The Waggle Dance as an Intended Flight: A Cognitive Perspective

The notion of the waggle dance simulating a flight towards a goal in a walking pattern has been proposed in the context of evolutionary considerations. Behavioral components, like its arousing effect on the social community, the attention of hive mates induced by this behavior, the direction of the waggle run relative to the sun azimuth or to gravity, as well as the number of waggles per run, have been tentatively related to peculiar behavioral patterns in both solitary and social insect species and are thought to reflect phylogenetic pre-adaptations. Here, I ask whether these thoughts can be substantiated from a functional perspective. Communication in the waggle dance is a group phenomenon involving the dancer and the followers that perform partially overlapping movements encoding and decoding the message respectively. It is thus assumed that the dancer and follower perform close cognitive processes. This provides us with access to these cognitive processes during dance communication because the follower can be tested in its flight performance when it becomes a recruit. I argue that the dance message and the landscape experience are processed in the same navigational memory, allowing the bee to fly novel direct routes, a property understood as an indication of a cognitive map

Multi-level algorithms for modularity clustering

Modularity is one of the most widely used quality measures for graph clusterings. Maximizing modularity is NP-hard, and the runtime of exact algorithms is prohibitive for large graphs. A simple and effective class of heuristics coarsens the graph by iteratively merging clusters (starting from singletons), and optionally refines the resulting clustering by iteratively moving individual vertices between clusters. Several heuristics of this type have been proposed in the literature, but little is known about their relative performance. This paper experimentally compares existing and new coarsening- and refinement-based heuristics with respect to their effectiveness (achieved modularity) and efficiency (runtime). Concerning coarsening, it turns out that the most widely used criterion for merging clusters (modularity increase) is outperformed by other simple criteria, and that a recent algorithm by Schuetz and Caflisch is no improvement over simple greedy coarsening for these criteria. Concerning refinement, a new multi-level algorithm is shown to produce significantly better clusterings than conventional single-level algorithms. A comparison with published benchmark results and algorithm implementations shows that combinations of coarsening and multi-level refinement are competitive with the best algorithms in the literature.Comment: 12 pages, 10 figures, see http://www.informatik.tu-cottbus.de/~rrotta/ for downloading the graph clustering softwar

Non-symmetric Convex Polytope and Gabor Orthonormal Bases

In this paper, we show that the non-symmetric convex polytope cannot be served as a window function to produce a Gabor orthonormal basis by any time-frequency sets.Comment: In-press for Proc. Amer. Math So

Parameter estimation for semilinear SPDEs from local measurements

This work contributes to the limited literature on estimating the diffusivity or drift coefficient of nonlinear SPDEs driven by additive noise. Assuming that the solution is measured locally in space and over a finite time interval, we show that the augmented maximum likelihood estimator introduced in Altmeyer, Reiss (2020) retains its asymptotic properties when used for semilinear SPDEs that satisfy some abstract, and verifiable, conditions. The proofs of asymptotic results are based on splitting the solution in linear and nonlinear parts and fine regularity properties in $L^p$-spaces. The obtained general results are applied to particular classes of equations, including stochastic reaction-diffusion equations. The stochastic Burgers equation, as an example with first order nonlinearity, is an interesting borderline case of the general results, and is treated by a Wiener chaos expansion. We conclude with numerical examples that validate the theoretical results.Comment: corrected versio

The role of the life cycle for the survival of the riparian wolf spiders Pardosa wagleri (HAHN, 1822) and Pirata knorri (SCOPOLl, 1763)

Quantitative, time-limited samplings in monthly intervals from June 1995 to August 1996, in combination with the measurement of carapace width of juvenile and adult spiders has revealed the life cycle patterns of the riparian wolf spiders Pardosa wagleri and Pirata knorri and showed the effect of floods on their abundance at the Isar River (Germany, Bavaria). Adults and juvenile spiders are heavily affected by floods but the populations of both species are able to recover quickly. The life cycles of both species are synchronized with the season and display a spring/summer stenochrony. P. wagleri shows a second reproductive phase in early summer. This reproductive behaviour supports the persistence of populations in this disturbed environment

Ökoweinbau: Mit Qualität zum Erfolg!

Im Vorfeld der 13. IFOAM-Wissenschaftskonferenz fand vom 25.-26.August 2000 in Basel der 6. Internationale Kongress für ökologischen Weinbau statt. Organisiert vom Forschungsinstitut für biologischen Landbau (FiBL), dem Schweizerischen Bioweinbauverein (BIOVIN), ECOVIN/ Deutschland und der Stiftung Ökologie & Landbau (SÖL) sowie einem Expertengremium aus Deutschland und der Schweiz trafen sich ca. 180 Teilnehmer zum Erfahrungsaustausch im Kongresszentrum Basel. Der Kongress bot unter dem Titel „Mit Qualität zum Erfolg“ ein breites Informations- und Diskussionsforum zu anbautechnischen, oenologischen sowie vermarktungstechnischen Aspekten

Publikationsliste Randolf Kauer

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Muonic hydrogen and the proton radius puzzle

The extremely precise extraction of the proton radius by Pohl et al. from the measured energy difference between the 2P and 2S states of muonic hydrogen disagrees significantly with that extracted from electronic hydrogen or elastic electron-proton scattering. This is the proton radius puzzle. The origins of the puzzle and the reasons for believing it to be very significant are explained. Various possible solutions of the puzzle are identified, and future work needed to resolve the puzzle is discussed.Comment: Minor modifications, some references added, to appear in Annu. Rev. Nucl. Part. Sci. Vol 63 (2013). 60 pages, 5 figures, 1 tabl