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81.
This study was conducted to improve our understanding of how earthworms and microorganisms interact in the decomposition of litter of low quality (high C : N ratio) grown under elevated atmospheric [CO2]. A microcosm approach was used to investigate the influence of endogeic earthworm (Aporrectodea caliginosa Savigny) activity on the decomposition of senescent Charlock mustard (Sinapis arvensis L.) litter produced under ambient and elevated [CO2]. Earthworms and microorganisms were exposed to litter which had changed in quality (C : N ratio) while growing under elevated [CO2]. After 50 d of incubation in microcosms, C mineralization (CO2 production) in the treatment with elevated‐[CO2] litter was significantly lower in comparison to the ambient‐[CO2] litter treatment. The input of Charlock mustard litter into the soil generally induced N immobilization and reduced N2O‐emission rates from soil. Earthworm activity enhanced CO2 production, but there was no relationship to litter quality. Although earthworm biomass was not affected by the lower quality of the elevated‐[CO2] litter, soil microbial biomass (Cmic, Nmic) was significantly decreased. Earthworms reduced Cmic and fungal biomass, the latter only in treatments without litter. Our study clearly showed that A. caliginosa used the litter grown under different [CO2] independent of its quality and that their effect on the litter‐decomposition process was also independent of litter quality. Soil microorganisms were shown to negatively react to small changes in Charlock mustard litter quality; therefore we expect that microbially mediated C and N cycling may change under future atmospheric [CO2].  相似文献   
82.
Short‐rotation forestry (SRF) on arable soils has high potentials for biomass production and leads to long‐term no‐tillage management. In the present study, the vertical distributions of soil chemical and microbial properties after 15 y of SRF with willows and poplar (Salix and Populus spp.) in 3‐ and 6‐year rotations on an arable soil were measured and compared to a pertinent tilled arable site. Two transects at different positions in the relief (upper and lower slope; transect 1 and 2) were investigated. Short‐rotation forestry caused significant changes in the vertical distribution of all investigated soil properties (organic and microbial C, total and microbial N, soil enzyme activities), however, the dimension and location (horizons) of significant effects varied. The rotation periods affected the vertical distribution of the soil properties within the SRF significantly. In transect 1, SRF had higher organic‐C concentrations in the subsoil (Bv horizon), whereas in transect 2, the organic‐C concentrations were increased predominantly in the topsoil (Ah horizon). Sufficient plant supply of P and K in combination with decreased concentrations of these elements in the subsoil under SRF pointed to an effective nutrient mobilization and transfer from the deeper soil horizons even in the long term. In transect 1, the microbial‐C concentrations were higher in the B and C horizons and in transect 2 in the A horizons under SRF than under arable use. The activities of β‐glucosidases and acid phosphatases in the soil were predominantly lower under SRF than under arable use in the topsoil and subsoil. We conclude, that long‐term SRF on arable sites can contribute to increased C sequestration and changes in the vertical distribution of soil microbial biomass and soil enzyme activities in the topsoil and also in the subsoil.  相似文献   
83.
In recent years, worldwide socioeconomic, ecological, and cultural changes have led to a paradigm shift in forestry and forest management. Some years ago, most forest enterprises exclusively focused on wood production, whereas today, forest management is expected to be multifunctional and economically as well as socially and ecologically sustainable [Harrison, S., Herbohn, J., Niskanen, A., 2002. Non-industrial, smallholder, small-scale and family forestry: what's in a name? Small-scale Forest Economics. Management and Policy 1 (1), 1–11; Schmithuesen, F., 2004. Forest policy developments in changing societies — political trends and challenges to research. Towards the sustainable use of Europe's forests: Forest ecosystems and landscape research: Joensuu: European Forest Institute, Proc., vol. 49, pp. 87–99]. In this context, non-timber forest products (NTFPs) such as forest honey, mushrooms, or berries could gain importance as an additional source of income for the forestry sector. To assess the market potential of NTFPs in Switzerland, two corresponding surveys were conducted. A consumer survey (N = 897) conducted in six cities in Switzerland investigated the purchase of Swiss NTFPs, consumer preferences, and demand potentials. An additional survey of sellers of NTFPs (N = 105) looked at these aspects from a complementary perspective. The results showed that there is a high esteem and considerable demand potential for such products among urban consumers. Food products were mentioned most frequently. Both consumers and sellers considered quality and environmental friendliness the most important attributes of NTFPs. Structural and organizational innovations and considerable marketing efforts and sales promotion would be required to expand the market for Swiss NTFP, however. Our results indicate that certification of the products' origin, environmental performance, and quality could support such efforts and that recreational and ecological forest services have a synergetic potential for the marketing of NTFPs.  相似文献   
84.
85.
Addition of clay-rich subsoil to sandy soil results in heterogeneous soil with clay peds(2-mm) or finely ground( 2 mm) clay soil(FG), which may affect the nutrient availability. The aim of this study was to assess the effect of clay soil particle size(FG or peds)and properties on nutrient availability and organic C binding in sandy soil after addition of residues with low(young kikuyu grass,KG) or high(faba bean, FB) C/N ratio. Two clay soils with high and low smectite percentage, clay and exchangeable Fe and Al were added to a sandy soil at a rate of 20%(weight/weight) either as FG or peds. Over 45 d, available N and P as well as microbial biomass N and P concentrations and cumulative respiration were greater in soils with residues of KG than FB. For soils with KG residues,clay addition increased available N and initial microbial biomass C and N concentrations, but decreased cumulative respiration and P availability compared to sandy soil without clay. Differences in measured parameters between clay type and size were inconsistent and varied with time except the increase in total organic C in the 53 μm fraction during the experiment, which was greater for soils with FG than with peds. We concluded that the high exchangeable Fe and Al concentrations in the low-smectite clay soil can compensate a lower clay concentration and proportion of smectite with respect to binding of organic matter and nutrients.  相似文献   
86.
