Historical biogeography and evolutionary diversification of Lilium(Liliaceae): New insights from plastome phylogenomics

Here, we infer the historical biogeography and evolutionary diversification of the genus Lilium. For this purpose, we used the complete plastomes of 64 currently accepted species in the genus Lilium(14plastomes were newly sequenced) to recover the phylogenetic backbone of the genus and a timecalibrated phylogenetic framework to estimate biogeographical history scenarios and evolutionary diversification rates of Lilium. Our results suggest that ancient climatic changes and geological tectonic activities jointly shaped the distribution range and drove evolutionary radiation of Lilium, including the Middle Miocene Climate Optimum(MMCO), the late Miocene global cooling, as well as the successive uplift of the Qinghai-Tibet Plateau(QTP) and the strengthening of the monsoon climate in East Asia during the late Miocene and the Pliocene. This case study suggests that the unique geological and climatic events in the Neogene of East Asia, in particular the uplift of QTP and the enhancement of monsoonal climate, may have played an essential role in formation of uneven distribution of plant diversity in the Northern Hemisphere.

The coordinated impact of forest internal structural complexity and tree species diversity on forest productivity across forest biomes

Forest structural complexity can mediate the light and water distribution within forest canopies,and has a direct impact on forest biodiversity and carbon storage capability.It is believed that increases in forest structural complexity can enhance tree species diversity and forest productivity,but inconsistent relationships among them have been reported.Here,we quantified forest structural complexity in three aspects(i.e.,horizontal,vertical,and internal structural complexity)from unmanned aerial vehicle light detection and ranging data,and investigated their correlations with tree species diversity and forest productivity by incorporating field measurements in three forest biomes with large latitude gradients in China.Our results show that internal structural complexity had a stronger correlation(correlation coefficient=0.85)with tree species richness than horizontal structural complexity(correlation coefficient=-0.16)and vertical structural complexity(correlation coefficient=0.61),and it was the only forest structural complexity attribute having significant correlations with both tree species richness and tree species evenness.A strong scale effect was observed in the correlations among forest structural complexity,tree species diversity,and forest productivity.Moreover,forest internal structural complexity had a tight positive coordinated contribution with tree species diversity to forest productivity through structure equation model analysis,while horizontal and vertical structural complexity attributes have insignificant or weaker coordinated effects than internal structural complexity,which indicated that the neglect of forest internal structural complexity might partially lead to the current inconsistent observations among forest structural complexity,tree species diversity,and forest productivity.The results of this study can provide a new angle to understand the observed inconsistent correlations among forest structural complexity,tree species diversity,and forest productivity.

Mathematical beauty and Palladian architecture:Measuring and comparing visual complexity and diversity

Palladio’s design principles,including proportion and harmony,have often been associated with mathematical definitions of beauty.However,the geometric and semantic properties of his fac¸ades have rarely been analysed in a holistic manner.There is little evidence of how mathematical beauty may be embodied in his architecture.This research investigates complexity(fractal dimension or D)and diversity(perplexity or PP)as aesthetic indices,aiming to capture distinct characteristics of Palladian architecture.The D and PP values of 22 Palladian villa fac¸ades are measured and analysed,before being compared with those of three Renaissance facades by Sebastiano Serlio.The combination of D and PP captures the geometric and semantic aesthetic qualities of architectural compositions.Importantly,the developed scatter plot of D and PP results supports the identification of four distinct aesthetic types of Palladian fac¸ade designs.The novel combination of D and PP measures contributes to a better understanding of one definition of the mathematical beauty of architecture,wherein“the whole is other than the sum of the parts”in compositional terms(a famous Gestalt principle).Specifically,this research provides new mathematical insights into the visual character of Palladian architecture and compares two important measures thereof.

Measurement of Characteristic Self-Similarity and Self-Diversity for Complex Mechanical Systems

Based on similarity science and complex system theory,a new concept of characteristic self-diversity and corre- sponding relations between self-similarity and self-diversity for complex mechanical systems are presented in this paper.Methods of system self-similarity and self-diversity measure between main system and sub-system are studied.Numerical calculations show that the characteristic self-similarity and self-diversity measure method is validity.A new theory and method of self-similarity and self- diversity measure for complexity mechanical system is presented.

