基于Landsat的重庆市生态环境质量动态监测及其时空格局演变分析

长江流域是我国重要的生态屏障之一,重庆市作为长江上游最后一道关口,研究其生态质量发展对于有效保护长江流域生态环境具有重要指导意义。基于2011—2021年间的Landsat影像等数据,计算遥感生态指数(Remote sensing based ecological index, RSEI),并采用Sen(Theil-Sen median)趋势分析法和MK(Mann-Kendall)检验研究其变化趋势以及利用Hurst指数模型分析RSEI的持续特征。利用空间转移矩阵和重心迁移模型研究其在空间上分布特征的变化情况,最后使用降水、风速、近地表气温、海拔等辅助数据为影响因素,结合地理探测器进一步探究RSEI变化驱动力,探讨重庆市2011—2021的RSEI空间分布及演变趋势。结果表明：(1)重庆市多年平均RSEI为0.593,使用等间距法将其划分的等级为差、较差、中等、良、优的面积占比分别为2.48%、8.28%、38.32%、41,87%、9.05%。从整体来看重庆市生态质量水平较高,重庆市年际RSEI以显著趋势波动增长。(2)RSEI等级为差的地区空间上主要集中于重庆西部;较差等级主要围绕...     

成人革兰阴性杆菌肺炎23例临床分析

本文以临床体征,胸片和连续二次以上细菌培养阳性为诊断标准,报告革兰阴性杆菌肺炎２３例,并就其临床表现,并发症及预后进行分析,提出８种情况应考虑革兰阴性杆菌肺炎,对临床诊断和治疗有指导意义．     

梨果黑斑病菌AaCaMK基因克隆、生物信息学分析及其在侵染结构分化中的表达分析

[背景] 钙/钙调素依赖型蛋白激酶（Calcium/Calmodulin-Dependent Protein Kinase,CaMK）是真核生物细胞钙信号途径中钙调素下游的一类重要靶蛋白,对病原物生长、胁迫响应及致病性等具有重要的调控作用。[目的] 对梨果黑斑病菌互隔交链孢（Alternaria alternata）AaCaMK基因进行克隆、生物信息学分析,并对其在侵染结构分化过程中的基因表达情况进行分析,为进一步研究梨果黑斑病菌钙离子信号途径中AaCaMK对A.alternata侵染结构分化调控的分子机制提供一定的理论依据。[方法] 采用同源克隆法从A. alternata JT-03中克隆得到3个AaCaMK基因;通过TMHMM、ProtScale、SOPMA等软件对AaCaMK基因进行生物信息学分析;利用实时荧光定量PCR （RT-qPCR）技术分析AaCaMK在梨果黑斑病菌侵染结构分化过程中的表达情况。[结果] 克隆得到片段分别为1 212、1 200、2 349 bp的AaCaMK1、AaCaMK2和AaCaMK3基因;生物信息学分析表明,AaCaMK1、AaCaMK2和AaCaMK3均含有典型的蛋白激酶超家族催化结构域（PKC_Like Superfamily）,并且AaCaMK1和AaCaMK2共同含有CaMK类丝/苏氨酸蛋白激酶催化结构域（STKc_CaMK）,AaCaMK3含有LKB1/CaMKK类丝/苏氨酸蛋白激酶催化结构域（STKc_LKB1_CaMKK）;同源性分析表明,AaCaMK1、AaCaMK2和AaCaMK3分别与玉米大斑病菌CAK1、CAK2和CAK3的相似性高达94.32%、97.49%和86.57%;RT-qPCR分析表明,AaCaMK1、AaCaMK2和AaCaMK3在疏水及果蜡诱导A. alternata侵染结构分化过程中均显著上调表达（P<0.05）,而且果蜡诱导作用更显著。其中AaCaMK1和AaCaMK2在附着胞形成时期（6 h）表达量为对照的1.51倍和3.05倍,而AaCaMK3在侵染菌丝形成阶段（8 h）表达量最高,为对照的2.86倍,并且在果蜡诱导下,这3个基因在芽管伸长阶段（4 h）的上调表达量显著高于疏水界面。[结论] 钙信号中AaCaMK基因在疏水及果蜡诱导A.alternata侵染结构分化过程中发挥重要的调控作用。     

海南地区与环渤海湾美人鱼发光杆菌美人鱼亚种水产动物分离株的表型与遗传特征分析

美人鱼发光杆菌美人鱼亚种（Photobacterium damselae subsp.damselae,PDD）是一种广泛分布于海洋环境内的重要病原菌,可导致多种海洋生物患病死亡,近年来在我国不同养殖区域内均有发现和报道。[目的] 通过生理代谢表型、毒力基因分布和分子遗传分析,系统比较我国海南地区和环渤海湾不同株系PDD的表型与遗传多样性特征。[方法] 使用选择性培养基测定PDD的蔗糖发酵能力、运动性、溶血性和磷脂酶活性;通过PCR检测质粒pPHDD1复制起始点基因pPHDD1 replication origin和毒力基因dly,hlyA_pl,hlyA_ch,plpV;基于toxR基因序列构建系统发育树,分析16株PDD的遗传关系。[结果] 4株PDD蔗糖发酵测试呈阳性,12株PDD蔗糖发酵测试呈阴性。不同株系PDD运动能力存在显著差异,其中环渤海湾分离株Pdd1608、Pdd2009和Pdd1704的运动能力较强。仅有环渤海湾分离株Pdd1608表现为强溶血性、强磷脂酶活性;海南地区分离株Pdd1612和Pdd0912表现为弱溶血性、无磷脂酶活性;其余菌株表现为弱溶血性、弱磷脂酶活性。菌株Pdd1608的毒力基因谱为pPHDD1 replication origin-dly-hlyA_p-hlyA_ch-plpV,其余菌株的毒力基因谱为hlyA_ch-plpV。系统发育分析揭示不同株系PDD具有高度的遗传多样性。[结论] 流行于海南地区和环渤海湾的PDD可能都由多克隆种群组成,它们具有复杂的表型特征、相似的毒力基因分布和高度的遗传多样性。     

