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1.
Biodegradation of organic matter is required to reduce the potential of municipal solid waste for producing gaseous emissions and leaching contaminants. Therefore, we studied leachates of an aerobic-treated waste from municipal solids and a sewage sludge mixture that were re-circulated to decrease the concentration of biodegradable organic matter in laboratory-scale reactors. After 12 months, the total organic C and biological and chemical oxygen demands were reduced, indicating the biodegradation of organic compounds in the leachates. Curie-point pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and pyrolysis-field ionization mass spectrometry (Py-FIMS) revealed that phenols, alkylaromatic compounds, N-containing compounds and carbohydrates were the predominate compounds in the leachates and solid waste. Leachate re-circulation led to a higher thermal stability of the residual organic matter as indicated by temperature-resolved Py-FIMS. Admixture of sewage sludge to solid waste was less effective in removing organic compounds from the leachates. It resulted in drastic higher and more bio-resistant loads of organic matter in the leachates and revealed increased proportions of alkylaromatic compounds. The biodegradation of organic matter in leachates, re-circulated through municipal solid waste, offers the potential for improved aerobic waste treatments and should be investigated on a larger scale. 相似文献
2.
Exchange of heme among hemoglobins and between hemoglobin and albumin 总被引:29,自引:0,他引:29
3.
Bernhard Zehetgruber Johannes Kobler Thomas Dirnböck Robert Jandl Rupert Seidl Andreas Schindlbacher 《Plant and Soil》2017,420(1-2):239-252
Aims
Slow or failed tree regeneration after forest disturbance is increasingly observed in the central European Alps, potentially amplifying the carbon (C) loss from disturbance. We aimed at quantifying C dynamics of a poorly regenerating disturbance site with a special focus on the role of non-woody ground vegetation.Methods
Soil CO2 efflux, fine root biomass, ground vegetation biomass, tree increment and litter input were assessed in (i) an undisturbed section of a ~ 110 years old Norway spruce stand, (ii) in a disturbed section which was clear-cut six years ago (no tree regeneration), and (iii) in a disturbed section which was clear-cut three years ago (no tree regeneration).Results
Total soil CO2 efflux was similar across all stand sections (8.5 ± 0.2 to 8.9 ± 0.3 t C ha?1 yr.?1). The undisturbed forest served as atmospheric C sink (2.1 t C ha?1 yr.?1), whereas both clearings were C sources to the atmosphere. The source strength three years after disturbance (?5.5 t C ha?1 yr.?1) was almost twice as high as six years after disturbance (?2.9 t C ha?1 yr.?1), with declining heterotrophic soil respiration and the high productivity of dense graminoid ground vegetation mitigating C loss.Conclusions
C loss after disturbance decreases with time and ground vegetation growth. Dense non-woody ground vegetation cover can hamper tree regeneration but simultaneously decrease the ecosystem C loss. The role of ground vegetation should be more explicitly taken into account in forest C budgets assessing disturbance effects.4.
Eugenio Díaz-Pinés Andreas Schindlbacher Marina Godino Barbara Kitzler Robert Jandl Sophie Zechmeister-Boltenstern Agustín Rubio 《Plant and Soil》2014,384(1-2):243-257
Background and Aims
Tree species composition shifts can alter soil CO2 and N2O effluxes. We quantified the soil CO2 and N2O efflux rates and temperature sensitivity from Pyrenean oak, Scots pine and mixed stands in Central Spain to assess the effects of a potential expansion of oak forests.Methods
Soil CO2 and N2O effluxes were measured from topsoil samples by lab incubation from 5 to 25 °C. Soil microbial biomass and community composition were assessed.Results
Pine stands showed highest soil CO2 efflux, followed by mixed and oak forests (up to 277, 245 and 145 mg CO2-C m?2 h?1, respectively). Despite contrasting soil microbial community composition (more fungi and less actinomycetes in pine plots), carbon decomposability and temperature sensitivity of the soil CO2 efflux remain constant among tree species. Soil N2O efflux rates and its temperature sensitivity was markedly higher in oak stands than in pine stands (70 vs. 27 μg N2O-N m?2 h?1, Q10, 4.5 vs. 2.5).Conclusions
Conversion of pine to oak forests in the region will likely decrease soil CO2 effluxes due to decreasing SOC contents on the long run and will likely enhance soil N2O effluxes. Our results present only a seasonal snapshot and need to be confirmed in the field. 相似文献5.
Effect of H. pylori on the expression of TRAIL, FasL and their receptor subtypes in human gastric epithelial cells and their role in apoptosis 总被引:6,自引:0,他引:6
Martin JH Potthoff A Ledig S Cornberg M Jandl O Manns MP Kubicka S Flemming P Athmann C Beil W Wagner S 《Helicobacter》2004,9(5):371-386
BACKGROUND AND AIMS: In the human stomach expression of TNF-related apoptosis inducing ligand (TRAIL) and its receptors and the modulatory role of Helicobacter pylori are not well described. Therefore, we investigated the effect of H. pylori on the expression of TRAIL, FasL and their receptors (TRAIL-R1-R4, Fas) in gastric epithelial cells and examined their role in apoptosis. MATERIALS AND METHODS: mRNA and protein expression of TRAIL, FasL and their receptors were analyzed in human gastric epithelial cells using RT-PCR, Western blot, and immunohistochemistry. Gastric epithelial cells were incubated with FasL, TRAIL and/or H. pylori, and effects on expression, cell viability and epithelial apoptosis were monitored. Apoptosis was analyzed by histone ELISA, DAPI staining and immunohistochemistry. RESULTS: TRAIL, FasL and their receptor subtypes were expressed in human gastric mucosa, gastric epithelial cell primary cultures and gastric cancer cells. TRAIL, FasL and H. pylori caused a time- and concentration-dependent induction of DNA fragmentation in gastric cancer cells with synergistic effects. In addition, H. pylori caused a selective up-regulation of TRAIL, TRAIL-R1 and Fas mRNA and protein expression in gastric cancer cells. CONCLUSIONS: Next to FasL and Fas, TRAIL and all of its receptor subtypes are expressed in the human stomach and differentially modulated by H. pylori. TRAIL, FasL and H. pylori show complex interaction mediating apoptosis in human gastric epithelial cells. These findings might be important for the understanding of gastric epithelial cell kinetics in patients with H. pylori infection. 相似文献
6.
