Evaluating the reliability of microsatellite genotyping from low-quality DNA templates with a polynomial distribution model

Molecular studies using trace DNA, such as from museum specimens, ancient or forensic samples and samples obtained noninvasively, often have a common problem of low quality of DNA templates. Amplification errors, such as allelic dropout and false allele, may arise during polymerase chain reaction (PCR) using such samples. A mathematical model which treats homozygotes and heterozygotes discriminately has been developed to measure sample quality and compute the confidence level of using multipletube approaches. We use plucked hair samples collected from 26 individual Sichuan snub-nosed monkeys (Rhinopithecus roxel- lana) to test the model. In this case, a confidence level of 99% can be achieved by three positive PCRs. If the sample quality is very poor and requires many PCR replicates, an alternative multiplestep genotyping method is recommended. This model enables researchers to optimize experimental protocols through pilot studies and obtain reliable genetic information using noninvasive sampling method.     

Propagation of planetary-scale zonal mean wind anomalies and polar oscillations

Global atmospheric variables can be physically decomposed into four components:(1) the zonal time averaged climate symmetric component,(2) the time averaged climate asymmetric,(3) the zonal-mean transient symmetric anomaly,and (4) the transient asymmetric anomaly.This study analyzes the relationships between the intra-seasonal and inter-annual variability of planetary scale decomposed zonal and meridional winds in the tropopause,and oscillations such as those from the El Ni o-Southern Oscillation (ENSO),the Arctic Oscillation (AO) and the Antarctic Oscillation (AAO).The tropical inter-annual zonal mean wind anomalies in the tropopause are linked with the ENSO cycle and can propagate into the subtropics,mid-latitudes,and polar front regions via abnormal meridional vertical cells.Similarly,tropical intra-seasonal (40-60-d) zonal wind anomalies can reach the subtropics and mid-latitudes.The polar intra-seasonal zonal wind anomalies in the tropopause can propagate toward high-latitude areas.Thus,the AO and the AAO are the result of the interaction and propagation of these planetary scale zonal wind anomalies.     

Novel protein detection method based on proximity-dependent polymerase reaction and aptamers

In recent years, specific detection of proteins is one of the hot issues about aptamers in proteomics. Here we reported a simple, sensitive and specific proximity-dependent protein assay with dual DNA aptamers. Thrombin was used as the model protein, and two aptamer probes with complementary sequence at 3′-end were designed for the two distinct epitopes of the protein. Association of the two aptamers with thrombin resulted in stable hybrids due to the proximity of 3′-end, then polymerase reaction was induced. The amount of obtained dsDNA was indicated using the fluorescence dye Sybr Green I. The results showed that the initial velocity of polymerase reaction had a positive correlation with concentration of thrombin. The advantages of this dual-aptamer-based approach included simple and flexible design of aptamer probes, high selectivity and high sensitivity. The detection limit was 6.9 pmol/L.     

mRNA detection in living cell using phosphorothioate-modified molecular beacon

In this study, GFP mRNA in COS-7 cell and GFP-transfected COS-7 cell was detected in real time using phosphorothioate-modified molecular beacon based on living cell imaging method. Results showed that phosphorothioate-modified molecular beacon still kept the advantages of molecular beacon, such as, excellent selectivity, high sensitivity, and no separation detection. In addition, this modification could significantly increase the nuclease resistance of molecular beacon. Phosphorothioate-modified molecular beacon can efficiently reduce the false positive signal and improve the accuracy of living cell mRNA detection. Supported by the National Key Basic Research Program (Grant No. 2002CB513110), International Technologies Collaboration Program of China (Grant No. 2003DF000039), and National Natural Science Foundation of China (Grant Nos. 90606003 and 20620120107)     

