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101.
Hui Sun Eeva Terhonen Kaisa Koskinen Lars Paulin Risto Kasanen Fred O. Asiegbu 《Biological Control》2013,64(3):238-246
The biocontrol agent Phlebiopsis gigantea has been intensively applied to the surface of Picea abies stumps to control Heterobasidion root rot. But little is known about the possible impact of this treatment on the resident bacteria community in the stumps. High throughput DNA bar-coded pyrosequencing was used to characterize the diversity of bacteria in the stumps of P. abies at 1, 6 and 13 years after treatment with P. gigantea. The sequences were classified into 12 phyla and 160 genera, of which Proteobacteria and Acidobacteria were the most abundant groups over time. Moreover, at the initial stages of decay, Proteobacteria were the most abundant whereas Acidobacteria were the most common at advanced stages of decay. Treatment with P. gigantea led to significant increase of the genus Acidobacteria-Gp1 at 1 year after treatment. The analysis of observed and estimated operational taxonomic units (OTUs) as well as diversity indices revealed that P. gigantea treatment significantly decreased the initial bacterial richness in the stumps, but the bacterial community gradually recovered and the negative effects of P. gigantea was attenuated. These results provide additional insight on the risk assessment as well as environmental impact on the long-term use of P. gigantea in the control of Heterobasidion root rot in conifer forests. 相似文献
102.
c-Ha-rasVal 12 oncogene-transformed NIH-3T3 fibroblasts display more decondensed nucleosomal organization than normal fibroblasts 总被引:5,自引:0,他引:5
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We have compared the nucleosomal organization of c-Ha-rasVal 12 oncogene-transformed NIH-3T3 fibroblasts with that of normal fibroblasts by using micrococcal nuclease (MNase) as a probe for the chromatin structure. The bulk chromatin from asynchronously and exponentially growing ras-transformed cells was much more sensitive to MNase digestion than chromatin from the normal cells. Southern hybridization analyses of the MNase digests with probes specific for the ornithine decarboxylase (odc) and c-myc genes showed that the coding and/or 3' end regions of these growth-inducible genes carry a nucleosomal organization both in ras-transformed and normal cells. Studies with cells synchronized by serum starvation showed that in both cell lines the nucleosomal organization of chromatin is relatively condensed at the quiescent state, becomes highly decondensed during the late G1 phase of the cell cycle, and starts again to condense during the S phase. However, in ras-transformed cells the decondensation state stayed much longer than in normal cells. Moreover, irrespective of the phase of the cell cycle the bulk chromatin as well as that of the odc and c-myc genes was more sensitive to MNase digestion in the ras-transformed cell than in the normal fibroblast. Decondensation of the chromatin was also observed in the normal c-Ha-ras protooncogene-transfected cells, but to a lesser extent than in the mutant ras-transformed cells. Whether the increased degree of chromatin decondensation plays a regulatory role in the increased expression of many growth-related genes in the ras-transformed cells remains an interesting object of further study. 相似文献
103.
Risto Laitinen 《Biological trace element research》1990,25(1):71-78
The relationships between serum levels of zinc and copper and sexual maturation were analyzed in 2291 9-18-yr-old Finnish girls and boys. Development of public hair, breasts, and genitalia were used to grade maturation according to Tanner's classification. Serum zinc and sexual maturation were not related. However, 15- and 18-yr-old girls who had matured most slowly had low serum levels of zinc compared with their age mates. Thus, sexual maturation seems not to be affected by zinc deficiency in Finland; effects of zinc status on maturation in some minor groups cannot, however, be excluded. Serum copper levels were associated with age and sexual maturation, which complicates the drawing of conclusions about possible deficiencies. 相似文献
104.
