University of Marburg

About: University of Marburg is a education organization based out in Marburg, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 23195 authors who have published 42907 publications receiving 1506069 citations. The organization is also known as: Philipps University of Marburg & Philipps-Universität.

Two routes to actorhood: lexicalized potency to act and identification of the actor role

Abstract: The inference of causality is a crucial cognitive ability and language processing is no exception: recent research suggests that, across different languages, the human language comprehension system attempts to identify the primary causer of the state of affairs described (the "actor") quickly and unambiguously (Bornkessel-Schlesewsky & Schlesewsky, 2009). This identification can take place verb-independently based on certain prominence cues (e.g. case, word order, animacy). Here, we present two experiments demonstrating that actor potential is also encoded at the level of individual nouns (a king is a better actor than a beggar). Experiment 1 collected ratings for 180 German nouns on 12 scales defined by adjective oppositions and deemed relevant for actorhood potential. By means of structural equation modeling, an actor potential (ACT) value was calculated for each noun. Experiment 2, an ERP study, embedded nouns from Experiment 1 in verb-final sentences, in which they were either actors or non-actors. N400 amplitude increased with decreasing ACT values and this modulation was larger for highly frequent nouns and for actor versus non-actor nouns. We argue that potency to act is lexically encoded for individual nouns and, since it modulates the N400 even for non-actor participants, it should be viewed as a property that modulates ease of lexical access (akin, for example, to lexical frequency). We conclude that two separate dimensions of actorhood computation are crucial to language comprehension: an experience-based, lexically encoded (bottom-up) representation of actorhood potential, and a prominence-based, computational mechanism for calculating goodness-of-fit to the actor role in a particular (top-down) sentence context.

DrugScore(CSD)-knowledge-based scoring function derived from small molecule crystal data with superior recognition rate of near-native ligand poses and better affinity prediction.

Abstract: Following the formalism used for the development of the knowledge-based scoring function DrugScore, new distance-dependent pair potentials are obtained from nonbonded interactions in small organic molecule crystal packings. Compared to potentials derived from protein−ligand complexes, the better resolved small molecule structures provide relevant contact data in a more balanced distribution of atom types and produce potentials of superior statistical significance and more detailed shape. Applied to recognizing binding geometries of ligands docked into proteins, this new scoring function (DrugScoreCSD) ranks the crystal structures of 100 protein−ligand complexes best among up to 100 generated decoy geometries in 77% of all cases. Accepting root-mean-square deviations (rmsd) of up to 2 A from the native pose as well-docked solutions, a correct binding mode is found in 87% of the cases. This translates into an improvement of the new scoring function of 57% with respect to the retrieval of the crystal structu...

Investigating the zoonotic origin of the West African Ebola epidemic

Abstract: The severe Ebola virus disease epidemic occurring in West Africa stems from a single zoonotic transmission event to a 2-year-old boy in Meliandou, Guinea. We investigated the zoonotic origins of the epidemic using wildlife surveys, interviews, and molecular analyses of bat and environmental samples. We found no evidence for a concurrent outbreak in larger wildlife. Exposure to fruit bats is common in the region, but the index case may have been infected by playing in a hollow tree housing a colony of insectivorous free-tailed bats (Mops condylurus). Bats in this family have previously been discussed as potential sources for Ebola virus outbreaks, and experimental data have shown that this species can survive experimental infection. These analyses expand the range of possible Ebola virus sources to include insectivorous bats and reiterate the importance of broader sampling efforts for understanding Ebola virus ecology.

Population size and the risk of local extinction: empirical evidence from rare plants

Abstract: 488.Due to habitat fragmentation many plant species today occur mainly in small andisolated populations. Modeling studies predict that small populations will bethreatened more strongly by stochastic processes than large populations, but there islittle empirical evidence to support this prediction for plants. We studied therelationship between size of local populations (number of flowering plants) andsurvival over ten years for 359 populations of eight short-lived, threatened plants innorthern Germany (Lepidium campestre, Thlaspi perfoliatum, Rhinanthus minor, R.serotinus, Melampyrum arvense, M. nemorosum, Gentianella ciliata and G.germanica). Overall, 27% of the populations became extinct during the study period.Probability of survival of a local population increased significantly with its size in allbut one species (R. minor). However, estimated population sizes required for 90%probability of survival over 10 years varied widely among species. Survival probabilityincreased with decreasing distance to the nearest conspecific population in R. serotinus,but not in the other species. The mean annual growth rate of surviving populationsdiffered greatly between species, but was only for G. germanica significantly lower than1, suggesting that there was no general deterministic decline in the number of plantsdue to deteriorating habitat conditions. We conclude that the extinction of populationswas at least partly due to stochastic processes. This is supported by the fact that in allspecies a considerable proportion of small populations survived and developed intolarge populations.D. Matthies, Plant Ecology, Dept of Biology, Univ. of Marburg, DE-35032 Marburg,Germany (matthies@staff.uni-marburg.de).

Testing enforcement strategies in the field: threat, moral appeal and social information

Abstract: We run a large-scale natural field experiment to evaluate alternative strategies to enforce compliance with the law. The experiment varies the text of mailings sent to potential evaders of TV license fees. We find a strong effect of mailings, leading to a substantial increase in compliance. Among different mailings, a threat treatment which makes a high detection risk salient has a significant deterrent effect. Neither appealing to morals nor imparting information about others' behavior enhances compliance on aggregate. However, the information condition has a weak positive effect in municipalities where evasion is believed to be common. (authors' abstract)