Communicating climate science: The role of perceived communicator’s motives

In two experimental studies, we investigated the effects of public perceptions of climate scientists’ communicative motives on trust in scientists and willingness to engage with climate science messages. Study 1 demonstrated that members of the public who were led to believe that scientists aim to inform about the consequences of climate change (rather than to persuade to take a particular course of action) reported higher trust in scientists and stronger willingness to engage in environmental behaviour. Study 2 revealed that this effect was moderated by the style of the scientific message that participants were exposed to. Participants who expected scientists to engage in persuasion were more receptive to persuasive rather than informative messages, while the opposite was true for participants who believed that scientists’ purpose was purely to inform. In both studies the effects of perceived motives on willingness to act in line with the climate change messages were mediated through trust in scientists. The data demonstrate that managing public expectations about the purposes of science communication and delivering messages that are consistent with these expectations are a key to successful communication of climate science.     

Conversion of nitrogen oxides on commercial photocatalytic dispersion paints

In the present study, photocatalytic reactions of nitrogen oxides (NO_x = NO + NO₂) were studied on commercial TiO₂ doped facade paints in a flow tube photoreactor under simulated atmospheric conditions. Fast photocatalytic conversion of NO and NO₂ was observed only for the photocatalytic paints and not for non-catalytic reference paints. Nitrous acid (HONO) was formed in the dark on all paints studied, however, it efficiently decomposes under irradiation only on the photocatalytic samples. Thus, it is concluded that photocatalytic paint surfaces do not represent a daytime source of HONO, in contrast to other recent studies on pure TiO₂ surfaces. As main final product, the formation of adsorbed nitric acid/nitrate anion (HNO₃/NO₃^?) was observed with near to unity yield. In addition, traces of H₂O₂ were observed in the gas phase only in the presence of O₂. Formation of the greenhouse gas nitrous oxide (N₂O) could be excluded. The uptake kinetics of NO, NO₂ and HONO was very fast under atmospheric conditions (e.g. γ(NO + TiO₂) > 10^?5). Thus, the uptake on urban surfaces (painted houses, etc.) will be limited by transport. For a hypothetically painted street canyon, an average reduction of nitrogen oxide levels of ca. 5% is estimated. Since the harmful HNO₃/NO₃^? is formed on the surface of the photoactive paints, whereas it is formed in the gas phase in the atmosphere, the use of photocatalytic paints may also help to reduce acid deposition, e.g. on plants, or nitric acid related health issues.     

Occupational embeddedness and job performance

While researchers have recently focused their attention on organizational embeddedness, occupational embeddedness has received little theoretical and empirical attention. Using multisource data on 162 employees in multiple jobs and organizations, we found that occupational embeddedness is positively related to both task performance and creativity and is negatively related to counterproductive work behavior, even after controlling for the effects of organizational embeddedness. In addition, we found that trait affect moderated the relationships of occupational embeddedness to job performance. Occupational embeddedness was more strongly related to counterproductive work behavior when trait negative affect was high, while occupational embeddedness was more strongly related to both citizenship behavior and creativity when trait positive affect was high. Results also indicated that the various components of occupational embeddedness had different effects on job outcomes. Fit had a strong positive effect on core task performance, links had a positive effect on creativity, and sacrifice had a small positive effect on citizenship behavior. The article concludes with a discussion of implications for future research and management practice. Copyright © 2009 John Wiley & Sons, Ltd.     

Dust explosions: How should the influence of humidity be taken into account?

In this work, the influence of humidity on dust explosions of metallic (aluminium) and organic materials (icing sugar, polyethylene and magnesium stearate) has been studied. The impact of pre-humidification of powders on their ignition sensitivity, their volume resistivity and charge decay time has been assessed. The influence of humidity on explosion severity has also been studied by two methods: on the one hand, the dust sample was stored in a controlled workstation at constant relative humidity; on the other hand, the dry dust was dispersed in a humidity controlled atmosphere in the vessel.As expected, the effect of humidity strongly depends on the chemical nature of the particles. Experiments on powders volume resistivity and charge decay time have shown typical trends but have especially pointed out the inadequacy of some standards. Inhibition phenomena have been verified for polyethylene and magnesium stearate, whereas both inhibition and promotion have been observed for icing sugar and could be explained by an evolution of sucrose structure. Dry aluminium dust explosions in humid atmosphere show that water vapour inerts the explosion. However, when aluminium is stored at controlled humidity, the maximum rise of pressure rate increases with the water content, which is probably due to hydrogen generation.     