Jussi Kuusipalo Gran djers Yusuf Jafarsidik Antti Otsamo Kari Tuomela Risto Vuokko 《植被学杂志》1995,6(2):205-210
Abstract. Reclamation of former, degraded forest lands occupied by Imperata cylindrica is one of the crucial environmental and forestry issues in the humid tropics, notably Southeast Asia. We suggest that it is possible to gradually restore the original natural forest cover with the help of a sacrifice fallow crop of fast-growing exotic tree species. Recently, a set of suitable fast-growing plantation tree species has been identified and stand establishment methods developed for this purpose. We assessed the regeneration of natural vegetation in stands of different plantation tree species and evaluated the ecological impact of species composition in the plantation understorey. PCA ordination, regression analysis and analysis of covariance were applied at different stages of the study. We found a marked vegetational resemblance between stands dominated by Acacia mangium: they had the highest number of indigenous trees in their understorey, whereas stands of other plantation trees supported more diverse grass and herb vegetation. A high proportion of evergreen woody vegetation reduces the risk of fire and grass competition and enhances secondary succession towards natural forest. 相似文献
105.
The ornithine decarboxylase (odc) gene is an early response gene, whose increased expression and relaxed chromatin structure is closely coupled to neoplastic growth. In various tumour cells, the odc gene displays hypomethylation at the sequences CCGG. Hypomethylation of genes is believed to correlate with chromatin decondensation and gene expression. Since a given pattern of DNA methylation may not be preserved in neoplastic cells, we studied the methylation status of odc gene at the CCGG sequences in c-Ha-rasVal 12 oncogene-transformed NIH-3T3 fibroblasts during the growth cycle and relative to their normal counterparts. We found that the methylation state of the odc gene and its promoter and mid-coding and 3' regions remain unaltered during the cell cycle. We also found that in ras oncogene-transformed cells, which display a more decondensed nucleosomal organization of chromatin than the normal cells, the CCGG sequences in bulk DNA and at the odc gene were methylated to the same extent as in the nontransformed cells. These data suggest that DNA hypomethylation at the CCGG sequences is not a prerequisite for chromatin decondensation and cell transformation by the c-Ha-rasVal 12 oncogene. 相似文献
106.
Risto K. Heikkinen 《Plant Ecology》1996,126(2):151-165
This paper is an attempt, using statistical modelling techniques, to understand the patterns of vascular plant species richness at the poorly studied meso-scale within a relatively unexplored subarctic zone. Species richness is related to floristic-environmental composite variables, using occurrence data of vascular plants and environmental and spatial predictor variables in 362 1 km2 grid squares in the Kevo Nature Reserve. Species richness is modelled in two different way. First, by detecting the major floristic-environmental gradients with the ordination procedure of canonical correspondence analysis, and subsequently relating these ordination axes to species richness by generalized linear modelling. Second, species richness is directly related to the composite environmental factors of explanatory variables, using partial least squares regression. The most important explanatory variables, as suggested by both approaches, are relatively similar, and largely reflect the influence of altitude or altitudinally related variables in the models. The most prominent floristic gradient in the data runs from alpine habitats to river valleys, and this gradient is the main source of variation in species richness. Some local environmental variables are also relatively important predictors; the grid squares rich in vascular plant taxa are mainly located in the lowlands of the reserve and are characterised by rivers and brooks, as well as by abundant cliff walls. The two statistical models account for approximately the same amount of variation in the species richness, with more than half of the variation unexplained. Potential reasons for the relatively modest fit are discussed, and the results are compared to the characteristics of the diversity-environment relationships at both broader- and finer-scales. 相似文献
107.
Anita Laitinen Sofia Oja Lotta Kilpinen Tanja Kaartinen Johanna Möller Saara Laitinen Matti Korhonen Johanna Nystedt 《Cytotechnology》2016,68(4):891-906
Efficient xenofree expansion methods to replace fetal bovine serum (FBS)-based culture methods are strongly encouraged by the regulators and are needed to facilitate the adoption of mesenchymal stromal cell (MSC)-based therapies. In the current study we established a clinically-compliant and reproducible animal serum-free culture protocol for bone marrow-(BM-) MSCs based on an optimized platelet-derived supplement. Our study compared two different platelet-derived supplements, platelet lysate PL1 versus PL2, produced by two different methods and lysed with different amounts of freeze–thaw cycles. Our study also explored the effect of a low oxygen concentration on BM-MSCs. FBS-supplemented BM-MSC culture served as control. Growth kinetics, differentiation and immunomodulatory potential, morphology, karyotype and immunophenotype was analysed. Growth kinetics in long-term culture was also studied. Based on the initial results, we chose to further process develop the PL1-supplemented culture protocol at 20 % oxygen. The results from 11 individual BM-MSC batches expanded in the chosen condition were consistent, yielding 6.60 × 109 ± 4.74 × 109 cells from only 20 ml of bone marrow. The cells suppressed T-cell proliferation, displayed normal karyotype and typical MSC differentiation potential and phenotype. The BM-MSCs were, however, consistently HLA-DR positive when cultured in platelet lysate (7.5–66.1 %). We additionally show that culture media antibiotics and sterile filtration of the platelet lysate can be successfully omitted. We present a robust and reproducible clinically-compliant culture method for BM-MSCs based on platelet lysate, which enables high quantities of HLA-DR positive MSCs at a low passage number (p2) and suitable for clinical use. 相似文献
108.
