Search results for "Veterinary Science"
showing 10 items of 2359 documents
Test procedures for obtaining representative extracts suitable for reliable in vitro toxicity assessment of paper and board intended for food contact.
2009
International audience; This paper describes the use of a suite of extraction procedures applicable to the assessment of the in vitro toxicity of paper/board samples intended for food-contact applications. The sample is extracted with ethanol, water, or exposed to modified polyphenylene oxide (Tenax) for fatty, non-fatty and dry food applications, respectively. The water extracts are directly suitable for safety assessment using in vitro bioassays. The ethanol extracts of the paper/board and of the exposed Tenax require pre-concentration to give acceptable sensitivity. This is because the in vitro bioassays can tolerate only a small percentage of added organic solvent before the solvent its…
The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and bo…
2008
International audience; Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-foo…
Representativeness of Extracts of Offset Paper Packaging and Analysis of the Main Odor-Active Compounds
2004
Packagings often carry odors due to the support and printing inks. The aim of the investigation was to define a representative solvent-free extract of paper-based packaging materials printed by the offset process, for the identification of the odor-causing volatile compounds. Static headspace and solid-phase microextraction were the two applied extraction methods. Representativeness tests showed that the odor of the PDMS fiber extract gave satisfying odor similarities with the original packaging. The sample incubation was performed at 40 degrees C for 30 min, whereas the extraction time was 3 min at 40 degrees C. Extracts of both the nonprinted and printed papers of different batches were a…
Commentary: Dogs and the classic route of Guinea Worm transmission: an evaluation of copepod ingestion
2020
Dracunculus medinensis, the causative agent of Guinea worm disease in humans, is being reported with increasing frequency in dogs. However, the route(s) of transmission to dogs is still poorly understood. Classical transmission to humans occurs via drinking water that contains cyclopoid copepods infected with third stage larvae of D. medinensis, but due to the method of dog drinking (lapping) compared to humans (suction and/or retrieval of water into containers), it seems unlikely that dogs would ingest copepods readily through drinking. We exposed lab raised beagles to varying densities of uninfected copepods in 2 liters of water to evaluate the number of copepods ingested during a drinkin…
The impact of baking on chlorinated paraffins: Characterization of C10–C17 chlorinated paraffins in oven-baked pastry products and unprocessed pastry…
2019
Abstract This study presents an HPLC–ESI–Q–TOF method for simultaneous quantification of short-chain chlorinated paraffins (SCCPs, C10–13) and an additional characterization of medium-chain chlorinated paraffins (MCCPs, C14–17) in oven-baked pastry products (n = 38) and unprocessed pastry dough material (n = 15). Almost 2 times higher SCCP levels were found in the dough material. ΣSCCP concentrations in products ranged from 0.3 ng g−1 to 23.0 ng g−1 (mean: 6.3 ng g−1), while the results for dough ranged from 5.8 ng g−1 to 22.8 ng g−1 (mean: 12.9 ng g−1). Regardless of the sample matrix, the most abundant CP homologue groups were hepta- and octa-chlorinated undecanes and dodecanes. The avera…
The role ofSphagnummosses in the methane cycling of a boreal mire
2010
Peatlands are a major natural source of atmospheric methane (CH4). Emissions from Sphagnum-dominated mires are lower than those measured from other mire types. This observation may partly be due to methanotrophic (i.e., methane-consuming) bacteria associated with Sphagnum. Twenty-three of the 41 Sphagnum species in Finland can be found in the peatland at Lakkasuo. To better understand the Sphagnum-methanotroph system, we tested the following hypotheses: (1) all these Sphagnum species support methanotrophic bacteria; (2) water level is the key environmental determinant for differences in methanotrophy across habitats; (3) under dry conditions, Sphagnum species will not host methanotrophic ba…
The impact of long-term water level draw-down on microbial biomass : A comparative study from two peatland sites with different nutrient status
2017
We examined the effects of long-term (51 years) drainage on peat microbial communities using phospholipid fatty acid (PLFA) analysis. We analysed the peat profiles of natural and adjacent drained fen and bog sites. Viable microbes (i.e. microbial PLFA) were present in relatively large amounts even in the deepest peat layers of both peatland sites, a finding that warrants further investigation. Microbial biomass was generally higher in the fen than in the bog. Microbial community structure (indexed from PLFA) differed between the fen and bog sites and among depths. Although we did not exclude other factors, the effect of drainage on the total microbial biomass and community structure was not…
Stable carbon isotopic composition of peat columns, subsoil and vegetation on natural and forestry-drained boreal peatlands.
2018
We studied natural and forestry-drained peatlands to examine the effect of over 34 years lowered water table on the δ13C values of vegetation, bulk peat and subsoil. In the seven studied sites, δ13C in the basal peat layer was 1.1 and 1.2 ‰ lower than that of the middle-layer and surface layer, respectively. Furthermore, there was a positive correlation between the δ13C values of the basal and surface peat layers, possibly due to carbon (C) recycling within the peat column. In the same mire complex, natural fen peat δ13C values were lower than those of the nearby bog, possibly due to the dominance of vascular plants on fen and the generally larger share of recycled C in the fens than in the…
Heterogeneity of carbon loss and its temperature sensitivity in East-European subarctic tundra soils
2016
Arctic peatlands store large stocks of organic carbon which are vulnerable to the climate change but their fate is uncertain. There is increasing evidence that a part of it will be lost as a result of faster microbial mineralization. We studied the vulnerability of 3500-5900 years old bare peat uplifted from permafrost layers by cryogenic processes to the surface of an arctic peat plateau. We aimed to find biotic and abiotic drivers of CLOSS from old peat and compare them with those of adjacent, young vegetated soils of the peat plateau and mineral tundra. The soils were incubated in laboratory at three temperatures (4°C, 12°C and 20°C) and two oxygen levels (aerobic, anaerobic). CLOSS was …
A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands
2014
Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consi…