Phytoremediation, recovery and toxic effects of ionic gadolinium using the free-floating plant Lemna gibba.

The biosorption and recovery of ionic gadolinium (Gd) from contaminated water by the free-floating duckweed Lemna gibba was studied. The highest non-toxic concentration range was determined as (6.7 mg L-1). The concentration of Gd in the medium and in the plant biomass was monitored and a mass balance was established. Tissue Gd concentration of Lemna increased with increasing Gd concentration of the medium. The bioconcentration factor was up to 1134 and in nontoxic concentrations up to 2.5 g kg-1 Gd tissue concentration was reached. Lemna ash contained 23.2 g Gd kg-1. Gd removal efficiency from the medium was 95%, however, only 17-37% of the initial Gd content of the medium accumulated in Lemna biomass, an average of 5% remained in the water, and 60-79% was calculated as a precipitate. Gadolinium-exposed Lemna plants released ionic Gd into the nutrient solution when they were transferred to a Gd-free medium. The experimental results revealed that in constructed wetlands, L. gibba is able to remove ionic Gd from the water and can be suitable for bioremediation and recovery purposes.

Comparative Analysis of Bone Ingrowth in 3D-Printed Titanium Lattice Structures with Different Patterns.

In this study, metal 3D printing technology was used to create lattice-shaped test specimens of orthopedic implants to determine the effect of different lattice shapes on bone ingrowth. Six different lattice shapes were used: gyroid, cube, cylinder, tetrahedron, double pyramid, and Voronoi. The lattice-structured implants were produced from Ti6Al4V alloy using direct metal laser sintering 3D printing technology with an EOS M290 printer. The implants were implanted into the femoral condyles of sheep, and the animals were euthanized 8 and 12 weeks after surgery. To determine the degree of bone ingrowth for different lattice-shaped implants, mechanical, histological, and image processing tests on ground samples and optical microscopic images were performed. In the mechanical test, the force required to compress the different lattice-shaped implants and the force required for a solid implant were compared, and significant differences were found in several instances. Statistically evaluating the results of our image processing algorithm, it was found that the digitally segmented areas clearly consisted of ingrown bone tissue; this finding is also supported by the results of classical histological processing. Our main goal was realized, so the bone ingrowth efficiencies of the six lattice shapes were ranked. It was found that the gyroid, double pyramid, and cube-shaped lattice implants had the highest degree of bone tissue growth per unit time. This ranking of the three lattice shapes remained the same at both 8 and 12 weeks after euthanasia. In accordance with the study, as a side project, a new image processing algorithm was developed that proved suitable for determining the degree of bone ingrowth in lattice implants from optical microscopic images. Along with the cube lattice shape, whose high bone ingrowth values have been previously reported in many studies, it was found that the gyroid and double pyramid lattice shapes produced similarly good results.

Relationship between gadolinium-based MRI contrast agent consumption and anthropogenic gadolinium in the influent of a wastewater treatment plant.

Gadolinium-based contrast agents (GBCAs) used in magnetic resonance imaging (MRI) are highly resistant in the environment. They pass through wastewater treatment plants (WWTPs) unhindered escaping degradation. Although GBCAs are subjects of intensive research, we recognized that a quantitative approach to the mass balance of gadolinium, based on known input and output data, is missing. The administered amount of Gd as GBCAs, the number of out- and inpatients and the concentration of rare earth elements (REEs) in wastewater were monitored for 45 days in a medium sized city (ca. 203,000 inhabitants) with two MRI centres. An advection-dispersion type model was established to describe the transport of Gd in the wastewater system. The model calculates with patient locality, excretion kinetics of Gd and the yield of wastewater. The estimated and measured daily amount of anthropogenic gadolinium released to the WWTP were compared. GBCAs (Omniscan and Dotarem) were administered to 1008 patients representing a total of 700 ± 1 g Gd. The amount of total Gd entering the WWTP was 531 ± 2 g, of which the anthropogenic contribution (i.e. GBCAs) was 261 ± 6 g (49 ± 1 % of the total Gd) during the sampling campaign. Local residents and inpatients should fully release Gd in the city, but outpatients only partially. Overall, 37 ± 1 % of the total administered Gd was recovered in the wastewater, so the remaining 63 ± 1 % of administered Gd is expected to be dispensed outside of the sewer system. Our approach enables to better understand the dispersion of GBCAs originated Gd in an urban environment.

