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91.
Celastrus orbiculatus is an exotic liana that exploits disturbed areas in the eastern United States and once established, can invade into relatively
undisturbed forest ecosystems. Mechanisms facilitating its invasion are not fully understood, including whether associations
with mycorrhizal fungi are related to its invasion success. We grew C. orbiculatus in a greenhouse and compared growth responses when mycorrhizal fungi or a fungistatic were added to growth media that was
either phosphorus-limiting or non-limiting. Results indicated C. orbiculatus forms association with native endomycorrhizal but not with native ectomycorrhizal fungi regardless of phosphorus level. Plants
grown with sufficient phosphorus had significantly higher above-ground morphological and physiological traits but significantly
lower root biomass compared to plants grown in low phosphorus conditions. Although above-ground traits did not vary significantly
between mycorrhizal versus fungistatic added treatments, root biomass was significantly less in plants inoculated with mycorrhizae
compared to plants receiving fungistatic. Under low phosphorus conditions, mycorrhizae appeared to be beneficial to the plant
although being mycorrhizal did not fully compensate for insufficient phosphorous in the greenhouse situation where pot size
limited soil exploration. Our results suggest that in the presence of mycorrhizae or sufficient phosphorus, C. orbiculatus can respond by preferentially allocating energy to above-ground growth, thus supporting its liana growth form onto trees
and allowing the exotic to outcompete native species for light resources. If mycorrhizal fungi aid in acquisition of phosphorus,
this association could be related to the invasion success of C. orbiculatus. 相似文献
92.
Michalski F Valdez FP Norris D Zieminski C Kashivakura CK Trinca CS Smith HB Vynne C Wasser SK Metzger JP Eizirik E 《Molecular ecology resources》2011,11(5):862-871
The use of scat surveys to obtain DNA has been well documented in temperate areas, where DNA preservation may be more effective than in tropical forests. Samples obtained in the tropics are often exposed to high humidity, warm temperatures, frequent rain and intense sunlight, all of which can rapidly degrade DNA. Despite these potential problems, we demonstrate successful mtDNA amplification and sequencing for faeces of carnivores collected in tropical conditions and quantify how sample condition and environmental variables influence the success of PCR amplification and species identification. Additionally, the feasibility of genotyping nuclear microsatellites from jaguar (Panthera onca) faeces was investigated. From October 2007 to December 2008, 93 faecal samples were collected in the southern Brazilian Amazon. A total of eight carnivore species was successfully identified from 71% of all samples obtained. Information theoretic analysis revealed that the number of PCR attempts before a successful sequence was an important negative predictor across all three responses (success of species identification, success of species identification from the first sequence and PCR amplification success), whereas the relative importance of the other three predictors (sample condition, season and distance from forest edge) varied between the three responses. Nuclear microsatellite amplification from jaguar faeces had lower success rates (15-44%) compared with those of the mtDNA marker. Our results show that DNA obtained from faecal samples works efficiently for carnivore species identification in the Amazon forest and also shows potential for nuclear DNA analysis, thus providing a valuable tool for genetic, ecological and conservation studies. 相似文献
93.
Ignatiadis M Rothé F Chaboteaux C Durbecq V Rouas G Criscitiello C Metallo J Kheddoumi N Singhal SK Michiels S Veys I Rossari J Larsimont D Carly B Pestrin M Bessi S Buxant F Liebens F Piccart M Sotiriou C 《PloS one》2011,6(1):e15624
Purpose
Circulating Tumor Cells (CTCs) detection and phenotyping are currently evaluated in Breast Cancer (BC). Tumor cell dissemination has been suggested to occur early in BC progression. To interrogate dissemination in BC, we studied CTCs and HER2 expression on CTCs across the spectrum of BC staging.Methods
Spiking experiments with 6 BC cell lines were performed and blood samples from healthy women and women with BC were analyzed for HER2-positive CTCs using the CellSearch®.Results
Based on BC cell lines experiments, HER2-positive CTCs were defined as CTCs with HER2 immunofluoresence intensity that was at least 2.5 times higher than the background. No HER2-positive CTC was detected in 42 women without BC (95% confidence interval (CI) 0–8.4%) whereas 4.1% (95%CI 1.4–11.4%) of 73 patients with ductal/lobular carcinoma in situ (DCIS/LCIS) had 1 HER2-positive CTC/22.5 mL, 7.9%, (95%CI 4.1–14.9%) of 101 women with non metastatic (M0) BC had ≥1 HER2-positive CTC/22.5 mL (median 1 cell, range 1–3 cells) and 35.9% (95%CI 22.7–51.9%) of 39 patients with metastatic BC had ≥1 HER2-positive CTC/7.5 mL (median 1.5 cells, range 1–42 cells). In CTC-positive women with DCIS/LCIS or M0 BC, HER2-positive CTCs were more commonly detected in HER2-positive (5 of 5 women) than HER2-negative BC (5 of 12 women) (p = 0.03).Conclusion
HER2-positive CTCs were detected in DCIS/LCIS or M0 BC irrespective of the primary tumor HER2 status. Nevertheless, their presence was more common in women with HER2-positive disease. Monitoring of HER2 expression on CTCs might be useful in trials with anti-HER2 therapies. 相似文献94.
