The Greedy Dirichlet Process Filter - An Online Clustering Multi-Target Tracker

Reliable collision avoidance is one of the main requirements for autonomous driving. Hence, it is important to correctly estimate the states of an unknown number of static and dynamic objects in real-time. Here, data association is a major challenge for every multi-target tracker. We propose a novel multi-target tracker called Greedy Dirichlet Process Filter (GDPF) based on the non-parametric Bayesian model called Dirichlet Processes and the fast posterior computation algorithm Sequential Updating and Greedy Search (SUGS). By adding a temporal dependence we get a real-time capable tracking framework without the need of a previous clustering or data association step. Real-world tests show that GDPF outperforms other multi-target tracker in terms of accuracy and stability

Antagonism of the mammalian target of rapamycin selectively mediates metabolic effects of epidermal growth factor receptor inhibition and protects human malignant glioma cells from hypoxia-induced cell death

Although inhibition of the epidermal growth factor receptor is a plausible therapy for malignant gliomas that, in vitro, enhances apoptosis, the results of clinical trials have been disappointing. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that integrates starvation signals and generates adaptive responses that aim at the maintenance of energy homeostasis. Antagonism of mTOR has been suggested as a strategy to augment the efficacy of epidermal growth factor receptor inhibition by interfering with deregulated signalling cascades downstream of Akt. Here we compared effects of antagonism of mTOR utilizing rapamycin or a small hairpin RNA-mediated gene silencing to those of epidermal growth factor receptor inhibition or combined inhibition of epidermal growth factor receptor and mTOR in human malignant glioma cells. In contrast to epidermal growth factor receptor inhibition, mTOR antagonism neither induced cell death nor enhanced apoptosis induced by CD95 ligand or chemotherapeutic drugs. However, mTOR inhibition mimicked the hypoxia-protective effects of epidermal growth factor receptor inhibition by maintaining adenosine triphosphate levels. These in vitro experiments thus challenge the current view of mTOR as a downstream target of Akt that mediates antiapoptotic stimuli. Under the conditions of the tumour microenvironment, metabolic effects of inhibition of epidermal growth factor receptor, Akt and mTOR may adversely affect outcome by protecting the hypoxic tumour cell fractio

Schülervorstellungen zu ''Energie im biologischen Kontext'' : Ermittlungen, Analysen und Schlussfolgerungen

Burger J. Schülervorstellungen zu ''Energie im biologischen Kontext'' : Ermittlungen, Analysen und Schlussfolgerungen. Bielefeld (Germany): Bielefeld University; 2001.Zahlreiche Untersuchungen zur Effizienz des aktuellen naturwissenschaftlichen Unterrichts machen auch auf einen mangelnden Kompetenzzuwachs der Schüler im Biologieunterricht aufmerksam. Die vorliegende Arbeit ist ein Beitrag zur Verminderung von Lernschwierigkeiten im Biologieunterricht der Sekundarstufen durch vermehrte Berücksichtigung von Schülervorstellungen zu "Energie im biologischen Kontext" in konstruktivistischer Lernumgebung. Es werden zwei Lösungsansätze verfolgt: Der inhaltliche Ansatz versucht, durch das vermehrte Analysieren von Phänomenen des Lebendigen aus energetischer Sicht Lernschwierigkeiten im Biologieunterricht zu vermindern. Der methodische Ansatz versucht, durch eine vermehrte Berücksichtigung von Schülervorstellungen bei der inhaltlichen und methodischen Planung und Durchführung von Biologieunterricht eine effektivere Vermittlung naturwissenschaftlichen Wissens zu ermöglichen. Zur unterrichtlichen Umsetzung der beiden Ansätze wurden zunächst die themenrelevanten Schülervorstellungen zu "Energie im biologischen Kontext" ermittelt und analysiert. Die hierzu nötige Befragung wurde 1996 mit Schülern von 6 Gymnasien und einer Gesamtschule aus städtischen und ländlichen Regionen Nordrhein-Westfalens in einer Fragebogenstudie durchgeführt. Zur qualitativen Absicherung der erhobenen Vorstellungen fanden zum einen eine Interviewstudie und zum anderen neun eigenständige Begleitstudien zu eingegrenzten Aspekten der Thematik "Energie im biologischen Kontext" statt

