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Abstract. Questions: How do physical microsite conditions of microsites affect germination and seedling survival in different successional stages? Do different species germinate in similar microsites in a given successional stage? Location: Coleman Glacier foreland, Mount Baker, Washington State, USA. Methods: Two methods were used to characterize safe sites. 1. Grids of 300 10 cm × 10 cm plots were located in four different age classes on the foreland. 2.105 pairs of plots, with and without seedlings of Abies amabilis, were located in each age class. For each plot we identified all seedlings and all individuals < 1 m tall. Microsite characteristics such as topography and presence of rocks or woody debris were noted for each plot. Microsite characteristics were compared between plots with and without each species. In addition we examined the effect of distance from seed sources on the presence of Alnus viridis seeds and seedlings in a newly disturbed area. Results: In early successional sites, seedlings of several species were positively associated with depressions and presence of rocks, and negatively associated with ridges. Patterns were generally consistent among species. In later succession, seedlings were not significantly associated with any microsite characteristics. For Alnus viridis, seed density decreased with distance from seed sources but seedling density did not. Conclusions: Because of harsh conditions in early succession, physical microsites are important, and most species have similar microsite requirements. In later succession, physical microsites characteristics are not as important and are more variable. Microsites appear to be more important than seed rain in controlling the distribution of Alnus viridis in early succession.  相似文献   
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We revisit the framework for brain-coupled image search, where the Electroencephalography (EEG) channel under rapid serial visual presentation protocol is used to detect user preferences. Extending previous works on the synergy between content-based image labeling and EEG-based brain-computer interface (BCI), we propose a different perspective on iterative coupling. Previously, the iterations were used to improve the set of EEG-based image labels before propagating them to the unseen images for the final retrieval. In our approach we accumulate the evidence of the true labels for each image in the database through iterations. This is done by propagating the EEG-based labels of the presented images at each iteration to the rest of images in the database. Our results demonstrate a continuous improvement of the labeling performance across iterations despite the moderate EEG-based labeling (AUC <75%). The overall analysis is done in terms of the single-trial EEG decoding performance and the image database reorganization quality. Furthermore, we discuss the EEG-based labeling performance with respect to a search task given the same image database.  相似文献   
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Plant Cell, Tissue and Organ Culture (PCTOC) - Pyrostegia venusta (Ker Gawl.) Miers is a plant used for the treatment of respiratory diseases, diarrhea, vitiligo, jaundice and to attenuate...  相似文献   
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