Effects of Intermittent Hypoxia Exposure on Symptoms of Chronic Fatigue Syndrome in Repeated Restraint Stress and Forced Swimming Induced-Mouse Model

Background: Chronic fatigue syndrome (CFS) shows as its main symptoms debilitating fatigue that is not relieved by physiological rest, depression, inflammation, learning disability and memory impairment. But, intermittent hypoxia, consisting of alternating exposure to hypoxia and normoxia, plays a very important role in improving CFS. However, the essential components for improving learning and memory in CFS patients as well as their mechanism are largely unknown. Objectives: This study aims to analyze the effects of 12% and 15% hypoxia on the expression of alpha tumor necrosis factor (TNF-α) and nuclear factor kappa B (NF-κB) in CFS induced-mouse model for clarifying the effects on the learning and memory function. Methods: A total of 48 type IC mice were used. The CFS mouse model was established using restrained stress and repeated forced swimming. Treatment of CFS was done by exposing CFS mice to intermittent hypoxia at 12% and 15%. The effects of intermittent hypoxia on learning and memory as well as its mechanism of action on inflammation were tested respectively with the Morris test, the SDS page, the immunohistochemistry technique and the Nissl staining. Results: We found that 12% and 15% intermittent hypoxia exposure improved learning capacity and memory of CFS induced-mice. SDS page showed that CFS caused higher TNF-α expression. By exposing CFS mice to 12% and 15% intermittent hypoxia, TNF-α expression decreased significantly, with a much better effect at 15%. Both TNF-α and NF-κB increased in CFS state and decreased after treatment with intermittent hypoxia. Conclusion: Intermittent hypoxia improves learning capacity and memory. It acted by decreasing NF-κB come to down-regulating TNF-α and ameliorates learning capacity and memory impairment in CFS mice.

The impact of OFDI on firm pro-environmental behavior:Evidence from China

Outward Foreign Direct Investment(OFDI)is a crucial decision in the internationalization strategy of firms and they confront diversified environmental policies and practices of host countries,when engaging in cross-border investments.However,there is a lack of research to investigate whether foreign direct investment(OFDI)is an important factor affecting the environmental commitment of firms.This study aims to empirically analyze the impact and mechanism by which firm outward foreign direct investment(OFDI)influences pro-environmental commitments,utilizing data collected from Chinese listed companies between 2010 and 2020.The results show:1)there is a significant positive relationship between firm OFDI and pro-environmental commitments;2)mechanistic tests show that the OFDI can promote pro-environmental commitments through two channels:public attention and technological learning capacity;3)heterogeneity analysis reveals that the green effects of OFDI are more pronounced firms with institutional investors and state ownership,as well as in firms situated in host countries with more stringent environmental regulations;4)further analysis reveals OFDI-induced greater green commitments generated real environmental and economic outcomes:firms invested more in environmental protection and reduced CO_(2)emissions.In the meantime,they experienced lower excessive debt risk and higher innovative performance.The findings have positive implications for the promotion of firms’pro-environmental behavior and sustainable development.

The effect of the endosymbiont Wolbachia on the behavior of insect hosts

As one of the most successful intracellular symbiotic bacteria,Wolbachia can infect many arthropods and nematodes.Wolbachia infection usually affects the reproduction of their hosts to promote their own proliferation and transmission.Currently,most of the studies focus on the mechanisms of Wolbachia interactions with host reproduction.However,in addition to distribution in the reproductive tissues,Wolbachia also infect various somatic tissues of their hosts,including the brain.This raises the potential that Wolbachia may influence some somatic processes,such as behaviors in their hosts.Sofar,information about the effects of Wolbachia infection on host behavior is still very limited.The present review presents the current literature on different aspects of the influence of Wolbachia on various behaviors,including sleep,learning and memory,mating,feeding and aggression in their insect hosts.We then highlight ongoing scientific efforts in the field that need addressing to advance this field,which can have significant implications for further developing Wolbachia as environmentally friendly biocontrol agents to control insect-borne diseases and agricultural pests.