Emma Ojala Ville Uusitalo Terhi Virkki-Hatakka Antti Niskanen Risto Soukka 《The International Journal of Life Cycle Assessment》2016,21(8):1092-1105
Purpose
The Product Environmental Footprint (PEF) method was launched by the European Commission to harmonize the measurement of the product’s environmental performance. The PEF aims to increase the supply of green products in EU markets by lowering the cost of measuring the product’s environmental performance, enabling reliable environmental claims, and conducting proper product comparison. This study assesses whether the methodological choices of PEF enable reliable and comparable PEF studies to be conducted in a cost-efficient way.Methods
The PEF was compared with ISO 14044, ISO/TS 14067, and the Greenhouse Gas Protocol Product Standard to identify the differences in the methodological choices. From a practical perspective, the possible challenges for PEF that could not be identified by a method comparison were obtained via interviews. The interviewees were company representatives participating in a 3-year PEF pilot phase to create Product Environmental Footprint Category Rules (PEFCR). To discover the possible advantages and disadvantages of the PEF, the methodological choices for PEF itself were assessed from the standpoints of reliability, comparability, and cost. In conclusion, some proposals for improvements have been suggested.Results and discussion
The impact assessment phase, i.e., some of the predefined impact assessment methods, together with a selected normalization method include disadvantages as regards reliability and comparability. They are not sufficiently mature to properly reflect both the product studied and its potential environmental impact. From a cost perspective, the inventory analysis phase increases the workload due to the cutoff ban, the numerous predefined impact assessment categories, and the data quality assessment of all data. However, the predefined issues, e.g., requirements for data quality to be determined in PEFCRs, could also increase the comparability and lower the costs of the PEF study, since these need not be determined separately for each study. Additionally, the reliability maybe increased due to the data quality assessment of all data.Conclusions
Currently, in the PEFs 3-year pilot phase, both advantages and disadvantages exist as regards reliability, costs, and comparability. Since PEF aims are important, the Commission and PEFCR developers should devote time to finding the most appropriate methodological choices and continue developing the method further. It is important to find a balance between comparability, reliability, and costs. Additionally, the current issues and characteristics of EU green products market should be taken into account when implementing PEF.109.
Phlebiopsis gigantea (Fr.) Jül. is one of the most common fungal species in coniferous forests and commonly used as a biological control agent to prevent aerial infections of conifers by Heterobasidion fungi. We used feeding experiments to examine whether Hylobius abietis L. (Coleoptera: Curculionidae) could serve as a vector for P. gigantea and associated viruses by disseminating the fungus in its faecal pellets. Two different P. gigantea strains were used in the experiments: the virus-free Rotsop biocontrol strain and P. gigantea 93073 infected with the virus strain PgLV-1. The Rotstop strain showed 100% viability during insect feeding, while the viability of the virus-infected strain 93073 was only 35%. Virus persistence was 100% during the passage of the host fungus through the alimentary tract. Based on growth experiments using virus-infected and virus-free strains obtained by hyphal tip or oidial isolation, the presence of PgLV-1 did not significantly affect the growth rate of the host fungus. 相似文献
110.
Saku V??t?inen Henna Cederberg Risto Roine Sirkka Kein?nen-Kiukaanniemi Jouko Saramies Hannu Uusitalo Jaakko Tuomilehto Janne Martikainen 《PloS one》2016,11(2)