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Unexpected ecotone dynamics of a sand dune vegetation complex following water table decline

Journal of Plant Ecology 2016年第1期9卷 40-50页

作者： Csaba Tölgyesi Márta Zalatnai LászlóErdős zoltán bátori nicole Rosemary Hupp LászlóKörmöczi Department of Ecology University of SzegedSzeged H-6726Hungary Wildlife biology Program College of Forestry and ConservationUniversity of Montana32 Campus DriveMissoulaMontanaMT 59812USA

Aims Central Hungarian inland dune ranges harbor heterogeneous grassland vegetation with an extensive network of ecotones,arranged perpendicular to topography-driven hydrologic *** area suffers from severe aridification due to climate change and local anthropogenic factors,which have led to a dramatic decline of the water *** a result,groundwater is no longer reachable for lowlying plant communities;thus,we expect they are bound to undergo profound *** study investigates how the plant communities respond to this changing environment over time by monitoring ecotones,since they are frequently the hotspots of ecosystem *** monitored five ecotones along permanent belt transects for 15 years to characterize their dynamic response,and to identify the internal structural changes of the plant communities the ecotones *** Ecotones were delineated with the split moving window *** dynamics of two ecotone parameters,location and contrast,were analyzed with linear regression models incorporating two independent variables:study year as a measure of time since the loss of groundwater,and precipitation as a possible driver of interannual *** internal changes of the patches separated by the ecotones were analyzed using plant functional *** Findings Precipitation had no detectable effect on the ecotone descriptors,but study year influenced ecotones in an unusual *** position of the ecotones appeared to be very stable in time;their dynamics are stationary,not directional as we *** contrasts had clear tendencies;two ecotones disappeared,one new one was formed and two ecotones showed no *** internal changes of the patches over time were dramatic,showing a shift toward more xeric and more open plant assemblages in most stretches of the ***,the dynamic response of the vegetation was not patch expansion ***,but fusion ***,which profoundly restructured the vegetati

关键词： groundwater decline plant functional group sand dune vegetation split moving window stationary ecotone

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Effect of IbD sera on expression of inducible and endothelial nitric oxide synthase in human umbilical vein endothelial cells

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World Journal of Gastroenterology 2006年第11期12卷 1730-1738页

作者： Károly Palatka zoltán Serf(o|″)z(o|″) zoltán Veréb Róbert bátori beáta Lontay zoltán Hargitay zoltán nemes Miklós Udvardy Ferenc Erd(o|″)di István Altorjay Department of Gastroenterology University of Debrecen Nagyerdei k(o|¨)rút 98.Debrecen H-4001Hungary Department of Experimental Zoology bLRI-HAS TihanyHungary Institute of Immunology University of Debrecen Nagyerdei k(o|¨)rút 98.Debrecen H-4001 Hungary Department of Medical Chemistry University of Debrecen Nagyerdei k(o|¨)rút 98.Debrecen H-4001Hungary Department of Pathology Gyula Kenezy Hospital DebrecenBartók Béla út 10.Debrecen H-4026Hungary Institute of Pathology University of Debrecen Nagyerdei k(o|¨)rút 98.Debrecen H-4001Hungary Institute of Internal Medicine University of Debrecen Nagyerdei k(o|¨)rút 98.Debrecen H-4001Hungary

AIM： To study the expression of endothelial and inducible nitric oxide synthases （enOS and inOS） and their role in inflammatory bowel disease （IbD）. METHODS： We examined the effect of sera obtained from patients with active Crohn＇s disease （CD） and ulcerative colitis （UC） on the function and viability of human umbilical vein endothelial cells （HUVEC）. HUVECs were cultured for 0-48 h in the presence of a medium containing pooled serum of healthy controls, or serum from patients with active CD or UC. Expression of enOS and inOS was visualized by immunofluorescence, and quantified by the densitometry of Western blots. Proliferation activity was assessed by computerized image analyses of Ki-67 immunoreactive cells, and also tested in the presence of the nOS inhibitor, 10^-4 mol/L L-nAME. Apoptosis and necrosis was examined by the annexin-V-biotin method and by propidium iodide staining, respectively. RESULTS： In HUVEC immediately after exposure to UC, serum enOS was markedly induced, reaching a peak at 12 h. In contrast, a decrease in enOS was observed after incubation with CD sera and the enOS level was minimal at 20 h compared to control （18%±16% vs 23%± 15% P〈0.01）. UC or CD serum caused a significant increase in inOS compared to control （UC： 300%±21%; CD： 275% ± 27% vs 108% ± 14%, P〈0.01）. Apoptosis/necrosis characteristics did not differ significantly in either experiment. Increased proliferation activity was detected in the presence of CD serum or after treatment with L-nAME. Cultures showed tube-like formations after 24 h treatment with CD serum. COnCLUSIOn： IbD sera evoked changes in the ratio of enOS/inOS, whereas did not influence the viability of HUVEC. These involved down-regulation of enOS and up-regulation of inOS simultaneously, leading to increased proliferation activity and possibly a reduced antiinflammatory protection of endothelial cells.

关键词： Crohn's disease Human umbilical vein endothelial cells Inflammatory bowel disease nitric oxide synthase Ulcerative colitis

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