Executive compensation following mergers and acquisitions : the impact of institutional ownership

This thesis investigates the monitoring effect from institutional ownership on bidder Chief Executive Officer (hereafter CEO) compensation in mergers and acquisitions (hereafter M&A) as well as the shift in compensation structure. While it is well-established in the literature that bidder CEO compensation soars significantly after conducting such transactions, the sources of the growth are left unclear. One major argument, the traditional theory, proposes that the growth derives from additional wealth created to shareholders in M&A, because according to the nature of compensation contract, CEOs’ interests are effectively aligned with shareholders’ benefits. On the other hand, scholars of managerial power theory argue that managerial power is stronger than shareholders’ oversight, so managers use M&A as a cover to expropriate wealth from shareholders. Whether the traditional theory or the managerial power theory dominates depends on the presence of optimal contract and the effectiveness of corporate governance. Institutional owners have more motivation and resources to restrict managerial behaviour than diffused owners. Thus, the change in CEO compensation following M&A and the driving factors behind the change could be different in firms with different types of ownership. After examining the 268 merger events from 266 US public non-family bidding firms from 2001 to 2005, this study finds that the magnitude of increase in CEO cash-based compensation is significantly alleviated in the presence of large institutional shareholders, and that the increase seems to be positively related to good short-term performance rather than managerial power. However, the concentrated institutional ownership does not seem to affect CEO equity-based compensation or the change in compensation structure. Besides, we do not find any significant relation between firm long-term post-acquisition performance and the market reaction to the announcement of M&A. Thus, we propose that without a reliable indication from short-term performance, large institutional shareholders could have problems in understanding the potential impact of M&A and they might adjust CEO equity-based compensation in a serial process after M&A

Double-loop sliding mode control of reentry hypersonic vehicle with RCS

In order to solve the problem of insufficient aerodynamic moment caused by thin air in the re-entry stage of hypersonic vehicle, this paper establishes an attitude angle model of hypersonic vehicle with reaction control system (RCS), and derives its affine linear model to decoupled the internal and external loop. According to the dead zone and saturation characteristics of RCS thruster, a control method to convert continuous moment into discrete switching instruction using pulse width modulation (PWM) is proposed. Since the number of thrusters is usually redundant, the installation matrix of thrusters in the body coordinate is established, and the command moment is coordinately distributed to the individual thrusters. Then a double-loop sliding mode controller (DSMC) is designed to achieve attitude stability and trajectory tracking. Finally, the simulation results show that DSMC has higher maneuverability, fewer thruster switches and stronger robustness to interference

Association of tea and its extracts with colorectal adenomas: meta-analysis and systematic review

BackgroundThere are many studies on the association of tea and its extracts with colorectal adenomas, but the results have varied. The study aims to investigate the effect of tea and its extracts on colorectal adenomas using meta analysis and systematic review.MethodsLiterature was obtained through PubMed, Cochrane Library, Embase and Chinese BioMedical Literature Service System since the establishment of the database until April 31, 2023. Search terms include adenomas, polyps, colorectal, rectal, rectum, tea, epigallocatechin, drinking and beverages. Meta-regression analysis was used to infer the source of heterogeneity. Heterogeneity was assessed using I2 statistics and Q test. The effect measures were odds ratio (OR) and 95% confidence interval (95% CI). Stata17.0 software was used for data processing.ResultsThe findings indicated that study design (t = 0.78, P = 0.454), types of tea intake (t = 1.35, P = 0.205), occurrences (t = -0.19, P = 0.852), regions (t = 1.13, P = 0.281) and grades of adenomas (t = 0.06, P = 0.952) were statistical homogeneity. Tea and its extracts were negatively correlated with the risk of colorectal adenomas (OR = 0.81, 95% CI: 0.66–0.98). No publication bias was found in this study (t = -0.22, P = 0.828) and the results are robust.ConclusionThis study suggests that tea and its extracts have a certain protective effect on colorectal adenomas, which provides scientific evidence for preventive strategies for colorectal adenomas. As for the causal relationship between tea and its extracts on colorectal adenomas, further prospective studies are needed

Gut microbiota influences feeding behavior via changes in olfactory receptor gene expression in Colorado potato beetles

The Colorado potato beetle (CPB) is an internationally recognized plant quarantine pest that causes serious losses to potato agricultural production. The gut microbiota plays an important role in its growth and development, and the olfactory system plays an important role in insect feeding behavior. The gut microbiota is known to be capable of inducing changes in the olfactory systems of insects. However, the way these associated gut microbes influence the feeding-related behaviors of CPBs remains unclear. To explore the relationship between them, fresh potato leaves immersed in a mixture of five antibiotics (tetracycline, penicillin, ofloxacin, ciprofloxacin, and ampicillin) at specific concentrations for 1 h were fed to adult CPBs to reduce the abundance of gut microbes. We found that the feeding behavior of CPBs was significantly affected by the gut microbiota and that Pseudomonas was significantly higher in abundance in the control group than in the antibiotic group. We then used transcriptome sequencing to explore the differences in olfactory receptor genes in the heads of non-treatment and antibiotic-fed CPBs. Through Illumina Hiseq™ sequencing and screening of differential genes, we found that the olfactory receptor gene LdecOR9 was significantly upregulated and LdecOR17 was significantly downregulated after antibiotic feeding. A real-time polymerase chain reaction was used to verify the changes in olfactory receptor gene expression in the non-treatment groups and antibiotic-treated groups. The feeding behavior was partially rescued after CPBs were re-fed with intestinal bacteria. These results indicate that a certain amount of gut microbiota can result in the loss of the olfactory discrimination ability of CPBs to host plants. In summary, this study investigated the relationship between gut microbiota and olfactory genes, providing a reference for research on microbial control

