艾滋病病毒通过性接触、体液和母婴传播,那第一个艾滋病患者是如何感染的?

<正>A:现在比较认可的观点是,人类免疫缺陷病毒HIV(Human Immunodeficiency Virus)起源于感染非洲狒狒(chimpanzee)和黑猩狸(gorillas)的类人猿免疫缺陷病毒SIV(Simian Immunodeficiency Virus)。SIV最初只在非人灵长类之间传播,到了20世纪,SIV侵入到人体并且发生基因突变和重组,成为HIV。     

科学家首次绘制出倭黑猩猩基因图谱

倭黑猩猩和人类、黑猩猩拥有共同的祖先,而今一个由德国马普研究所科学家领导的小组,首次绘制出一只名为乌林迪的18岁雌性倭黑猩猩的基因图谱,这是人类绘制出的第5种类人猿物种基因图谱。它收集到的数据将有助于解释为什么倭黑猩猩与黑猩猩之间会有非常明显的行为差异。并帮助科学家们找出让人类与各种猩猩区分开来的遗传变异。     

新书

《权谋——诺贝尔科学奖的幕后》；《物理定律的本性》；《类人猿和寿司大师》。     

成功的期限

海獭（tǎ）属于鼬科动物，它们生活在阿留申群岛周围的海域中，智能在某些方面超过了类人猿。比如在摘食海胆时，它们同时也会从水底捞起一块石头，然后平躺在水面，将石头故在肚皮上，用两只前爪抓住海胆用力地往石块上砸，直至将海胆坚硬的壳砸破，最后便可队享受鲜美的海胆肉了。[第一段]     

Rock magnetic studies on the hominoid-bearing sediments at Zhupeng, Yuanmou Basin, southwestern China and its paleoclimatic significance

It has been proposed that paleoclimatic changes and tectonic events strongly affect hominoid evolution. The Zhupeng section at Yuanmou Basin, southwestern China, with the hominoid-bearing fluvial-lacustrine sediments, is an ideal natural laboratory to test this hypothesis. This study provided an integrated magnetic study, including low-frequency susceptibility, the anisotropy of magnetic susceptibility, temperature-dependent susceptibility, hysteresis loops, isothermal remanent magnetization, and anhysteretic remanent magnetization, on samples from the Baozidongqing section at Zhupeng. Results show that the dominant mag- netic carrier is hematite, with minor amount of magnetite. Both the composition and concentration of magnetic miner- als strongly correlate with the lithostratigraphy. At least eight short-term events defined by higher concentrations of magnetite were identified. These short events reflect that the subtropical dry-hot climate is similar to today＇s climate. Basing on the lithostratigraphic and rock magnetic results, we suggest that Yuanmou Basin was in a steady deposition environment from about 11 to 7 Ma, which is characterized by alternating of long-term torrid-humid climate and short-term dry-hot climate. Our study provides invaluable environment information for understanding the climate shift and the relationship between paleoenvironment and hominoid evolution in southwestern China during late Miocene.     

Q＆A

Q：艾滋病病毒通过性接触、体液和母婴传播,那第一个艾滋病患者是如何感染的？ A：现在比较认可的观点是,人类免疫缺陷病毒HIV（Human Immunodeficiency Virus）起源于感染非洲狒狒（chimpanzee）和黑猩猩（gorillas）的类人猿免疫缺陷病毒SIV（Simian Immunodeficiency Virus）。