Several hydrolysate-based diets have been commercialized for helping diagnose or treat dogs with cutaneous adverse food reactions (CAFR). This systematic review was performed to examine the evidence in favour of reduced immunological and clinical allergenicity of hydrolysates in dogs with CAFR. Citation databases, meeting abstracts and article bibliographies were scanned for relevant citations, and companies were contacted to provide unpublished reports. Eleven studies relevant to this study were identified. Some evidence of reduced serum IgE binding to a soy hydrolysate (1 study) and decreased intradermal test reactivity to hydrolysed proteins (three studies) was found. In four reports, the feeding of dogs suspected of having CAFR with hydrolysate-based diets reduced or eliminated clinical signs in a variable proportion of subjects. The percentage of dogs with CAFR that still reacted to these hydrolysate-based diets could not be assessed, however. Importantly, up to 50% of dogs with CAFR enrolled in three controlled studies exhibited increases in clinical signs after ingesting partial hydrolysates derived from foods to which they were hypersensitive. In conclusion, the limited number of studies undertaken point to reduced – but not eliminated – immunological and clinical allergenicity of hydrolysate-based commercial diets. A variable proportion of dogs with CAFR will exhibit a worsening of clinical signs when fed partial hydrolysates. Clinicians must weigh the clinical benefit of these diets versus their high cost and low risk of reduced appetence or gastrointestinal sign development. At this time, hydrolysate-containing diets are probably best used in dogs suspected not to be hypersensitive to their individual components.  相似文献   
87.
Laminin‐332 (laminin‐5) is a basement membrane heterotrimeric protein composed of alpha‐3, beta‐3 and gamma‐2 laminin chains. Laminin‐332 polypeptides are targeted by auto‐antibodies in human patients with mucous membrane (cicatricial) pemphigoid or, more rarely, subepidermal vesicular diseases that resemble epidermolysis bullosa acquisita (EBA) or bullous pemphigoid (BP). The objectives of this report were to characterize the clinical, histopathological and immunological characteristics of nine dogs with auto‐antibodies targeting laminin‐332. Immunological investigations consisted of direct immunofluorescence (IF), indirect IF with intact and salt‐split canine gingival, and salt‐split normal or laminin‐332‐deficient human skin, immunoblotting with purified human laminin‐332 and immunoblotting with recombinant NC1 domain of human collagen VII. All dogs exhibited varying degrees of skin blistering and ulceration associated with microscopic subepidermal vesiculation with or without inflammatory cells. Indirect IF established that circulating IgG auto‐antibodies bound the dermal side of salt‐split canine lip and human skin. In five dogs, IgG variably recognized the basement membrane of laminin‐332‐deficient human skin (three dogs negative, two dogs positive). In all nine dogs, IgG auto‐antibodies detected purified human laminin‐332 by immunoblotting. In two dogs, additional targeting of collagen VII‐NC1 was present. These observations establish laminin‐332 as a novel basement membrane antigen in dogs with autoimmune blistering diseases with variable clinical phenotypes. The names ‘acquired junctional epidermolysis bullosa’, ‘anti‐laminin‐332 mucous membrane pemphigoid (MMP)’ and ‘mixed auto‐immune subepidermal blistering dermatosis’ are proposed for dogs with clinical signs reminiscent of EBA, MMP or BP respectively.  相似文献   
88.
Alopecia areata is a hair loss disorder in humans, dogs and horses with a suspected autoimmune aetiology targeting anagen hair follicles. Alopecia areata is only sporadically reported in cows. Recently, we observed several cases of suspected alopecia areata in Eringer cows. The aim of this study was to confirm the presumptive diagnosis of alopecia areata and to define the clinical phenotype and histopathological patterns, including characterization of the infiltrating inflammatory cells. Twenty Eringer cows with alopecia and 11 Eringer cows without skin problems were included in this study. Affected cows had either generalized or multifocal alopecia or hypotrichosis. The tail, forehead and distal extremities were usually spared. Punch biopsies were obtained from the centre and margin of alopecic lesions and normal haired skin. Histological examination revealed several alterations in anagen hair bulbs. These included peri‐ and intrabulbar lymphocytic infiltration, peribulbar fibrosis, degenerate matrix cells with clumped melanosomes and pigmentary incontinence. Mild lymphocytic infiltrative mural folliculitis was seen in the inferior segment and isthmus of the hair follicles. Hair shafts were often unpigmented and dysplastic. The large majority of infiltrating lymphocytes were CD3+ T cells, whereas only occasional CD20+ lymphocytes were present in the peribulbar infiltrate. Our findings confirm the diagnosis of T‐cell‐mediated alopecia areata in these cows. Alopecia areata appears to occur with increased frequency in the Eringer breed, but distinct predisposing factors could not be identified.  相似文献   
89.
90.

Purpose  

A sequential phosphorus (P) fractionation procedure for sediments was applied to silicon (Si) to test its applicability. We wanted to know (1) whether it would be used in a cost-efficient way to study the finding of both elements, defining Si pools corresponding to the respective P pools, and in particular, (2) whether it could be shown that redox-sensitive processes affect Si mobility in sediment.  相似文献   
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