Risk communication as an operation meant to produce and share audiences

In this article, Luhmann's system theory is used as a theoretical framework for analysing the way risk communicators view their social functions. Narrated experiences from risk communicators in practice facilitate an understanding of risk communication as both an external irritation to society and part of the mass communication system. They also aid in clarifying how perceptions of audiences are reflected in the risk-communication strategies. The analysis is based on qualitative data collected from in-depth interviews conducted with 22 risk communicators (scientific professionals, spokespeople and journalists) in Israel. Thematic areas reflected in interviewees' reported strategies embody their perception of audiences. Those themes include: the reduction of complexities; coding and sorting of information; autopoiesis (realisation/non-realisation of the risk); rationality; inherent paradoxes; and schema formation. In sum, the findings suggest that risk communicators play a major role in defining, creating and producing audiences for the mass communication system

DEGRADATION AND MOBILITY OF PETROLEUM HYDROCARBONS IN OILSANDS WASTE AT THE AURORA FORT HILLS DISPOSAL AREA

Surface mining in the Athabasca oil sands region of Northern Alberta, Canada, results in the disturbance of significant areas of boreal forest landscape. The Aurora Soil Capping Study is a reclamation research project that aims to find the optimal soil capping (cover) material and thickness to re-establish a boreal forest ecosystem above a lean oil sands (LOS) disposal area at Syncrude's Aurora North mine. The objectives of this laboratory and field-based study are to (1) characterize the in-situ hydrocarbon composition of the LOS material, (2) determine the effect of temperature on rates of gas flux and the biodegradation potential of petroleum hydrocarbons (PHC) as a result of microbial activity and (3) determine the potential for PHC to leach into the groundwater system. The results of the laboratory-study show that temperature has a significant effect on the rate of PHC degradation as indicated by the linear relationship observed between temperature and CO2 gas flux rates. The respiratory results from the laboratory-based study were consistent and relatively comparable with data from the field study, which indicates that the column study could be useful in estimating in situ PHC degradation

Gold nanoparticles electrodeposited on glassy carbon using cyclic voltammetry: Application to Hg(II) trace analysis

The electrochemical determination of Hg(II) at trace level using gold nanoparticles–modified glassy carbon (AuNPs–GC) electrodes is described. Starting from HAuCl4 in NaNO3, gold nanoparticles (AuNPs) were deposited onto Glassy Carbon (GC) electrodes using Cyclic Voltammetry (CV). Different deposits were obtained by varying the global charge consumed during the whole electroreduction step, depending on the number of cyclic potential scans (N). AuNPs were characterized as a function of the charge using both CV in H2SO4 and Field Emission Gun Scanning Electron Microscopy (FEG-SEM). The AuNPs–GC electrodes were then applied to determine low Hg(II) concentrations using Square Wave Anodic Stripping Voltammetry (SWASV). The AuNPs–GC electrodes provided significantly improved performances in Hg(II) determination compared to unmodified GC and bare Au electrodes. It was shown that the physico-chemical properties of the deposits are correlated to the performances of the AuNPs–GC electrode with respect to Hg(II) assay. The best results were obtained for four electrodeposition cyclic scans, where small-sized particles (36 ± 13 nm) with high density (73 particles μm-²) were obtained. Under these conditions, a linearity range from 0.64 to 4.00 nM and a limit of detection of 0.42 nM were obtained

Molybdenum Induces the expression of a protein containing a new heterometallic Mo-Fe cluster in desulfoVibrio alaskensis

Biochemistry. 2009 Feb 10;48(5):873-82. doi: 10.1021/bi801773t.The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.5 Da. The UV/visible absorption spectrum of the as-isolated protein shows absorption peaks around 280, 320, and 570 nm with extinction coefficients of 18700, 12800, and 5000 M(-1) cm(-1), respectively. Metal content, EXAFS data and DFT calculations support the presence of a Mo-2S-[2Fe-2S]-2S-Mo cluster never reported before. Analysis of the available genomes from Desulfovibrio species shows that the MorP encoding gene is located downstream of a sensor and a regulator gene. This type of gene arrangement, called two component system, is used by the cell to regulate diverse physiological processes in response to changes in environmental conditions. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 microM molybdenum. Involvement of this system in Mo tolerance of sulfate reducing bacteria is proposed

Using markers and field evaluation to identify the source of eyespot resistance gene Pch1 in the collection of wheat breeding lines

Pch1 gene translocated from Aegilops ventricosa provides effective resistance to eyespot in wheat. To track the Pch1 gene introgression, we investigated 372 genotypes obtained from various breeding programs using endopeptidase EpD1b marker, sequence-tagged-site (STS) marker XustSSR2001-7DL, and the score of infection index (K-index) evaluated after in vivo inoculation test. These genotypes were divided into three groups with 136, 124 and 112 genotypes for the field test lasting three years. In 2011, the mean K-index was 0.81, while 2012 and 2013 the mean K-indexes were 1.60 and 1.46, respectively. Both marker results indicated that 18 genotypes possessed Pch1 gene. Statistical analysis of the level of K-index showed that these 18 genotypes were resistant to eyespot, which verified the proper assignment of wheat genotypes with Pch1 gene based on the marker data. Thus, the endopeptidase and XustSSR2001-7DL are useful for identifying sources of eyespot resistance gene Pch1 in wheat breeding program