The effect of the exposure time on the value of a manSievert averted

The basis of the manSievert as a unit for collective radiation dose is discussed and previous recommendations are considered for how much should be spent to avert a collective dose of 1 manSv. New calculations are given using the J-value method. It is shown that the value to be assigned to averting a manSievert depends on the duration of averted exposure as well as on the net discount rate and the loan rate thought to be appropriate. Different figures will result depending on whether the exposed group consists of workers or the general public. The variation with dose duration is so large that it is not possible to recommend a single figure for the value of a manSievert. Instead, tables are given at two conservative, loan and net discount rates for the value of a manSievert as a function of exposure time. The base data for the J-value method need to be updated annually, and this means that the values given in the tables will increase over time as people live longer and become richer.     

Spatial Variability of Nitrate Concentrations Under Diverse Conditions in Tributaries to a Lake Watershed1

Abstract: Nitrate‐nitrogen (NO₃‐N) concentrations in stream water often respond uniquely to changes in inter‐annual conditions (e.g., biological N uptake and precipitation) in individual catchments. In this paper, we assess (1) how the spatial distribution of NO₃‐N concentrations varies across a dense network of nonnested catchments and (2) how relationships between multiple landscape factors [within whole catchments and hydrologically sensitive areas (HSAs) of the catchments] and stream NO₃‐N are expressed under a variety of annual conditions. Stream NO₃‐N data were collected during two synoptic sampling events across >55 tributaries and two synoptic sampling periods with >11 tributaries during summer low flow periods. Sample tributaries drain mixed land cover watersheds ranging in size from 0.150 to 312 km² and outlet directly to Cayuga Lake, New York. Changes in NO₃‐N concentration ratios between each sampling event suggest a high degree of spatial heterogeneity in catchment response across the Cayuga Lake Watershed, ranging from 0.230 to 61.4. Variations in NO₃‐N concentrations within each of the large synoptic sampling events were also high, ranging from 0.040 to 8.7 mg NO₃‐N/l (March) and 0.090 to 15.5 mg NO₃‐N/l (October). Although Pearson correlation coefficients suggest that this variability is related to multiple landscape factors during all four sampling events, partial correlations suggest percentage of row crops in the catchments as the only similar factor in March and October and catchment area as the only factor during summer low flows. Further, the strength of the relationships is typically lower in the HSAs of catchment. Advancing current understanding of such variations and relationships to landscape factors across multiple catchments – and under a variety of biogeochemical and hydrological conditions – is important, as (1) nitrate continues to be employed as an indicator of regional aquatic ecosystem health and services and (2) a unified framework approach for understanding individual catchment processes is a rapidly evolving focus for catchment‐based science and management.     

Daily Updating of Operational Statistical Seasonal Water Supply Forecasts for the western U.S.1

Abstract: Official seasonal water supply outlooks for the western United States are typically produced once per month from January through June. The Natural Resources Conservation Service has developed a new outlook product that allows the automated production and delivery of this type of forecast year‐round and with a daily update frequency. Daily snow water equivalent and water year‐to‐date precipitation data from multiple SNOTEL stations are combined using a statistical forecasting technique (“Z‐Score Regression”) to predict seasonal streamflow volume. The skill of these forecasts vs. lead‐time is comparable to the official published outlooks. The new product matches the intra‐monthly trends in the official forecasts until the target period is partly in the past, when the official forecasts begin to use information about observed streamflows to date. Geographically, the patterns of skill also match the official outlooks, with highest skill in Idaho and southern Colorado and lowest skill in the Colorado Front Range, eastern New Mexico, and eastern Montana. The direct and frequent delivery of objective guidance to users is a significant new development in the operational hydrologic seasonal forecasting community.     