华南杂交稻亲本间产量配合力评价与分子标记鉴定

选用华南地区广泛应用的8个杂交稻不育系与10个恢复系,按NCII设计配制两套不完全双列杂交组合61个,通过在湛江的两年种植试验,结合62对与产量性状QTL连锁SSR标记,对18个亲本的产量配合力进行综合评价和标记位点鉴定。结果表明：供试亲本间一般配合力存在较大差异,其中不育系珍汕97A、万金A和恢复系直龙、广恢3550的一般配合力相对较高;两套组合共检测出36个与亲本产量配合力显著相关的标记位点,其中RM1、RM216、RM231和RM542为两套材料所共有;检测出的杂合标记位点中,23个为增效标记位点,13个为减效标记位点,其中杂合标记位点RM231、RM209可使F1的单株粒重增加13.50 %和16.43 %。该结果可为华南地区杂交稻育种的亲本改良及选配提供了理论指导。     

Family Income Affects Children’s Altruistic Behavior in the Dictator Game

This study aimed to examine how family income and social distance influence young rural Chinese children’s altruistic behavior in the dictator game (DG). A total of 469 four-year-old children from eight rural areas in China, including many children left behind by parents who had migrated to urban areas for work, played the DG. Stickers comprised the resource, while recipients in the game were assumed to be either their friends or strangers, with the social distance (i.e., strangers compared to friends) as a between-subjects variable. Children donated significantly more stickers to their friends than to strangers. Moreover, children from lower income families donated more stickers than children from higher income families. However, no gender and parental migrant status differences in children’s prosocial behaviors were evident in this sample. Findings of this study suggest that children’s altruistic behaviours to peers are influenced by family characteristics since preschool age. The probable influence of local socialization practices on development and the possible adaptive significance were discussed.     

基于基因组序列的脑膜炎奈瑟菌分型方法

【目的】建立并评估1种适宜的脑膜炎奈瑟菌(Neisseriameningitidis,Nm)基因组分子分型方法。【方法】本研究以125株代表性Nm菌株的基因组序列为对象,建立了基于核心基因SNP的基因组分型方法,并与pubMLST网站公布的MLST和cgMLST分型方法进行比较。【结果】基于核心基因SNP的基因组分型方法和cgMLST方法对125株Nm菌株的分型结果一致性较高,两种方法均明显优于MLST分型方法。基于SNP的基因组分型方法在认识Nm菌的种群结构、界定克隆群方面具有优势;cgMLST分型方法能够对任一菌株进行分型,但不能进行克隆群的界定和归类。【结论】基于核心基因SNP的基因组分型方法和cgMLST均明显优于MLST分型方法,未来仍有待进一步整合和提高。     

Correlations and comparisons of quantitative trait loci with family per se and testcross performance for grain yield and related traits in maize

Simultaneous improvement in grain yield and related traits in maize hybrids and their parents (inbred lines) requires a better knowledge of genotypic correlations between family per se performance (FP) and testcross performance (TP). Thus, to understand the genetic basis of yield-related traits in both inbred lines and their testcrosses, two F _2:3 populations (including 230 and 235 families, respectively) were evaluated for both FP and TP of eight yield-related traits in three diverse environments. Genotypic correlations between FP and TP, $ \hat{r}_{\text{g}} $ (FP, TP), were low (0–0.16) for grain yield per plant (GYPP) and kernel number per plant (KNPP) in the two populations, but relatively higher (0.32–0.69) for the other six traits with additive effects as the primary gene action. Similar results were demonstrated by the genotypic correlations between observed and predicted TP values based on quantitative trait loci positions and effects for FP, $ \hat{r}_{\text{g}} $ (M _FP, Y _TP). A total of 88 and 35 QTL were detected with FP and TP, respectively, across all eight traits in the two populations. However, the genotypic variances explained by the QTL detected in the cross-validation analysis were much lower than those in the whole data set for all traits. Several common QTL between FP and TP that accounted for large phenotypic variances were clustered in four genomic regions (bin 1.10, 4.05–4.06, 9.02, and 10.04), which are promising candidate loci for further map-based cloning and improvement in grain yield in maize. Compared with publicly available QTL data, these QTL were also detected in a wide range of genetic backgrounds and environments in maize. These results imply that effective selection based on FP to improve TP could be achieved for traits with prevailing additive effects.     

A tailing genome walking method suitable for genomes with high local GC content

The tailing genome walking strategies are simple and efficient. However, they sometimes can be restricted due to the low stringency of homo-oligomeric primers. Here we modified their conventional tailing step by adding polythymidine and polyguanine to the target single-stranded DNA (ssDNA). The tailed ssDNA was then amplified exponentially with a specific primer in the known region and a primer comprising 5′ polycytosine and 3′ polyadenosine. The successful application of this novel method for identifying integration sites mediated by φC31 integrase in goat genome indicates that the method is more suitable for genomes with high complexity and local GC content.