Occupational exposure

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.     

Keeping the blood flowing—plasminogen activator genes and feeding behavior in vampire bats

The blood feeding vampire bats emerged from New World leaf-nosed bats that fed on fruit and insects. Plasminogen activator, a serine protease that regulates blood coagulation, is known to be expressed in the saliva of Desmodus rotundus (common vampire bat) and is thought to be a key enzyme for the emergence of blood feeding in vampire bats. To better understand the evolution of this biological function, we studied the plasminogen activator (PA) genes from all vampire bat species in light of their feeding transition to bird and subsequently mammalian blood. We include the rare species Diphylla ecaudata and Diaemus youngi, where plasminogen activator had not previously been studied and demonstrate that PA gene duplication observed in Desmodus is not essential to the vampire phenotype, but relates to the emergence of predominant mammalian blood feeding in this species. Plasminogen activator has evolved through gene duplication, domain loss, and sequence evolution leading to change in fibrin-specificity and susceptibility to plasminogen activator inhibitor-1. Before undertaking this study, only the four plasminogen activator isoforms from Desmodus were known. The evolution of vampire bat plasminogen activators can now be linked phylogenetically to the transition in feeding behavior among vampire bat species from bird to mammalian blood. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Estimated trends and patterns of road traffic fatalities in China, 2002–2012

Objective: This study examined the time trends and age distribution patterns of estimated road traffic fatalities (RTFs) in China over the period 2002–2012. Methods: Data on age-, sex-, and region-specific RTF rates were provided by the Chinese Ministry of Health. The crude rates were standardized and the Mann-Kendall test was used to test the significance of time trends. Annual number of RTFs was calculated. To minimize the effect of yearly variations, magnitude of changes in and age distribution patterns of the RTFs were examined using mean values of 2 years. Results: RTFs increased significantly in China during the study period. Several features were identified for the RTFs in China. First, RTF rates skyrocketed in rural areas including towns and counties. Second, a significant increase in RTFs was also observed in cities even though the change in RTF rates was not statistically significant there. Third, individuals aged 20–24, 40–49, and 55–64, especially in rural areas, were particularly at risk for RTFs in recent years. Finally, RTFs became more common among middle-aged and older adults than young Chinese, with roughly 57% of all RTFs occurring among individuals aged 45 and above during 2011–2012. Conclusions: RTFs increased dramatically in China during the past decade, especially in rural areas. Age distribution patterns of RTFs have changed there. Community-based public health education and intervention programs are warranted.     

Seasonal modulation of flight speed among nocturnal passerine migrants: differences between short- and long-distance migrants

Migrating birds are expected to fly at higher airspeeds when minimizing time rather than energy costs of their migratory journeys. Spring migration has often been suggested to be more time selected than autumn migration, because of the advantage of early arrival at breeding sites. We have earlier demonstrated that nocturnal passerine migrants fly at higher airspeeds during spring compared to autumn, supporting time-selected spring migration. In this study, we test the hypothesis that seasonal airspeeds are modulated differently between short- and long-distance migrants, because of a stronger element of time selection for autumn migration over long distances. In support of this hypothesis, we demonstrate that the seasonal difference in airspeed is significantly larger (spring airspeed exceeding autumn airspeed by a factor of 1.16 after correcting for the influence of altitude, wind and climb/descent on airspeed) among short-distance compared to long-distance (factor 1.12) migrants. This result is based on a large sample of tracking radar data from 3 years at Falsterbo, South Sweden. Short-distance migrants also tend to fly with more favourable winds during autumn, indicating relaxed time constraints (being able to afford to wait for favourable winds) compared to long-distance migrants. These results indicate surprisingly fine-tuned seasonal modulation of airspeed and responses to wind, associated with behavioural strategies adapted to different levels of time selection pressures during spring and autumn migration.     

Identifying trophic relationships within the high Arctic benthic community: how much can fatty acids tell?

Multivariate analysis of fatty acids (FA) profiles proved to be a useful tool for demonstrating feeding preferences of Arctic invertebrates belonging to several taxonomic groups collected during summer and winter seasons in the Spitsbergen fjords (Arctic). Within phytodetrivorous taxa, the enhanced proportions of 16:1n-7, C16 polyunsaturated fatty acids (PUFA) and 20:5n-3 in crustaceans clearly reflected selective ingestion of diatoms, while high amounts of 22:6n-3 and C18 FAs found in molluscs indicated flagellate-based nutrition. High levels of C20 PUFA and 16:1n-7 together with the typical bacterial FAs were found in winter specimens of deposit-feeding polychaetes showing their reliance on highly reworked organic matter during this season. Our results suggest that 18:1n-9 may not be a reliable marker of carnivory feeding within benthic taxa. Lipid signatures of omnivores and carnivores/detrivores usually originated from a variety of dietary sources, of which few possess highly characteristic FA features. Still, elevated levels of Calanus markers (20:1 and 22:1 moieties) characterized species linked to the pelagic food chains, while 20:4n-6 proved to be a useful indicator of foraminiferan consumption. We highlight the need for a multimethod approach, since complexity of benthic food webs along with general lack of unambiguous FA trophic markers prevents tracking of trophic relationships with use of FA analysis alone. Based on their FA composition, we showed that benthic species represent a source of essential PUFA and could play a fundamental role in the Arctic food webs transferring energy derived from variable pelagic and benthic resources to upper trophic levels.     

