传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)是双RNA病毒属的重要成员,其超强毒株不仅导致60%以上鸡的死亡率,还可以导致鸡严重的免疫抑制,造成疫苗的免疫失败,同时诱发严重继发感染,对养禽业危害严重。IBDV感染的第一...传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)是双RNA病毒属的重要成员,其超强毒株不仅导致60%以上鸡的死亡率,还可以导致鸡严重的免疫抑制,造成疫苗的免疫失败,同时诱发严重继发感染,对养禽业危害严重。IBDV感染的第一步是吸附及进入靶细胞,其主要衣壳蛋白VP2决定了病毒的细胞嗜性,而IBDV进入靶细胞的具体机制仍未完全明确。近期有研究团队发表在《Journal of virology》杂志的一项研究“Identification of chicken CD44 as a novel B lymphocyte receptor for infectious bursal dis-ease virus”对IBDV的细胞受体进行了一系列的筛选与鉴定。展开更多
[ Objective] The aim was to study the spatial and temporal changes of extreme precipitation events in Ningxia in recent 50 years. [ Method] Using dally precipitation data at 20 stations in Ningxia from 1961 to 2010, a...[ Objective] The aim was to study the spatial and temporal changes of extreme precipitation events in Ningxia in recent 50 years. [ Method] Using dally precipitation data at 20 stations in Ningxia from 1961 to 2010, and defining the threshold value of extreme precipitation in each sta- tion by percentage method, choosing indicators such as precipitation, frequency and intensity of extreme precipitation events, the characteristics of the spatial and temporal distribution and linear trend of extreme precipitation events in Ningxia were analyzed based on linear regression and M-K non-parameter statistical test method. [ Result] The percentage method suggested the threshold value of average extreme precipitation in Ningxia in recent 50 years decreased from south to north. The large threshold value was in southern Haiyuan, Tongxin and northern Yancheng, which was similar to the distribution of mean annual precipitation in Ningxia. In recent 50 years, extreme precipitation frequency and extreme precipitation de- creased in most part of Ningxia but the intensity tended to strengthen. Study of extreme precipitation in Mahuang Mountain and Liupan Mountain in- dicated that precipitation frequency, intensity and extreme precipitation reduced. Annual extreme precipitation frequency narrowed and then in- creased after 1994 and had mutation in 2003. Annual extreme precipitation intensity enhanced since 1984. Mutation took place in 1984. Intensity in Liupan Mountain had weakened since 1978. [ Conclusion] The study provided theoretical basis for the mutation of climate in Ningxia.展开更多
文摘传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)是双RNA病毒属的重要成员,其超强毒株不仅导致60%以上鸡的死亡率,还可以导致鸡严重的免疫抑制,造成疫苗的免疫失败,同时诱发严重继发感染,对养禽业危害严重。IBDV感染的第一步是吸附及进入靶细胞,其主要衣壳蛋白VP2决定了病毒的细胞嗜性,而IBDV进入靶细胞的具体机制仍未完全明确。近期有研究团队发表在《Journal of virology》杂志的一项研究“Identification of chicken CD44 as a novel B lymphocyte receptor for infectious bursal dis-ease virus”对IBDV的细胞受体进行了一系列的筛选与鉴定。
基金Supported by Climate Changes in Chinese Meteorological Bureau (CCSF2011-26)Ningxia Science and Technology Development(KGX12-09-02)Ningxia Natural Science Fund(NZ11246) and (NZ10212)
文摘[ Objective] The aim was to study the spatial and temporal changes of extreme precipitation events in Ningxia in recent 50 years. [ Method] Using dally precipitation data at 20 stations in Ningxia from 1961 to 2010, and defining the threshold value of extreme precipitation in each sta- tion by percentage method, choosing indicators such as precipitation, frequency and intensity of extreme precipitation events, the characteristics of the spatial and temporal distribution and linear trend of extreme precipitation events in Ningxia were analyzed based on linear regression and M-K non-parameter statistical test method. [ Result] The percentage method suggested the threshold value of average extreme precipitation in Ningxia in recent 50 years decreased from south to north. The large threshold value was in southern Haiyuan, Tongxin and northern Yancheng, which was similar to the distribution of mean annual precipitation in Ningxia. In recent 50 years, extreme precipitation frequency and extreme precipitation de- creased in most part of Ningxia but the intensity tended to strengthen. Study of extreme precipitation in Mahuang Mountain and Liupan Mountain in- dicated that precipitation frequency, intensity and extreme precipitation reduced. Annual extreme precipitation frequency narrowed and then in- creased after 1994 and had mutation in 2003. Annual extreme precipitation intensity enhanced since 1984. Mutation took place in 1984. Intensity in Liupan Mountain had weakened since 1978. [ Conclusion] The study provided theoretical basis for the mutation of climate in Ningxia.
