艾滋病的传播与生殖道局部免疫

艾滋病的传播与生殖道局部免疫贲昆龙（中国科学院昆明动物研究所，昆明６５０２２３）引起人类艾滋病的人类免疫缺陷病毒（ＨＩＶ）可通过性交、血液、母婴和哺乳等方式传播，性交是主要的传播途径。据推测，全世界已感染ＨＩＶ的１，０００多万成年人当中，７５％是通过...

我国几种猕猴属动物肠道寄生虫的调查

通过尸体解剖、肉眼查找虫体和镜检虫卵三方法,从云南、四川、湖北等地产的猕猴(M. mulatta)、熊猴(M. assamensis)、豚尾猴(M. nemestrina)、红面猴(M. arctoides)和毛耳猕猴(M. mulatta lasiota)等五种猕猴属动物体内获得肠道寄生虫13种,多为人畜共患的旧种,列表给出了其分布及感染率。表1

嗜盐菌中的类视紫红质蛋白

在嗜盐菌中发现了4种含视黄醛的膜蛋白: 细菌视紫红质、氯视紫红质、感觉视紫红质-I(M 慢视紫红质)和感觉视紫红质-Ⅱ(憎光视紫红质)。文中着重介绍了上述4中膜蛋白的结构、 功能及其相似性等方面的研究进展。图6参20

主分量分析(PCA)在动物分类学中的运用

就主量分析(PCA)的基本原理、 运用发展过程及在动物分类学上的应用作了 阐明。并以亚洲疣猴类5个属为例, 利用其面颅和颅骨的6项变量进行分析, 且 叙述了PCA的主要计算过程。 结果表明, 在分类过程中, 主要是面颅的凸度和宽 度结构起贡献作用。图5参21

湖南尖吻吻蝮蛇毒两个出血毒素的纯化和理化性质

经Sephadex G-75凝胶过滤, QAE-Sephadex A-50和CM-Sephadex C-25离子交换层析, 从尖吻蝮蛇毒中纯化出两个出血毒素(DaHT-1和DaHT-2)。SDS-PAGE测得分子量均为23.5kD,IEF-PAGE测得等电点分别为5.6和5.2, DaHT-1和DaHT-2的最小出血剂量分别为0.5#mu#g和0.8#mu#g。都具蛋白水解酶活性, DaHT-1和DaHT-2的最适温度分别为35℃和40℃, 最 适pH为6-9, 对热均不稳定, 温度高于60℃活性完全丧失。图7表1参13

The reproductive strategies of an endemic Tibetan fish, Gymnocypris selincuoensis

The reproductive traits of Gymnocypris selincuoensis from Selincuo Lake and its tributaries were investigated in 1997 and 1998. The youngest mature male was age 7 with a standard length (SL) of 172.0 mm, and the youngest mature female was age 8 with a SL of 194.0 mm. The L(50)s Of SL and age at first maturity were respectively 250.32 mm and age 9 for males and 224.71 mm and age 8 for females. The gonadosomatic index (GSI) significantly changed with seasons for mature individuals but not for immature individuals. GSIs of mature females at stages IV and V of ovary development increased with SL and reached a maximum value at the SL range from 370 mm to 390 mm; the GSIs of mature males were negatively correlated with SL. The breeding season lasted from early April to early August. Egg size did not significantly change with SL but increased with the delay of spawning. The individual absolute fecundity varied from 1,341 to 28,002 eggs (mean 12,607+/-7,349), and the individual relative fecundity varied from 6.4 to 42.0 eggs.g(-1) (mean 25.5+/-9.7). The individual fecundity increased with total body weight; it also increased with SL for those of SL less than 370 mm. There was a rest of spawning for mature individuals.

Closing the gap: Improved bounds on optimal POMDP solutions

POMDP algorithms have made significant progress in recent years by allowing practitioners to find good solutions to increasingly large problems. Most approaches (including point-based and policy iteration techniques) operate by refining a lower bound of the optimal value function. Several approaches (e.g., HSVI2, SARSOP, grid-based approaches and online forward search) also refine an upper bound. However, approximating the optimal value function by an upper bound is computationally expensive and therefore tightness is often sacrificed to improve efficiency (e.g., sawtooth approximation). In this paper, we describe a new approach to efficiently compute tighter bounds by i) conducting a prioritized breadth first search over the reachable beliefs, ii) propagating upper bound improvements with an augmented POMDP and iii) using exact linear programming (instead of the sawtooth approximation) for upper bound interpolation. As a result, we can represent the bounds more compactly and significantly reduce the gap between upper and lower bounds on several benchmark problems. Copyright © 2011, Association for the Advancement of Artificial Intelligence. All rights reserved.