Plasma PBDE and thyroxine levels in rats exposed to Bromkal or BDE-47

In experimental models, polybrominated diphenyl ethers (PBDEs), a group of brominated flame retardants, have caused effects in a number of biological end-points, including neurobehavioural effects, disturbances in thyroid and steroid hormone homeostasis, and other steroid-related effects. Almost exclusively, only external dose metrics (dose per body weight basis) have been studied in connection to the observed effects. In this study we report on new analyses of plasma PBDE levels in surplus samples from earlier studies on thyroid hormones (TH) in exposed rodents. Female, 7-week old Sprague-Dawley rats were given either Bromkal 70-5 DE (Study I; 18 or 36 mg/kg bw/day) or BDE-47 (Study II; 1, 6 or 18 mg/kg bw/day) daily by gavage for two weeks. At an external dose of 18 mg/kg bw/day significant TH effects (decreased plasma free thyroxin levels) were observed in both studies, corresponding to an internal (plasma) dose of 463 microg sumPBDE/g lipid (Study I) or 421 microg BDE-47/g lipid (Study II). If we compare the contribution of different BDE congeners to the total BDE level in rat plasma after Bromkal exposure (Study II), and in the Bromkal mixture itself, the most important congener in the Bromkal mixture were also found in plasma. However, the relative concentration of BDE-99 was lower, and that of BDE-153 was higher, than that of the mixture, indicating selectivity in uptake, metabolism and/or excretion of the individual BDE congeners. Explicitly, the possible in vivo conversion of BDE-99 to BDE-47, and of BDE-154 to BDE-153 could not be excluded. The internal dose in the present rat study could be compared to reported human serum doses of PBDE. Human serum/blood levels have a wide range, from 3 to 6 ng sumPBDE/g lipid in background samples from Europe, about 10 times higher in US sample, and up to 100 times higher (300-600 ng/g lipid) in upper-end levels in collected samples from USA. As a consequence, the margin between effects levels in the rat and exposure levels in man varies widely, with a quotient roughly from 1000 to 100,000. Generally, it could be expected that this margin is lower than if external dose metrics would be used. An even lower margin could be expected as recent studies have shown effects in offspring at lower doses than those giving effects in our studies. Lastly, it should be noted that humans are already exposed to a mixture of chemicals in daily life, a fact that complicates this kind of comparison.     

Developing Biocomposites Panels from Food Packaging and Textiles Wastes: Physical and Biological Performance

The urban solid waste problem has been one of the biggest environmental challenges these days. In this context, developing biocomposites with improved performance by using various sources and wastes has been intensified in the last decades for economic and environmental points of view. In this study, physical behavior, fungal decay and termite attack tests were conducted in laboratory conditions to investigate the performance of composites developed from TetraPak and textile wastes. All the results were compared to standard wood products. The water swelling properties strongly decreased in the manufactured TetraPak composites when compared with the conventional particleboard panels. The fungal decay resistance tests revealed that the stand alone TetraPak based composites were not completely resistant to wood-decaying fungi. A significant amelioration in the decay durability was observed for the manufactured TetraPak composites compared to the standard wood samples. Durability classes were determined according to the criteria given in the European standard (CEN/TS15083-1). Interestingly, the data indicated that the increment of the wool waste proportion in the produced boards lead to a significant enhancement counter the test fungi. The results of termite screening test showed further considerable resistance for whole TetraPak based composites against termites when compared to traditional wood samples. Such panels could be an available alternative without any additives for wood based composite structures and it can be used in a wide range of applications.     

Scenario analysis for regional decision-making on sustainable multifunctional land uses

Land-use patterns are influenced by both top-down and bottom-up (local) factors, with their interactions varying in both space and time. This provides a major challenge to decision-making for sustainable multifunctional landscapes. A cross-scale scenario structure has been developed to integrate top-down and bottom-up context based upon the familiar IPCC Special Report on Emission Scenarios framework. Qualitative scenario storylines are converted into multiple quantified simulations of regional land-use change using a series of rules, with information translated across scales using a hierarchical land-use classification. Land-use parcels (fields) are used as key landscape reference units representing the local dimension of regional changes. Biophysical limitations on land use are represented through land capability classes (climate, soils and topography). Socio-economic factors are characterised in reference to global drivers, policy targets or local preferences. A flexible stochastic software tool (LandSFACTS) ensures spatiotemporal coherence of land-use allocation simulations consistent with scenario storylines. Scenario development is designed to be interactive, bridging ‘problem-focussed’ and ‘actor-focussed’ approaches. A case study is presented from NE Scotland, where plans to enhance multifunctionality through new woodland are evaluated against drivers of globalisation and climate change. Competing priorities, such as food security, mean that in some scenarios, a policy objective for woodland expansion to occur on farmland cannot be met. Woodland expansion would then have to occur on uncultivated upland areas. Scenario analysis has highlighted specific sensitivity to change in ‘marginal’ agricultural areas, with the varying influence of different top-down or bottom-up factors leading to divergent potential outcomes.     

