Major Extractable Organic Compounds in the Biologically Degradable Fraction of Fresh,Composted and Anaerobically Digested Household Waste

The recirculation of plant nutrients from urban areas to agriculture and horticulture and a need to reduce waste disposal by landfilling and incineration are the main reasons for recycling the biologically degradable fraction of household waste. However, before using the recycled material in agricultural and horticultural production it is necessary to make sure that the material does not contain any unwanted contaminants. In general, there is a lack of knowledge about organic contaminants in the degradable fraction of household waste and its compost and anaerobic digestion products. As a first step in a study of organic contaminants in household waste, and as part of the characterization of the degradation processes during composting and anaerobic digestion, the major extractable organic compounds were identified in the biologically degradable fraction of fresh, composted and anaerobically digested household waste. The organic compounds were isolated by supercritical fluid extraction using carbon dioxide as extraction medium. Gas chromatography-mass spectrometry was used for qualitative analyses. Natural products, such as fatty acids, fatty acid esters, n-alkanes, aliphatic alcohols, monoterpenes and triterpenes constituted the major organic components in the waste samples. In addition bis-(2-ethylhexyl) phthalate, frequently used as a plasticizer in polymers, was found in the extracts. In the chromatograms of the extracts of the fresh and composted household waste, fatty acids and fatty acid esters dominated with respect to peak heights and the number of peaks identified. In the anaerobically digested household waste n-alkanes were the dominating compound class. The pattern of the n-alkanes, also found in the fresh waste, possibly indicates a petrogenic origin of these compounds, perhaps caused by contamination during the collection of the household waste.     

New gene-based approaches for an AIDS vaccine

Vaccine approaches against AIDS have focused on inducing cellular immune responses, since many studies revealed the role of T cell responses in the control of human immunodeficiency virus or simian immunodeficiency virus (SIV) infections. The experimental infection of rhesus macaques with SIV or chimeric SHIV is routinely used as a model for AIDS. In such models, DNA immunization is a tool to elicit specific T cell responses and to study their protective efficacy. DNA immunogenicity in primates depends on parameters such as level of antigen expression, choice of the antigen among SIV proteins, use of fusion proteins, route of immunization, and addition of adjuvants. Recent results suggest that priming with DNA and boosting with attenuated recombinant viral vectors, each expressing corresponding SIV antigens, leads to improved specific immunity and, in some cases, affords protection against pathogenic challenge. After preclinical evaluations, DNA has entered clinical trials for a therapeutic or prophylactic gene-based AIDS vaccine.     

Lymphangioma in the metacarpal pad of a dog

A five-year-old English springer spaniel was presented with a three year history of metacarpal ulceration causing lameness. The lesion was initially thought to be caused by a foreign body, but subsequently diagnosed as lymphangioma. The dog was surgically treated with resection of the metacarpal pad and transposition of the second digital pad. A severe infection developed 11 days postoperatively but was managed with antibiotics and intensive wound therapy. The surgical technique was successful, considerable adaptation of the transposed pad occurred and the dog returned to full weightbearing on the leg. However, one year later another area of new ulceration developed on the dorsomedial aspect of the paw. This, too, was resected but recurred after a short time and the owner elected for euthanasia of the dog.     

Testing and evaluation of natural durability of wood in above ground conditions in Europe – an overview

Natural durability of wood is determined by the European standard EN 252 for specimens in ground contact and EN 113 for basidiomycetes in the laboratory, but no test exists for above ground conditions. For above ground conditions, the European prestandard ENV 12037 and EN 330 are used to determine the durability of treated wood. The most important factors for fungal establishment on the surface and within wood are the moisture content, the surrounding temperature, and the relative humidity. Strength tests are the most sensitive for decay detection, but neither strength tests nor identification of fungi responsible for the decay are included in the standards of above ground durability in field tests. To detect decay, visual examination, pick or splinter tests, and mass loss determination are used. Identifying fungi with traditional methods, e.g., growth on solid medium, is time consuming and complicated. Molecular methods like polymerase chain reaction and sequencing do not require mycological skill for identification to species level, and furthermore the methods do not depend on the subjective judgement like most traditional methods, but are based on the objective information of the target organism (e.g., nucleotide sequences). The next generation of standard field tests will probably consider the drawbacks of standard tests today and be rapid and include both quality tests like molecular identification and nondestructive quantitative tests, e.g., acoustic tests. Laboratory tests can be improved by using fungi identified from field trials and by combining different fungi in the same test and thus simulate degradation in practice.     

