Three essays on acquisition and CSR choices and firm value: Role of managerial traits and actions

This thesis consists of three essays that examine the role of managerial traits (specifically managerial conservatism, interest alignment with shareholders and debtholders, beliefs about firm value and hubris) on their firms’ acquisition and CSR choices and their valuation effects. All the essays use hand-collected pension plan data. The first essay finds support for a managerial conservatism explanation for acquirer acquisition choices and M&A price effects. More conservatively managed acquirers are more likely to use cash as the method of payment and to target less risky firms (e.g. being public or having lower leverage or managerial conservatism). We find that acquirers experience poorer price effects for stock versus cash payment even after controlling for the equity price effect and that these price effects monotonically deteriorate with increasing managerial conservatism, consistent with the agency problems associated with managerial conservatism. These results remain robust using propensity score matching, a four- or five-factor model, the BHAR methodology, top five executives instead of CEO when measuring managerial conservatism, and the inclusion of various controls (e.g., multiple or single acquirers, policy uncertainty, business cycle, managerial hubris, firm mispricing and Republican orientation). The second essay finds that managerial interest alignment with shareholders (debtholders) of acquirers is positively related to the likelihood of using stock (cash) as the M&A payment method, positively (negatively) related with M&A acquirer equity price effects, and negatively (positively) related with M&A acquirer bond price effects. While managerial conservatism is positively related with an acquirer’s CSR ranking it is negatively related with an acquirer’s M&A price effects. Information about an acquirer’s misvaluation contained in pre-announcement short selling by investors and the abnormal trading of its executives also affects the acquirer’s choice of payment method and M&A price effects

Binding energies of hydrogen-like impurities in a semiconductor in intense terahertz laser fields

A detailed theoretical study is presented for the influence of linearly polarised intense terahertz (THz) laser radiation on energy states of hydrogen-like impurities in semiconductors. The dependence of the binding energy for 1s and 2p states on intensity and frequency of the THz radiation has been examined.Comment: 14 pages, 4 figure

IC classifier: a classifier for 3D industrial components based on geometric prior using GNN

In this paper, we propose an approach to address the problem of classifying 3D industrial components by introducing a novel framework named IC-classifier (Industrial Component classifier). Our framework is designed to focus on the object's local and global structures, emphasizing the former by incorporating specific local features for embedding the model. By utilizing graphical neural networks and embedding derived from geometric properties, IC-classifier facilitates the exploration of the local structures of the object while using geometric attention for the analysis of global structures. Furthermore, the framework uses point clouds to circumvent the heavy computation workload. The proposed framework's performance is benchmarked against state-of-the-art models, demonstrating its potential to compete in the field.Comment: 15 pages including citations, 3 pages of figure

Gastric cancer cell proliferation is inhibited by α-santonin via targeting of PI3K and AKT activation

Purpose: To investigate the effect of α-santonin on proliferation of gastric cancer cells.Methods: Cell proliferation was analysed by 3-4-5-Dimethylthiazol-2-yl-25-diphenyltetrazolium bromide (MTT) assay and migration by wound healing assay. Matrigel coated Transwell chamber was used for determination of cell invasion. Expression of proteins and mRNA was assessed using western blot and RT-PCR assay, respectively.Results: In NUGC4 and MKN45 cell cultures, treatment with α-santonin promoted miR 145 expression significantly when compared to control. Treatment of NUGC4 cells with α-santonin for 48 h significantly increased apoptosis in comparison to control. At 100, 150 and 200 μM concentrations of α-santonin, the level of cell apoptosis increased to 45, 53 and 64 %, respectively (p < 0.05). Treatment with α-santonin caused NUGC4 cell population increase in G1/G0 phase with reduction in S and G2/M phases. A significant reduction in NUGC4 cell invasion was observed following treatment with α-santonin. The α- santonin treatment of NUGC4 cells at 200 μM concentration markedly reduced cell invasion (p < 0.05). Treatment of NUGC4 cells with α-santonin reduced the expression of c Myc, PI3K, and p AKT. The production of MMP-2 and MMP-9 in NUGC4 cells was also decreased by α-santonin treatment.Conclusion: The study demonstrates that α-santonin plays important role in inhibition of gastric cancer cell proliferation by arrest of cell cycle and apoptosis induction. Moreover, the activation of PI3K and AKT was also suppressed by α-santonin. Therefore, α-santonin can potentially be used for the treatment of gastric cancer. Keywords: Apoptosis, MicroRNA, Tumor suppressor, Metastasis, Infiltratio

Observation of Landau level-like quantizations at 77 K along a strained-induced graphene ridge

Recent studies show that the electronic structures of graphene can be modified by strain and it was predicted that strain in graphene can induce peaks in the local density of states (LDOS) mimicking Landau levels (LLs) generated in the presence of a large magnetic field. Here we report scanning tunnelling spectroscopy (STS) observation of nine strain-induced peaks in LDOS at 77 K along a graphene ridge created when the graphene layer was cleaved from a sample of highly oriented pyrolytic graphite (HOPG). The energies of these peaks follow the progression of LLs of massless 'Dirac fermions' (DFs) in a magnetic field of 230 T. The results presented here suggest a possible route to realize zero-field quantum Hall-like effects at 77 K

Information Filtering on Coupled Social Networks

In this paper, based on the coupled social networks (CSN), we propose a hybrid algorithm to nonlinearly integrate both social and behavior information of online users. Filtering algorithm based on the coupled social networks, which considers the effects of both social influence and personalized preference. Experimental results on two real datasets, \emph{Epinions} and \emph{Friendfeed}, show that hybrid pattern can not only provide more accurate recommendations, but also can enlarge the recommendation coverage while adopting global metric. Further empirical analyses demonstrate that the mutual reinforcement and rich-club phenomenon can also be found in coupled social networks where the identical individuals occupy the core position of the online system. This work may shed some light on the in-depth understanding structure and function of coupled social networks