(M)VOC and composting facilities. Part 1: (M)VOC emissions from municipal biowaste and plant refuse

GOAL, SCOPE AND BACKGROUND: Malodorous volatiles derived from the decomposition of biowaste within the process of composting might pose a risk to human health. Different techniques of process engineering have been developed to minimise the burden of malodorous compounds in air possibly affecting compost workers and residents in the vicinity. METHODS: In the present study, three different composting facilities were examined for the emission of volatiles to estimate the impact of process engineering on the dispersal of odorous compounds and to discuss its relevance for human health. RESULTS AND DISCUSSION: Concentrations of single compounds belonging to alcohols, ketones, furanes, sulfur-containing compounds and especially terpenes ranged from 10(2) up to nearly 10(6) ng/m3 depending on the sampling sites and the process engineering. The ratio of MVOC and total VOC measured changed throughout the process of biodegradation. A certain combination of volatile compounds coincided with the occurrence of typical compost odour. CONCLUSION: The type of process engineering seemed to have a major impact on the emission of volatiles, as amounts of (microbial) volatiles emitted were characteristic for the different techniques used. Thus, the MVOC emission basically depends on the degree of biodegradation. It is likely that the concentrations workers are exposed to can have an impact on human health. RECOMMENDATIONS AND OUTLOOK: It is obvious that less sophisticated types of process engineering give rise to greater amounts of bioaerosols and volatiles and, therefore, technical devices have to be improved and controlled regularly to minimise adverse health effects on workers.     

Mental representations of animal and plant species in their social contexts: Results from a survey across Europe

Despite a growing body of literature on public views on biodiversity and nature, our understanding of public attitudes towards animal and plant species is still rudimentary. This study investigates mental representations, constituted by beliefs, of three types of species (a large mammal, a spider and a non-native plant), and explores their links with cultural factors such as value orientations and cultural capital, in order to better understand attitudes towards these species.We conducted a survey in eight sites across Europe (n = 2378) and found strong relationships between beliefs about species, in particular with regard to their harmlessness, value and previous population change, and the desirability of an increase in this species. Other beliefs, such as perceived nativeness, were less influential. We discuss how respondents combined beliefs to mental representations of species, and show how representations are related to species-independent factors that tap respondents’ cultural context, such as socially shared value orientations and education.     

Communicating About Smoke from Wildland Fire: Challenges and Opportunities for Managers

Wildland fire and associated management efforts are dominant topics in natural resource fields. Smoke from fires can be a nuisance and pose serious health risks and aggravate pre-existing health conditions. When it results in reduced visibility near roadways, smoke can also pose hazardous driving conditions and reduce the scenic value of vistas. Communicating about smoke, whether in the preparation phases before a planned burn or during a wildfire event, can enable those at risk to make informed decisions to minimize their exposure to smoke or choose alternate activities that mitigate smoke completely. To date, very little research has been completed on the social aspects of smoke, such as communication or public perceptions. Here, we present findings from an exploratory study that examined challenges and opportunities related to communication (within agencies or to the public) for management of smoke from wildland fires. Interviews were conducted in California, Oregon, Montana, and South Carolina among a purposive sample of individuals, who are involved in fire or smoke management. Findings indicate that smoke poses several challenges to management agencies. Findings also provide insight into potential strategies to address such challenges by improving communication in both inter- and intra-agency situations as well as with members of the public. In particular, prioritizing fire and smoke-related communication within agencies, allocating agency resources specifically for training in communication and outreach endeavors, taking advantage of existing resources including informal social networks among the public, and building long-term relationships both between agencies and with the public were viewed as effective.     

Higher calcification costs at lower temperatures do not break the temperature-size rule in an intertidal gastropod with determinate growth

The vast majority of ectothermic organisms grow larger when developing at cooler environmental temperatures, a pattern frequently referred to as the temperature-size rule (TSR). Assuming that this reaction norm has adaptive significance, life history theory predicts that converse patterns may evolve if favored by natural selection, namely if the costs associated with complying to the TSR outweigh the benefits. Calcifying ectotherms may comprise such an exception not following the TSR, because calcification is expected to be more costly at lower temperatures thus increasing associated costs. To test this hypothesis, we reared wild-caught juveniles of the intertidal gastropod Monetaria annulus and compared their shell sizes at the end of the juvenile stage between two rearing temperatures. Contrary to our prediction, M. annulus does follow the TSR, suggesting that increased calcification costs at lower temperatures are not high enough to break the TSR. Such plastic responses should be considered when interpreting geographical patterns such as latitudinal size clines, which may be caused at least partly by phenotypic plasticity.     

Male baboon responses to experimental manipulations of loud “wahoo calls”: testing an honest signal of fighting ability

Among male chacma baboons (Papio hamadryas ursinus), rank positions in the dominance hierarchy are fiercely contested. Physical fighting is costly but relatively rare in this species. Instead, disputes are frequently resolved using displays that include loud, repetitive “wahoo” (two-syllable bark) vocalizations. We previously found that males of all ranks adjust their contest behavior based on the relative fighting ability of opponents and that length of the second syllable (“hoo” duration), calling rate, and fundamental frequency reliably indicate fighting ability. To test whether males indeed attend to hoo duration when assessing opponents, we designed two sets of playback experiments in which call sequence pairs were identical except for this single modified feature. In experiment 1, we used calls recorded from high-ranking males unfamiliar to all subjects. In experiment 2, callers were familiar rivals that ranked one position below subjects in the dominance hierarchy. In paired analyses, subjects in both experiments responded more strongly to sequences with more intense signal features (most commonly associated with high-quality males) compared to sequences with relatively less exaggerated features (most often associated with low-quality males). Results suggest that males can use acoustic features to both indirectly evaluate strangers and to monitor the changing condition of those rivals that present the biggest intragroup threat to their position in the dominance hierarchy. Taken together with our previous research, baboons appear to follow a classic assessor strategy—signal features related to rank and condition are salient to males and directly affect their propensity to respond to rivals.     

Are micro reactors inherently safe? An investigation of gas phase explosion propagation limits on ethene mixtures

A method for the determination of safety properties for micro reactors and micro structured components is presented. Micro structured reactors are not inherently safe but the range of safe operating conditions of micro reactors are extended since the explosion region is reduced. The λ/3 rule was demonstrated to be applicable to micro scale tubes for stoichiometric mixtures of ethane–oxygen and ethane–nitrous oxide. Furthermore first results from an investigation concerning detonation propagation through a micro reactor of non-ideal geometry are shown. Initial pressure investigated is ranging from low pressure up to 100 kPa.