Semantic-based policy engineering for autonomic systems

This paper presents some important directions in the use of ontology-based semantics in achieving the vision of Autonomic Communications. We examine the requirements of Autonomic Communication with a focus on the demanding needs of ubiquitous computing environments, with an emphasis on the requirements shared with Autonomic Computing. We observe that ontologies provide a strong mechanism for addressing the heterogeneity in user task requirements, managed resources, services and context. We then present two complimentary approaches that exploit ontology-based knowledge in support of autonomic communications: service-oriented models for policy engineering and dynamic semantic queries using content-based networks. The paper concludes with a discussion of the major research challenges such approaches raise

Phylogenetic and non-phylogenetic structure in trophic links between gall-forming herbivores and their parasitoid natural enemies.

Revealing processes that structure species interactions is central to understanding community assembly and dynamics. Species interact via their phenotypes, but identifying and quantifying the traits that structure species-specific interactions (links) can be challenging. Where these traits show phylogenetic signal, however, link properties are predictable using models that incorporate phylogenies in place of trait data. We analysed variation in link richness, frequency, and identity in a multi-site dataset of interactions between host oak cynipid galls and parasitoid natural enemies, using a Bayesian mixed modelling framework allowing concurrent fitting of terms for phylogenies of both trophic levels. In both link incidence (presence/absence) and link frequency datasets, we identified strong signatures of cophylogeny (related parasitoids attack related host galls) and patterns independent of either phylogeny. Our results are robust to simulations of substantially reduced sample completeness, and are consistent with the structuring of trophic interactions by a combination of phylogenetically conserved and convergently evolving traits at both trophic levels. We discuss our results in light of phenotypic traits thought to structure gall-parasitoid interactions and wider applications of this approach, including inference of underlying community assembly processes and prediction of economically important trophic interactions

Phylogenetic and non-phylogenetic structure in trophic links between gall-forming herbivores and their parasitoid natural enemies.

Revealing processes that structure species interactions is central to understanding community assembly and dynamics. Species interact via their phenotypes, but identifying and quantifying the traits that structure species-specific interactions (links) can be challenging. Where these traits show phylogenetic signal, however, link properties are predictable using models that incorporate phylogenies in place of trait data. We analysed variation in link richness, frequency, and identity in a multi-site dataset of interactions between host oak cynipid galls and parasitoid natural enemies, using a Bayesian mixed modelling framework allowing concurrent fitting of terms for phylogenies of both trophic levels. In both link incidence (presence/absence) and link frequency datasets, we identified strong signatures of cophylogeny (related parasitoids attack related host galls) and patterns independent of either phylogeny. Our results are robust to simulations of substantially reduced sample completeness, and are consistent with the structuring of trophic interactions by a combination of phylogenetically conserved and convergently evolving traits at both trophic levels. We discuss our results in light of phenotypic traits thought to structure gall-parasitoid interactions and wider applications of this approach, including inference of underlying community assembly processes and prediction of economically important trophic interactions

Structure and composition of tritrophic communities associated with Fagaceae-feeding cynipid gallwasps in Sichuan, China

We provide the first description and analysis of species-rich communities of Fagaceae host plants, cynipid gall inducers and Hymenopteran parasitoids from two sites in western Sichuan, China. We use quantified interaction data to test the hypothesis that metabolically intimate cynipid-Fagaceae interactions are more specialised, resulting in more modular networks and stronger signatures of turnover than nestedness for beta diversity, than associations between parasitoids and Fagaceae. Rearing of nearly 27,000 cynipid gall specimens from 22 host plant species in Castanea, Castanopsis, Lithocarpus and Quercus (sections Cerris, Cyclobalanopsis, Ilex and Quercus) yielded 168 morphologically distinct cynipid gall morphotypes, and 3800 parasitoids in 67 morphospecies. The Sichuan parasitoid assemblage is similar in composition to cynipid-centred communities in the Western Palearctic and Nearctic. All of our predictions were confirmed. We discuss our findings in light of the processes thought to structure tritrophic interactions centred on gall inducing insect herbivores

Evolution of host-plant associations and biogeographic patterns on a global scale within the oak gall wasps

Co-evolutionary interactions between insect herbivores and their host plants underlie much contemporary biodiversity and are vital to assembly of natural ecosystems. Assemblages of galls on oaks induced by Cynipini wasps (Hymenoptera: Cynipidae) occur across much of the Northern Hemisphere, their diversity peaking in the Nearctic and on white oaks (Quercus section Quercus). However, the evolutionary history of the clade has been debated with respect to geographic origins, direction and timings of dispersal events, and shifts in host plant associations. We examined these questions using a global-scale, 6-gene phylogeny of 430 Cynipini species and a dataset of their associated host plants encompassing all eight sections within Quercus plus five Fagaceae genera. Likelihood-based ancestral state reconstructions demonstrate a Nearctic origin of the Cynipini followed by repeated colonisations of the Palearctic via both westwards and eastwards dispersal. These inferences are robust to bias in taxon sampling across continents and the inclusion of Protobalandricus as the sister lineage to Cynipini sensu stricto. Likewise, the association with white oaks is probably ancestral and has been retained by many Cynipini lineages. However, host shifts to other sections within Quercus and related Fagaceae genera are widely distributed across the cynipid phylogeny. They are associated with both global-scale range shifts and within-bioregion exploitation of alternative hosts, and their frequency typically correlates with host-plant relatedness. These findings highlight the evolutionary success of cynipids on white oak hosts and the connectedness of continental assemblages of gall wasps over evolutionary time

Diffusion in supersonic, turbulent, compressible flows

We investigate diffusion in supersonic, turbulent, compressible flows. Supersonic turbulence can be characterized as network of interacting shocks. We consider flows with different rms Mach numbers and where energy necessary to maintain dynamical equilibrium is inserted at different spatial scales. We find that turbulent transport exhibits super-diffusive behavior due to induced bulk motions. In a comoving reference frame, however, diffusion behaves normal and can be described by mixing length theory extended into the supersonic regime.Comment: 11 pages, incl. 5 figures, accepted for publication in Physical Review E (a high-resolution version is available at http://www.aip.de./~ralf/Publications/p21.abstract.html

Thermoregulation of foraging honeybees on flowering plants: seasonal variability and influence of radiative heat gain

1. During nectar and pollen foraging in a temperate climate, honeybees are exposed to a broad range of ambient temperatures, challenging their thermoregulatory ability. The body temperature that the bees exhibit results from endothermic heat production, exogenous heat gain from solar radiation, and heat loss. In addition to profitability of foraging, season was suggested to have a considerable influence on thermoregulation. To assess the relative importance of these factors, the thermoregulatory behaviour of foragers on 33 flowering plants in dependence on season and environmental factors was investigated

Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201

Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

The $B_s^0\to J/\psi K_S^0$ branching fraction is measured in a data sample corresponding to 0.41$fb^{-1}$ of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2$\beta$ measurement from $B^0\to J/\psi K_S^0$ The time-integrated branching fraction is measured to be $BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}$. This is the most precise measurement to date