78 research outputs found

    Microclimate buffering of winter temperatures by pine stumps in a temperate forest

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    In the presented study we evaluated the role of wood in buffering its inhabitants against winter temperatures. We followed the microscale temperature patterns inside and outside decaying pine stumps during two winter periods. We analyzed the data by extracting the minimum, maximum and mean temperatures for the episodes of snow, frost or no frost. We compared the temperature variation by applying an absolute values calculation (=modulus) for the subsequent measurements. Finally, we tested the buffering effect of the horizontal depth inside the stumps by comparing the pattern for 5 and 15 cm depths. The results show that (1) the minimum temperature was significantly higher inside than outside the stumps, while temperature variation tended to be larger outside than inside, (2) the dynamics of temperature varied between weather episodes, i.e. the periods characterized by the presence/absence of snow and of frost, (3) the minimum temperature inside the stumps increased with the horizontal depth, while temperature variation decreased. The results presented are the first truly microclimatic data on wood buffering and they are important for the understanding of the possible effects of climate change on the thermal relationships at the microscale

    Input of heavy metals to the forest floor as the result of zinc smelter pollution in southern Poland

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    The aim of this study was to assess the impact of zinc smelter on heavy metals concentration in the litter fall collected from three different sites in Olkusz Forest located in southern Poland. Furthermore the study was designed to investigate the input of these metals to the forest floor. Three forest areas Podlesie I and Podlesie II located 3 and 4 km south-east from Bukowno zinc smelter and Cegielnia situated 6 km north-east from the smelter were selected. At the beginning of September 2006 five litter traps were set at each site. The quantity of litter fall, along with percent age composition of each species, were estimated for an area of 1m^2. The concentration of Cd, Pb, Cu, Zn and Fe in the litter fall and leaves of four main tree species were analysed. The input of these metals to the forest floor were determined. The input of cadmium ranged from 204 μg m^2 at Cegielnia to 1340 μg m^2 at Podlesie I. The input of lead was higher than cadmium and varied from 1031 μg m^2 at Cegielnia to 3252 μg m^2 at Podlesie II. The input of zinc and iron were about 10 times than cadmium and lead. The less input of all invesigated metals was noticed in control site located at WNP. for those metals. The high input of heavy metals to the forest floor may have negative effects on investigated part of Olkusz forest ecosystem

    PRZYSPIESZANIE PROCESU REKONSTRUKCJI OBRAZU W ELEKTRYCZNEJ TOMOGRAFII POJEMNOŚCIOWEJ 3D Z WYKORZYSTANIEM HETEROGENICZNEGO SYSTEMU MULTI-GPU

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    Electrical capacitance tomography is an innovative method for visualization of industrial processes. One of its main advantages is it’s high time resolution that allows to the usage of ECT in systems with high volatility. In recent years there has been significant development of electrical capacitance tomography 3D, which however, has significantly reduced industrial it’s applications due to the complicated process of image reconstruction. The authors propose the use of multi-node, multi-GPU system to accelerate the process of image reconstruction in ECT 3D.Elektryczna tomografia pojemnościowa jest innowacyjną metodą wizualizacji procesów przemysłowych. Jedną z jej głównych zalet jest duża rozdzielczość czasowa pozwalająca na zastosowanie ECT w instalacjach o dużej zmienności. W ostatnich latach nastąpił znaczący rozwój elektrycznej tomografii pojemnościowej 3D, która jednakże ma znacznie ograniczone zastosowanie przemysłowe ze względu na skomplikowany proces rekonstrukcji obrazu. Autorzy artykułu proponują zastosowanie wielowęzłowego systemu Multi-GPU do przyspieszenia procesu rekonstrukcji obrazu w ECT 3D

    Do heavy-metal grassland species survive under a Scots pine canopy during early stages of secondary succession?

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    The highly specialized flora of localities affected by former metal ore mining and metallurgy is endangered by succession or intentional afforestation all over Europe. Its last remnants therefore deserve our attention. We examined whether Scots pine encroaching on a heavy-metal grassland (Olkusz Zn-Pb mining area, S Poland) is outcompeting specialized herbaceous species, as has been observed elsewhere. Plant species composition and richness sampled at 124 plots were analysed in relation to pine stand parameters (canopy cover, stand age, stand basal area), abiotic environmental factors (e.g. soil properties) and spatial variables (e.g. plot coordinates). Plots were divided into three shading categories and compared in terms of vegetation and habitat parameters. Scots pine outcompeted several light-demanding species, leading to a decrease of total species richness and cover. Characteristic species of this grassland (Biscutella laevigata, Silene vulgaris) and some metal-tolerant plants were clearly insensitive to shading. For these early successional species, more important was the availability of microsites with shallow skeletal soil or bare subsoil. Tree stand parameters differently affected grassland vegetation: canopy cover caused primarily a compositional shift in the community, while stand age was the principal agent of decline in species richness. Scots pine increased the soil concentrations of available Ca and Mg, and negatively affected soil development (organic matter and mineral particle accumulation), which might be beneficial to some shade-tolerant grassland species. Maintaining the studied grassland’s present species richness and composition would require cutting woody plants less frequently than recommended for dry grasslands of non-metalliferous sites, and disturbing the soil surface

    Dysregulation of transcription factor activity during formation of cancer-associated fibroblasts

