Effect of leached cement paste samples with different superplasticiser content on germination and initial root growth of white mustard (<Emphasis Type="Italic">Sinapis alba</Emphasis>) and cress (<Emphasis Type="Italic">Lepidium sativum</Emphasis>)     

Veronika Märkl  Stephan Pflugmacher  Dietmar A. Stephan 《Water, air, and soil pollution》2017,228(3):111

With an annual production of about 10 Gt concrete is by far the most used solid man-made material. In order to adjust the workability of fresh concrete most often so-called superplasticisers, essentially water-soluble organic polymers, are utilised. As concrete is commonly in direct contact with soil or water, the leaching of organic and inorganic compounds and their environmental impact need to be assessed. The present study contributes to this purpose by investigating leachates from hardened cement pastes gained using the horizontal dynamic surface leaching test. Pastes were prepared with and without superplasticiser. The root growths as well as the germination behaviour of cress (Lepidium sativum) and white mustard (Sinapis alba) were examined with respect to phytotoxicity. Different proportions (100, 50, 25 and 12.5%) of the leachates were considered in the test scheme. The results indicate a positive effect of most of the leachates on seed germination and root growth, although statistical significance was only found in some cases. Both test species showed no or only slight harmful effects as relative root growth exceeded always 66% for S. alba and 74% for L. sativum. Seed germination was not negatively influenced by the leachates. Slight beneficial effects on both test species could be observed for leachates containing superplasticiser compared to samples in absence of superplasticiser.  相似文献   

Distribution and Conservation Status of Catarrhine Primates in Côte d'Ivoire (West Africa)     

Gonedelé Bi S  Koné I  Bitty AE  Béné Koffi JC  Akpatou B  Zinner D 《Folia primatologica; international journal of primatology》2012,83(1):11-23

C?te d'Ivoire holds 18 catarrhine taxa, with 3 endemic to C?te d'Ivoire and neighbouring Ghana. Nine of the taxa occurring in C?te d'Ivoire are listed as threatened at the global level. However, information on their conservation status within the country is available for only a limited number of taxa. In order to assess the current distribution of primates and their conservation status, we conducted foot surveys and interviews in protected forests in the southern part of C?te d'Ivoire. Our data suggest that 22 out of 23 surveyed forests have lost 25-100% of the primate taxa expected to occur in these areas. The only exception is the Ta? National Park where all of the expected primate taxa were encountered. Based on our surveys, we propose an updated national list according to the IUCN Red List criteria for all diurnal primate species of C?te d'Ivoire.  相似文献   

Biodiversity at the landscape level: recent concepts and perspectives for multifunctional land use     

Annette Otte  Dietmar Simmering  Volkmar Wolters 《Landscape Ecology》2007,22(5):639-642

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Quantifying determinants contributing to plant species richness in mosaic landscapes: a single- and multi-patch perspective     

Dietmar Simmering  Rainer Waldhardt  Annette Otte 《Landscape Ecology》2006,21(8):1233-1251

Despite good theoretical knowledge about determinants of plant species richness in mosaic landscapes, validations based on complete surveys are scarce. We conducted a case study in a highly fragmented, traditional agricultural landscape. In 199 patches of 20 representative multi-patch-plots (MPPs, 1 ha) we recorded a total of 371 plant species. In addition to an additive partitioning of species diversity at the (a) patch- and (b) MPP-scale, we adopted the recently proposed ‘specificity’ measure to quantify the contribution of a spatial subunit to landscape species richness (subunit-to-landscape-contribution, SLC). SLC-values were calculated at both scales with respect to various spatial extents. General regression models were used to quantify the relative importance of hypothesis-driven determinants for species richness and SLC-values. At the patch scale, habitat type was the main determinant of species richness, followed by area and elongated shape. For SLC-values, area was more important than habitat type, and its relevance increased with the extent of the considered landscape. Influences of elongated shape and vegetation context were minor. Differences between habitat types were pronounced for species richness and also partly scale-dependent for SLC-values. Relevant predictors at the MPP-scale were nonlinear habitat richness, the gradient from anthropogenic to seminatural vegetation, and the proportions of natural vegetation and rare habitats. Linear elements and habitat configuration did not contribute to species richness and SLC. Results at the MPP-scale were in complete accordance with the predictions of the mosaic concept. Hence, our study represents its first empirical validation for plant species diversity in mosaic landscapes.  相似文献   

Intrinsic radiosensitivity and repair of sublethal radiation-induced damage in canine osteosarcoma cell lines     

Fitzpatrick CL  Farese JP  Milner RJ  Salute ME  Rajon DA  Morris CG  Bova FJ  Lurie DM  Siemann DW 《American journal of veterinary research》2008,69(9):1197-1202

