Vertebrate-type intron-rich genes in the marine annelid Platynereis dumerilii

Previous genome comparisons have suggested that one important trend in vertebrate evolution has been a sharp rise in intron abundance. By using genomic data and expressed sequence tags from the marine annelid Platynereis dumerilii, we provide direct evidence that about two-thirds of human introns predate the bilaterian radiation but were lost from insect and nematode genomes to a large extent. A comparison of coding exon sequences confirms the ancestral nature of Platynereis and human genes. Thus, the urbilaterian ancestor had complex, intron-rich genes that have been retained in Platynereis and human.     

视觉

善男信女2010年1月3日,俄罗斯选手莎拉波娃参加曼谷华欣网球表演赛之余抽空拜佛,美少女下跪许愿虔诚之至。不过似乎莎娃并没有为自己祈得好运,在新赛季第一个大满贯澳大利亚网球公开赛首轮即遭同胞基里连科淘汰。     

Osedax: bone-eating marine worms with dwarf males

We describe a new genus, Osedax, and two new species of annelids with females that consume the bones of dead whales via ramifying roots. Molecular and morphological evidence revealed that Osedax belongs to the Siboglinidae, which includes pogonophoran and vestimentiferan worms from deep-sea vents, seeps, and anoxic basins. Osedax has skewed sex ratios with numerous dwarf (paedomorphic) males that live in the tubes of females. DNA sequences reveal that the two Osedax species diverged about 42 million years ago and currently maintain large populations ranging from 10(5) to 10(6) adult females.     

无公害蔬菜病虫害综合防治技术

为充分贯彻"预防为主,综合防治"的植保方针,增强蔬菜植株自身抗病虫能力,控制病虫害的发生,提高蔬菜安全水平和市场竞争力,达到经济、安全、高效的目的,针对我区实际,特提出以下综合防治措施.     

Pattern Vision in Newborn Infants

Human infants under 5 days of age consistently looked more at black-and-white patterns than at plain colored surfaces, which indicates the innate ability to perceive form.     

Recent Advances in Color Vision

Until a few years ago it was possible to account for nearly all the aspects of human color perception on the basis of the three-color theory, but such is no longer the case. This is largely due to improvements in the older methods of investigation and to the invention of new ones. Among the latter may be mentioned the microelectrode technique of Granit and the retinal direction effect of Stiles and Crawford. Modern requirements are met by a polychromatic theory, comprising 7 types of receptor, but there is no necessity for these to have such narrow spectral response curves as those exhibited by Granit's modulators. Modifications of the three- and four-color theories have been examined to see to what extent they can be made to fit in with experimental results. Particular notice has been taken of the possibility that there is polychromatism of the retinal receptors, but trichromatism of the nerve paths which connect these to the brain or even of the brain itself. The conclusion arrived at is that there must be polychromatism throughout the entire visual mechanism for color perception if a complete account is to be given of all the known facts.     

虫克星对黑熊消化道寄生虫的驱虫试验

１９９４年１月份和６月份，对延边两家养熊场３８只熊进行消化道寄生虫区系普查，并在此基础上用虫克星和盐酸左咪唑进行了对比驱虫试验。结果，两种药物使犬蛔虫、犬钩虫和类圆线虫的虫卵减少率、转阴率均达到１００％，但虫克星组的排虫时间显著长于盐酸左旋咪唑组。     

Vision and development in Trichoderma atroviride

Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to conidiate upon exposure to light. In total darkness, T. atroviride grows indefinitely as a mycelium provided that nutrients are not limiting. However, nutrient deprivation and light trigger the conidiation process. A pulse of blue light given to a radially growing colony induc…