Toward Developing Techniques─Agnostic Machine Learning Classification Models for Forensically Relevant Glass Fragments.

Glass fragments found in crime scenes may constitute important forensic evidence when properly analyzed, for example, to determine their origin. This analysis could be greatly helped by having a large and diverse database of glass fragments and by using it for constructing reliable machine learning (ML)-based glass classification models. Ideally, the samples that make up this database should be analyzed by a single accurate and standardized analytical technique. However, due to differences in equipment across laboratories, this is not feasible. With this in mind, in this work, we investigated if and how measurement performed at different laboratories on the same set of glass fragments could be combined in the context of ML. First, we demonstrated that elemental analysis methods such as particle-induced X-ray emission (PIXE), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS), particle-induced Gamma-ray emission (PIGE), instrumental neutron activation analysis (INAA), and prompt Gamma-ray neutron activation analysis (PGAA) could each produce lab-specific ML-based classification models. Next, we determined rules for the successful combinations of data from different laboratories and techniques and demonstrated that when followed, they give rise to improved models, and conversely, poor combinations will lead to poor-performing models. Thus, the combination of PIXE and LA-ICP-MS improves the performances by ∼10-15%, while combining PGAA with other techniques provides poorer performances in comparison with the lab-specific models. Finally, we demonstrated that the poor performances of the SEM-EDS technique, still in use by law enforcement agencies, could be greatly improved by replacing SEM-EDS measurements for Fe and Ca by PIXE measurements for these elements. These findings suggest a process whereby forensic laboratories using different elemental analysis techniques could upload their data into a unified database and get reliable classification based on lab-agnostic models. This in turn brings us closer to a more exhaustive extraction of information from glass fragment evidence and furthermore may form the basis for international-wide collaboration between law enforcement agencies.

Disentangling the mechanisms sustaining a stable state of submerged macrophyte dominance against free-floating competitors.

Free-floating and rootless submerged macrophytes are typical, mutually exclusive vegetation types that can alternatively dominate in stagnant and slow flowing inland water bodies. A dominance of free-floating plants has been associated with a lower number of aquatic ecosystem services and can be explained by shading of rootless submerged macrophytes. Vice versa, high pH and competition for several nutrients have been proposed to explain the dominance of rootless submerged macrophytes. Here, we performed co-culture experiments to disentangle the influence of limitation by different nutrients, by pH effects and by allelopathy in sustaining the dominance of rootless submerged macrophytes. Specifically, we compared the effects of nitrogen (N), phosphorus (P), iron (Fe) and manganese (Mn) deficiencies and an increased pH from 7 to 10 in reducing the growth of free-floating Lemna gibba by the rootless Ceratophyllum demersum. These macrophyte species are among the most common in highly eutrophic, temperate water bodies and known to mutually exclude each other. After co-culture experiments, additions of nutrients and pH neutralisation removed the growth inhibition of free-floating plants. Among the experimentally tested factors significantly inhibiting the growth of L. gibba, an increase in pH had the strongest effect, followed by depletion of P, N and Fe. Additional field monitoring data revealed that in water bodies dominated by C. demersum, orthophosphate concentrations were usually sufficient for optimal growth of free-floating plants. However, pH was high and dissolved inorganic N concentrations far below levels required for optimal growth. Low N concentrations and alkaline pH generated by dense C. demersum stands are thus key factors sustaining the stable dominance of rootless submerged vegetation against free-floating plants. Consequently, N loading from e.g. agricultural runoff, groundwater or stormwater is assumed to trigger regime shifts to a dominance of free-floating plants and associated losses in ecosystem services.

Can aquatic macrophytes be biofilters for gadolinium based contrasting agents?

The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue concentration of Gd reached its maximum value between day one and four in L. gibba and C. demersum, respectively, and its volume was significantly higher in C. demersum than in L. gibba. In C. demersum, the open-chain ligand Omniscan causes two-times higher tissue Gd concentration than the macrocyclic ligand Dotarem. Gadolinium was released from Gd-treated duckweeds into the water as they were grown further in Gd-free nutrient solution. Tissue Gd concentration dropped by 50% in duckweed treated by Omniscan and by Dotarem within 1.9 and 2.9 days respectively. None of the macrophytes had a significant impact on the Gd concentration of water in low and medium concentration levels (1-256 µg L-1). Biofiltration of GBCA-s by common macrophytes could not be detected in our experiments. Therefore it seems that in constructed wetlands, aquatic plants are not able to reduce the concentration of GBCA-s in the water. Furthermore there is a low risk that these plants cause the accumulation of anthropogenic Gd in the food chain.