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    The reciprocal interactions between cancer cells and the quiescent fibroblasts leading to the activation of cancer-associated fibroblasts (CAFs) serve an important role in cancer progression. Here, we investigated the activation of transcription factors (TFs) in prostate fibroblasts (WPMY cell line) co-cultured with normal prostate or tumorous cells (RWPE1 and RWPE2 cell lines, respectively). After indirect co-cultures, we performed mRNA-seq and predicted TF activity using mRNA expression profiles with the Systems EPigenomics Inference of Regulatory Activity (SEPIRA) package and the GTEx and mRNA-seq data of 483 cultured fibroblasts. The initial differential expression analysis between time points and experimental conditions showed that co-culture with normal epithelial cells mainly promotes an inflammatory response in fibroblasts, whereas with the cancerous epithelial, it stimulates transformation by changing the expression of the genes associated with microfilaments. TF activity analysis revealed only one positively regulated TF in the RWPE1 co-culture alone, while we observed dysregulation of 45 TFs (7 decreased activity and 38 increased activity) uniquely in co-culture with RWPE2. Pathway analysis showed that these 45 dysregulated TFs in fibroblasts co-cultured with RWPE2 cells may be associated with the RUNX1 and PTEN pathways. Moreover, we showed that observed dysregulation could be associated with FER1L4 expression. We conclude that phenotypic changes in fibroblast responses to co-culturing with cancer epithelium result from orchestrated dysregulation of signaling pathways that favor their transformation and motility rather than proinflammatory status. This dysregulation can be observed both at the TF and transcriptome levels

    Low expression of miR-375 and miR-190b differentiates grade 3 patients with endometrial cancer

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    Endometrial cancer (EC) is treated according to the stage and prognostic risk factors. Most EC patients are in the early stages and they are treated surgically. However some of them, including those with high grade (grade 3) are in the intermediate and high intermediate prognostic risk groups and may require adjuvant therapy. The goal of the study was to find differences between grades based on an miRNA gene expression profile. Tumor samples from 24 patients with grade 1 (n = 10), 2 (n = 7), and 3 (n = 7) EC were subjected to miRNA profiling using next generation sequencing. The results obtained were validated using the miRNA profile of 407 EC tumors from the external Cancer Genome Atlas (TCGA) cohort. We obtained sets of differentially expressed (DE) miRNAs with the largest amount between G2 to G1 (50 transcripts) and G3 to G1 (40 transcripts) patients. Validation of our results with external data (TCGA) gave us a reasonable gene overlap of which we selected two miRNAs (miR-375 and miR190b) that distinguish the high grade best from the low grade EC. Unsupervised clustering showed a high degree of heterogeneity within grade 2 samples. MiR-375 as well as 190b might be useful to create grading verification test for high grade EC. One of the possible mechanisms that is responsible for the high grade is modulation by virus of host morphology or physiology

    Invasive plants affect arbuscular mycorrhizal fungi abundance and species richness as well as the performance of native plants grown in invaded soils

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    We studied the effects of invasions by three plant species: Reynoutria japonica, Rudbeckia laciniata,and Solidago gigantea, on arbuscular mycorrhizal fungi (AMF) communities in habitats located within and outside river val- leys. Arbuscular mycorrhizal colonization, AMF abundance and species richness in soils were assessed in adjacent plots with invaders and native vegetation. We also quantified the performance (expressed as shoot mass, chlorophyll fluores- cence, and the concentration of elements in shoots) of two common, mycorrhizal native plants, Plantago lanceolata and Trifolium repens, grown in these soils. The invasions of R. japonica, R. laciniata, and S. gigantea influenced AMF communities compared to native vegetation, but the changes depended on the mycorrhizal status of invaders. The effects of non-mycorrhizal R. japonica were the most pronounced. Its invasion reducedAMF abundance and species richness. In the plots of both mycorrhizal plants, R. laciniata and S. gigantea, we observed decreased AMF species richness in comparison to native vegetation. The AMF community alterations could be due to (i) depletion of organic C inputs toAMF in the case of R. japonica, (ii) plant secondary metabolites that directly inhibit or selectively stimulate AMF species, or (iii) changes in soil physicochemical properties induced by invasions. The effect of invasion onAMF abundance and species richness did not generally differ between valley and outside-valley habi- tats. The invasions affected photosynthetic performance and the concentrations of elements in the shoots of P. lanceolata or T. repens. However, the directions and magnitude of their response depended on both species identity and the mycorrhi- zal status of invaders

    Can lichen secondary compounds impact upon the pathogenic soil fungi Fusarium oxysporum and F. avenaceum?

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    The antifungal activity of secondary lichen metabolites extracted by means of acetone and ethanol from Cetraria islandica, Cladonia mitis, C. rangiferina, Pseudevernia furfuracea and Usnea dasopoga on the pathogenic fungi Fusarium oxysporum and F. avenacuem was examined. The activity of extracted compounds was tested after their mixture with PDA medium before solidification. The most active extracts inhibiting the growth of fungal mycelia contained fumarprotocetraric, salazinic and usnic acids, and atranorin. Unparalleled activity was demonstrated by an ethanol extract from mixed C. islandica and P. furfuracea thalli, which accelerated the growth of F. avenaceum compared with the control test with ethanol. The growth rate of the two Fusarium representatives was strongly inhibited by both alcoholic extracts from C. mitis and from C. rangiferina, more strongly than by the extracts from the mixed thalli of the two terricolous taxa. A dose of 1 ml of acetone added to the medium had no significant effect on the growth of the tested fungi; it indicates usefulness of acetone as a solvent for some lichen compounds in this type of experiment
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