CO2 and ozone effects on canopy development of potato crops across Europe

This paper describes the effects of elevated CO₂ (550 and 680 μl l⁻¹) and O₃ (60 nl l⁻¹ O₃ as an 8 h mean), alone or in combination, on canopy development and senescence in potato (Solanum tuberosum L. cv Bintje) across a range of European agro-climatic conditions. The assessments were made within the European CHIP project (CHanging climate and potential Impacts on Potato yield and quality) that was conducted for two growing seasons (1998 and 1999) in free air CO₂ enrichment systems (FACE) and open-top chamber facilities (OTCs) at seven European sites. A comparison of chambered and unchambered experimental plots was included to examine the effects of chamber enclosure. Phenological growth stages, plant height, leaf area index (LAI) and the number of green and yellow leaves were recorded non-destructively throughout the growing season and by a destructive intermediate harvest at maximum leaf area (MLA). In the dynamic growth analysis CO₂ and O₃ effects were studied over three developmental stages: canopy expansion, full canopy and canopy senescence. Chamber enclosures promoted potato crop development (taller plants, more leaves) during the initial growth stages and led to a faster decline of LAI and a higher number of yellow leaves. The growth in ambient plots varied between sites and seasons, as did the scale of the treatment responses. Despite the large background variation, some overall treatment effects could be detected across all sites. Both levels of increased CO₂ reduced final plant height in comparison to ambient concentrations, which indicates a premature ending of the active plant growth. At the stage of full canopy and crop senescence the average number of green leaves was significantly (P<0.05) decreased by 680 μl l⁻¹ CO₂ (OTC experiments) and LAI showed the same tendency (P=0.07). As there was however no indication of a decreased leaf formation during initial growth and at full canopy, this must have been due to an earlier leaf fall. In the FACE experiments LAI had already began to decline at the stage of full canopy at 550 μl l⁻¹ CO₂ but not in ambient CO₂ (DAE×CO₂, P<0.05). These observations strongly indicated that elevated CO₂ induced a premature senescence during full canopy. O₃ did not have an overall detrimental effect on crop development during initial growth nor at full canopy, but did induce a faster reduction of LAI during crop senescence (DAE×O₃, P<0.05). Final plant height was not affected by O₃. There were few CO₂×O₃ interactions detected. There was a suggestion (P=0.06) that O₃ counteracted the CO₂-induced decrease of green leaves at full canopy, but on the other hand during crop senescence the decline of LAI due to elevated O₃ was faster at ambient compared to elevated CO₂ (P<0.05). These responses of canopy development to elevated CO₂ and O₃ help to explain the treatment responses of potato yield within the CHIP project at sites across Europe.     

Half a Century of Mercury Contamination in Lake Vänern (Sweden)

Lake Vänern is Sweden's largest freshwater reservoir. It has been significantly affected by mercury contamination during the latter half of the 20th century. The aim of this study was to analyse the spatial and vertical mercury distribution, whereas 46 sediment cores were sampled in 2001 and analysed for total mercury. Several of these cores were dated presenting sediment accumulation rates varying from 6–8 mm yr^?1 outside major rivers to ～2 mm yr^?1 in the deeper areas. This was made using ¹³⁷ Cs, which was verified by ²¹⁰ Pb dating. Cluster analysis was used to identify five areas with similar accumulation and mercury concentration regimes. In areas far from shore, surface concentrations ranged from 0.1 to 0.5 ppm Hg, while the deeper layers in contaminated areas held concentrations up to 11 ppm Hg. In total, ～50 tonnes of mercury accumulated in the lake's sediment between ～1940–2001; almost 80% (or 37 tonnes) originate from before the mid 70's when the recovery period began, and at least 30 tonnes can be attributed to the former point source – a chlor-alkali industry.     

Aluminium speciation: Variations caused by the choice of analytical method and by sample storage

We have compared a new FIA method (M1) for aluminium speciation in natural waters and a manual one based on one of Driscoll's proposals (M2). In synthetic solutions, aluminium's fluoro complexes were measured as ‘labile monomeric AP (Al _i ) by M2, but not as ‘quickly reacting Al’ (Al _qr ) by M1. Aluminium's complexes with Nordic Reference Humic Acid were measured neither as Al _i nor as Al _qr , and the same result was obtained for Al's citrato complexes. After excluding aluminium's fluoro complexes from Al _i , the results of the two methods agreed well for soil leaching samples and fairly well for natural water samples. Detection limits: 10μg L^?1 (ca. 0.4 μM) for both methods. Sample throughputs: M1∶66 injections h^?1; M2∶5 samples h^?1. Repeatabilities (RSD) on natural water samples: M1∶0.6–5.8% and M2 0.7–4.6%. Sample storage studies on soil solutions (FIA method) indicated that storage effects were ‘sample type specific’. A sample with a low level of Al _qr and a high DOC level (P2A) was more sensitive to storage than one with a high [Al] _qr and a low [DOC] (P2B^*). The decrease in [Al] _qr was statistically significant after 10 h (P2A) and 24 h (P2B^*), respectively. After 3 days' storage, [Al] _qr had decreased by some 40% in P2A, while the decrease in P2B^* was less than 10% after 8 days. The results of this part of the study also emphasize the importance of careful method standardization in sample storage studies.     

