On the Issue of Camera Calibration with Narrow Angular Field of View

This paper considers the issue of calibrating a camera with narrow angular field of view using standard, perspective methods in computer vision. In doing so, the significance of perspective distortion both for camera calibration and for pose estimation is revealed. Since narrow angular field of view cameras make it difficult to obtain rich images in terms of perspectivity, the accuracy of the calibration results is expectedly low. From this, we propose an alternative method that compensates for this loss by utilizing the pose readings of a robotic manipulator. It facilitates accurate pose estimation by nonlinear optimization, minimizing reprojection errors and errors in the manipulator transformations at the same time. Accurate pose estimation in turn enables accurate parametrization of a perspective camera

Äthiopien - ein Reisebericht

Äthiopien ist ein Bauernland, etwa 80 Prozent der Menschen dort leben direkt oder indirekt von der Landwirtschaft. Und trotzdem ist der Hunger allgegenwärtig. Eine Situation, in der die Teilnehmer einer Informationsreise nicht umhin kamen, manche ihrer vorgefassten „Bio-Überzeugungen“ zu hinterfragen

The in vivo effects of beta-3-receptor agonist CGP-12177 on thyroxine deiodination in cold-exposed, sympathectomized rat brown fat

Objective: The effects of the beta-3-receptor agonist CGP-12177 on thyroxine (T4) deiodination in sympathectomized (SX) interscapular brown adipose tissue (BAT) were assessed in 300 g body weight (BW) Wistar rats. Design: Seven days after SX, groups of rats were implanted s.c. with pellets containing 5 mg CGP-12177 or 5 mg norepinephrine (NE) and were immediately placed at 4°C for 24 h. Other SX groups were injected with CGP-12177 or NE 1 mg/kg BW i.p. and placed in the cold for 4 h. The latter group was injected, in addition, with prazosin 0.4 mg/100 g BW i.p. or propranolol 0.5 mg/100 g BW i.p. 15 min before and 2 h after the administration of CGP-12177 or NE. Methods: Two hours after the last injection of prazosin or propranolol, animals were killed and BAT was removed, homogenized and centrifuged at 500g for 10min at 4°C. The infranatants were incubated during 60min in the presence of dithiothreitol and 1 μCi [125I]T4. Aliquots were chromatographed on paper for the measurement of [125I]T4 and its deiodinated subproducts. Results: CGP-12177 restored normal T4 deiodination in SX BAT from both groups, but NE was slightly more effective. Propranolol, although not prazosin, blocked the CGP-12177 effects. Contrariwise, the NE-induced rise in deiodination was blocked by prazosin and to a lesser extent by propranolol. Conclusions: The results indicate that CGP-12177 stimulated the in vivo activation of 5'-deiodinase type II activity predominantly via beta-3-receptor, without participation of alpha-1-receptors.Fil: Hofer, Dietmar. Karl-Franzens-Universität Graz; AustriaFil: Raices, Marilina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular ; ArgentinaFil: Schauenstein, Konrad. Karl-Franzens-Universität Graz; AustriaFil: Porta, Sepp. Karl-Franzens-Universität Graz; AustriaFil: Korsatko, Wolfgang. Karl-Franzens-Universität Graz; AustriaFil: Hagmüller, Karl. Karl-Franzens-Universität Graz; AustriaFil: Zaninovich, Angel Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular ; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentin

Endovascular thrombectomy is cost-saving in patients with acute ischemic stroke with large infarct

ObjectiveEndovascular thrombectomy (EVT) is the standard of care for acute large vessel occlusion stroke. Recently, the ANGEL-ASPECT and SELECT 2 trials showed improved outcomes in patients with acute ischemic Stroke presenting with large infarcts. The cost-effectiveness of EVT for this subpopulation of stroke patients has only been calculated using data from the previously published RESCUE-Japan LIMIT trial. It is, therefore, limited in its generalizability to an international population. With this study we primarily simulated patient-level costs to analyze the economic potential of EVT for patients with large ischemic stroke from a public health payer perspective based on the recently published data and secondarily identified determinants of cost-effectiveness.MethodsCosts and outcome of patients treated with EVT or only with the best medical care based on the recent prospective clinical trials ANGEL-ASPECT, SELECT2 and RESCUE-Japan LIMIT. A A Markov model was developed using treamtment outcomes derived from the most recent available literature. Deterministic and probabilistic sensitivity analyses addressed uncertainty.ResultsEndovascular treatment resulted in an incremental gain of 1.32 QALYs per procedure with cost savings of $17,318 per patient. Lifetime costs resulted to be most sensitive to the costs of the endovascular procedure.ConclusionEVT is a cost-saving (i.e., dominant) strategy for patients presenting with large ischemic cores defined by inclusion criteria of the recently published ANGEL-ASPECT, SELECT2, and RESCUE-Japan LIMIT trials in comparison to best medical care in our simulation. Prospective data of individual patients need to be collected to validate these results