Reconstructed Streamflows for the Headwaters of the Wind River,Wyoming, United States1

Abstract: Tree rings offer a means to extend observational records of streamflow by hundreds of years, but dendrohydrological techniques are not regularly applied to small tributary and headwaters gages. Here we explore the potential for extending three such gage records on small streams in the Wind River drainage of central Wyoming, United States. Using core samples taken from Douglas fir (Pseudotsuga menziesii), piñon pine (Pinus edulis), and limber pine (Pinus flexilis) at 38 sites, we were able to reconstruct streamflows for the headwaters of the Wind River back to 1672 AD or earlier. The streamflow reconstructions for Bull Lake Creek above Bull Lake; the Little Popo Agie River near Lander, Wyoming; and Wind River near Dubois, Wyoming explained between 40% and 64% of the observed variance, and these extended records performed well in a variety of statistical verification tests. The full reconstructions show pronounced inter‐annual variability in streamflow, and these proxy records also point to the prevalence of severe, sustained droughts in this region. These reconstructions indicate that the 20th Century was relatively wet compared to previous centuries, and actual gage records may capture only a limited subset of potential natural variability in this area. Further analyses reveal how tree‐ring based reconstructions for small tributary and headwaters gages can be strongly influenced by the length and quality of calibration records, but this work also demonstrates how the use of a spatially extensive network of tree‐ring sites can improve the quality of these types of reconstructions.     

Leaching from MSWI bottom ash: evaluation of non-equilibrium in column percolation experiments

Impacts of non-equilibrium on results of percolation experiments on municipal solid waste incineration (MSWI) bottom ash were investigated. Three parallel column experiments were performed: two columns with undisturbed percolation and one column with two sets of 1-month-long flow interruptions applied at liquid-to-solid (L/S) ratios of L/S 2L/kg and 12L/kg, respectively. Concentrations of Na, K, Cl(-), Ca, Si, SO(4)(2-), Al, Cu, Ni, Mo, Ba, Pb, Zn, and dissolved organic carbon (DOC) were monitored throughout the entire leaching period; geochemical modeling was used to identify non-equilibrium-induced changes in the solubility control. Despite both physical and chemical non-equilibrium, the columns were found to provide adequate information for readily soluble compounds (i.e., Na, Cl(-), and K) and solubility-controlled elements (i.e., Ca, SO(4)(2-), Ba, Si, Al, Zn, and Pb). The leaching of Cu and Ni was shown to depend strongly on DOC leaching, which was likely affected by physical non-equilibrium during flow interruptions. Consequently, the leaching of Cu and Ni in the undisturbed columns was shown to be by about one order of magnitude lower compared with the interrupted column. The results indicate that the leaching of DOC-related metals in laboratory column experiments may be considerably underestimated compared with full-scale scenarios in which the impacts from non-equilibrium may be significantly lower. The leaching of Mo (or MoO(4)(2-)) may be controlled solely by its availability in the mobile zone, which in turn appeared to be controlled by diffusion from the stagnant zone; no Mo controlling minerals were predicted by the geochemical modeling.     

Occurrence and distribution of PCB metabolites in blood and their potential health effects in humans: a review

In recent years, attention has been directed to chemicals with possible endocrine-disrupting properties. Polychlorinated biphenyls (PCBs) and their metabolites belong to one group of environmental contaminants that have been shown to interact with the endocrine system in mammals, including humans. Although recent developments have been made in terms of determination of PCB metabolites in blood samples, still limited number of studies have been able to elucidate their profiles and toxicological and health effects in humans. This review aims to evaluate and compare the levels of hydroxylated PCBs (OH-PCBs) and methyl sulfone PCBs (MeSO₂-PCBs) in blood and their relationship to parent compounds and also address the potential risks and adverse health effects in humans. Levels of OH-PCBs varied between 0.0002 and 1.6 ng g^?1 w/w in human serum/plasma from the selected literature, correlating well with ∑PCBs. In contrast, ∑OH-PCB/∑PCB ratio in animals did not show a significant correlation, which might suggest that the bioaccumulation plays an even more important role in the concentration of OH-PCBs compared to PCB metabolism. Highest levels of MeSO₂-PCBs were reported in marine mammals with high selectivity retention in the liver. Health effects of PCB metabolites included carcinogenicity, reproductive impairment, and developmental neurotoxicity, being more efficiently transferred to the brain and across the placenta from mother to fetus in comparison to the parent PCBs. Based on the lack of knowledge on the occurrence and distribution of lower chlorinated OH-PCBs in humans, further studies to identify and assess the risks associated to human exposure are essential.