Biochemical, Histopathological and Molecular Responses in Gills of Leuciscus cephalus Exposed to Metals.

Gills are major targets for acute metal toxicity in fish, due to their permanent contact with aquatic pollutants. To assess the effects of metals on gills of the Leuciscus cephalus (chub), fish individuals were collected from two sites in the Tur River, Romania, in upstream (site 1) and downstream (site 2) of a metal pollution source. Quantitative and hyperspectral analyses showed that Zn, Sr, and Fe concentrations were significantly higher in gills from site 2 compared with site 1. Malondialdehyde and advanced oxidation protein products levels increased 17 and 28%, respectively, whereas reduced glutathione level diminished significantly in the gills of fish collected from site 2 compared to site 1. The activities of superoxide dismutase, catalase, and glutathione-S-transferase increased significantly at 41, 21, and 28%, respectively. Proliferating cell nuclear antigen (PCNA) protein levels, as well as the amount of DNA damage, were significantly increased for site 2 compared with site 1. The induced oxidative stress generated hyperplasia, hypertrophy, and inflammation in the epithelial cells and apoptosis. Hence, this could suggest that gill cells have tried to counteract the oxidative stress-induced DNA fragmentation by PCNA up-regulation, but the PCNA expression decreased on longer time due to the low level of GSH, resulting in apoptosis.

Coordinated underground measurements of gamma-ray emitting radionuclides for plasma physics research.

Forty-eight samples made of CaF2, LiF and YVO4 were placed inside the KSTAR Tokamak and irradiated by neutrons and charged particles from eight plasma pulses. The aim was to provide information for plasma diagnostics. Due to the short pulse durations, the activities induced in the samples were low and therefore measurements were performed in five low-background underground laboratories. Details of the underground measurements, together with data on the quality control amongst the radiometric laboratories, are presented.

Exploring river pollution based on sediment analysis in the Upper Tisza region (Hungary).

We assessed contamination in the Upper Tisza region (Hungary, Central Europe), analyzing the elemental concentrations in sediment cores of oxbows. Our hypothesis was that the metal contamination which occurred in the year 2000 and which came from the mining area in Transylvania (Romania) may be detected even 15 years after the contamination, based on the vertical profile of sediment cores. Sediment cores were collected from five oxbows, and the following elements were measured with microwave plasma-atomic emission spectrometry (MP-AES): Cu, Cr, Ba, Fe, Mn, Pb, Sr, and Zn. Among the oxbows studied, there was one protected oxbow, three were used for fishing, and one was contaminated with sewage. Our results indicated that the year of contamination is still observable in the vertical profile of the sediment cores. The pollution index (PI) was used to characterize the sediment enrichment of metal elements in the sediment cores. In the case of Cu, Pb, and Zn, the contamination which originated in the year 2000 was detected in the layers of the sediment cores. The contamination levels of Cu, Pb, and Zn were high or moderate in the studied oxbows. All oxbows were moderately contaminated by Mn, while a moderate level of contamination was found for Fe in the protected oxbow, one fishing oxbow, and the sewage-contaminated oxbow. In the fishing oxbows, a low level of contamination was found for Fe. The contamination level of Sr was low in the protected oxbow and in the two fishing oxbows, while in one of the fishing oxbows and in the sewage-contaminated oxbow, a moderate level of Sr contamination was found. The pollution index scores indicated that the contamination level for Ba and Cr was low in the sediment cores of the oxbows studied. Our results indicated that the contamination of the Tisza River from the mining area in Northern Romania has been continuous and is still ongoing.

The effect of a fireworks event on the amount and elemental concentration of deposited dust collected in the city of Debrecen, Hungary.