基于NSGA-Ⅱ的二氧化碳氢化反应热力学多目标优化

二氧化碳氢化合成低碳烯烃反应是化学储能技术路径中重要的单元反应,二氧化碳首先与由可再生能源获得的氢气进行化学反应合成低碳烯烃,随后通过齐聚反应将能量储存到清洁燃料中。以二氧化碳氢化合成低碳烯烃反应为研究对象,使用Gibbs自由能最小化方法进行了平衡热力学分析,得到反应温度、反应压力、进料气H₂与CO₂的物质的量比对CO₂平衡转化率、低碳烯烃选择性及平衡组分的影响;基于统计学理论建立了反应参数对CO₂平衡转化率、低碳烯烃选择性和反应系统中H₂O平衡摩尔分数的回归函数模型;最后采用基于快速非支配排序遗传算法（NSGA-Ⅱ）的多目标优化方法对反应系统性能进行多目标优化。结果表明：从提高反应系统性能和降低催化剂水解失效风险角度进行的多目标优化与CO₂平衡转化率最大的单目标优化相比,H₂O的平衡摩尔分数从47.2%减少到24.9%;与低碳烯烃选择性最大的单目标优化相比,H₂O的平衡摩尔分数从51.1%减少到18.7%;与H₂O平衡摩尔分数最小的单目标优化相比,CO₂平衡转化率和低碳烯烃选择性从64.9%和8.7%分别提高到72.9%和58.6%。     

Dominance rank of adult females and mating competition in Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains, China

Dominance hierarchy reflects resource competition in male primates as well as females.In this study,we collected data on the social rank and mating competition of female Sichuan snub-nosed monkeys from September 2009 to June 2010 in the Qinling Mountains,Shaanxi,China.Displacement was used to determine social hierarchy of the studied wild females.A total of 1223 displacement bouts between adult females and 316 mating behaviors within one-male units(OMUs) were recorded.Competitive displacement among females was very low(0.22 displacements per observation hour).The dominant ranks of females in target OMUs were determined by displacement,from one OMU to another:JB unit:YL > DBC > YCM >XBC > BD;JZT unit:XHW > JG > DT;PK unit:QQ > TM > HF;LP unit:SK > TH > WM.Higher-ranking females performed significantly more sexual behavior than lower-ranking females in this rare monkey.High-ranking females were more likely to win mating contests within those OMUs.Based on these studies,we assessed the social relationships among adult females and clarified possible explanations for the strategies of female mating competition in the OMUs.Furthermore,the notion that reproductive success may also be related to female dominance hierarchies in this polygynous species should be considered in future research.     

Reconstructed index of summer monsoon dry-wet modes in East Asia for the last millennium

Monthly precipitation datasets collected at 160 stations in China as well as the monthly winds and humidity data derived from the US National Centers for Environmental Prediction (NCEP) were used to construct the relationship between six summer dry-wet modes in eastern China and the summer monsoon airflow northward advance in East Asia. A millennial series of the monsoon dry-wet index (MDWI) was reconstructed based on Wang’s six summer dry-wet modes in eastern China since 950 AD. A high (low) index indicate...     

Ultrasensitive monitoring of ribozyme cleavage product using molecular-beacon-ligation system

This paper reports a new approach to detect ribozyme cleavage product based on the molecular-beacon-ligation system. The molecular beacon, designed in such a way that one-half of its loop is complementary to ribozyme cleavage product, is used to monitor ligation process of RNA/DNA com-plex in a homogeneous solution and to convert directly cleavage product information into fluorescence signal. The method need not label ribozyme and ribozyme substrate, which is fast, simple and ultra-sensitive for detection of cleavage product. Detection limit of the assay is 0.05 nmol/L. The cleavage product of hammerhead ribozyme against hepatitis C virus RNA (HCV-RNA) was detected perfectly based on this assay. Owing to its ultrasensitivity, excellent specificity, convenience and fidelity, this method might hold out great promise in ribozyme reaction and ribozyme gene therapy.     

多层电路板的深层充电研究

以欧空局的FLUMIC2模型为输入电子能谱,基于Monte Carlo方法和辐射诱导电导率模型进行多层电路板充电分析,可模拟地球同步轨道上有2 mm铝层屏蔽时的多层FR4印刷电路板的深层充电过程,得到电场和电势随介质深度的变化.研究发现与双面接地电路板相比较,电路板四层铺铜接地内部最大充电电场减少54%,有效地减小介质内部电场,降低深层放电风险.充电时间常数和电介质的物理特性有关而与电路板分层情况无关.分析各接地层的电流,两层电路板为90~150 p A m?2,四层电路板为10~100 p A m?2.