OBJECTIVE: To characterize the radiosensitivity and capacity for sublethal damage repair (SLDR) of radiation-induced injury in 4 canine osteosarcoma cell lines. SAMPLE POPULATION: 4 canine osteosarcoma cell lines (HMPOS, POS, COS 31, and D17). PROCEDURES: A clonogenic colony-forming assay was used to evaluate the cell lines' intrinsic radiosensitivities and SLDR capacities. Dose-response curves for the cell lines were generated by fitting the surviving fractions after radiation doses of 0 (control cells), 1, 2, 3, 6, and 9 Gy to a linear quadratic model. To evaluate SLDR, cell lines were exposed to 2 doses of 3 Gy (split-dose experiments) at an interval of 0 (single 6-Gy dose), 2, 4, 6, or 24 hours, after which the surviving fractions were assessed. RESULTS: Mean surviving fraction did not differ significantly among the 4 cell lines at the radiation doses tested. Mean surviving fraction at 2 Gy was high (0.62), and the alpha/beta ratios (predictor of tissue sensitivity to radiation therapy) for the cell lines were low (mean ratio, 3.47). The split-dose experiments revealed a 2.8- to 3.9-fold increase in cell survival when the radiation doses were applied at an interval of 24 hours, compared with cell survival after radiation doses were applied consecutively (0-hour interval). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that these canine osteosarcoma cell lines are fairly radioresistant; alpha/beta ratios were similar to those of nonneoplastic, late-responding tissues. Future clinical investigations should involve increasing the fraction size in a manner that maximizes tumor killing without adverse effects on the nonneoplastic surrounding tissues.  相似文献   

Estimation and prediction of plant species richness in a mosaic landscape     

Rainer Waldhardt  Dietmar Simmering  Annette Otte 《Landscape Ecology》2004,19(2):211-226

Traditional agricultural mosaic landscapes are likely to undergo dramatic changes through either intensification or abandonment of land use. Both developmental trends may negatively affect the vascular plant species richness of such landscapes. Therefore, sustainable land-use systems need to be developed to maintain and re-establish species richness at various spatial scales. To evaluate the sustainability of specific land-use systems, we need approaches for the effective assessment of the present species richness and models that can predict the effects on species richness as realistically as possible. In this context, we present a methodology to estimate and predict vascular plant species richness at the local and the regional scale. In our approach, the major determinants of vascular plant species richness within the study area are taken into consideration: These are according to Duelli's mosaic concept the number of habitat types and of habitat patches within area units. Furthermore, it is based on the relative frequencies of species within habitat types. Our approach comprises six steps: (i) the determination of present habitat patterns within an observation area, (ii) the creation of a land-use scenario with simulated habitat patterns, (iii) the determination of species frequencies within habitat types of this area, (iv) a grouping of habitat-specific species, (v) the estimation of the probabilities for all species (or habitat specialists) to occur, either in stepwise, exponentially enlarged landscape tracts (local scale), or in the entire observation area (regional scale), and (vi) the validation of the estimated species numbers. The approach will be exemplified using data from the municipal district of Erda, Lahn-Dill Highlands, Germany. The current species numbers to be expected on the basis of probability calculations were compared with those recorded on the basis of extensive field work. This comparison shows that, on the basis of our simple calculations, the current local plant species richness can be predicted well, with a slight underestimation. This revised version was published online in May 2005 with corrections to the Cover Date. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Impact of bark beetle (Ips typographus L.) disturbance on timber production and carbon sequestration in different management strategies under climate change   总被引：2，自引：0，他引：2  

Rupert Seidl  Werner Rammer  Dietmar Jger  Manfred J. Lexer 《Forest Ecology and Management》2008,256(3):209-220

