It is well-known that limb muscle reflexes are modulated during human movements. However, little is known about the existence of equivalent masticatory muscle reflex modulation. We hypothesized that masticatory reflexes would be modulated during chewing so that smooth masticatory movements occur. To examine this hypothesis, we studied the modulation of inhibitory reflexes evoked by periodontal mechanoreceptor activation and of excitatory reflexes evoked by muscle spindle activation during simulated mastication. In 28 participants, 1- and 2-N mechanical taps were delivered to the incisor. Reflex responses to these taps were examined in the average masseteric electromyogram. To differentiate between periodontal mechanoreceptor- and muscle-spindle-mediated reflex components, we performed experiments prior to, and in the presence of, periodontal anesthesia. Both periodontal mechanoreceptor and muscle spindle reflexes were reduced during simulated masticatory movements.

This paper investigates empirically the impact of stock liquidity and investor protection on corporate capital structure. We predict that stock liquidity has a significantly negative impact on firm leverage and this negative impact is stronger in a country where the investor protection is strong. The sample consists of 2,203 firms listed in the UK, Germany, France, and Italy over the period from 2009 to 2018. Using a firm fixed effects model, we find evidence supporting our prediction. Our results are robust when we use a random effects model model, or when we employ an alternative measure of investor protection. Additionally, we find that an exogenous event that reduced the investor protection could dampen the negative impact of stock liquidity on firm leverage. Our paper suggests that future studies should consider the effects of factors related to the level of investor protection when investigating the relationship between stock liquidity and firm characteristics, such as firms’ default risk.