The aim was to investigate how short rotation coppice (SRC) on arable soil in Northern Germany altered the concentrations of soil lipids, and thus, soil organic matter (SOM) quality. The concentrations of organic C and aliphatic lipids were determined in the litter and underlying soil layers under two willow (Salix caprea × viminalis clone 6, S. viminalis clone 78–183) and two poplar (Populus trichocarpa × deltoides cv. Beaupré, P. nigra × maximowiczii cv. Max 4) clones at a 14-year-old SRC and a permanent arable reference site. High organic C concentrations in the topsoil under S. viminalis and P. trichocarpa × deltoides agreed with high concentrations of long C-chain saturated n-alkanoic acids, n-alkanols and n-alkanes. These disproportionally higher concentrations of long C-chain saturated n-alkanoic acids (factor 3.6) and n-alkanols (factor 3.8) under S. viminalis and of n-alkanols (factor 3.9) under P. trichocarpa × deltoides than in an arable reference treatment indicated a lower microbial decomposability and, thus, a clone-specific accumulation of these SOM constituents. The clone-specific enrichments in long C-chain saturated n-alkanoic acids, n-alkanols and n-alkanes indicate that clone selection may be an approach to additional long-term storage of atmosphere CO2 in the form of stable SOM under SRC. 相似文献
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8.
Stanley I. Dodson William R. Everhart Andrew K. Jandl Sara J. Krauskopf 《Hydrobiologia》2007,579(1):393-399
Results of a field survey of southern Wisconsin shallow lakes suggested that watershed (catchment basin) land use has a significant and adverse effect on zooplankton species richness. Zooplankton communities in lakes with no riparian buffer zone, in agriculture-dominated watersheds, contained about half as many species as lakes in least-impact watersheds. In that study, the age of the lake was not taken into account. It is possible that agricultural lakes, often artificial, were so recently-constructed that they had not yet accumulated the equilibrium number of species characteristic of older lakes. In other words, it is possible that the interpretation of the results of the previous study is fatally flawed, if the results were an artifact of lake age, rather than an effect of land use. The major aim of this current study was to determine the ages of agricultural lakes and of lakes in least-impact watersheds, to test for an effect of lake age on zooplankton species richness, using the same sites from the previous study. We used an anova approach to test the null hypothesis that two factors, watershed land use and lake age, had no systematic effect on zooplankton species richness. We determined the age of 35 shallow lakes, using aerial photos, satellite images, and interviews of resource managers and land owners. We identified five artificial agricultural sites and five artificial sites in least-impact prairie watersheds. The artificial sites in this study ranged from 3 to 37 years in age, while natural lakes dated from the melting of the last glacier, about 9500 years ago. Our results suggest, that because artificial lake made up only about a third of the sites, and for the range of lake age and watershed land use, lake age did not have a significant effect on zooplankton species richness, while land use had a highly significant adverse effect. These results pose a larger question for future research. Namely, how quickly do newly-constructed lakes attain the equilibrium number of species seen in the previous study, and what is the quantitative relationship between lake age and zooplankton richness? 相似文献
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10.
Andreas Schindlbacher Sophie Zechmeister-Boltenstern Barbara Kitzler Robert Jandl 《Plant and Soil》2008,303(1-2):323-330
We warmed the top soil of a mature coniferous forest stand by means of heating cables on control and trenched plots within
24 h by 10°C at 1 cm soil depth (9°C at 5 cm depth) and measured the effect on the autotrophic (RA) and heterotrophic (RH) component of total soil CO2 efflux (RS). The short time frame of warming enabled us to exclude confounding fluctuations in soil moisture and carbon (C) flow from
the canopy. The results of the field study were backed up by a lab soil incubation experiment. During the first 12 h of warming,
RA strongly responded to soil warming; The Q
10 values were 5.61 and 6.29 for 1 and 5 cm soil depth temperature. The Q
10 values for RA were almost twice as high as the Q
10 values of RH (3.04 and 3.53). Q
10 values above 5 are above reasonable plant physiological values for root respiration. We see interactions of roots, mycorrhizae
and heterotrophic microbes, combined with fast substrate supply to the rhizosphere as an explanation for the high short-term
temperature response of RA. When calculated over the whole duration (24 h) of the field soil-warming experiment, temperature sensitivities of RA and RH were similar (no significant difference at P < 0.05); Q
10 values were 3.16 and 3.96 for RA and 2.94 and 3.35 for RH calculated with soil temperatures at 1 and 5 cm soil depth, respectively. Laboratory incubation showed that different soil
moisture contents of trenched and control plots affected rates of RH, but did not affect the temperature sensitivity of RH. We conclude that a single parameter is sufficient to describe the temperature sensitivity of RS in soil C models which operate on larger temporal and spatial scales. The strong short-term response of RA may be of relevance in soils suspected to experience increasingly strong diurnal temperature variations. 相似文献