Evolutionary origins of members of a superfamily of integral membrane cytochrome c biogenesis proteins

We have analyzed the relationships of homologues of the Escherichia coli CcmC protein for probable topological features and evolutionary relationships. We present bioinformatic evidence suggesting that the integral membrane proteins CcmC (E. coli; cytochrome c biogenesis System I), CcmF (E. coli; cytochrome c biogenesis System I) and ResC (Bacillus subtilis; cytochrome c biogenesis System II) are all related. Though the molecular functions of these proteins have not been fully described, they appear to be involved in the provision of heme to c-type cytochromes, and so we have named them the putative Heme Handling Protein (HHP) family (TC #9.B.14). Members of this family exhibit 6, 8, 10, 11, 13 or 15 putative transmembrane segments (TMSs). We show that intragenic triplication of a 2 TMS element gave rise to a protein with a 6 TMS topology, exemplified by CcmC. This basic 6 TMS unit then gave rise to two distinct types of proteins with 8 TMSs, exemplified by ResC and the archaeal CcmC, and these further underwent fusional or insertional events yielding proteins with 10, 11 and 13 TMSs (ResC homologues) as well as 15 TMSs (CcmF homologues). Specific evolutionary pathways taken are proposed. This work provides the first evidence for the pathway of appearance of distantly related proteins required for post-translational maturation of c-type cytochromes in bacteria, plants, protozoans and archaea.     

The use of an unoccupied aerial vehicle to survey shark species over sand and rocky-reef habitats in a marine protected area

Cabo Pulmo National Park was established in 1995 and has since seen a large increase in fish biomass. An unoccupied aerial vehicle (UAV) was used to survey shallow coastal habitat in which lemon sharks (Negaprion brevirostris), bull sharks (Carcharhinus leucas) and Pacific nurse sharks (Ginglymostoma unami) were recorded. Sharks were more common in the afternoon, potentially using warmer shallow areas to behaviourally thermoregulate. This study highlights UAV surveying to be a viable tool for species identification, a limitation of previous terrestrial surveys conducted in the area.     

中国2种归化植物新记录

报道了发现于辽宁省的2种中国归化植物新记录:白毛马鞭草(Verbena stricta Vent.)和向日葵(Helianthus annuus L.),白毛马鞭草穗状花序粗壮而紧凑,单生枝顶或呈简单的聚伞状或圆锥状排列,且花序轴在果期显著延长,叶卵圆形,无柄,与中国有报道的本属其他物种区别明显。该种原产美国西部至中部地区,近来在辽宁省铁岭市发现有归化。向日葵原产于北美地区,被发现广泛归化于辽宁省大连市,营口市鲅鱼圈也有发现。归化种群形态特征与该地区栽培类型完全不同,其花序极多分枝,头状花序直径较小,瘦果极小,表面纹饰多样性很高。     

Maternal-Fetal Distribution of Calcium,Iron, Copper,and Zinc in Pregnant Teenagers and Adults

Adolescence is marked by intensive growth and development. When pregnancy occurs during this period of the mother’s growth, there is an increase in her nutritional needs. The aim of this study was to determine the levels of calcium, iron, copper, and zinc in maternal plasma, the placenta, and in the cord plasma of pregnant teenagers and adults. A total of 80 sets of maternal plasma, placentas, and cord plasma (40 from teenagers and 40 from adults) were analyzed using synchrotron radiation total reflection X-ray fluorescence. The levels of calcium, copper, and zinc in the maternal and cord plasma from teenagers were not significantly different than those from adults. Iron levels in the teenagers maternal and cord plasma were higher than in the adults. All of the minerals analyzed were present at higher levels in the placentas from adults than those from teenagers. However, the low quantities of placental calcium, iron, copper, and zinc in the teenagers do not compromise the levels of these minerals in the cord plasma. Future research regarding the placental transport of these minerals is recommended to investigate the efficiency of mechanisms of transfer of these minerals in pregnant teenagers.     

Preliminary studies on leaf beetle, Galeruca daurica on grassland

沙葱萤叶甲Galeruca daurica Joannis是近年来严重危害葱属(AUium)植物建群草场的重要食叶害虫.该虫在内蒙古地区一年发生1代,以卵越冬.本文介绍了该虫生活史、生活习性、发生范围、发生面积、危害症状、生境特征、危害损失,并提出了防治策略.     

Reinstatement of short-latency responses after asymptotic Pavlovian conditioning training by the presentation of an extraneous stimulus

The purpose of this study was to examine whether the progressive disappearance of short-latency conditioned responses, or inhibition of delay, observed in Pavlovian conditioning with long inter-stimulus intervals, could be reverted by the presentation of a novel stimulus. In one experiment, two groups of rabbits received extensive training with a short (250 ms) or a long (1500 ms) tone that overlapped and terminated with a periorbital shock unconditioned stimulus. After training, the presentation of an extraneous stimulus prior to tone onset produced a reinstatement of short latency CRs in the group trained with the long CS, but did not affect CR latency in the group trained with the short CS. This finding is consistent with Pavlov's (1927) view that conditioning with long conditioned stimuli involves the acquisition of response tendencies in the early portion of the stimulus that are subsequently suppressed by the development of an inhibitory process.     

蚜虫不同分类阶元之间遗传距离的RAPD-PCR研究(英文)

应用RAPD PCR技术研究了蚜虫不同分类阶元的遗传距离。从 2 0种随机引物中筛选出 7种引物 ,并用它们的扩增结果进行Nei’s的遗传距离的计算和聚类分析。结果表明 :蚜虫的遗传距离在不同科之间为 0 .56 6 3± 0 .0 6 89,亚科之间为 0 .4 586± 0 .0 2 142 ,属之间为 0 .3816± 0 .0 375,种之间为 0 .2 975±0 0 6 2 7,同一种的不同种群之间为 0 .0 4 33± 0 .0 2 2 2。同时 ,本研究结果为在DNA水平上研究蚜虫的分化和种的鉴定 ,尤其是对于近缘种的鉴定具有重要的价值。     

Evaluation of the effectiveness of the FWS-DBL-1 solar insect killer and its safety with respect to predatory insects in the Turpan grape growing region

本文研究了FWS-DBL-1新型太阳能灭虫器在320～580、360、400、460和520nm 5种不同波长下对吐鲁番葡萄产区害虫的诱捕效果及对天敌安全性.结果表明:在5种波长下,灭虫器诱捕昆虫的种类相似,以鞘翅目、鳞翅目、半翅目、脉翅目、双翅目、直翅目和膜翅目等为主.诱捕的主要昆虫是蜉金龟Aphodius sp.、白云斑鳃金龟Polyphyyla alba vicaria Semenov、额喙丽金龟Adoretus nigriforns Steven、毛喙丽金龟Adoretus hirsutus Ohaus、绣罗夜蛾Leucanitis picta Christoph和淘赏夜蛾Catocala puerpera Gioma等.其中:灭虫器在400nm波长下的诱捕量最多,其次是320～580nm和360nm波长.综合分析比较:400nm波长对鞘翅目害虫的诱捕效果最好,360nm波长对鳞翅目和双翅目害虫的诱捕能力最强,520nm波长对半翅目害虫的诱捕效果最好.对天敌的安全性研究表明:FWS-DBL-1太阳能灭虫器对天敌有一定的诱捕作用,益害比为1:4～1:5.诱捕量较多的是步甲科和草蛉科的天敌,占天敌总诱捕量的85.82％.在这5个波长中,360nm波长下,灭虫器对天敌的诱捕作用最小,对天敌的安全性相对较高.