Many social celebrations in urban areas are followed by fireworks show. The organic and inorganic pollutants emitted during detonations are expected to affect the ambient air quality of these celebration sites. The environmental aspects of fireworks events are usually investigated by analyzing the concentration and composition of airborne particulate matter, while there is limited information regarding the effect of fireworks on the elemental concentration of deposited dust. In this study, foliage dust samples were collected in the city of Debrecen (Hungary) before and after the fireworks show, organized on the 20th of August for the celebration of a historical event. Leaf samples (Tilia tomentosa) were collected around the location of the area of festivities. The sampling sites were further divided into five areas: city center (center), Southeast (SE), Southwest (SW), Northeast (NE), and Northwest (NW). We found that the amount of deposited dust particles increased significantly after the fireworks show compared to the background; we also found significant differences in the amount of dust deposition between the different locations of the city. A statistically higher level of Ca, Mg, and Sr was detected in samples collected after the display compared to those collected during the previous days, while the concentration of other studied elements were not statistically different from the background level. Our study confirmed previous findings that the relatively high altitude of detonations allows chemicals to disperse in the fine and ultrafine aerosol fractions; thus, the emitted pollutants by fireworks shows do not increase the level of elements as markedly in deposited dust as in the inhalable fraction.

Histopatological alterations and oxidative stress in liver and kidney of Leuciscus cephalus following exposure to heavy metals in the Tur River, North Western Romania.

Pollution of the aquatic environment by heavy metals is a great concern worldwide. Freshwater fish ingests various metals through gills, skin or diet. Our aim was to investigate the oxidative stress and histopathological injuries induced by Fe, Cu, Zn, Pb, Cd in the liver and kidney of Leuciscus cephalus. Fish samples were collected from two sites in the Tur River, NW Romania, in upstream and downstream of a pollution source. Metals were differently distributed in the liver and kidney of fish. The highest concentrations of Fe, Cu and Pb were found in liver, whereas Zn and Cd concentrations were the highest in kidney in specimens collected from the downstream site. The histopathological changes were associated with metal bioaccumulation, being more severe in kidney than liver. Malondialdehyde (MDA) and advanced oxidation protein products (AOPP) increased significantly in the liver and kidney of fish from downstream site compared to upstream one, whereas reduced glutathione (GSH) decreased. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) increased significantly in livers, whereas SOD increased in kidney. Our study revealed that liver has a higher capacity and adaptability to counteract ROS compared to kidney. The more pronounced increase of hepatic SOD, CAT and GST activities is related milder structural changes observed in liver compared to kidney, where lesions were not reduced by antioxidant defense system.

Elemental concentrations in deposited dust on leaves along an urbanization gradient.

Environmental health is an essential component of the quality of life in modern societies. Monitoring of environmental quality and the assessment of environmental risks are often species based on the elemental concentration of deposited dust. Our result suggested that stomata size and distribution were the most important factors influencing the accumulation of air contaminants in leaves. We found that the leaves' surfaces of Acer negundo and Celtis occidentalis were covered by a large number of trichomes, and these species have proven to be suitable biomonitors for atmospheric pollution difficult; these can be overcome using bioindicator species. Leaves of Padus serotina, Acer campestre, A. negundo, Quercus robur and C. occidentalis were used to assess the amount of deposited dust and the concentration of contaminants in deposited dust in and around the city of Debrecen, Hungary. Samples were collected from an urban, suburban and rural area along an urbanization gradient. The concentrations of Ba, Cu, Fe, Mn, Ni, Pb, S, Sr and Zn were determined in deposited dust using ICP-OES. Scanning electron microscopy (SEM) was used to explore the morphological structure and dust absorbing capacity of leaves. We found significant differences in dust deposition among species, and dust deposition correlated with trichomes' density. Principal component analysis (PCA) also showed a total separation of tree.

Elemental concentration in mealworm beetle (Tenebrio molitor L.) during metamorphosis.

Mealworm beetles have been used in numerous experiments as bioindicators. The aim of our experiment was to study the elemental composition in three larvae, pupae and first and second generation adult stages during their life cycle. We selected 180 larvae from a genetically similar population and put them in three groups, in two boxes (60 larvae in each box). Larvae were fed with mashed potato made of the same quality and quantity of potato powder. Then, we selected 10 individuals from each stage to the elemental analysis, using the ICP-OES method. The following elements were analysed in the studied stages: Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Sr and Zn. The results of principal component analysis demonstrated that based on elemental composition, different stages were separated with each other, but in the cases of the three larvae stages, high overlap was found. The results of the GLM ANOVA showed significant differences between the different stages of metamorphosis-based elemental composition. Our results show that the calcium and magnesium were found in a relatively high concentration, while the iron and zinc may be essential elements during the metamorphosis. Our results also show that in insect, the concentration of sodium was higher than in the pupa which may cause by hemolymph. We also demonstrated that the metamorphosis has an effect on the concentration of elements. Our study shows that in the different stages of insects, there are significant changes in the elemental composition of different stages of insects during their metamorphosis.

