This paper aims to reveal the mechanism of Collateralized Debt Obligations (CDOs) and how CDOs extend the current global financial crisis. We first introduce the concept of CDOs and give a brief account of the de-velo...This paper aims to reveal the mechanism of Collateralized Debt Obligations (CDOs) and how CDOs extend the current global financial crisis. We first introduce the concept of CDOs and give a brief account of the de-velopment of CDOs. We then explicate the mechanism of CDOs within a concrete example with mortgage deals and we outline the evolution of the current financial crisis. Based on our overview of pricing CDOs in various existing random models, we propose an idea of modeling the random phenomenon with the feature of heavy tail dependence for possible implements towards a new random modeling for CDOs.展开更多
Background Taurine performs multiple physiological functions,and the maintenance of taurine level for most mammals relies on active uptake from diet and endogenous taurine synthesis through its synthesis enzymes,inclu...Background Taurine performs multiple physiological functions,and the maintenance of taurine level for most mammals relies on active uptake from diet and endogenous taurine synthesis through its synthesis enzymes,including cysteine dioxygenase(CDO).In addition,uterus tissue and uterus fluid are rich in to urine,and to urine synthesis is regulated by estrogen(E2)and progesterone(P_(4)),the key hormones priming embryo-uterine crosstalk during embryo implantation,but the functional interactions and mechanisms among which are largely unknown.The present study was thus proposed to identify the effects of CDO and taurine on embryo implantation and related mechanisms by using Cdo knockout(KO)and ovariectomy(OVX)mouse models.Results The uterine CDO expression was assayed from the first day of plugging(d 1)to d 8 and the results showed that CDO expression level increased from d 1 to d 4,followed by a significant decline on d 5 and persisted to d 8,which was highly correlated with serum and uterine taurine levels,and serum P_(4) concentration.Next,Cdo KO mouse was established by CRISPER/Cas9.It was showed that Cdo deletion sharply decreased the taurine levels both in serum and uterus tissue,causing implantation defects and severe subfertility.However,the implantation defects in Cdo KO mice were partly rescued by the taurine supplementation.In addition,Cdo deletion led to a sharp decrease in the expressions of P_(4)receptor(PR)and its responsive genes Ihh,Hoxa10 and Hand2.Although the expression of uterine estrogen receptor(ERa)had no significant change,the levels of ERa induced genes(Muc1,Ltf)during the implantation window were upregulated after Cdo deletion.These accompanied by the suppression of stroma cell proliferation.Meanwhile,E2inhibited CDO expression through ERa and P_(4)upregulated CDO expression through PR.Conclusion The present study firstly demonstrates that taurine and CDO play prominent roles in uterine receptivity and embryo implantation by involving in E2-ERa and P_(4)-PR signaling.These are crucial for our understanding the mechanism of embryo implantation,and infer that taurine is a potential agent for improving reproductive efficiency of livestock industry and reproductive medicine.展开更多
文摘This paper aims to reveal the mechanism of Collateralized Debt Obligations (CDOs) and how CDOs extend the current global financial crisis. We first introduce the concept of CDOs and give a brief account of the de-velopment of CDOs. We then explicate the mechanism of CDOs within a concrete example with mortgage deals and we outline the evolution of the current financial crisis. Based on our overview of pricing CDOs in various existing random models, we propose an idea of modeling the random phenomenon with the feature of heavy tail dependence for possible implements towards a new random modeling for CDOs.
基金supported by the Natural Science Foundation of China (32130098)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘Background Taurine performs multiple physiological functions,and the maintenance of taurine level for most mammals relies on active uptake from diet and endogenous taurine synthesis through its synthesis enzymes,including cysteine dioxygenase(CDO).In addition,uterus tissue and uterus fluid are rich in to urine,and to urine synthesis is regulated by estrogen(E2)and progesterone(P_(4)),the key hormones priming embryo-uterine crosstalk during embryo implantation,but the functional interactions and mechanisms among which are largely unknown.The present study was thus proposed to identify the effects of CDO and taurine on embryo implantation and related mechanisms by using Cdo knockout(KO)and ovariectomy(OVX)mouse models.Results The uterine CDO expression was assayed from the first day of plugging(d 1)to d 8 and the results showed that CDO expression level increased from d 1 to d 4,followed by a significant decline on d 5 and persisted to d 8,which was highly correlated with serum and uterine taurine levels,and serum P_(4) concentration.Next,Cdo KO mouse was established by CRISPER/Cas9.It was showed that Cdo deletion sharply decreased the taurine levels both in serum and uterus tissue,causing implantation defects and severe subfertility.However,the implantation defects in Cdo KO mice were partly rescued by the taurine supplementation.In addition,Cdo deletion led to a sharp decrease in the expressions of P_(4)receptor(PR)and its responsive genes Ihh,Hoxa10 and Hand2.Although the expression of uterine estrogen receptor(ERa)had no significant change,the levels of ERa induced genes(Muc1,Ltf)during the implantation window were upregulated after Cdo deletion.These accompanied by the suppression of stroma cell proliferation.Meanwhile,E2inhibited CDO expression through ERa and P_(4)upregulated CDO expression through PR.Conclusion The present study firstly demonstrates that taurine and CDO play prominent roles in uterine receptivity and embryo implantation by involving in E2-ERa and P_(4)-PR signaling.These are crucial for our understanding the mechanism of embryo implantation,and infer that taurine is a potential agent for improving reproductive efficiency of livestock industry and reproductive medicine.