Fast 3D Extended Target Tracking using NURBS Surfaces

This paper proposes fast and novel methods to jointly estimate the target's unknown 3D shape and dynamics. Measurements are noisy and sparsely distributed 3D points from a light detection and ranging (LiDAR) sensor. The methods utilize non-uniform rational B-splines (NURBS) surfaces to approximate the target's shape. One method estimates Cartesian scaling parameters of a NURBS surface, whereas the second method estimates the corresponding NURBS weights, too. Major advantages are the capability of estimating a fully 3D shape as well as the fast processing time. Real-world evaluations with a static and dynamic vehicle show promising results compared to state-of-the-art 3D extended target tracking algorithms.Comment: In Proceedings of IEEE Intelligent Transportation Systems Conference (ITSC), 201

Svortices and the fundamental modes of the "snake instability": Possibility of observation in the gaseous Bose-Einstein Condensate

The connection between quantized vortices and dark solitons in a long and thin, waveguide-like trap geometry is explored in the framework of the non-linear Schr\"odinger equation. Variation of the transverse confinement leads from the quasi-1D regime where solitons are stable to 2D (or 3D) confinement where soliton stripes are subject to a transverse modulational instability known as the ``snake instability''. We present numerical evidence of a regime of intermediate confinement where solitons decay into single, deformed vortices with solitonic properties, also called svortices, rather than vortex pairs as associated with the ``snake'' metaphor. Further relaxing the transverse confinement leads to production of 2 and then 3 vortices, which correlates perfectly with a Bogoliubov-de Gennes stability analysis. The decay of a stationary dark soliton (or, planar node) into a single svortex is predicted to be experimentally observable in a 3D harmonically confined dilute gas Bose-Einstein condensate.Comment: 4 pages, 4 figure

A revised density split statistic model for general filters

Studying the statistical properties of the large-scale structure in the Universe with weak gravitational lensing is a prime goal of several current and forthcoming galaxy surveys. The power that weak lensing has to constrain cosmological parameters can be enhanced by considering statistics beyond second-order shear correlation functions or power spectra. One such higher-order probe that has proven successful in observational data is the density split statistics (DSS), in which one analyses the mean shear profiles around points that are classified according to their foreground galaxy density. In this paper, we generalise the most accurate DSS model to allow for a broad class of angular filter functions used for the classification of the different local density regions. This approach is motivated by earlier findings showing that an optimised filter can provide tighter constraints on model parameters compared to the standard top-hat case. We build on large deviation theory approaches and approximations thereof to model the matter density PDF, and on perturbative calculations of higher-order moments of the density field. The novel addition relies on the generalisation of these previously employed calculations to allow for general filter functions and is validated on several sets of numerical simulations. The revised model fits well the simulation measurements, with a residual systematic offset that is small compared to the statistical accuracy of current weak lensing surveys. The accuracy of the model is slightly lower for a compensated filter than for a non-negative filter function, and that it increases with the filter size. Using a Fisher matrix approach, we find constraints comparable to the commonly used two-point cosmic shear measures. Hence, our DSS model can be used in competitive analyses of current cosmic shear data, while it may need refinements for forthcoming lensing surveys.Comment: 21 pages, 13 figure

Population genomic analysis of elongated skulls reveals extensive female-biased immigration in Early Medieval Bavaria

Modern European genetic structure demonstrates strong correlations with geography, while genetic analysis of prehistoric humans has indicated at least two major waves of immigration from outside the continent during periods of cultural change. However, population-level genome data that could shed light on the demographic processes occurring during the intervening periods have been absent. Therefore, we generated genomic data from 41 individuals dating mostly to the late 5th/early 6th century AD from present-day Bavaria in southern Germany, including 11 whole genomes (mean depth 5.56×). In addition we developed a capture array to sequence neutral regions spanning a total of 5 Mb and 486 functional polymorphic sites to high depth (mean 72×) in all individuals. Our data indicate that while men generally had ancestry that closely resembles modern northern and central Europeans, women exhibit a very high genetic heterogeneity; this includes signals of genetic ancestry ranging from western Europe to East Asia. Particularly striking are women with artificial skull deformations; the analysis of their collective genetic ancestry suggests an origin in southeastern Europe. In addition, functional variants indicate that they also differed in visible characteristics. This example of female-biased migration indicates that complex demographic processes during the Early Medieval period may have contributed in an unexpected way to shape the modern European genetic landscape. Examination of the panel of functional loci also revealed that many alleles associated with recent positive selection were already at modern-like frequencies in European populations ∼1,500 years ago