Changes in toxicity and Ah receptor agonist activity of suspended particulate matter during flood events at the rivers Neckar and Rhine — a mass balance approach using in vitro methods and chemical analysis

Background, aim, and scope  

As a consequence of flood events, runoff and remobilized sediments may cause an increase of ecotoxicologically relevant effects from contaminant reservoirs. Aquatic and terrestrial organisms as well as cattle and areas of settlement are exposed to dislocated contaminants during and after flood events. In this study, the impacts of two flood events triggered by intense rain at the rivers Neckar and Rhine (Southern Germany) were studied. Effects in correlation to flood flow were assessed at the river Neckar using samples collected at frequent intervals. River Rhine suspended particulate matter (SPM) was sampled over a longer period at normal flow and during a flood event. Three cell lines (H4L1.1c4, GPC.2D.Luc, RTL-W1) were used to compare Ah receptor agonist activity in different biotest systems. Multilayer fractionation was performed to identify causative compounds, focusing on persistent organic contaminants.     

Wind energy and natural ventilation potential of a wind catcher in Yazd – Iran (a long-term measurement)

When designing energy efficient buildings it is useful to study existing climate—responsive building typologies. The wind towers or wind-catchers of Yazd city in Iran are typical examples of such a typology. Although many previous studies have investigated the performance of various types of wind catcher systems, studies based on a long-term real-life measurement can be rarely found. In this study a long-term whole year monitoring campaign on an existing full scale four sided wind catcher in Yazd was carried out in 2014–2015. Three prevailing wind directions were identified and the measured on-site wind speeds were used to estimate the wind induced natural ventilation potential of the tower. A shaft/tower airflow performance index was developed. The monitoring results were compared to the ASHRAE Standard 62:2001 ventilation rate requirement. Results show that the total ventilation rate of the wind tower surpasses the ASHRAE Standard requirements. Furthermore it shows that the shafts are exposed to the prevailing wind directions perform better. For more effective natural ventilation a wind tower with adaptable openings/shafts are proposed.     

Policy, personal dispositions and the evaluation of aircraft noise

In this paper, we hypothesize and test the ideas that (1) people’s subjectivity in relation to aircraft noise is shaped by the policy discourse, (2) this results in a limited number of frames towards aircraft noise, (3) the frames inform people how to think and feel about aircraft noise and (4) the distribution of the frames in the population is dependent on structural variables related to the individual. To reveal subjects’ frames of aircraft noise a latent class model is estimated based on survey data gathered among a sample of 250 residents living near Amsterdam Airport Schiphol, a major international airport in the Netherlands. In line with expectations, the results show that there are four evaluative frames of aircraft noise, three of which are strongly linked to the policy discourse. The frames are associated with fitting levels of annoyance response. In turn, frame membership is influenced by two structural variables, namely aircraft noise exposure and noise sensitivity. The results indicate that social factors operate discursively in the explanation of subjective reaction to noise, while psychological factors operate within a traditional cause-and-effect model. The paper concludes with several policy implications.     

Indoor NO2 pollution and personal exposure to NO2 in two areas with different outdoor NO2 pollution

Indoor NO₂ concentrations were measured in the kitchen, the living room and bedroom of 612 houses in two different areas in the Netherlands. In a group of housewives living in these homes, personal exposure to NO₂ was measured. NO₂ concentrations indoors were dependent on the presence or absence of (un)vented gas appliances. Personal NO₂ exposure was only different between the two areas in the group with the lowest indoor concentrations. In this study, it was determined that gas appliances inside the house are the most important factor with respect to NO₂ exposure and that outside NO₂ concentration played a secondary role, except in situations where gas appliances were absent.     