Genotype dynamics of Campylobacter jejuni in a broiler flock

We investigated the genotype diversity and dynamics of Campylobacter in a commercial broiler flock during rearing and slaughter. In total, 220 Campylobacter jejuni isolates collected on four sampling occasions during rearing and from routine sampling during slaughter were subtyped by SmaI macrorestriction and pulsed-field gel electrophoresis, PFGE. Eight different SmaI types were found. During rearing, a subsequent addition of genotypes occurred, with two SmaI types found at 2 weeks of age and six types on the day before slaughter. All types that were detected in more than one isolate were also found on all succeeding sampling occasions, including the slaughter sampling. Two new types were found in the slaughter samples. In two-thirds of the individual birds sampled the day before slaughter, more than one SmaI type were found, although there was a clear tendency for dominance of one type in individual birds. Our results show that multiple genotypes of C. jejuni may be present in a commercial broiler flock during rearing and even in gastrointestinal tracts of individual birds. Both recurring environmental exposure and genetic changes within the population may explain the genotype diversity. Although the distribution of genotypes varied between different sampling occasions, we found no indication that any subtype excluded another during the rearing of the broiler flock.     

Pheno- and genotyping of Staphylococcus epidermidis isolated from bovine milk and human skin

The purpose of this study was to improve our knowledge concerning the epidemiology and strain diversity of Staphylococcus epidermidis isolated from bovine milk in commercial dairy herds. A total of 341 S. epidermidis isolates obtained from cows' milk (317), farmers (17) and patients (7) were characterized. Of these 105 isolates were from cows' milk in two farms, where also 17 isolates were sampled from farmers. The remaining 212 isolates from cows' milk were from 170 farms. All isolates were examined by antimicrobial susceptibility, whereas 202 were examined by pulsed-field gel electrophoresis (PFGE) and 122 by ribotyping. PFGE showed single patterns in the human strains with one exception; one strain was categorised as the same clone as four of the milk strains. PFGE divided 73 of the milk strains into 62 different patterns. The PFGE method had high discriminatory power and shows that many different S. epidermidis types exist in milk samples. Antibiotic resistance patterns matched the SmaI profiles closely in the two herds, but poorly in the routinely collected milk samples. Isolates from herd 1 showed one to five patterns, depending on the typing method used. Isolates from the milker's skin showed one pattern, which was identical to the most common pattern found in the milk isolates. Isolates from herd 2 showed three to four patterns, two of these being identical to skin isolates from the milker. As dairy cows are not a natural host for S. epidermidis the results suggest a human source of these udder infections.     

Bioindication and modelling of atmospheric deposition in forests enable exposure and effect monitoring at high spatial density across scales

Key message

Moss surveys provide spatially dense data on environmental concentrations of heavy metals and nitrogen which, together with other biomonitoring and modelling data, can be used for indicating deposition to terrestrial ecosystems and related effects across time and areas of different spatial extension.

Context

For enhancing the spatial resolution of measuring and mapping atmospheric deposition by technical devices and by modelling, moss is used complementarily as bio-monitor.

Aims

This paper investigated whether nitrogen and heavy metal concentrations derived by biomonitoring of atmospheric deposition are statistically meaningful in terms of compliance with minimum sample size across several spatial levels (objective 1), whether this is also true in terms of geostatistical criteria such as spatial auto-correlation and, by this, estimated values for unsampled locations (objective 2) and whether moss indicates atmospheric deposition in a similar way as modelled deposition, tree foliage and natural surface soil at the European and country level, and whether they indicate site-specific variance due to canopy drip (objective 3).

Methods

Data from modelling and biomonitoring atmospheric deposition were statistically analysed by means of minimum sample size calculation, by geostatistics as well as by bivariate correlation analyses and by multivariate correlation analyses using the Classification and Regression Tree approach and the Random Forests method.

Results

It was found that the compliance of measurements with the minimum sample size varies by spatial scale and element measured. For unsampled locations, estimation could be derived. Statistically significant correlations between concentrations of heavy metals and nitrogen in moss and modelled atmospheric deposition, and concentrations in leaves, needles and soil were found. Significant influence of canopy drip on nitrogen concentration in moss was proven.

Conclusion

Moss surveys should complement modelled atmospheric deposition data as well as other biomonitoring approaches and offer a great potential for various terrestrial monitoring programmes dealing with exposure and effects.