Towards Constraining Parity-Violations in Gravity with Satellite Gradiometry

Parity violation in gravity, if existed, could have important implications, and it is meaningful to search and test the possible observational effects. Chern-Simons modified gravity serves as a natural model for gravitational parity-violations. Especially, considering extensions to Einstein-Hilbert action up to second order curvature terms, it is known that theories of gravitational parity-violation will reduce to the dynamical Chern-Simons gravity. In this letter, we outline the theoretical principles of testing the dynamical Chern-Simons gravity with orbiting gravity gradiometers, which could be naturally incorporated into future satellite gravity missions. The secular gravity gradient signals, due to the Mashhoon-Theiss (anomaly) effect, in dynamical Chern-Simons gravity are worked out, which can improve the constraint of the corresponding Chern-Simons length scale $\xi^{\frac{1}{4}}_{cs}$ obtained from such measurement scheme. For orbiting superconducting gradiometers or gradiometers with optical readout, a bound $\xi^{\frac{1}{4}}_{cs}\leq 10^6 \ km$ (or even better) could in principle be obtained, which will be at least 2 orders of magnitude stronger than the current one based on the observations from the GP-B mission and the LAGEOS I, II satellites.Comment: 15 pages, 6 figures. arXiv admin note: text overlap with arXiv:1606.0818

The Dark Side of Executive Compensation Duration: Evidence from Mergers and Acquisitions

We find that contrary to popular belief, CEOs with long compensation duration do not make better long-term investment decisions. Using a comprehensive pay duration measure, we find that acquisitions conducted by CEOs with long compensation duration receive more negative announcement returns, and experience significantly worse post-acquisition abnormal operating and stock performance, compared with deals conducted by CEOs with short compensation duration. The negative correlation between compensation duration and mergers and acquisitions (M&A) performance is driven by long-term time-vesting plans, not by performance-vesting plans. The results suggest that extending CEO pay horizons without implementing performance requirements is insufficient to improve managerial long-term investment decisions

A Comparative Study on Regularization Strategies for Embedding-based Neural Networks

This paper aims to compare different regularization strategies to address a common phenomenon, severe overfitting, in embedding-based neural networks for NLP. We chose two widely studied neural models and tasks as our testbed. We tried several frequently applied or newly proposed regularization strategies, including penalizing weights (embeddings excluded), penalizing embeddings, re-embedding words, and dropout. We also emphasized on incremental hyperparameter tuning, and combining different regularizations. The results provide a picture on tuning hyperparameters for neural NLP models.Comment: EMNLP '1

Psychological crisis intervention for the family members of patients in a vegetative state

OBJECTIVES: Family members of patients in a vegetative state have relatively high rates of anxiety and distress. It is important to recognize the problems faced by this population and apply psychological interventions to help them. This exploratory study describes the psychological stress experienced by family members of patients in a vegetative state. We discuss the effectiveness of a psychological crisis intervention directed at this population and offer suggestions for future clinical work. METHODS: A total of 107 family members of patients in a vegetative state were included in the study. The intervention included four steps: acquisition of facts about each family, sharing their first thoughts concerning the event, assessment of their emotional reactions and developing their coping abilities. The Symptom Check List-90 was used to evaluate the psychological distress of the participants at baseline and one month after the psychological intervention. Differences between the Symptom Check List-90 scores at the baseline and follow-up evaluations were analyzed. RESULTS: All participants in the study had significantly higher Symptom Check List-90 factor scores than the national norms at baseline. There were no significant differences between the intervention group and the control group at baseline. Most of the Symptom Check List-90 factor scores at the one-month follow-up evaluation were significantly lower than those at baseline for both groups; however, the intervention group improved significantly more than the control group on most subscales, including somatization, obsessive-compulsive behavior, depression, and anxiety. CONCLUSION: The results of this study indicate that the four-step intervention method effectively improves the mental health of the family members who received this treatment and lessens the psychological symptoms of somatization, obsessive-compulsive behavior, depression and anxiety