On nonepistemic values in conservation biology

Conservation biology is a uniquely interdisciplinary science with strong roots in ecology, but it also embraces a value‐laden and mission‐oriented framework. This combination of science and values causes conservation biology to be at the center of critique regarding the discipline's scientific credibility—especially the division between the realms of theory and practice. We identify this dichotomy between seemingly objective (fact‐based) and subjective (value‐laden) practices as the measure‐value dichotomy, whereby measure refers to methods and analyses used in conservation biology (i.e., measuring biodiversity) and value refers to nonepistemic values. We reviewed and evaluated several landmark articles central to the foundation of conservation biology and concepts of biodiversity with respect to their attempts to separate measures and values. We argue that the measure‐value dichotomy is false and that conservation biology can make progress in ways unavailable to other disciplines because its practitioners are tasked with engaging in both the realm of theory and the realm of practice. The entanglement of measures and values is by no means a weakness of conservation biology. Because central concepts such as biodiversity contain both factual and evaluative aspects, conservation biologists can make theoretical progress by examining, reviewing, and forming the values that are an integral part of those concepts. We suggest that values should be included and analyzed with respect to the methods, results, and conclusions of scientific work in conservation biology.     

Degradation of toxaphene in aged and freshly contaminated soil

Degradation of toxaphene in soil from both newly contaminated (from Sweden) and aged spills (from Nicaragua) were studied. The newly contaminated soil contained approximately 11 mg kg(-1) toxaphene while the aged Nicaraguan soil contained approximately 100 mg kg(-1). Degradation was studied in anaerobic bioreactors, some of which were supplied with lactic acid and others with Triton X-114. In this study we found that the lower isomers Parlar 11, 12 were degraded while the concentration of isomer Parlar 15 increased. This supported an earlier evaluation which indicated that less chlorinated isomers are formed from more heavily isomers. Lactic acid when added to the soil, interfere with the degradation of toxaphene. Lactic acid was added; several isomers appeared to degrade rather slowly in newly contaminated Swedish soil. The Swedish soil, without any external carbon source, showed the slowest degradation rate of all the compounds studied. When Triton X-114 at 0.4 mM was added, the degradation rate of the compounds increased. This study illustrates that biodegradation of toxaphene is a complex process and several parameters have to be taken into consideration. Degradation of persistent pollutants in the environment using biotechnology is dependent on bioavailability, carbon sources and formation of metabolites.     

Dufour gland secretion in the harvester ant genus <Emphasis Type="Italic">Pogonomyrmex</Emphasis>

Summary. Dufour gland secretions of the harvester ants Pogonomyrmex barbatus, P. rugosus and P. maricopa were investigated. The glandular blends exhibit species specific patterns, but more importantly, based on indiviual profiles of Dufour gland contents of colony members it is possible to separate the colonies from each other in each species. It is possible that these collective colony specific cues serve as longer lasting trunk route markers. Behavioral tests demonstrate that workers of P. rugosus prefer homing routes marked by members of their own colony to routes marked by a foreign conspecific colony.     

An agent based model to simulate structural and land use changes in agricultural systems of the argentine pampas

The Argentine Pampas, one of the main agricultural areas in the world, recently has undergone significant changes in land use and structural characteristics of agricultural production systems. Concerns about the environmental and societal impacts of the changes motivated development of an agent-based model (ABM) to gain insight on processes underlying recent observed patterns. The model is described following a standard protocol (ODD). Results are discussed for an initial set of simplified simulations performed to understand the processes that generated and magnified the changes in the Pampas. Changes in the structure of agricultural production and land tenure seem to be driven by differences among farmers’ ability to generate sufficient agricultural income to remain in business. In turn, as no off-farm or credit is modeled, economic sustainability is tied to initial resource endowment (area cropped). Farmers operating small areas are economically unviable and must lease out their farms to farmers operating larger areas. This leads to two patterns: (a) a concentration of production (fewer farmers operating larger areas) and, (b) an increase in the area operated by tenants. The simulations showed an increase of soybean area, linked to the higher profitability of this crop. Despite the stylized nature of initial simulations, all emerging patterns are highly consistent with changes observed in the Pampas.