGL2010-18312 (Spanish Ministry of Science and Innovation) and S2009AMB-1783 (Madrid Government REMEDINAL-2). We are in-\ud debted to Javier Salas and Cristian Echeverría for their input in this project. The manuscript benefited from\ud useful comments from Jorge Aubad and two anonymous\ud reviewers, who improved the contents and presentation\ud of this stud

Effect of orbital currents on the restricted optical sum rule

We derive the restricted optical-conductivity sum rule for a model with circulating orbital currents. It is shown that an unusual coupling of the vector potential to the interaction term of the model Hamiltonian results in a non-standard form of the sum rule. As a consequence, the temperature dependence of the restricted spectral weight could be compatible with existing experimental data for high-$T_c$ cuprates above the critical temperature $T_c$. We extend our results to the superconducting state, and comment on the differences and analogies between these two symmetry-breaking phenomena.Comment: Revised version, to appear in EPJ

Real-Time Optical Coherence Tomography Controlled Microsecond Laser Retinal Microsurgery: First In-vivo Results

Reliable mild photocoagulation and selective retina therapy (SRT) selectively damaging the retinal pigment epithelium (RPE) while sparing the neuroretina, the photoreceptors as well as the choroid are highly demanded. However, due to the inter- and intraindividual variability of RPE and choroidal absorption, optical microsurgery requires reliable real-time laser dosing to prevent unwanted overexposure and extended damage of the neuroretina. In this experiment optical coherence tomography (OCT) was implemented to detect minimal damage, and a laser feedback control algorithm was used for real-time dosing. For the first time in-vivo experiments on rabbits were performed with microsecond laser pulses of varying duration. Pigment rabbit eyes (n=6) were exposed to laser pulses of 4, 8, 12, and 20 μs in duration (wavelength, 532 nm; ramp-mode, maximum 15 pulses; repetition rate, 100 Hz). Therefore, a system with a scanning laser ophthalmoscope and spectral-domain OCT (Heidelberg Engineering) extended with a prototype laser (Meridian Medical) was used. For each laser lesion, the increasing ramp’s end energy was individually controlled in real-time using OCT dosimetry (central wavelength, 870 nm; scan rate, 80 kHz). Within 1 hour after irradiation, retinal changes were assessed with fluorescein angiography (FA), indocyanine green angiography (ICGA), color fundus photography (CFP) and OCT. OCT dosimetry utilizing the control algorithm can interrupt the ramp-mode in real-time for each lesion individually. The preconditioned algorithm enabled treatment with a clearly visible breakdown of the blood-retinal barrier (BRB) according to FA and ICGA imaging and barely visible treatment lesions according to CFP. OCT B-scans through the treated areas provided a first indication of the morphological tissue impact. Preliminary evaluation shows that the algorithm stopped the laser at 4 μs at a ramp end energy of 53 μJ (corresponds to 13/15 pulses), at 8 μs at 68 μJ (5/15 pulses), at 12 μs at 74 μJ (7/15 pulses), and at 20 μs at 100 μJ (1/15 pulses). The novel system with OCT based laser dosing proved to induce minimal visible damage and BRB breakdown in a wide range of pulse durations. The new irradiation scheme and algorithm are being optimized and tested in multiple subjects to further limit unwanted damage and enable pure RPE selective laser microsurgery in real-time. This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually