Chiral tricarbonylcyclobutadieneiron complexes

An optically active tricarbonylcyclobutadieneiron complex has been prepared and was found to racemize much more slowly than related butadienetricarbonyliron complexes

Geobiology of the late Paleoproterozoic Duck Creek Formation, Western Australia

The ca. 1.8 Ga Duck Creek Formation, Western Australia, preserves 1000 m of carbonates and minor iron formation that accumulated along a late Paleoproterozoic ocean margin. Two upward-deepening stratigraphic packages are preserved, each characterized by peritidal precipitates at the base and iron formation and carbonate turbidites in its upper part. Consistent with recent studies of Neoarchean basins, carbon isotope ratios of Duck Creek carbonates show no evidence for a strong isotopic depth gradient, but carbonate minerals in iron formations can be markedly depleted in C-13. In contrast, oxygen isotopes covary strongly with depth; delta O-18 values as positive as 2%. VPDB in peritidal facies systematically decline to values of 6 to 16% in basinal rocks, reflecting, we posit, the timing of diagenetic closure. The Duck Creek Formation contains microfossils similar to those of the Gunflint Formation, Canada; they are restricted to early diagenetic cherts developed in basinal facies, strengthening the hypothesis that such fossils capture communities driven by iron metabolism. Indeed, X-ray diffraction data indicate that the Duck Creek basin was ferruginous throughout its history. The persistence of ferruginous waters and iron formation deposition in Western Australia for at least several tens of millions of years after the transition to sulfidic conditions in Laurentia suggests that the late Paleoproterozoic expansion of sulfidic subsurface waters was globally asynchronous

Ferox Trout (Salmo trutta) as `Russian dolls':complementary gut content and stable isotope analyses of the Loch Ness foodweb

1. Conventional collection methods for pelagic fish species (netting, trawling) are impractical or prohibited in Loch Ness, U.K. To investigate trophic relationships at the top of the Loch Ness food web, an alternative strategy, angling, provided samples of the top predator, the purely piscivorous ferox trout (Salmo trutta). 2. The gut contents of these fish provided further samples of prey-fish, and subsequent examination of prey-fish guts revealed their dietary intake, analogous to the famous nested `Russian dolls'. Each trophic level separated by gut content analysis provided further complementary samples for stable isotope analysis and thus information on the longer term, assimilated diet. 3. Ferox trout exhibited considerable cannibalism to supplement a diet of Arctic charr (Salvelinus alpinus). However, conspecifics stemmed from a lower isotopic baseline in relation to charr, so ferox trout exhibited a lower trophic level than predicted (4.3) by using the δ15N values. Charr displayed dietary specialisation with increasing length, and isotopic values supported by the gut data placed the charr at a trophic level of 3.5. The isotope data also indicated that charr carbon was primarily autochthonous in origin

A new ultra long-spanning, combined steel formwork and reinforcement hybrid decking system using cold-formed components

A new ultra long-spanning, combined steel formwork and reinforcement system designed to span up to 6 or 7 metres (20.7 or 23 feet) without propping has been under development for nearly a decade in Australia. The steel decking system includes a number of innovative features that make it adaptable to almost any type of building construction ranging from conventional, shallow one-way composite slabs in steel-frame buildings to deep two-way post-tensioned slabs in concrete-frame buildings. The hybrid system comprises a number of distinctly different cold-formed steel components, which have efficient shapes and utilize different thicknesses, steel grades and coatings. The overall height of the main decking panel can vary from 90 to 260 mm (3.54 to 10.24 in) with an additional three intermediate sizes, despite the components being made from the same roll- forming equipment. The panel has a closed cellular section and is pre-cambered to limit the final deflection under wet-concrete conditions. These panels can be interconnected for maximum spanning capability, or else different types of in fill panels can be fitted between them to form composite slabs with a variety of cross-sectional shapes and features. Slabs of minimum overall depth or minimum weight can be constructed using the system. The cellular section can form a void in the concrete, or it can have holes pre-punched in its webs allowing it to be filled with concrete either partially or completely along its length. Prestressing cables and reinforcing bars can be fitted longitudinally and if need be transversely in the slab, even in the soffit region. Comprehensive sets of structural tests, some quite innovative, are currently being performed to thoroughly investigate the behaviour of the system for both the formwork and composite states. In particular, this involves developing a complete understanding of the complex behaviour of the main decking panel and its different cold-formed components under a variety of loading conditions that induce vertical and longitudinal shear, longitudinal and transverse bending, and torsion. The behaviour of the mechanical connection between the elements is being closely investigated experimentally, allowing the moment capacity of potentially critical cross-sections with partial shear connection to be accurately predicted and the spacing between connections optimised

Risk Analysis and Bioeconomics of Invasive Species to Inform Policy and Management

Risk analysis of species invasions links biology and economics, is increasingly mandated by international and national policies, and enables improved management of invasive species. Biological invasions proceed through a series of transition probabilities (i.e., introduction, establishment, spread, and impact), and each of these presents opportunities for management. Recent research advances have improved estimates of probability and associated uncertainty. Improvements have come from species-specific trait-based risk assessments (of estimates of introduction, establishment, spread, and impact probabilities, especially from pathways of commerce in living organisms), spatially explicit dispersal models (introduction and spread, especially from transportation pathways), and species distribution models (establishment, spread, and impact). Results of these forecasting models combined with improved and cheaper surveillance technologies and practices [e.g., environmental DNA (eDNA), drones, citizen science] enable more efficient management by focusing surveillance, prevention, eradication, and control efforts on the highest-risk species and locations. Bioeconomic models account for the interacting dynamics within and between ecological and economic systems, and allow decision makers to better understand the financial consequences of alternative management strategies. In general, recent research advances demonstrate that prevention is the policy with the greatest long-term net benefit

Modernising EU programme management

Unlike public administration systems in many member states, the management of EU programmes has not, until recently, been subject to a radical modernizing agenda. Following the resignation of the Santer Commission in March 1999, a wide ranging programme of management reform has been introduced by the European Commission. Based on the findings of the committee of independent experts reports of 1999, a reform White Paper was published by Commissioner Kinnock in March 2000 with the intention of implementing many of these proposals and adding some new ones. This article will review the content and progress of these reforms in the context of the 'New Public Management/Modernising Government' paradigm, and compare them with earlier change packages initiated by the outgoing commission. The likely trajectory of the current initiatives will be evaluated against this experience taking into account recent Court of Auditor'sfindings