Male Attractiveness Is Influenced by UV Wavelengths in a Newt Species but Not in Its Close Relative

Background: Functional communication in the UV range has been reported in Invertebrates and all major groups of Vertebrates but Amphibians. Although perception in this wavelength range has been shown in a few species, UV signalling has not been demonstrated in this group. One reason may be that in lentic freshwater habitats, litter decomposition generates dissolved organic carbon that absorbs UV radiation and thus hinders its use for visual signalling. We tested the effect of male UV characteristics on female sexual preference in two newt species that experience contrasting levels of UV water transmission when breeding. Methodology/Principal Findings: We analysed water spectral characteristics of a sample of breeding ponds in both species. We quantified male ventral coloration and measured male attractiveness under two lighting conditions (UV present, UV absent) using a no-choice female preference design. UV transmission was higher in Lissotriton vulgaris breeding sites. Male UV patterns also differed between experimental males of the two species. We observed a first common peak around 333 nm, higher in L. vulgaris, and a second peak around 397 nm, more frequent and higher in L. helveticus. Male attractiveness was significantly reduced in L. vulgaris when UV was not available but not in L. helveticus. Male attractiveness depended on the hue of the first UV peak in L. vulgaris. Conclusion/Significance: Our study is the first report of functional UV-based communication in Amphibians. Interestingly

Towards robust vision-based self-localization of vehicles in dense urban environments

Self-localization of ground vehicles in densely populated urban environments poses a significant challenge. The presence of tall buildings in close proximity to traversable areas limits the use of GPS-based positioning techniques in such environments. This paper presents an approach to global localization on a hybrid metric-topological map using a monocular camera and wheel odometry. The global topology is built upon spatially separated reference places represented by local image features. In contrast to other approaches we employ a feature selection scheme ensuring a more discriminative representation of reference places while simultaneously rejecting a multitude of features caused by dynamic objects. Through fusion with additional local cues the reference places are assigned discrete map positions allowing metric localization within the map. The self-localization is carried out by associating observed visual features with those stored for each reference place. Comprehensive experiments in a dense urban environment covering a time difference of about 9 months are carried out. This demonstrates the robustness of our approach in environments subjected to high dynamic and environmental changes. © 2012 IEEE

Basic Services, Architecture and Design

This report is the first publicly available technical deliverable of SEMPER, "Secure Electronic Marketplace for Europe." It describes the main results on the security architecture of the first year (September 1995- August 1996). The main objective of SEMPER is to develop, implement, trial and evaluate an open security architecture for electronic commerce over open networks (e.g., the Internet). This will be done in several steps starting with a trial of basic services after the first year followed by the implementation and evaluation of more advanced trials in the following two years. This report describes the initial version of the SEMPER architecture, the initial design and how it will be implemented. Details on the integration of this implementation in the trials can be found in Deliverable D04 ("Basic Services, Prototype and Internet Trial"), while more information on the trials can be found in Deliverable D05 ("First Year Surveys and Evaluation"). The architecture of SEMPER defines a set of service layers. The lowest layer contains supporting services (archiving, cryptographic functions, communication, user interface). On top of this, a transfer layer provides services for electronic payment and secure transfer of documents. The next layer, the exchange layer, combines transfers into fair exchanges, e.g., contract signing, certified mail. These services are used by the commerce layer to provide more complex business primitives, e.g., "send order" for filling in a pre-defined order template, signing it, and sending it to the business partner. The architecture is open: New service modules can be integrated via generic API's (e.g., new payment systems by adapting them to a generic payment API). New business applications (e.g., an on-line auction) can be supported via ..