Density dependence across multiple life stages in a temperate old-growth forest of northeast China

Recent studies on species coexistence suggest that density dependence is an important mechanism regulating plant populations. However, there have been few studies of density dependence conducted for more than one life-history stage or that control for habitat heterogeneity, which may influence spatial patterns of survival and mask density dependence. We explored the prevalence of density dependence across multiple life stages, and the effects of controlling for habitat heterogeneity, in a temperate forest in northeast China. We used generalized linear mixed-effects models to test for density-dependent mortality of seedlings and spatial point pattern analysis to detect density dependence for sapling-to-juvenile transitions. Conspecific neighbors had a negative effect on survival of plants in both life stages. At the seedling stage, we found a negative effect of conspecific seedling neighbors on survival when analyzing all species combined. However, in species-level analyses, only 2 of 11 focal species were negatively impacted by conspecific neighbors, indicating wide variation among species in the strength of density dependence. Controlling for habitat heterogeneity did not alter our findings of density dependence at the seedling stage. For the sapling-to-juvenile transition stage, 11 of 15 focal species showed patterns of local scale (<10 m) conspecific thinning, consistent with negative density dependence. The results varied depending on whether we controlled for habitat heterogeneity, indicating that a failure to account for habitat heterogeneity can obscure patterns of density dependence. We conclude that density dependence may promote tree species coexistence by acting across multiple life-history stages in this temperate forest. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00442-012-2481-y) contains supplementary material, which is available to authorized users

A sample-driven classification and identification method with KPCA and multi-SVM

It is difficult to develop an accurate fault diagnosis model for aero-engines due to their complex structure. In present paper, a new method for classifying and identifying fault modes according to the effective information extracted from history fault samples was proposed. This method includes three steps: firstly, find out independent source vibration signals through diagnosing and separating vibration signals. Secondly, find out the features that have great contribution to fault analysis using kernel principal component analysis (KPCA), and extract the eigenvector that is sensitive to status. Finally, classify the eigenvectors characterizing fault nature using support vector machine (SVM), meanwhile, select and analyze the parameters affecting classification effect. Two typical fault samples of aero-engine were used for verifying the feasibility of this method. Results show that for fault classification, this method has high identification accuracy, fast diagnosis speed, and is applicable to solving the classification and identification of small and nonlinear faults

Prognostic implications of ezrin and phosphorylated ezrin expression in non-small cell lung cancer

BACKGROUND: The cytoskeletal organizer ezrin is a member of the ezrin-radixin-moesin (ERM) family and plays important roles in not only cell motility, cell adhesion, and apoptosis, but also in various cell signaling pathways. Phosphorylation at Thr-567 and Tyr-353 are key regulatory events in the transition of the dormant to active form of ezrin. This study investigated the prognostic implications of ezrin and phosphorylated ezrin (p-ezrin) expression in non-small cell lung carcinoma (NSCLC). METHODS: Ezrin and p-ezrin protein expressions were examined by immunohistochemistry in 150 NSCLC and adjacent non-tumor tissues and 14 normal lung tissues. qRT-PCR was used to determine ezrin mRNA expression levels in fresh tissues. The correlations between overexpression of ezrin and p-ezrin and the clinicopathological features of NSCLC were analyzed. The survival rates were calculated by the Kaplan-Meier method for 108 NSCLC cases. RESULTS: Ezrin and ezrin(Thr-567) proteins showed cytosolic and membranous staining patterns; however, ezrin(Tyr-353) protein only showed cytosolic staining. Ezrin and p-ezrin were significantly upregulated in NSCLC compared with the normal counterparts. Increased ezrin, ezrin(Thr-567), and ezrin(Tyr-353) levels were correlated with the late stage and poor differentiation of NSCLC. However, only ezrin(Thr-567) was correlated with the presence of lymph node metastasis. In regard to survival, only ezrin(Thr-567) was related with the overall survival time of patients with NSCLC, and both ezrin and ezrin(Thr-567) were associated with shortened survival time for patients with early stage NSCLC. CONCLUSIONS: Ezrin and p-ezrin, especially ezrin(Thr-567), may prove to be useful as a novel prognostic biomarker of NSCLC

Overexpression of the miR-141/200c cluster promotes the migratory and invasive ability of triple-negative breast cancer cells through the activation of the FAK and PI3K/AKT signaling pathways by secreting VEGF-A

Migration in miR-141/200c-transduced HCC-38 and Hs578T cells treated with an anti-VEGF-A-neutralizing antibody. (A, D) Migration in miR-141/200c-transduced HCC-38 and Hs578T cells. Images of the crystal violet-stained cells that migrated horizontally in the trans-well migration assay (upper). The absorbance values of extracted crystal violet in migrated cells (lower). The migratory abilities of the miR-200c cells (~1.6-fold and ~1.7-fold, HCC-38 and Hs578T, respectively) were significantly increased compared with those of the control cells. (B, E) Measurement of the secreted levels of cytokines and growth factors (IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, GM-CSF, IFN-γ, TNF-α, and VEGF-A). Transduction of miR-141/200c into HCC-38 and Hs578T cells promoted significantly higher VEGF-A secretion than that of control cells. (C, F) Trans-well migration of anti-VEGF-A-neutralizing antibody-treated cells. The enhanced migration of the miR-141/200c-transduced HCC-38 cells were significantly suppressed by treatment with anti-VEGF-A-neutralizing antibodies, but miR-141/200c-transduced Hs578T cells still showed increased migratory ability compared with control cells. *p < 0.05, **p < 0.001. (JPG 188 kb

Vision-force-fused curriculum learning for robotic contact-rich assembly tasks

Contact-rich robotic manipulation tasks such as assembly are widely studied due to their close relevance with social and manufacturing industries. Although the task is highly related to vision and force, current methods lack a unified mechanism to effectively fuse the two sensors. We consider coordinating multimodality from perception to control and propose a vision-force curriculum policy learning scheme to effectively fuse the features and generate policy. Experiments in simulations indicate the priorities of our method, which could insert pegs with 0.1 mm clearance. Furthermore, the system is generalizable to various initial configurations and unseen shapes, and it can be robustly transferred from simulation to reality without fine-tuning, showing the effectiveness and generalization of our proposed method. The experiment videos and code will be available at https://sites.google.com/view/vf-assembly