Objectives: Epithelial-mesenchymal transition (EMT) is an important process in tumor development, and several studies suggest that the Wnt/b-catenin signal pathway may play an important role in EMT. However, there is no direct evidence showing that the Wnt/b-catenin pathway actually determines the EMT induced by an exogenous signal. Our previous research has successfully proved that overexpression of hypoxiainducible factor-1a (HIF-1a) could induce EMT in LNCaP cells, but not in PC-3. The present study aims to determine whether the signal of HIF-1a for inducing prostate cancer cells to undergo EMT might possibly pass through the Wnt/b-catenin pathway. Methods: Epithelial-mesenchymal transition associated proteins were detected in several human prostate carcinoma cell lines by Western blot, and then we distinguished the EMT positive cell lines from the EMT negative cell lines. Furthermore, we evaluated the possible correlation between potency of invasiveness and proliferation among these cell lines with different characteristics of EMT using Matrigel transwell and thiazolyl blue tetrazolium bromide (MTT) assays. Finally, the different expression of some critical proteins and genes in Wnt/b-catenin signaling pathway were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) in these cells with different characteristics of EMT. Results: Among several prostate cancer cell lines, PC-3, LNCaP and PC-3/HIF-1a are EMT negative cell lines, whereas LNCaP/HIF-1a and IA8 have undergone the EMT process. EMT positive cells (LNCaP/HIF-1a and IA8) exhibit much stronger potency of invasiveness and proliferation than those of PC-3 and LNCaP, which belong to EMT negative cells. Interestingly, although PC-3/HIF-1a had not completed the EMT process, it still displayed stronger potency of invasion and proliferation, resembling EMT positive cells. The protein expression level of total glycogensynthase kinase 3b (GSK-3b) and phospho-GSK-3b in LNCaP/HIF-1a, IA8 and PC-3/HIF-1a cells significantly decreased; however, the relative ratios of p-GSK3b/t-GSK3b in LNCaP/HIF-1a, IA8 and PC-3/HIF-1a cells were significantly higher than PC-3 and LNCaP. Consistently, b-catenin protein expression increased in LNCaP/HIF-1a and IA8 cells, but not in PC-3/HIF-1a; RT-PCR confirmed these results, except for the enhanced transcription activity of b-catenin mRNA in PC-3/HIF-1a. Conclusion: Our data suggests that activation of the Wnt/b-catenin signaling pathway correlates with the characteristic of EMT and potency of invasiveness and proliferation. This may be the critical factor that directly controls the process of EMT induced by HIF-1a in prostate cancer cells.

This paper first answers the question "why do the two most powerful techniques Dropout and Batch Normalization (BN) often lead to a worse performance when they are combined together?" in both theoretical and statistical aspects. Theoretically, we find that Dropout would shift the variance of a specific neural unit when we transfer the state of that network from train to test. However, BN would maintain its statistical variance, which is accumulated from the entire learning procedure, in the test phase. The inconsistency of that variance (we name this scheme as "variance shift") causes the unstable numerical behavior in inference that leads to more erroneous predictions finally, when applying Dropout before BN. Thorough experiments on DenseNet, ResNet, ResNeXt and Wide ResNet confirm our findings. According to the uncovered mechanism, we next explore several strategies that modifies Dropout and try to overcome the limitations of their combination by avoiding the variance shift risks.

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This study investigates the relationship between gender diversity on the board and dividend payouts in China using a large sample over the period 2003–2017. Our results provide robust and strong evidence showing that gender diversity on the board is positively associated with cash payments of dividends. The empirical outcomes confirm that gender diversity on the board facilitates corporate governance and subsequently promotes dividend payouts. We demonstrate that gender diversity on the board has the greatest effect when the board has critical mass participation (three or more female directors) compared with only their token participation. However, independent female directors increase dividend payouts, while female executive directors do not have a significant impact. Furthermore, we extend the literature on the relationship between dividend payments and government ownership by providing evidence that gender diversity has a higher impact on dividend payouts for state-owned enterprises than non-state-owned enterprises. After controlling the endogeneity problems, our findings are reliable and robust. JEL classifications: G30, G35

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Piezoelectric bimorph cantilever is a typical structure for vibration energy harvesting. This paper studies the method to improve the accuracy of FEA (finite element analysis) simulation for piezoelectric bimorph cantilever. The COSMOL simulation methods based on 1 D (dimension) model of Euler Bernoulli beam, as well as 2 D and 3 D models of solid mechanics are proposed respectively. Compared with the theory and experiment results given by Erturk A, the influences of 1 D and 3 D piezoelectric material parameters on simulation accuracy in FEA modeling is discussed. The simulation error can be reduced to less than 1.2% by using 1D piezoelectric material parameters in COMSOL simulation, while the maximum simulation error can be up to 28% by using 3D piezoelectric material parameters. Comparing serial and parallel configurations of piezoelectric bimorph cantilever, the output electrical powers, varying with the excitation frequency and load resistance, are also discussed in COMSOL simulation. Performance comparation of three kinds of piezoelectric bimorph cantilevers with tip mass shows that the modelling and simulation in finite element methods by COMSOL are simple and convenient, and are suitable for the electromechanical coupling analysis and optimization of complex topological structures.