Simian immunodeficiency virus (SIV) is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates.

给定一个预层，我们总可以构造一个层，即预层的层化 (sheafification). 令 S\stackrel {p} {\rightarrow}X 是满的连续映射，并且具有一个连续的横截 (section) X\stackrel {s_0} {\rightarrow}S 使得 p\circ s_0=id_X. 定义 (Set_*) 类型的范畴 \Gamma (U,S/X):= (\ {all\ continuous\ section\ X\stackrel {s} {\rightarrow}S\},\ s_0|_U) . 在规范理论 中，选择一个横截相当于选定一个规范，因此此集合可以看成是所有规范的集合。

Simian immunodeficiency viruses (SIV) are members of the Lentivirus genus of Retroviruses that infect nonhuman primates such as monkeys, chimpanzees, and gorillas. For the most part, these SIVs are either nonpathogenic or result in slow progression to a debilitating immunodeficiency or …

他先在一种允许有奇点的Stein复流形上引入了十分重要的coherence sheaf的概念(它可以看成是纤维丛的某种模拟)，凝聚层的上同调群具有十分良好的性质。 接着塞尔又看出层论也可以用在比Stein流形更特殊的复代数簇上，于是他就立即系统地将层论大规模运用到了 ...

定义2'层(Sheaf) 设 X,\mathcal F 是拓扑空间, \pi:\mathcal F\rightarrow X 满足. 1) \pi 是满射. 2) \pi 是局部同胚，即任何一点( X 的点或 \mathcal F 的点),均存在它的一个开邻域和它的像点(或某个原象点)的开邻域， \pi 是这两个开邻域的同胚

Simian immunodeficiency viruses (SIVs) are primate lentiviruses that infect no fewer than 36 different nonhuman primate species in sub-Saharan Africa (4, 9, 62).

Simian immunodeficiency viruses (SIV) are a group of genetically related viruses belonging to the lentivirus subgroup of retroviruses. The natural hosts of SIV include many species of African monkeys and the chimpanzee (Pan troglodytes) (Gardner et al., 1994; Peeters et al., 2002).

2010年8月24日 · Sequencing the capsid region of “escaped” viruses showed novel mutations in the amino acid sequence of macaque-adapted, TRIM5-resistant SIV that are not present in sooty mangabey-adapted SIV.

2024年8月3日 · Explore the structure, transmission, and evolution of Simian Immunodeficiency Virus and its impact on host immune response and current research. Originating in primate populations, Simian Immunodeficiency Virus (SIV) has had profound implications for both animal and human health.

2014年3月19日 · Here, we review current knowledge about the genetic diversity, molecular epidemiology, prevalence, and pathogenicity of simian immunodeficiency viruses (SIVs). SIVs have crossed species boundaries from simian hosts to humans on at least 12 separate occasions, one of which led to the global HIV–AIDS crisis.