Fungicides transport in runoff from vineyard plot and catchment: contribution of non-target areas

Surface runoff and erosion during the course of rainfall events are major processes of pesticides transport from agricultural land to aquatic ecosystem. These processes are generally evaluated either at the plot or the catchment scale. Here, we compared at both scales the transport and partitioning in runoff water of two widely used fungicides, i.e., kresoxim-methyl (KM) and cyazofamid (CY). The objective was to evaluate the relationship between fungicides runoff from the plot and from the vineyard catchment. The results show that seasonal exports for KM and CY at the catchment were larger than those obtained at the plot. This underlines that non-target areas within the catchment largely contribute to the overall load of runoff-associated fungicides. Estimations show that 85 and 62 % of the loads observed for KM and CY at the catchment outlet cannot be explained by the vineyard plots. However, the partitioning of KM and CY between three fractions, i.e., the suspended solids (>0.7 μm) and two dissolved fractions (i.e., between 0.22 and 0.7 µm and <0.22 µm) in runoff water was similar at both scales. KM was predominantly detected below 0.22 μm, whereas CY was mainly detected in the fraction between 0.22 and 0.7 μm. Although KM and CY have similar physicochemical properties and are expected to behave similarly, our results show that their partitioning between two fractions of the dissolved phase differs largely. It is concluded that combined observations of pesticide runoff at both the catchment and the plot scales enable to evaluate the sources areas of pesticide off-site transport.     

Contribution of a New PCR assay to the prenatal diagnosis of congenital toxoplasmosis

A polymerase chain reaction (PCR) assay has been developed for the detection of Toxoplasma gondii. The target sequence (88 bp) is part of a rDNA repetitive gene. A signal can be observed with only one parasite. It is directly and rapidly detected by electrophoresis and ethidium bromide staining. We report a prospective study of 80 documented cases of toxoplasmic seroconversions during pregnancy. The PCR assay of the amniotic fluids was compared with the current standard methods for diagnosis of fetal infection. Seventy specimens gave no PCR signal, and were negative according to prenatal tests and postnatal examinations. The presence of T. gondii was detected in ten specimens by PCR analysis. Four were confirmed by isolation of the parasite from the amniotic fluid; four by biological study of the fetal blood. For the remaining two, infection was diagnosed after birth. Together with ultrasonographic and biological data, this technique permits prenatal diagnosis within 1 day.     

Polygyny,relatedness and nest founding in the polygynous myrmicine ant Leptothorax acervorum (Hymenoptera; Formicidae)

Summary There is high within-nest relatedness for functional queens (with corpora lutea), nonfunctional queens (without corpora lutea), and workers in polygynous nests of Leptothorax acervorum. The high functional queen relatedness suggests that young mated queens are adopted back to their mother nest. Functional queen relatedness does not change with the number of queens present in the nest, suggesting that the number of generations of queens, on average two to three, is rather stable. Worker relatedness decreases with increasing number of functional queens per nest (Tables 5, 6). The number of queens contributing offspring to the nest (mothers), estimated from worker and functional queen relatedness, is lower than the number of functional queens, particularly in highly polygynous nests. Estimates of number of mothers in monogynous nests indicate that these nests previously were polygynous (Table 7). There is no correlation between nest relatedness and distance between nests, and budding-off, if present, thus appears to be a rare mode of nest founding (Table 8). There are no indications of inbreeding in the two populations studied since the frequency of heterozygotes is as high as expected from random mating (Table 4). Most likely, polygyny is the rule in L. acervorum and serves to secure the presence of queens in the nest.     

Wind tunnel attraction of grapevine moth females, Lobesia Botrana, to natural and artificial grape odour

Summary. Host plant volatiles which attract insect herbivores for egg-laying are of principal interest with respect to insect ecology and evolution. Direct applications concern population monitoring and control through behavioural manipulation. Identification of behaviourally active plant secondary metabolites is essential also for plant breeding for insect resistance. Grapevine moth females Lobesia botrana are attracted by upwind flight to green grape berries Vitis vinifera. The headspace of grape berries was collected on air filters. A solvent extract of these filters, released from a sprayer, attracted females in the wind tunnel. The results demonstrate that volatile cues mediate attraction of grapevine moth females to grape berries, and that headspace collections capture the essence of this odour signal. The air filter extracts were examined by gas chromatography coupled with electroantennographic detection, and the compounds eliciting a consistent antennal response in L. botrana females were identified by mass spectrometry. The headspace collection apparatus was calibrated for collection efficiency of the active compounds. Their recovery rate ranged from 35 % for methyl salicylate to 83 % for (E,E)-α-farnesene. A synthetic ten-component blend was then formulated. The blend consisted of compounds eliciting an antennal response, formulated in a blend ratio corrected for differences in collection efficiency. Subsequent wind tunnel tests showed that female attraction to this synthetic ten-component blend was not significantly different from attraction to grape berries, or to headspace collections of the same berries. At a release rate of 35 ng/h of the most abundant compound (E)-β-caryophyllene, 20 % of the test females approached the source of sprayed headspace collections and the ten-component synthetic blend, respectively. In comparison, 100 g of green berries, releasing the main compound (E)-β-caryophyllene at a rate of ca. 4.7 ng/h, attracted 10 % of the females by upwind flight followed by source contact.