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96.
Arthur A. D. Broadbent Jennifer Firn James M. McGree Elizabeth T. Borer Yvonne M. Buckley W. Stanley Harpole Kimberly J. Komatsu Andrew S. MacDougall Kate H. Orwin Nicholas J. Ostle Eric W. Seabloom Jonathan D. Bakker Lori Biederman Maria C. Caldeira Nico Eisenhauer Nicole Hagenah Yann Hautier Joslin L. Moore Carla Nogueira Pablo L. Peri Anita C. Risch Christiane Roscher Martin Schütz Carly J. Stevens 《Global Ecology and Biogeography》2020,29(7):1126-1138
97.
Katharine Reed Carly Wood Jo Barton Jules N. Pretty Daniel Cohen Gavin R. H. Sandercock 《PloS one》2013,8(7)
Exercising in natural, green environments creates greater improvements in adult''s self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called ‘green exercise’ affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = −0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = −0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise. 相似文献
98.
Satyvaldy Jatayev Igor Sukhikh Valeriya Vavilova Svetlana E. Smolenskaya Nikolay P. Goncharov Akhylbek Kurishbayev Lyudmila Zotova Aiman Absattarova Dauren Serikbay Yin-Gang Hu Nikolai Borisjuk Narendra K. Gupta Bertus Jacobs Stephan de Groot Francois Koekemoer Badr Alharthi Katso Lethola Dan T. Cu Carly Schramm Peter Anderson Colin L. D. Jenkins Kathleen L. Soole Yuri Shavrukov Peter Langridge 《Plant, cell & environment》2020,43(10):2355-2364
99.
Segregation of the apical and basolateral plasma membrane domains is the key distinguishing feature of epithelial cells. A series of interrelated cues and processes follow this primary polarization event, resulting in the morphogenesis of the mammalian epithelium. This review focuses on the role of the interactions between the extracellular matrix and neighbouring cells during the initiation and establishment of epithelial polarity, and the role that membrane transport and polarity complexes play in this process. An overview of the formation of the apical junctional complexes is given in relation to the generation of distinct membrane domains characterized by the asymmetric distribution of phosphoinositides and proteins. The mechanisms and machinery utilized by the trafficking pathways involved in the generation and maintenance of this apical-basolateral polarization are expounded, highlighting processes of apical-directed transport. Furthermore, the current proposed mechanisms for the organization of entire networks of cells into a structured, polarized three-dimensional structure are described, with an emphasis on the proposed mechanisms for the formation and expansion of the apical lumen. 相似文献
100.
Dotta BT Buckner CA Cameron D Lafrenie RF Persinger MA 《General physiology and biophysics》2011,30(3):301-309
Photon emissions were measured at ambient temperature (21°C) in complete darkness once per min from cultures of 10(6) cells during the 12 h following removal from 37°C. The energy of emission was about 10(-20) J/s/cell. Of 8 different cell lines, B16-BL6 (mouse melanoma cells) demonstrated the most conspicuous emission profile. Acridine orange and ethidium bromide indicated the membranes were intact with no indication of (trypan blue) cell necrosis. Treatments with EGF and ionomycin produced rapid early (first 3 h) increases in energy emission while glutamine-free, sodium azide and wortmanin-treated cells showed a general diminishment 3 to 9 h later. The results suggested the most probable origin of the photon emission was the plasma cell membrane. Measures from cells synchronized at the M- and S-phase supported this inference. 相似文献