Residential building and occupant vulnerability to pyroclastic density currents in explosive eruptions

International audienceA major hazard during the eruption of explosive volcanoes is the formation of pyroclastic density currents (PDCs). Casualties and physical building damage from PDCs are caused by the temperature, pressure, and particle load of the flow. This paper examines the vulnerability of buildings and occupants to the forces imposed by PDCs along with associated infiltration of PDC particle and gas mixtures into an intact building. New studies are presented of building and occupant vulnerability with respect to temperature, pressure, and ash concentration. Initial mitigation recommendations are provided

Use of near- and mid-IR hyperspectral imaging for paint identification, as an aid for artwork authentication

In recent years various scientific practices have been adapted to the artwork analysis process and a set of techniques was found advantageous for conservation and restoration works. Apart of these applications, art market also benefits from scientific testing of artwork. Although these services are already available to support determination of the authenticity of traded pieces, they are very expensive and time consuming and therefore serve only very limited range of transactions. As a response for requirements of growing market there is a need for rapid and non-destructive methods empowering art authentication

Use of hyperspectral imaging for artwork authentication

In recent years various scientific practices have been adapted to the artwork analysis process and a set of techniques was found advantageous for conservation and restoration works. Apart of these applications, art market also benefits from scientific testing of artwork. Although these services are available to determine authenticity of traded pieces, they are very expensive and time consuming and therefore serve only very limited range of transactions. As a response for requirements of growing market there is a need for rapid and non-destructive methods empowering art authentication. Hyperspectral imaging combined with signal processing and classification techniques are proposed as a tool to enhance the identification of art forgeries. Using bespoke paintings designed for this work, a spectral library of selected pigments was established and the viability of training and the application of classification techniques based on this data was demonstrated. Developed techniques were used for the analysis of actual forged paintings held by the Berlin police, which comprised known and suspected forgeries from the infamous Beltracchi case. The analysis resulted in the identification of anachronistic paint, confirming the falsity of the artwork. Figure 1 illustrates one of analysed paintings and result of the classification, indicating Titanium White – a pigment known as anachronistic for this case

Cuttlefish responses to visual orientation of substrates, water flow and a model of motion camouflage

Low-level mechanisms in vertebrate vision are sensitive to line orientation. Here we investigate orientation sensitivity in the cuttlefish Sepia pharaonis, by allowing animals to settle on stripe patterns. When camouflaging themselves cuttlefish are known to be sensitive to image parameters such as contrast and spatial scale, but we find no effect of background orientation on the patterns displayed. It is nonetheless clear that the animals see orientation, because they prefer to rest with the body-axis perpendicular to the stripes. We consider three possible mechanisms to account for this behaviour. Firstly, that the body patterns are themselves oriented, and that the cuttlefish align themselves to aid static camouflage. This is unlikely, as the patterns displayed have no dominant orientation at any spatial scale. A second possibility is that motion camouflage favours alignment of the body orthogonal to background stripes, and we suggest how this alignment can minimise motion signals produced by occlusion. Thirdly we show that cuttlefish prefer to rest with their body-axis parallel to the water flow, and it is possible that they use visual patterns such as sand ripples to determine water flow

Centerscope

Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.

Structure of an archaeal PCNA1-PCNA2-FEN1 complex: elucidating PCNA subunit and client enzyme specificity.

The archaeal/eukaryotic proliferating cell nuclear antigen (PCNA) toroidal clamp interacts with a host of DNA modifying enzymes, providing a stable anchorage and enhancing their respective processivities. Given the broad range of enzymes with which PCNA has been shown to interact, relatively little is known about the mode of assembly of functionally meaningful combinations of enzymes on the PCNA clamp. We have determined the X-ray crystal structure of the Sulfolobus solfataricus PCNA1-PCNA2 heterodimer, bound to a single copy of the flap endonuclease FEN1 at 2.9 A resolution. We demonstrate the specificity of interaction of the PCNA subunits to form the PCNA1-PCNA2-PCNA3 heterotrimer, as well as providing a rationale for the specific interaction of the C-terminal PIP-box motif of FEN1 for the PCNA1 subunit. The structure explains the specificity of the individual archaeal PCNA subunits for selected repair enzyme 'clients', and provides insights into the co-ordinated assembly of sequential enzymatic steps in PCNA-scaffolded DNA repair cascades