Trace element concentrations in soils along urbanization gradients in the city of Wien, Austria.

Urban soil is an important component of urban ecosystems. This study focuses on heavy metal contamination in soils of Wien (Austria) and results are compared to those for a few large European cities. We analysed the elemental contents of 96 samples of topsoil from urban, suburban and rural areas in Wien along a dynamic (floodplain forest) and a stable (oak-hornbeam forest) urbanization gradient. The following elements were quantified using ICP-OES technique: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Pb, P, S and Zn. For heavy metals PI (pollution index) values were used to assess the level of pollution. The PI values indicated high level of pollution by Pb in the suburban and rural area of stable gradient and in the urban area of dynamic gradient; moderate level of pollution was indicated for Cd in the urban area of stable gradient. The level of pollution was moderate for Co in the suburban and rural area of the stable gradient, and for Cu in suburban area of stable gradient, and urban area of dynamic gradient. The pollution level of Zn was moderate in all areas. Urban soils, especially in urban parks and green areas may have a direct influence on human health. Thus, the elemental analysis of soil samples is one of the best ways to study the effects of urbanization. Our results indicated that the heavy metal contamination was higher in Wien than in a few large European cities.

Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source.

An inexpensive photoreactor using LED light sources and a fibre-optic CCD spectrophotometer as a detector was built by designing a special cell holder for standard 1.000 cm cuvettes. The use of this device was demonstrated by studying the aqueous photochemical reaction of 2,5-dichloro-1,4-benzoquinone. The developed method combines the highly quantitative data collection of CCD spectrophotometers with the possibility of illuminating the sample independently of the detecting light beam, which is a substantial improvement of the method using diode array spectrophotometers as photoreactors.

Effect of high relative humidity on dried Plantago lanceolata L. leaves during long-term storage: effects on chemical composition, colour and microbiological quality.

INTRODUCTION: Modern phytotherapy and quality assurance requires stability data on bioactive metabolites to identify and minimise decomposing factors during processing and storage. A compound's stability in a complex matrix can be different from the stability of the purified compound. OBJECTIVE: To test the stability of iridoids and acteoside and quantify changes in colour and microbiological quality in a common herbal tea, dried P. lanceolata leaves during exposure to high-humidity air. To test the contribution of fungi to metabolite decomposition. METHODOLOGY: Dried P. lanceolata leaves were exposed to atmospheres of different relative humidity (75, 45 and 0%) for 24 weeks. Changes in aucubin and catalpol concentration were determined by CE-MEKC, and those in acteoside on TLC. Colour and chlorophyll-like pigments were measured by different spectrophotometric methods. The number of fungi was monitored; 10 strains were isolated from the plant drug, and their ability to decompose the analytes of interest was tested. RESULTS: During incubation at 75% relative humidity (RH), aucubin, catalpol and acteoside concentrations decreased by 95.7, 97.0 and 70.5%, respectively. Strong shifts were detected in CIELAB parameters a* and b* (browning) as a result of conversion of chlorophyll to pheophytin. Intensive microbial proliferation was also observed. Changes at 45 or 0% RH were typically insignificant. Seven of the 10 isolated fungal strains could decompose both iridoids, and five could decompose acteoside in vitro. CONCLUSION: It was shown that exposure to water results in loss of bioactive molecules of P. lanceolata dried leaves, and that colonising fungi are the key contributors to this loss.

Assessment of the effects of urbanization on trace elements of toe bones.

