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This study investigates the relationship between managerial optimism, investment efficiency and firm valuation. This study follows the Campbell’s measurement for managerial optimism and investigates the influences of the different levels of managerial optimism on improving investment efficiency and firm value when firms tend to under-invest or over-invest. The results indicate that an under-invested firm with a CEO who has a higher level of managerial optimism can improve the firm’s investment efficiency by reducing the degree of underinvestment, which further increases the firm’s value. However, when firms tend to overinvest, there is insufficient evidence to show that a firm with a lower level of CEO managerial optimism will effectively improve the firm’s investment efficiency and increase firm value by reducing the degree of overinvestment.The results generated in this study help scholars and practitioners understand how managerial optimism affects the investment efficiency of firms

This study applies backpropagation neural network for forecasting TXO price under different volatility models, including historical volatility, implied volatility, deterministic volatility function, GARCH and GM-GARCH models. The sample period runs from 2008 to 2009, and thus contains the global financial crisis stating in October 2008. Besides RMSE, MAE and MAPE, this study introduces the best forecasting performance ratio (BFPR) as a new performance measure for use in option pricing. The analytical result reveals that forecasting performances are related to the moneynesses, volatility models and number of neurons in the hidden layer, but are not significantly related to activation functions. Implied and deterministic volatility function models have the largest and second largest BFPR regardless of moneyness. Particularly, the forecasting performance in 2008 was significantly inferior to that in 2009, demonstrating that the global financial crisis during October 2008 may have strongly influenced option pricing performance.

We follow the measurement of Campbell et al. (2011) for managerial optimism and investigate the influences of the different levels of managerial optimism on improving the investment efficiency when firms tend to under-invest or over-invest. The results indicate that an under-invested firm with a CEO that has a high level of managerial optimism can improve the firm's investment efficiency by reducing the degree of underinvestment, further increasing the value of a firm.

Focal adhesion kinase (FAK) and human p70 ribosomal S6 kinase (S6K1) are non-receptor protein tyrosine plays a vital role in cell signaling pathways, such as cell proliferation, survival, and migration. In this study, the 3D structure of FAK (PDB ID: 2AL6) and S6K1 (3A60) were chosen for docking 60 natural compounds attempted to identify novel and specific inhibitors from them. The 30 selected molecules with high scores were further analyzed using DSSTox tools and DS 3.5 ADMET software. Based on a high docking score and energy interaction, 3 of the 9 candidate compounds, neferine B, neferine A, and antroquinonol D, were identified and the inhibitory activity of these compounds were subsequently validated in the C6 glioma cell line. All three selected compounds show potential effects on cell viability by MTT assay. Neferine B, neferine A, and antroquinonol D showed an IC50 value of 10-, 12-, and 16-μM, respectively. Moreover, these compounds decreased the p-FAk and p-S6k1 proteins in a dose-dependent manner. The results of best docked neferine B, neferine A, and antroquinonol D have the potential for further development as a supplement to treat tumorigenesis and metastasis.