A Biochemically Active MCM-like Helicase in Bacillus Cereus

The mini-chromosome maintenance (MCM) proteins serve as the replicative helicases in archaea and eukaryotes. Interestingly, an MCM homolog was identified, by BLAST analysis, within a phage integrated in the bacterium Bacillus cereus (Bc). BcMCM is only related to the AAA region of MCM-helicases; the typical amino-terminus is missing and is replaced by a segment with weak homology to primases. We show that BcMCM displays 3'-->5' helicase and ssDNA-stimulated ATPase activity, properties that arise from its conserved AAA domain. Isolated BcMCM is a monomer in solution but likely forms the functional oligomer in vivo. We found that the BcMCM amino-terminus can bind ssDNA and harbors a zinc atom, both hallmarks of the typical MCM amino-terminus. No BcMCM-catalyzed primase activity could be detected. We propose that the divergent amino-terminus of BcMCM is a paralog of the corresponding region of MCM-helicases. A divergent amino terminus makes BcMCM a useful model for typical MCM-helicases since it accomplishes the same function using an apparently unrelated structure.Molecular and Cellular Biolog

Securing Water, Sustaining Growth: Report of the GWP/OECD Task Force on Water Security and Sustainable Growth

Peer Revie

Reflections on conspicuous sustainability: Creating Small Island Dependent States (SIDS) through Ostentatious Development Assistance (ODA)?

It is frequently noted that small islands, including Small Island Developing States (SIDS), receive hugely disproportionate levels of aid or official development assistance (ODA) relative to other states and territories. However, the precise relationship between 'islandness' and aid remains underexamined. This paper uses the concept of 'conspicuous sustainability' as a framework for understanding the propensity for aid to be directed toward small island territories. We argue (1) that aid donors have reasons for preferring engagement in development projects that are particularly conspicuous, irrespective of actual development outcomes and (2) that small island territories are exceptionally well-placed to produce such conspicuousness. We use the case of the construction of the 'climate-resilient' Dominica label following Hurricane Maria in 2017 to illustrate how both aid donors and recipients can be motivated to pursue short-term projects aimed at currently fashionable areas in the field of development (such as climate change resilience) instead of addressing areas with greater potential to foster lasting improvements and built local capacity. We ultimately recommend a greater awareness of the false economies of conspicuous ODA and aid

Precautionary Regulation in Europe and the United States: A Quantitative Comparison

Much attention has been addressed to the question of whether Europe or the United States adopts a more precautionary stance to the regulation of potential environmental, health, and safety risks. Some commentators suggest that Europe is more risk-averse and precautionary, whereas the US is seen as more risk-taking and optimistic about the prospects for new technology. Others suggest that the US is more precautionary because its regulatory process is more legalistic and adversarial, while Europe is more lax and corporatist in its regulations. The flip-flop hypothesis claims that the US was more precautionary than Europe in the 1970s and early 1980s, and that Europe has become more precautionary since then. We examine the levels and trends in regulation of environmental, health, and safety risks since 1970. Unlike previous research, which has studied only a small set of prominent cases selected non-randomly, we develop a comprehensive list of almost 3,000 risks and code the relative stringency of regulation in Europe and the US for each of 100 risks randomly selected from that list for each year from 1970 through 2004. Our results suggest that: (a) averaging over risks, there is no significant difference in relative precaution over the period, (b) weakly consistent with the flip-flop hypothesis, there is some evidence of a modest shift toward greater relative precaution of European regulation since about 1990, although (c) there is a diversity of trends across risks, of which the most common is no change in relative precaution (including cases where Europe and the US are equally precautionary and where Europe or the US has been consistently more precautionary). The overall finding is of a mixed and diverse pattern of relative transatlantic precaution over the period