基金经理能否通过主动性管理提升业绩,这是实务界和理论界共同关注的一个重要问题。本文利用开放式基金2005～2009年的数据进行研究发现:将容易获得的跟踪误差和R^2综合为复合主动性指标(Composite Active Index,CAI),可以作为主动性管...基金经理能否通过主动性管理提升业绩,这是实务界和理论界共同关注的一个重要问题。本文利用开放式基金2005～2009年的数据进行研究发现:将容易获得的跟踪误差和R^2综合为复合主动性指标(Composite Active Index,CAI),可以作为主动性管理能力的测量指标;在我国使用包括了完整的上升和下降阶段的时间段(两年)作为测量主动性的估计期是恰当的;主动性确实能够作为基金未来业绩的预测指标,即基金经理通过主动性管理显著地提升了基金业绩。展开更多
The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty ...The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty Simmental crossbred male calves(body weight=86.47±4.41 kg and 70±4 d of age)were randomly divided into 2 groups:control(CON)(fed basal ration)and ADY(fed basal ration and 5 g/d ADY per calf).The dietary concentrate-to-roughage ratio was 35:65.All the calves were regularly provided rations 3 times a day at 07:00,13:00,and 19:00 and had free access to wate r.The experiment lasted for 60 d.The average daily gain of ADY group was higher(P=0.007)than that of the CON group,and the ratio of feed intake to average daily gain in the ADY group was reduced(P=0.022)as compared to the CON group.The concentration of ruminal ammonia-N was higher(P=0.023)in the CON group than that in the ADY group,but an opposite trend of microbial protein was found between the 2 groups.Also,the ruminal concentrations of propionate and butyrate were higher(P<0.05)in the ADY group than those in the CON group.Calves fed ADY exhibited higher(P<0.05)crude protein and neutral detergent fiber digestibility.Supplementation of ADY increased(P<0.05)the contents of glucose,glutathione peroxidase,superoxide dismutase,immunoglobulin A,immunoglobulin M,and interleukin 10 in the serum of calves,but an opposite trend was observed in malondialdehyde,interleukin 1 beta,and tumor necrosis factor alpha contents between the 2 groups.In conclusion,dietary supplementation with ADY could improve the growth performance,rumen fermentation,nutrient digestibility,antioxidant ability,and immune response of weaned beef calves.展开更多
文摘基金经理能否通过主动性管理提升业绩,这是实务界和理论界共同关注的一个重要问题。本文利用开放式基金2005～2009年的数据进行研究发现:将容易获得的跟踪误差和R^2综合为复合主动性指标(Composite Active Index,CAI),可以作为主动性管理能力的测量指标;在我国使用包括了完整的上升和下降阶段的时间段(两年)作为测量主动性的估计期是恰当的;主动性确实能够作为基金未来业绩的预测指标,即基金经理通过主动性管理显著地提升了基金业绩。
基金supported by the National Key Research and Development Program(2017YFD0502005)Sichuan Science and Technology Program(2018NZ0002)China Agriculture(Beef Cattle/Yak)Research System of MOF and MARA(CARS-37)。
文摘The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty Simmental crossbred male calves(body weight=86.47±4.41 kg and 70±4 d of age)were randomly divided into 2 groups:control(CON)(fed basal ration)and ADY(fed basal ration and 5 g/d ADY per calf).The dietary concentrate-to-roughage ratio was 35:65.All the calves were regularly provided rations 3 times a day at 07:00,13:00,and 19:00 and had free access to wate r.The experiment lasted for 60 d.The average daily gain of ADY group was higher(P=0.007)than that of the CON group,and the ratio of feed intake to average daily gain in the ADY group was reduced(P=0.022)as compared to the CON group.The concentration of ruminal ammonia-N was higher(P=0.023)in the CON group than that in the ADY group,but an opposite trend of microbial protein was found between the 2 groups.Also,the ruminal concentrations of propionate and butyrate were higher(P<0.05)in the ADY group than those in the CON group.Calves fed ADY exhibited higher(P<0.05)crude protein and neutral detergent fiber digestibility.Supplementation of ADY increased(P<0.05)the contents of glucose,glutathione peroxidase,superoxide dismutase,immunoglobulin A,immunoglobulin M,and interleukin 10 in the serum of calves,but an opposite trend was observed in malondialdehyde,interleukin 1 beta,and tumor necrosis factor alpha contents between the 2 groups.In conclusion,dietary supplementation with ADY could improve the growth performance,rumen fermentation,nutrient digestibility,antioxidant ability,and immune response of weaned beef calves.
