The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractThis paper examines the impact of political uncertainty (caused by the civil uprisings in the Arab World i.e., "Arab Spring") on the volatility of major stock markets in the MENA region.Our main findings are as follows. First, by distinguishing between conventional and Islamic stock market indices, we find that these two groups of investments react heterogeneously to the recent political turmoil. Specifically, we document a significant increase in the volatility of Islamic indices during the period of political unrests whereas the uprisings have had little or no significant effect on the volatility in conventional markets. Such difference is confirmed by further analysis in a multivariate GARCH model. Second, regardless of its impact on volatility, there is little evidence to suggest that MENA markets have become more integrated with international markets after the political revolution. Third, similar results are not found for the benchmark indices which indicate that the changes are the result of political tensions.In general, these results are robust to model specification and consistent with the notion that political uncertainty contributes to financial volatility. Overall, the findings are important in understanding the role of political uncertainty on stock market stability and are of great significance to investors and market regulators.

Previous research argues that large non-controlling shareholders enhance firm value because they deter expropriation by the controlling shareholder. We propose that the conflicting incentives faced by large shareholders may induce a nonlinear relationship between the relative size of large shareholdings and firm value. Consistent with this prediction, we present evidence that there are costs of having a second (and third) largest shareholder, especially when the largest shareholdings are similar in size. Our results are robust to various relative size proxies, firm performance measures, model specifications, and potential endogeneity issues. JEL classification: G32; G34.We would like to thank the Centre for Advanced Studies in Finance, University of Leeds, for its financial support. We are grateful to

The centrosome is crucial for mitotic fidelity, and centrosome aberrations are associated with genomic instability and tumorigenesis. The centrosomal protein Cep70 has been reported to play a role in various cellular activities. However, whether this protein is involved in pathological processes remains unknown. In this study, we demonstrate that Cep70 is highly expressed in pancreatic cancer tissues. Cep70 expression correlates with clinicopathological parameters of pancreatic cancer, including histological grade, pathological tumor node metastasis stage, lymph node metastasis, and carbohydrate antigen 19-9 level. Depletion of Cep70 significantly suppresses pancreatic cancer cell proliferation and promotes apoptotic cell death, and exogenous expression of Cep70 can rescue the above effects. Cep70 also stimulates colony formation in soft agar and enhances tumor growth in mice. Our data further show that ectopic expression of Cep70 in pancreatic cancer cells results in the mislocalization of centrosomal proteins, including γ-tubulin and pericentrin, and the formation of intracellular aggregates. In addition, Cep70 overexpression leads to microtubule disorganization and the formation of multipolar spindles during mitosis. Our study thus unravels a critical role for Cep70 in pancreatic cancer and suggests Cep70 as a potential biomarker and therapeutic target for this deadly disease.

Despite their increasing uses for cardiovascular and cerebrovascular tissue engineering, synthetic polymeric conduits still have their limitations in clinical applications, particularly in small vessels, mainly due to the thrombus formation. Seeding the synthetic scaffolds with endothelial cells (ECs) will potentially solve this problem, but this endothelialization approach demands synthetic materials with better hemacompatibility and cell affinity. To improve the currently used materials and screen for better surface properties, we synthesized copolymer of poly(lactide-co-beta-malic acid) (PLMA), and its derivatives with pendant hydroxyl arms (PLMAHE) or extended carboxyl arms (PLMA-ECA). We analyzed their physical and chemical properties, their hydrophilicity, and their degradation in physiological conditions. More importantly, their blood compatibility was investigated by the measurements of prothrombin time, activated partial thromboplastin time, and interaction with platelets; their cell affinity and cell growth potentials were observed using the human umbilical vein EC cultures. Results from these experiments showed that the copolymer with the carboxyl arms attracted little platelets, and exhibited better cell affinity and supported the cell proliferation, thus demonstrating the potential usefulness of PLMA-ECA for tissue engineering. We speculate that this novel material will offer new opportunities for the design of better vascular-engineered scaffolds owing to its improved biological and chemical properties.

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