The Effects of Host Diversity in Anthracnose Management and Race Composition of Colletotrichum sublineolum in Sorghum Lineage Mixtures

Alternative strategies of management of sorghum diseases were implemented using field experiments conducted in Embrapa Maize and Sorghum Research Center,Brazil in 2001 until 2003 to evaluate the efficacy of lineage mixtures of Sorghum bicolor for the control of anthracnose(caused by Colletotrichum sublineolum).The calculated values for disease severity considered the area under the disease progress curve(AUDPC)observed for the nine susceptible and resistant elite strains of sorghum planted in 30 stands randomly.Each stand was drawn in mixtures of three genotypes each,in the same proportions per plant.This design was compared with the severity of the disease measured in AUDPC calculated for each of the same nine strains of sorghum in pure stands.In most of the cases,the disease severity on the susceptible cultivars was decreased;and in some cases,reached 85%of disease reduction compared with disease progress in pure stand of correspondent plant.The implication and effect of these sorghum mixtures on the populations of C.sublineolum on each treatment were evaluated and revealed that there was an increase of frequency of complex races in most of these mixtures and a highest phenotypic diversity for virulence to pathogen populations from pure stands,than the characterized on populations collected from the mixtures,despite of the effectiveness on decrease of the anthracnose severity.

Gamma-aminobutyric acid A receptors in Alzheimer＇s disease： highly localized remodeling of a complex and diverse signaling pathway

Alzheimer＇s disease （AD）, the predominant form of dementia, is a chronic, incurable neurodegenerative disorder presenting with symptoms includ- ing progressive memory loss and disturbed emotional state. It has been estimated that dementia affects over 47 million people worldwide （Prince et al., 2015）, and with 60-80% of cases attributable to AD.

UPLINK PERFORMANCE OF CWP-MC-CDMA WITH SPACE DIVERSITY COMBINING TECHNIQUE OVER RAYLEIGH FADING CHANNEL

In this paper, a Complex Wavelet Packet （CWP-MC-CDMA） system uplink model is proposed, based Multi-Carrier Code Division Multiple Access based on the analysis of the principle of MC-CDMA and the use of the optimized complex wavelet packet. Considering that the base station can adopt multiple re- ceiver antennas in the uplink, we employ the Space Diversity Combining （SDC） technique to improve the sys- tem pertbrmance via multiple antennas. The uplink performance of proposed CWP-MC-CDMA system with SDC technique is investigated over Rayleigh lading channel, and corresponding bit error rate analysis is given in detail. The system can avoid the decrease of spectrum efficiency of conventional MC-CDMA due to inserting cyclic prefix. Theoretical analysis and simulation result show that the application of SDC technique can improve the CWP-MC-CDMA system ability to combat spatial lading and various interferences effectively. Moreover, the proposed system based on SDC technique has superior Bit Error Rate （BER） performance over the Discrete Fourier Transform （DFT） and SDC based MC-CDMA system and the real wavelet packet and SDC based MC-CDMA system.

The Origin of Population Diversity: Stochastic Interactions between a Modifier Variant and the Individual Genetic Background

Stochastic epistasis that is one of the characteristics of epistatic gene modules can have an important role in the maintenance of intraspecific population diversity. The effect of an epistatic modifier variant can vary in size and direction among the modifier careers on the basis of stochastic genetic individuality and the entire module effect can be also individually stochastic. This stochastic genetic contribution under a genetic background may be conditional upon the presence of a monomorphic switch locus in the gene module. The genetic background includes multiple modifier variants and the gene module is composed of the switch and the modifiers. The bell-shaped distribution of quantitative traits can be well simulated by the involvement of multiple stochastic epistatic modules. The phenotypic stochasticity makes the presence of switch and modifiers cryptic or missing in the research field and this cryptic gene networks can maintain and innovate in the phenotypic diversity under selection as a process of the evolution of complexity.

