Quantitative structure-activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: wing spot test of Drosophila melanogaster

Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.     

Development of a biotic ligand model (BLM) predicting nickel toxicity to barley (Hordeum vulgare)

A biotic ligand model (BLM) was developed to predict nickel toxicity, affecting root growth of barley (Hordeum vulgare), in nutrient solutions. The extent to which Ca(2+), Mg(2+), Na(+), K(+) ions and pH each influenced nickel toxicity was determined. Higher activities of Mg(2+) linearly increased the 4d EC50 Ni (2+) , while Ca(2+), Na(+), K(+) and H(+) activities did not significantly influence Ni(2+) toxicity. Stability constants for the binding of Ni(2+) and Mg(2+) to the biotic ligand were obtained: logK(NiBL)=5.27 and logK(MgBL)=3.47. Further, it was calculated that on average 57% of the biotic ligand sites needed to be occupied by nickel to induce 50% root growth inhibition. Auto-validation of the BLM indicated that predicted EC50s differed from the observed EC50s by a factor of less than 2, indicating that the BLM concept may also be used to predict metal toxicity to terrestrial plants.     

Resource management as a key factor for sustainable urban planning

Due to fast urbanization and increasing living standards, the environmental sustainability of our global society becomes more and more questionable. In this historical review we investigate the role of resources management (RM) and urban planning (UP) and propose ways for integration in sustainable development (SD). RM follows the principle of circular causation, and we reflect on to what extent RM has been an element for urban planning. Since the existence of the first settlements, a close relationship between RM, urbanization and technological development has been present. RM followed the demand for urban resources like water, energy, and food. In history, RM has been fostered by innovation and technology developments and has driven population growth and urbanization. Recent massive resource demand, especially in relation to energy and material flows, has altered natural ecosystems and has resulted in environmental degradation. UP has developed separately in response to different questions. UP followed the demand for improved living conditions, often associated to safety, good manufacturing and trading conditions and appropriate sanitation and waste management. In history UP has been a developing research area, especially since the industrial era and the related strong urbanization at the end of the 18th century. UP responded to new emerging problems in urban areas and became increasingly complex. Nowadays, UP has to address many objectives that are often conflicting, including, the urban sustainability. Our current urban un-sustainability is rooted in massive resource consumption and waste production beyond natural limits, and the absence of flows from waste to resources. Therefore, sustainable urban development requires integration of RM into UP. We propose new ways to this integration.     

The use of navigation systems in naturalistic driving

Objective: In this study, we assessed the use of portable navigation systems in everyday driving by applying in-vehicle naturalistic driving.

Method: Experienced users of navigation systems, 7 females and 14 males, were provided with a specially equipped vehicle for approximately 1 month. Their trips were recorded using 4 cameras, Global Positioning System (GPS) data, and other sensor data. The drivers’ navigation system use data were coded from the video recordings, which showed how often and for how long the system was activated and how often and for how long a driver operated the system.

Results: The system was activated for 23% of trips, predominantly on longer and unique trips. Analyses of the percentage of time for which the speed limit was exceeded showed no evidence of differences between trips for which the navigation system was used or not used. On trips for which the navigation system was activated, participants spent about 5% of trip time interacting with the device. About 40% of interacting behavior took place in the first 10% of the trip time, and about 35% took place while the car was standing still or moving at a very low speed; that is, 0–10 km/h.

Conclusion: These results shed light on how and when drivers use navigation systems. They suggest that although drivers regulate their use of such systems to some extent, they often perform risky tasks while driving.     

Biomonitoring in the protected areas of the Czech Republic

The purpose of the biomonitoring project in the Nature Conservancy in the Czech Republic is to obtain information on long-term development of some selected living components of ecosystems in protected areas. A survey of methods was conducted to select the monitoring areas as well as to study birds, epigean, vegetation and water communities (a minimal programme). A system for the monitoring areas and data storage and processing (to gather a body of evidence) was established. Simultaneously, close linkage with abiotic factor monitoring is planned. The project has been carried out by the Czech Institute for Nature Conservation.     

Catalytic NOx reduction with simultaneous dioxin and furan oxidation

The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/Nm3 has been demonstrated. At the same time, NOx- and CO-emissions are reduced by 90% and 20% to about 50 mg/Nm3 and below 10 mg/Nm3, respectively.     

The analysis of soil cores polluted with certain metals using the Box-Cox transformation

To define the soil properties for a given area or country including the level of pollution, soil survey and inventory programs are essential tools. Soil data transformations enable the expression of the original data on a new scale, more suitable for data analysis. In the computer-aided interactive analysis of large data files of soil characteristics containing outliers, the diagnostic plots of the exploratory data analysis (EDA) often find that the sample distribution is systematically skewed or reject sample homogeneity. Under such circumstances the original data should be transformed. The Box-Cox transformation improves sample symmetry and stabilizes spread. The logarithmic plot of a profile likelihood function enables the optimum transformation parameter to be found. Here, a proposed procedure for data transformation in univariate data analysis is illustrated on a determination of cadmium content in the plough zone of agricultural soils. A typical soil pollution survey concerns the determination of the elements Be (16 544 values available), Cd (40 317 values), Co (22 176 values), Cr (40 318 values), Hg (32 344 values), Ni (34 989 values), Pb (40 344 values), V (20 373 values) and Zn (36 123 values) in large samples.     

Biosynthetic studies on marking pheromones of bumblebee males

Summary. The biosynthetic pathway of the formation of males'marking pheromones of two bumblebee species, Bombus lucorum and B.lapidarius, was studied for the first time. After applications ofdeuterium labelled palmitic acid ([2H31]-hexadecanoic acid) into eitherthe head capsules or abdomens the corresponding deuterium labelledpheromone components were detected in the labial gland (LG) extracts ofmales of both species. In B. lucorum, ethyl [2H29]-hexadec-9-enoate andethyl [2H31]-hexadecanoate were identified. No deuterium-labelled ethyltetradecenoate, that would correspond to shortening of the carbon chain,was detected. In B. B. lapidarius, [2H31]-hexadecan-1-ol and[2H29]-hexadec-9-en-1-ol were found in the LG. Furthermore, thedeuterium labelled precursor was incorporated into triacylglycerols(TAG) of the fat bodies of males. In vitro incubation of the labialglands of B. lucorum males with deuterium-and 13C-labelled palmiticacid lead to the formation of saturated ethyl esters only.