The likely environmental changes throughout the next century have the potential to strongly alter forest disturbance regimes which may heavily affect forest functions as well as forest management. Forest stands already poorly adapted to current environmental conditions, such as secondary Norway spruce (Picea abies (L.) Karst.) forests outside their natural range, are expected to be particularly prone to such risks. By means of a simulation study, a secondary Norway spruce forest management unit in Austria was studied under conditions of climatic change with regard to effects of bark beetle disturbance on timber production and carbon sequestration over a time period of 100 years. The modified patch model PICUS v1.41, including a submodule of bark beetle-induced tree mortality, was employed to assess four alternative management strategies: (a) Norway spruce age-class forestry, (b) Norway spruce continuous cover forestry, (c) conversion to mixed species stands, and (d) no management. Two sets of simulations were investigated, one without the consideration of biotic disturbances, the other including possible bark beetle damages. Simulations were conducted for a de-trended baseline climate (1961–1990) as well as for two transient climate change scenarios featuring a distinct increase in temperature. The main objectives were to: (i) estimate the effects of bark beetle damage on timber production and carbon (C) sequestration under climate change; (ii) assess the effects of disregarding bark beetle disturbance in the analysis.Results indicated a strong increase in bark beetle damage under climate change scenarios (up to +219% in terms of timber volume losses) compared to the baseline climate scenario. Furthermore, distinct differences were revealed between the studied management strategies, pointing at considerably lower amounts of salvage in the conversion strategy. In terms of C storage, increased biotic disturbances under climate change reduced C storage in the actively managed strategies (up to −41.0 tC ha⁻¹) over the 100-year simulation period, whereas in the unmanaged control variant some scenarios even resulted in increased C sequestration due to a stand density effect.Comparing the simulation series with and without bark beetle disturbances the main findings were: (i) forest C storage was higher in all actively managed strategies under climate change, when biotic disturbances were disregarded (up to +31.6 tC ha⁻¹ over 100 years); and (ii) in the undisturbed, unmanaged variant C sequestration was lower compared to the simulations with bark beetle disturbance (up to −69.9 tC ha⁻¹ over 100 years). The study highlights the importance of including the full range of ecosystem-specific disturbances by isolating the effect of one important agent on timber production and C sequestration.  相似文献   

Comparison of German and Swiss Rainfall Simulators - Experimental Setup     

Karl Auerswald  Maximilian Kainz  Dietmar Schrder  W. Martin 《植物养料与土壤学杂志》1992,155(1):1-5

Rainfall simulators, that are commonly used in erosion research should produce comparable runoff and soil loss. At present five types of field rainfall simulators are used in Germany and Switzerland. The experimental setup on a Hapludalf soil site for testing these simulators and one laboratory rainfall simulator are described. Fifty rainfall simulations were carried out during two days on a homogeneous field. Hence, small deviations in slope steepness (< 2%) resulted in 40% deviations in the S factor of the USLE. This strong influence of slope steepness necessitates a high accuracy in the measurement of this parameter. Soil moisture during the two days was very high. This reduced slaking due to air inclusions and should have helped to detect differences in soil detachment due to the different rain structures and test procedures.  相似文献   

Phosphine in the Urban Air of Beijing and Its Possible Sources     

Ji-ang  Liu  Yahui  Cao Haifeng Zhuang  Kuschk  Peter  Eismann  Frank  Glindemann  Dietmar 《Water, air, and soil pollution》1999,116(3-4):597-604

Water, Air, &; Soil Pollution - Both as an air pollutant and as a gaseous component of the local phosphorus cycle, phosphine (PH3) was found in the urban air of Beijing. Other possible sources,...  相似文献   

Xanthophylls in commercial egg yolks: quantification and identification by HPLC and LC-(APCI)MS using a C30 phase     

Schlatterer J  Breithaupt DE 《Journal of agricultural and food chemistry》2006,54(6):2267-2273

The xanthophylls lutein and zeaxanthin have attracted a lot of interest since it was presumed that an increased nutritional uptake may prevent adult macula degeneration (AMD). Although egg yolks serve as an important dietary source of lutein and zeaxanthin, data on xanthophyll concentrations in commercial egg yolks are not available. Thus, an high-performance liquid chromatography-diode array detector (HPLC-DAD) method was developed allowing for simultaneous separation of eight xanthophylls used to fortify poultry feed. Peak identification was carried out by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [LC-(APCI)MS]. Egg yolks of four types of husbandry (seven batches each) were examined. Lutein and zeaxanthin were the predominant xanthophylls in egg yolks produced in accordance with ecological husbandry (class 0) because the concentrations of these xanthophylls ranged from 1274 to 2478 microg/100 g and from 775 to 1288 microg/100 g, respectively. Analysis of variance (ANOVA) proved that both mean lutein and mean zeaxanthin concentrations of eggs from class 0 were statistically discriminable from mean lutein and zeaxanthin concentrations from eggs of all other classes (P < 0.01). Mean concentrations of synthetic xanthophylls in eggs of classes 1 (free range), 2 (barn), and 3 (cage) were as follows: canthaxanthin, 707 +/- 284 microg/100 g; beta-apo-8'-carotenoic acid ethyl ester, 639 +/- 391 microg/100 g; and citranaxanthin, 560 +/- 231 microg/100 g. Experiments with boiled eggs proved that beta-apo-8'-carotenoic acid ethyl ester was the xanthophyll with the highest stability, whereas lutein was degraded to the largest extent (loss of 19%). Detailed knowledge about the xanthophyll amounts in eggs is indispensable to calculate the human uptake.  相似文献