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Journal of Soils and Sediments - To understand the impact of geochemical sedimentation history for arsenic (As) distribution in the sediment profiles of the Hetao Basin, we (1) evaluated sediments...  相似文献   
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An experiment was carried out to study the effect of topical application of eprinomectin at early patency on the build up of infection and development of protection against Dictyocaulus viviparus in young cattle. Three groups of six calves were used and parasitological and blood variables were monitored at weekly intervals throughout the trial. At the start of the experiment calves in groups A and B were experimentally inoculated with 100 D. viviparus infective third-stage larvae (L3) for five consecutive days, whereas calves in group C served as uninfected controls. The calves in group A were each treated with eprinomectin (0.5mg/kg bodyweight) in a pour-on formulation at early patency at day 24 post the first inoculation, whereas the calves in groups B and C were left untreated. Seven weeks following anthelmintic treatment all groups were challenged with 1500 L3. Another 4 weeks later the animals were sacrificed and established worms in the lungs were counted. Moderate transient signs of lungworm disease occurred both in groups A and B. However, group B calves were found to be about 8 times more resistant than those in group A, whereas the naive infection controls in Group C was found to be about 35 times more susceptible to infection. Also the ELISA values showed that the course of infection was different between experimental groups. The eosinophil counts prior to and at the time of slaughter indicate that immunity was involved in the protection and the response was correlated with previous exposure and worm load. Weight gains differed significantly, but only between groups A and C and between groups B and C that on an average were approximately 13kg heavier at the termination of the experiment. It was concluded that eprinomectin was effective against established adult lungworms. However, the untreated calves (group B) developed a more marked resistance to lungworms compared to those that were subjected to anthelmintic treatment at early patency (group A). On the other hand, the cumulative number of excreted larvae was on an average 43 times higher in group B as compared to group A. Consequently, infected calves that remain out on pasture should be treated. This will restrain transmission of the parasite despite the fact that immunity is deteriorated.  相似文献   
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Lignin residues are available in large amounts as kraft lignin from chemical pulping processes. This lignin is mainly incinerated in recovery boilers. The recovery boilers are often the bottle-necks in the overall pulping process when pulp production increases are desired. Through cross-flow nano-filtration of the black liquor from kraft pulping, a low-molecular weight lignin fraction can be removed thus decreasing the organic load on the recovery boilers. The low-molecular weight lignin fraction furthermore exhibit different characteristics compared to other commercial kraft lignins and represents a new raw material source in novel applications.The low-molecular weight lignin was used together with a vegetable oil to produce a new hydrophobic lignin derivative similar to suberin. The lignin and the lignin derivative was analysed with FT-IR, UV–vis and SEC. The ability of the product to make paper surfaces hydrophobic was also evaluated.The results demonstrate the possibility to make a suberin-like lignin derivative that is potentially of interest in paper-coating applications due to its capability to interact well with wood fibres and make paper hydrophobic.  相似文献   
16.
Two isochinoline alkaloids, glaucine and oxoglaucine were investigated for their suggested anti-inflammatory influence concerning nitric oxide and cytokine production. Mouse peritoneal macrophages were stimulated with different Toll-like receptor (TLR) ligands such as LPS for TLR4, zymosan for TLR2 and CpG for TLR9. The alkaloids inhibited TNF-α and IL-6 production induced by these ligands. In regard to IL-12 suppressive effect was registered in the case of CpG stimulation. Glaucine succeeded to enhance LPS and zymosan-induced IL-10 production. The reduction of pro-inflammatory cytokines and increase of anti-inflammatory IL-10 are indicative for their use in different acute and chronic inflammatory diseases.  相似文献   
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Key message

Aggregated, consolidated, and derived soil physicochemical data of 286 ICP Forests Level II plots were completed with soil hydraulic properties for integrated use with forest monitoring data. Database access should be requested at http://icp-forests.net . Metadata associated available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=153e599e-6624-4e2b-b862-8124386ea9cd&hl=eng

Context

The ICP Forests database is one of the most comprehensive forest ecosystem datasets in Europe and contains the accumulated results of more than two decades of harmonised forest monitoring all over Europe.

