Evidence of microbial activity from a shallow water whale fall (Voghera, northern Italy)

The fossil bones, associated carbonate cements and enclosing concretion of a Miocene mysticete from inner shelf deposits (Monte Vallassa Formation, northern Italy) were analyzed for evidence of microbial activity. Optical and scanning electron microscopy, Raman spectroscopy, and stable C and O isotope geochemistry were used for high spatial resolution microfacies and biosedimentological analyses. Whale cancellous bones were filled by different carbonate cements including microcrystalline dolomite, rhombohedral dolomite and sparry calcite. Biofabric and biominerals such as microbial peloids, clotted textures and pyrite framboids were associated with the dolomite cements. Dolomite inside cancellous bones and in the enclosing concretion showed similar isotopic values (avg δ 13C: -7.12‰; avg δ 18O: +3.81‰), depleted with respect to the (late) sparry calcite cement (avg δ 13C: -0.55‰; avg δ 18O: -0.98‰). Microcrystalline barite (BaSO 4) was observed on the external surface of the bones. In addition, two different types of microborings were recognized, distinguished by their size and morphology and were ascribed respectively to prokaryote and fungal trace makers. Our results testify for the development of a diverse microbial ecosystem during the decay of a shallow water whale carcass, which could be detected in the fossil record. However, none of the observed biosignatures (e.g., microbial peloids, clotted textures) can be used alone as a positive fossil evidence of the general development of a sulfophilic stage of whale fall ecological succession. The occurrence of the hard parts of chemosynthetic invertebrates associated with fossil whale bones is still the more convincing proof of the development of a sulfide-base chemoautotrophic ecosystem. © 2011 Elsevier B.V

Complex delay dynamics on railway networks from universal laws to realistic modelling

This is the final version. Available from EDP Sciences via the DOI in this record.The datasets supporting the conclusions of this article are included within the article (and its additional files).Railways are a key infrastructure for any modern country. The reliability and resilience of this peculiar transportation system may be challenged by different shocks such as disruptions, strikes and adverse weather conditions. These events compromise the correct functioning of the system and trigger the spreading of delays into the railway network on a daily basis. Despite their importance, a general theoretical understanding of the underlying causes of these disruptions is still lacking. In this work, we analyse the Italian and German railway networks by leveraging on the train schedules and actual delay data retrieved during the year 2015. We use these data to infer simple statistical laws ruling the emergence of localized delays in different areas of the network and we model the spreading of these delays throughout the network by exploiting a framework inspired by epidemic spreading models. Our model offers a fast and easy tool for the preliminary assessment of the effectiveness of traffic handling policies, and of the railway network criticalities.John Templeton FoundationAustrian Research Promotion Agency FFGNewton International FellowshipThe Royal SocietyThe British AcademyAcademy of Medical Science

An Agent Based Model of Air Traffic Management

The WP-E ELSA project aims at developing an empirically grounded agent based model that describes some of the stylized facts observed in the Air Traffic Management of the European airspace. The model itself has two main parts: (i) The strategic layer, focused on the interaction between the Network Manager and the Airline Operators and (ii) the tactical layer, focused on aircraft and controllers behaviour in Air Traffic Control (ATC) sectors. The preliminary results for the strategic layer show that when we have a mixing of re-routing and shifting companies, the overall satisfaction can even increase together with the number of flights, which is an effect not observed when only one type of companies is present. The preliminary results for the tactical layer indicate that when shocks in the system are confined in small areas, the interplay between the re-routing and change of flight level strategies may even lead to trajectory modifications that give smaller average delays as long as the number of shocks increases

Coccolithophores from the Southeast Greenland Margin (Northern North Atlantic): production, ecology and the surface sediment record

A total of 27 coccolithophorid species were identified in water samples from the Southeast Greenland Margin taken during the late summer 1997. This is the first report of coccolithophorids present in this region, so close to the extreme environment of Greenland's shoreline. Surprisingly, a consistent standing crop of temperate coccolithophorid species occurs, despite environmental conditions with sea surface water covered by ice for most of the year. Cell concentrations range between 1.7×1