Human activities widely exhibit a power-law distribution.Considering stock trading as a typical human activity in the financial domain,the first aim of this paper is to validate whether the well-known power-law distri...Human activities widely exhibit a power-law distribution.Considering stock trading as a typical human activity in the financial domain,the first aim of this paper is to validate whether the well-known power-law distribution can be observed in this activity.Interestingly,this paper determines that the number of accumulated lead–lag days between stock pairs meets the power-law distribution in both the U.S.and Chinese stock markets based on 10 years of trading data.Based on this finding this paper adopts the power-law distribution to formally define the lead–lag effect,detect stock pairs with the lead–lag effect,and then design a pure lead–lag investment strategy as well as enhancement investment strategies by integrating the lead–lag strategy into classic alpha-factor strategies.Tests conducted on 20 different alpha-factor strategies demonstrate that both perform better than the selected benchmark strategy and that the lead–lag strategy provides useful signals that significantly improve the performance of basic alpha-factor strategies.Our results therefore indicate that the lead–lag effect may provide effective information for designing more profitable investment strategies.展开更多
Hexavalent chromium and its compounds are prevalent pollutants,especially in the work environment,pose a significant risk for multisystem toxicity and cancers.While it is known that chromium accumulation in the liver ...Hexavalent chromium and its compounds are prevalent pollutants,especially in the work environment,pose a significant risk for multisystem toxicity and cancers.While it is known that chromium accumulation in the liver can cause damage,the dose-response relationship between blood chromium(Cr)and liver injury,as well as the possible potential toxic mechanisms involved,remains poorly understood.To address this,we conducted a follow-up study of 590 visits from 305 participants to investigate the associations of blood Cr with biomarkers for liver injury,including serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),total bilirubin(TBIL),and direct bilirubin(DBIL),and to evaluate the mediating effects of systemic inflammation.Platelet(PLT)and the platelet-to-lymphocyte ratio(PLR)were utilized as biomarkers of systemic inflammation.In the linear mixed-effects analyses,each 1-unit increase in blood Cr level was associated with estimated effect percentage increases of 0.82%(0.11%,1.53%)in TBIL,1.67%(0.06%,3.28%)in DBIL,0.73%(0.04%,1.43%)in ALT and 2.08%(0.29%,3.87%)in AST,respectively.Furthermore,PLT mediated 10.04%,11.35%,and 10.77%increases in TBIL,DBIL,and ALT levels induced by chromate,respectively.In addition,PLR mediated 8.26%and 15.58%of the association between blood Cr and TBIL or ALT.These findings shed light on the mechanisms underlying blood Cr-induced liver injury,which is partly due to worsening systemic inflammation.展开更多
基金supported by the National Natural Science Foundation of China(72171059,71771041)the Fundamental Research Funds for the Central Universities(FRFCU5710000220)the Natural Science Foundation of Heilongjiang Province,China(No.YQ2020G003).
文摘Human activities widely exhibit a power-law distribution.Considering stock trading as a typical human activity in the financial domain,the first aim of this paper is to validate whether the well-known power-law distribution can be observed in this activity.Interestingly,this paper determines that the number of accumulated lead–lag days between stock pairs meets the power-law distribution in both the U.S.and Chinese stock markets based on 10 years of trading data.Based on this finding this paper adopts the power-law distribution to formally define the lead–lag effect,detect stock pairs with the lead–lag effect,and then design a pure lead–lag investment strategy as well as enhancement investment strategies by integrating the lead–lag strategy into classic alpha-factor strategies.Tests conducted on 20 different alpha-factor strategies demonstrate that both perform better than the selected benchmark strategy and that the lead–lag strategy provides useful signals that significantly improve the performance of basic alpha-factor strategies.Our results therefore indicate that the lead–lag effect may provide effective information for designing more profitable investment strategies.
基金supported by the National Natural Science Foundation of China(Nos.82273603,82003427,U2004202)。
文摘Hexavalent chromium and its compounds are prevalent pollutants,especially in the work environment,pose a significant risk for multisystem toxicity and cancers.While it is known that chromium accumulation in the liver can cause damage,the dose-response relationship between blood chromium(Cr)and liver injury,as well as the possible potential toxic mechanisms involved,remains poorly understood.To address this,we conducted a follow-up study of 590 visits from 305 participants to investigate the associations of blood Cr with biomarkers for liver injury,including serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),total bilirubin(TBIL),and direct bilirubin(DBIL),and to evaluate the mediating effects of systemic inflammation.Platelet(PLT)and the platelet-to-lymphocyte ratio(PLR)were utilized as biomarkers of systemic inflammation.In the linear mixed-effects analyses,each 1-unit increase in blood Cr level was associated with estimated effect percentage increases of 0.82%(0.11%,1.53%)in TBIL,1.67%(0.06%,3.28%)in DBIL,0.73%(0.04%,1.43%)in ALT and 2.08%(0.29%,3.87%)in AST,respectively.Furthermore,PLT mediated 10.04%,11.35%,and 10.77%increases in TBIL,DBIL,and ALT levels induced by chromate,respectively.In addition,PLR mediated 8.26%and 15.58%of the association between blood Cr and TBIL or ALT.These findings shed light on the mechanisms underlying blood Cr-induced liver injury,which is partly due to worsening systemic inflammation.