Aims

The aim of this paper is to share knowledge on the ICP Forests Level II soil data for broader use among forest scientists.

Methods

After standard analysis, quality checks, aggregation, and calculation of derived variables (e.g. nutrient stocks, base saturation, C:N ratio, and water retention parameters), data have been gathered into a static database (AFSCDB.LII.2.2), which will be updated to new versions as soon as new measurements become available.

Results

The database provides a basis for the combined evaluation of up to 130 unique soil variables of 286 plots with dynamic data on tree growth, ground vegetation, foliar chemistry, crown condition, tree phenology, leaf area index, ozone injury, litterfall, soil solution chemistry, deposition, ambient air quality, and meteorological data assessed on the same plots.

Conclusion

The unprecedented comprehensiveness and level of detail in this newly aggregated database may overcome existing restrictions so far impeding the realisation of large-scale forest ecosystem studies in Europe.
  相似文献   
18.
Water soluble polysaccharides from Norway spruce, Scots pine, and Siberian larch were compared. For all species the total amount of polysaccharides isolated from the heartwood was higher than that from the sapwood. The heartwood polysaccharides had a high content of galactose and arabinose units, and some glucuronic acid units, suggesting the presence of acidic arabinogalactans. The total amounts of recovered water-soluble arabinogalactans were 1.9 mg/g for spruce heartwood, 5.3 mg/g for pine heartwood, and as much as 106 mg/g for larch heartwood. The other water-soluble polysaccharides were mainly glucomannans. The average ratio of Gal:Ara:GlcA in the water-soluble arabinogalactans of spruce heartwood was about 4.3:1:1, pine heartwood about 4.5:1:0.2, and larch heartwood about 6.7:1:0.1. The corresponding molar ratios then being about 3.6:1:0.8 for spruce, 3.8:1:0.2 for pine, and 5.6:1:0.08 for larch. Thus, the content of glucuronic acid units was especially high in the spruce heartwood arabinogalactans. The content of arabinose was slightly higher in spruce and pine than in larch heartwood arabinogalactans.  相似文献   
19.
The antioxidant properties of hydrophilic extracts of knotwood of several industrially important tree species were evaluated by lipid-peroxidation inhibition and peroxyl-trapping capacity tests. The results were compared with the antioxidant properties of hydrophilic extracts of bark, and pure lignans and flavonoids isolated from knotwood extracts. The knot extracts from several tree species were stronger antioxidants than the bark extracts, which can, however, also be classified as strong antioxidants. In addition, the antioxidant properties of most of the knotwood extracts are stronger than the pure compounds. It is concluded that knotwood is a rich source of natural antioxidants.  相似文献   
20.
The conversion of anthropogenic into more natural, self-regenerating forests is one of the major objectives of forestry throughout Europe. In this study, we present investigations on permanent plots with different silvicultural treatment in NE German pine stands. Management of old-growth pine stands on acidic and nutrient-poor sandy sites differs in fencing, thinning, and planting of certain tree species. The investigations were carried out on the community, population, and individual level of the pine forest ecosystems. Thus, vegetation changes, size and height of tree populations, and height increment of tree individuals were observed over a time span of 6 years. Special attention was paid to short-lived tree species such as, e.g., Frangula alnus and Sorbus aucuparia, as well as to Fagus sylvatica as one of the most typical forest tree species of Central Europe. Vegetation changes are interpreted as a consequence of natural regeneration of formerly degraded forest sites, involving an increase in nutrient availability. High browsing pressure can be considered as a key factor for the inhibition of tree seedlings and growth of saplings. Some Sorbus aucuparia individuals, however, succeeded in growing out of the browsing height also in unfenced stands. Few found specimens of Fagus sylvatica proved that this species is able to establish spontaneously on these relatively dry, acidic sites under continental climate influence. Such natural regeneration processes, also including spontaneous rejuvenation of trees, can be integrated into silviculture as passive forest conversion management. An active management like thinning of stands, planting of trees, and fencing can accelerate forest conversion with regard to height growth and species number of trees.  相似文献   
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