Recycling Ability of Biodegradable Matrices and Their Cellulose-Reinforced Composites in a Plastic Recycling Stream

The effect of multiple injection-moulding reprocessing of three biodegradable matrices on their mechanical properties, melt flow rate, molecular weight, phase transition temperatures and degradation temperature is presented. It has been found that, with successive reprocessing, tensile, flexural and impact strength decreased. Drop in mechanical properties has been assigned to degradation of the matrices, as corroborated by melt flow and molecular weight analysis. Although reprocessing did not significantly affect the glass transition, it diminished the melting point and degradation temperature of polymers. Results indicate that neat PLLA can be recycled for up to five times without suffering a drastic loss in mechanical and thermal properties. The aliphatic polyester Mater-Bi TF01U/095R can be recycled for up to 10 times, whilst starch-based Mater-Bi YI014U/C wastes should be destined to composting, since its recyclability is very poor. The effect of reprocessing on composites reinforced with chemithermomechanical pulp (CTMP) followed the tendencies observed for the neat matrices. Whilst CTMP-fibres behave mainly as filler in PLLA composites, reinforced thermoplastic starch-based composites presented enhanced mechanical properties and recyclability.     

Sublethal concentrations of azinphos-methyl induce biochemical and morphological alterations in Rhinella arenarum embryos

Considering that amphibians are good sentinels of environmental conditions, Rhinella arenarum embryos were used to investigate the effects of sublethal concentrations of the organophosphorus insecticide azinphos-methyl, focusing on its anticholinesterasic or pro-oxidant actions and its possible connection with the appearance of morphological alterations. Early amphibian embryos exposed to azinphos-methyl displayed a protective response through glutathione S-transferase induction, along with superoxide dismutase inhibition. At intermediate embryonic stages, embryos exposed to azinphos-methyl displayed superoxide dismutase inhibition and morphological alterations, although cholinesterase activity was not altered, suggesting that molecular targets other than cholinesterase were involved in the development of morphological alterations. At the end of embryonic development, decreases in reduced glutathione and cholinesterase inhibition were observed, along with a significant increase in the number of malformed embryos. The connection between biochemical alterations and the appearance of malformations was not evident in R. arenarum embryos. However, increased glutathione S-transferase and decreased superoxide dismutase activities could be considered as early markers of exposure to azinphos-methyl. The results obtained demonstrate that sublethal concentrations of azinphos-methyl are a serious threat to toad embryos in their natural habitats because biochemical and morphological alterations could impair their ability to deal with environmental stresses.     

Exaggerated orientation scatter of nocturnal passerine migrants close to breeding grounds: comparisons between seasons and latitudes

Using tracking radars, we investigated the variability of flight directions of long-distance nocturnal passerine migrants across seasons (spring versus autumn migration) and sites at the southern (56° N) and northern (68° N) ends of the Scandinavian Peninsula (Lund versus Abisko). Whilst most migrants at Lund are on passage to and from breeding sites in Fennoscandia, the majority of the migrants at Abisko are close to their breeding sites, and migration at Abisko thus to a large degree reflects initial departure from breeding sites (autumn) or final approach to breeding destinations (spring). The radar data were used to test predictions about differences in orientation and wind drift effects between adult and juvenile birds (a large proportion of autumn migrants consists of juvenile birds on their first journey), between situations far away from or near the goals and between different phases of migration (initial departure, en route passage, final approach to goal). The concentrations (both total and within-night concentrations) of flight directions differed significantly between seasons as well as sites, with the highest concentration at Lund in spring (mean vector length of track directions, r = 0.79) and lowest at Abisko during spring (r = 0.35). Partial wind drift and partial compensation were recorded at Lund, with a similar effect size in spring and autumn, whilst possible wind drift effects at Abisko were obscured by the large directional scatter at this site. The results from Lund support the prediction that the high proportion of juveniles in autumn contributes to increase the directional scatter during this season, whilst there was no support for predictions of differential wind drift effects between seasons and situations with different goal distances. The most striking and surprising result was the exceedingly large scatter of flight directions at Abisko, particularly in spring. We suggest that such an exaggerated scatter may be associated with final approach orientation, where migrants reach their specific goals from all various directions by final navigation within a more wide-ranging goal region. The larger scatter of autumn flight directions at Abisko compared to Lund may be due to exploratory flights in variable directions being more common at initial departure from breeding sites than later during migratory passage. These surprising results highlight the importance of studying and analysing orientation during final approach to (and initial departure from) migratory goals for understanding the orientation systems of migratory birds.     

Effects of granulated baits on meso and macrofauna in soybean soil system

Studies were done to see the effects of five toxic baits based on metaldehyde and/or carbaryl on the taxonomic composition of soil meso and macrofauna, and determined the density of beneficial organisms in soybean under no tillage. Six treatments were tested and soil monoliths were taken before application and at 45 and 75 days after application (DAA). Before application, 1601 individuals were recorded, belonging 1086 to mesofauna and 515 to macrofauna. In soil mesofauna such as Annelida: Enchytraeidae (44%), Nematoda (33%) and Arthropoda (23%) were found. In the macrofauna Arthropoda 93% and Annelida: Oligochaeta, Megadrilli 7% were observed. No differences were observed among the treatments (p>0.05) in the total mesofauna density, at 45 and 75 DAA. The density of enchytraeids, mites, collembolans and symphylids showed no differences at45 and 75 DAA (p > 0.05). The total macrofauna density showed differences (p < 0.05) at 45 and 75 DAA. The highest density was obtained with 4 kg ha(-1) MataBibos Acay at 45 and 75 DAA. Earthworm and diplopod densities at45 and 75 DAA showed no differences (p>0.05). The diversity of meso and macrofauna was not affected at 45 and 75 DAA. Bait application did not affect either the abundance or the diversity of soil beneficial invertebrates.