Amphibians, particularly frogs and toads, are increasingly used as bioindicators of contaminant accumulation in pollution studies. We developed an analytical technique to analyse their elemental contents based on a small amount of toe bone samples. This method is environment-friendly as, unlike traditional methods, it is not necessary to kill animals during sampling. Using this technique, we explored the effects of urbanization on the elemental contents of toe bones. Bufo bufo specimens were collected from an urban and two rural ponds. The ratios of Ca and P at the ponds were: 20.5% Ca and 14.6% P at the urban pond and 30.4% and 29.6% Ca, 22.4% and 21.7% P at the rural ponds, respectively. For the other elements, the following percentage ratios were found: 0.7% B, 0.3% Mg and 0.06% Zn at the urban pond and 1.1% and 0.4% B, 0.4% Mg and 0.05% Zn at the rural ponds, respectively. Canonical discriminant analysis indicated the separation of the urban and the rural ponds based on the elemental concentrations of toe bones. Significant differences were found between the concentrations of Ca, P, Mg, B and Zn at the urban and the rural ponds (p < 0.05). Anthropogenic activity was found to have effects on the elemental contents of toe bones in the urbanized area. Our study also demonstrated that the developed method was appropriate for the elemental analysis of small samples to assess the effects of urbanization.

Population dynamics and genetic changes of Picea abies in the South Carpathians revealed by pollen and ancient DNA analyses.

BACKGROUND: Studies on allele length polymorphism designate several glacial refugia for Norway spruce (Picea abies) in the South Carpathian Mountains, but infer only limited expansion from these refugia after the last glaciation. To better understand the genetic dynamics of a South Carpathian spruce lineage, we compared ancient DNA from 10,700 and 11,000-year-old spruce pollen and macrofossils retrieved from Holocene lake sediment in the Retezat Mountains with DNA extracted from extant material from the same site. We used eight primer pairs that amplified short and variable regions of the spruce cpDNA. In addition, from the same lake sediment we obtained a 15,000-years-long pollen accumulation rate (PAR) record for spruce that helped us to infer changes in population size at this site. RESULTS: We obtained successful amplifications for Norway spruce from 17 out of 462 pollen grains tested, while the macrofossil material provided 22 DNA sequences. Two fossil sequences were found to be unique to the ancient material. Population genetic statistics showed higher genetic diversity in the ancient individuals compared to the extant ones. Similarly, statistically significant Ks and Kst values showed a considerable level of differentiation between extant and ancient populations at the same loci.Lateglacial and Holocene PAR values suggested that population size of the ancient population was small, in the range of 1/10 or 1/5 of the extant population. PAR analysis also detected two periods of rapid population growths (from ca. 11,100 and 3900 calibrated years before present (cal yr BP)) and three bottlenecks (around 9180, 7200 and 2200 cal yr BP), likely triggered by climatic change and human impact. CONCLUSION: Our results suggest that the paternal lineages observed today in the Retezat Mountains persisted at this site at least since the early Holocene. Combination of the results from the genetic and the PAR analyses furthermore suggests that the higher level of genetic variation found in the ancient populations and the loss of ancient allele types detected in the extant individuals were likely due to the repeated bottlenecks during the Holocene; however our limited sample size did not allow us to exclude sampling effect.This study demonstrates how past population size changes inferred from PAR records can be efficiently used in combination with ancient DNA studies. The joint application of palaeoecological and population genetics analyses proved to be a powerful tool to understand the influence of past population demographic changes on the haplotype diversity and genetic composition of forest tree species.

Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna.

Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load.

The effects of ethylene glycol and ethanol on the body mass and elemental composition of insects collected with pitfall traps.

Insects often used as accumulation indicators of hazardous elements. Pitfall traps with ethylene glycol as trapping fluid are frequently used to collect insects. We studied the effect of glycol and preservation with ethanol on the elemental composition of hand collected firebugs. Control samples were stored in a freezer and the following treatments were used: insect kept in trapping fluid for 2 weeks, and for 1 month, trapping fluid for 2 weeks plus 2 weeks in ethanol, and trapping fluid for 1 month plus ethanol for 1 month. Insects kept in trapping fluid gained mass with respect to control: 26% for the short trapping and 37% for the long trapping. Preservation in ethanol reversed this effect in each case. Trapping fluid did not alter the dry mass. A significant loss in dry mass only occurred in the long trapping plus long preservation treatment. We analysed the concentration of eight elements: Ca, Cu, K, Mg, Mn, Na, Sr and Zn. We found significant difference in the concentrations of elements among the four treatments in the case of all elements, except magnesium and zinc. Our results indicate the potential of both certain trapping fluids as well as preservation in ethanol influencing the concentration of certain elements in insects. Live trapping for collection and storage in under freezing conditions for preservation could be a more reliable method if quantitative analytical studies are to be performed, when invertebrates are used as indicators of the presence and concentrations of hazardous substances in the environment.