Isolation and characterization of 18 polymorphic microsatellite markers in Chinese mandarin fish Siniperca chuatsi (Basilewsky)

Eighteen microsatellite markers were isolated and characterized using an enrichment protocol in the Chinese mandarin fish Siniperca chuatsi (Basilewsky), a commercially important piscivorous fish in China. Out of 48 pairs of primers designed, 18 loci exhibited polymorphism with three to six alleles (mean 4.4 alleles/locus) and average observed heterozygosity ranged from 0.633 to 0.833 (mean 0.748) in a test population from Dongting Lake of China. Except for two loci, all other 16 loci were in the Hardy-Weinberg equilibrium. These markers would be useful for such studies as population genetics, ecology and selective breeding of the Chinese mandarin fish in future.

18 Gchips/s electronically-processed OCDMA spread spectrum for access networks

We demonstrate for the first time coding/decoding for OCDMA networks using electronic transversal filters at 18Gchips/s-a ten-fold improvement over previous demonstrations. The chip rate allows users at Gb/s rates in access applications. © 2007 Optical Society of America.

Characterization and phylogenetic analysis of the chitinase gene from the Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus

A putative chitinase gene was identified within the fragment EcoRI-K of the Helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (HearNPV, also called HaSNPIV) genome. The open reading frame (ORF) contains 1713 nucleotides (nt) and encodes a protein of 570 amino acids (aa) with a predicted molecular weight of 63.6 kDa. Transcription started at about 18 h post infection (p.i.) and the protein was first detected at 20 h p.i. The times of transcription and expression are characteristic of a late baculovirus gene. 5' and 3' RACE indicated that transcription was initiated from the adenine residue located at -246 nt upstream from the ATG start site and the poly (A) tail was added at 267 nt downstream from the stop codon. This is the first report on the molecular characterization of a chitinase from a single nucleocapsid NPV. The phylogeny of baculoviral chitinase genes were extensively examined in comparison with chitinases derived from bacteria, fungi, nematode, actinomycetes, viruses, insects and mammals. Neighbor-joining and most parsimony analyses showed that the baculoviral chitinases were clustered exclusively within gamma-proteobacteria. Our results strongly suggest that baculoviruses acquired their chitinase genes from bacteria. (C) 2004 Elsevier B.V. All rights reserved.

黄土区人工与天然植被对凋落物量和土壤有机碳变化的影响

在黄土丘陵区选择从耕地、草地、灌木林到乔木林样地,不同样地内设立1m×1m(乔木10m×10m)的样方,分析样方内凋落物积累量、碳氮含量、土壤有机碳(SOC)和可溶性碳(DOC)含量变化。结果表明:天然草地、灌木林、乔木林凋落物积累量依次为5.3,12.1和32.4t.hm-2;但人工灌木林和乔木林的凋落物积累量分别为6.7和11.4t.hm-2,分别是天然灌木林和乔木林的1/2和1/3。随着植被的恢复,天然植被凋落物的C/N高于人工植被(刺槐林除外)。与耕地SOC(4.67g·kg-1)相比,天然灌木林地SOC提高5.9倍,人工灌木林地提高1.8倍;天然乔木林地提高8.0倍,而人工乔木林地仅提高4.0倍。凋落物积累量与0～20cm土层土壤有机碳存在显著线性相关关系(R2>0.83),但20cm以下线性相关关系不显著。凋落物积累量与0～10cm土壤可溶性碳含量存在显著线性相关关系(R2>0.893),与10～60cm土层线性相关关系不显著,与80～100cm土壤可溶性碳存在显著线性负相关关系。

1×8阵列波导光栅型波分复用/解复用器设计的一种简单方法

用有效折射率法，采用近轴近似和波导模场分布的高斯近似，简化了阵列波导光栅(AWG)器件的设计过程中繁杂的计算，且保证了器件的性能指标。给出了设计思路，并给出了1×8路、中心波长为1550.9nm，波长间隔为1.6nm的AWG波分复用/解复用器的设计实例。

Optim ization of a 1×8 Arrayed-Waveguide Grating Multi/Dem ultiplexer

于2010-11-23批量导入