Drosophila Melanogaster as a Model System for Studies of Islet Amyloid Polypeptide Aggregation

Background: Recent research supports that aggregation of islet amyloid polypeptide (IAPP) leads to cell death and this makes islet amyloid a plausible cause for the reduction of beta cell mass, demonstrated in patients with type 2 diabetes. IAPP is produced by the beta cells as a prohormone, and proIAPP is processed into IAPP by the prohormone convertases PC1/3 and PC2 in the secretory granules. Little is known about the pathogenesis for islet amyloid and which intracellular mechanisms are involved in amyloidogenesis and induction of cell death. Methodology/Principal Findings: We have established expression of human proIAPP (hproIAPP), human IAPP (hIAPP) and the non-amyloidogenic mouse IAPP (mIAPP) in Drosophila melanogaster, and compared survival of flies with the expression driven to different cell populations. Only flies expressing hproIAPP in neurons driven by the Gal4 driver elavC(155,Gal4) showed a reduction in lifespan whereas neither expression of hIAPP or mIAPP influenced survival. Both hIAPP and hproIAPP expression caused formation of aggregates in CNS and fat body region, and these aggregates were both stained by the dyes Congo red and pFTAA, both known to detect amyloid. Also, the morphology of the highly organized protein granules that developed in the fat body of the head in hIAPP and hproIAPP expressing flies was characterized, and determined to consist of 15.8 nm thick pentagonal rod-like structures. Conclusions/Significance: These findings point to a potential for Drosophila melanogaster to serve as a model system for studies of hproIAPP and hIAPP expression with subsequent aggregation and developed pathology.Original Publication: Sebastian Schultz, Peter Nilsson and Gunilla Torstensdotter Westermark, Drosophila Melanogaster as a Model System for Studies of Islet Amyloid Polypeptide Aggregation, 2011, PLoS ONE, (6), 6. http://dx.doi.org/10.1371/journal.pone.0020221 Copyright: Public Library of Science (PLoS) http://www.plos.org/</p

Diacylglycerol triggers Rim101 pathway dependent necrosis in yeast: a model for lipotoxicity

The loss of lipid homeostasis can lead to lipid overload and is associated with a variety of disease states. However, little is known as to how the disruption of lipid regulation or lipid overload affects cell survival. In this study we investigated how excess diacylglycerol (DG), a cardinal metabolite suspected to mediate lipotoxicity, compromises the survival of yeast cells. We reveal that increased DG achieved by either genetic manipulation or pharmacological administration of 1,2-dioctanoyl-sn-glycerol (DOG) triggers necrotic cell death. The toxic effects of DG are linked to glucose metabolism and require a functional Rim101 signaling cascade involving the Rim21 dependent sensing complex and activation of a calpain-like protease. The Rim101 cascade is an established pathway that triggers a transcriptional response to alkaline or lipid stress. We propose that the Rim101 pathway senses DG-induced lipid perturbation and conducts a signaling response that either facilitates cellular adaptation or triggers lipotoxic cell death. Using established models of lipotoxicity i.e. high fat diet in Drosophila and palmitic acid administration in cultured human endothelial cells, we present evidence that the core mechanism underlying this calpain-dependent lipotoxic cell death pathway is phylogenetically conserved

Tackling Multi-sensory 3D Data Acquisition and Fusion

The development of applications for multi-sensor data fusion typically faces heterogeneous hardware components, a variety of sensing principles and limited computational resources. We present a concept for synchronization and communication which tackles these challenges in multi-sensor systems in a unified manner. Here, a combination of hardware synchronization and deterministic software signals is promoted for global synchronization. Patterns of event-driven communication ensure that sensor data processing and evaluation are not bound to runtime constraints induced by data acquisition anymore. The combination of unified range and pose data description, event-driven communication, and global synchronization allows to build 3dsensing applications for various tasks. The proposed concept is implemented and evaluated for a variety of applications based on the DLR Multisensory 3D-Modeller. Extendability to other range and pose sensors is straight forward

Mixed Reality for Intuitive Photo-Realistic 3D-Model Generation

Appropriate user-interfaces are mandatory for an intuitive and efficient digitisation of real objects with a hand-held scanning device. We discuss two central aspects involved in this process, i.e., view-planning and navigation. We claim that the streaming generation of the 3D model and the immediate visualisation best support the user in the view-planning task. In addition, we promote the mixed visualisation of the real and the virtual object for a good navigation support. The paper outlines the components of the used scanning device and the processing pipeline, consisting of synchronisation, calibration, streaming surface generation, and texture mapping