Partitioning Evapotranspiration in a Cotton Field under Mulched Drip Irrigation Based on the Water-Carbon Fluxes Coupling in an Arid Region in Northwestern China

Measuring evapotranspiration (ET) components in cotton fields under mulched drip irrigation is needed to improve water use efficiency and promote the development of water-saving agriculture. In this study, an Eddy Covariance (EC) system was used to observe the water-carbon fluxes of cotton fields under mulched drip irrigation in an arid region during two years (2021–2022). The Underlying Water Use Efficiency (uWUE) method was used to partition the ET into transpiration (T) and evaporation (E) in order to reveal the changing characteristics of ET and its components in cotton fields under mulched drip irrigation and analyze the effects of environmental factors on each component. The results showed that the diurnal variation of ET was the same as gross primary productivity (GPP), and their course of change showed a bimodal curve at budding, blooming, and boll stages. The relationship of T at different growth stages was the same as ET, which is blooming and boll stage > budding stage > boll opening stage > seedling stage. ET and its components were mainly affected by temperature (Tair) and net radiation (Rn). This study can provide a theoretical and practical basis for the application of uWUE in cotton fields under mulched drip irrigation and a scientific basis for the rational allocation of water resources and the formulation of a scientific water-saving irrigation system for farmland in an arid region

Alkaline Hydrolysis Kinetics Modeling of Bagasse Pentosan Dissolution

The main pentosan components of sugarcane bagasse, which can be subjected to alkaline hydrolysis, are xylose, arabinose, glucose, and galactose. The pentosan reaction mechanism was considered for alkali-treated bagasse with variation of temperature and time. The kinetics of pentosan degradation were studied concurrently at temperatures of 50 °C, 70 °C, and 90 °C, with a solid-liquid mass ratio of 1:15, a stirring speed of 500 revolutions/min, and different holding times for bagasse alkali pre-extraction. With respect to residual pentosan content and the losses of raw material, the hydrolysis rates of alkali pre-extraction and pentosan degradation reactions of bagasse all followed pseudo-first-order kinetic models. Finally, the main degradation activation energy was determined to be 20.86 KJ/mol, and the residual degradation activation energy was 28.75 KJ/mol according to the Arrhenius equation

Fumonisin B1 as a Tool to Explore Sphingolipid Roles in Arabidopsis Primary Root Development

Fumonisin B1 is a mycotoxin that is structurally analogous to sphinganine and sphingosine and inhibits the biosynthesis of complex sphingolipids by repressing ceramide synthase. Based on the connection between FB1 and sphingolipid metabolism, FB1 has been widely used as a tool to explore the multiple functions of sphingolipids in mammalian and plant cells. The aim of this work was to determine the effect of sphingolipids on primary root development by exposing Arabidopsis (Arabidopsis thaliana) seedlings to FB1. We show that FB1 decreases the expression levels of several PIN-FORMED (PIN) genes and the key stem cell niche (SCN)-defining transcription factor genes WUSCHEL-LIKE HOMEOBOX5 (WOX5) and PLETHORAs (PLTs), resulting in the loss of quiescent center (QC) identity and SCN maintenance, as well as stunted root growth. In addition, FB1 induces cell death at the root apical meristem in a non-cell-type-specific manner. We propose that sphingolipids play a key role in primary root growth through the maintenance of the root SCN and the amelioration of cell death in Arabidopsis

Bearing Fault Diagnosis Based on a Hybrid Classifier Ensemble Approach and the Improved Dempster-Shafer Theory

Bearing fault diagnosis of a rotating machine plays an important role in reliable operation. A novel intelligent fault diagnosis method for roller bearings has been developed based on a proposed hybrid classifier ensemble approach and the improved Dempster-Shafer theory. The improved Dempster-Shafer theory well considered the combination of unreliable evidence sources, the uncertainty information of basic probability assignment, and the relative credibility of the evidence on the weights in the process of decision making under the framework of fuzzy preference relations, which can effectively deal with conflicts of the evidences and then well improve the diagnostic accuracy for the hybrid classifier ensemble. The effectiveness of the improved Dempster-Shafer theory has been verified via a numerical example. In addition, deep neural networks, a support vector machine, and extreme learning machine techniques have been utilized in the single-stage classification based on singular spectrum entropy, power spectrum entropy, time-frequency entropy, and wavelet packet energy spectrum entropy in this work. Performances of the proposed hybrid ensemble classifier has been demonstrated on a bearing test-rig, compared with the original Dempster-Shafer theory. It can be found that the overall error rate can be greatly reduced with the hybrid ensemble classifier and the improved Dempster-Shafer theory