Negotiated Complexity: Framing Multi-Criteria Decision Support in Environmental Health Practice

The complexity we take into account when dealing with complex issues and the way we deal with that complexity is not given or self-evident, it is framed and negotiated. Based on two environmental health decision support case studies we address a set of key methodological choices, crucial in shaping the multi-criteria decision support and illuminate how they followed from transdisciplinary collaboration and negotiation: diversity tolerance, dealing with uncertainty and difference of opinion, weight of information and the epistemological divide between traditional closed and alternative open paradigms. The case studies exemplify the growing conviction amongst methodologists that, especially regarding complex issues, best methods do not exist as such: methods are chosen and tailored in practice and the quality to a large extent is dependent on the process in which methodological development is embedded. We hope to contribute to making explicit the importance of methodological decision making regarding environmental health complexity.

Genetic diversity and population structure of Prochilodus costatus and Prochilodus argenteus preceding dam construction in the Paraopeba River,Sao Francisco River Basin,Minas Gerais,Brazil

Curimat?-pioa (Prochilodus costatus) and curimat?-pacu (Prochilodus argenteus) are migratory fish species endemic to the S?o Francisco River Basin in Brazil. Both species play important roles in local fisheries and ecology in the Paraopeba River. A dam was recently constructed on this river and to help in the development and conservation programs, we characterized the genetic variation of both species before dam construction. Complex hypervariable repeats micro-satellite was used to asses genetic variation for both species within and between the five collection sites in order to detect population substructuring. Nucleotide substitutions and insertion/deletion polymorphisms (indels) resulted in 35 P. costatus haplotypes (sample size = 89) and 22 P. argenteus haplotypes (sample size = 32). Significant genetic diversity and population differentiation was detected between five sampling sites for both species. Therefore, each of the five sites should be regarded as a group comprising significant genetic differences in species conservation and maintenance plans. Comparing these results to genetic diversity measures after dam construction will be critical for future management in this region.

知识复杂性的测度方法综述与比较

[研究目的]复杂知识是突破关键核心技术的基础支撑,也是企业或区域建立竞争优势的关键要素。该文旨在全面把握知识复杂性测度方法的研究现状与前沿进展,为知识复杂性的深入研究提供测度理论基础。[研究方法]通过梳理国内外知识复杂性研究的相关文献,详细介绍三种主要的知识复杂性测度方法的核心思想、理论基础和计算过程,并进一步对比分析不同方法的适用层次和优缺点,最后提出未来研究方向。[研究结论]反射法主要基于知识的空间分布异质性间接衡量知识复杂性,虽然原理简单且操作相对容易,但无法揭示知识复杂性的本质特征;元素依赖性指数利用知识组合频次衡量知识元素之间的相互依赖程度,进而反映知识复杂性,忽视了其他影响知识组合的因素;结构多样性指数通过知识组合网络拓扑结构的多样性反映知识复杂性,综合考虑多个网络结构指标,并经过大量数值模拟检验,但存在估计结果不稳定、仅适用于二值网络等问题。

北京市南水北调配套工程调蓄工程勘察关键技术

北京市南水北调配套工程调蓄工程是北京市“26213”供水格局的重要组成部分,工程分布于北京市西、北、南不同地区,场地建设环境条件复杂,地层结构分布及组合多样,水文地质条件复杂,工程建设面临诸多地质问题及难题。工程勘察成果全面、涉及面广、涵盖工程勘察综合类的全专业领域,完成专业全面的技术成果文件与研究报告60余册,发表学术论文50余篇,取得七大方面技术创新、30余个技术创新点。勘察总体工作思路、技术路线、研发的创新技术、利用的先进手段等方面具有实践推广价值,特别是对城市复杂地质环境条件下建设城市供水调蓄工程具有借鉴作用。

复合菌剂提高青藏高原羊粪和尾菜混合堆肥微生物多样性并加快堆肥腐熟

【目的】研究添加自行筛选制备的复合菌剂对青藏地区羊粪尾菜混合堆肥进程和发酵品质的作用效果,为高原地区羊粪尾菜的资源化利用提供高效菌剂。【方法】将羊板粪和尾菜以质量比8∶1混合组成堆料,分为3份用于设置处理:自然发酵(CK),添加市售堆肥菌剂(T2),添加自行筛选制备的复合菌剂(T3),堆体均为锥形,高度在1.5 m左右,每个堆体堆料量5 t,发酵持续60天。在开始发酵后测定堆肥温度,在0、7、14、20、25、50、60天,取样分析pH、含水率、电导率(EC)值及总氮、铵态氮、硝态氮和亚硝态氮含量,腐熟期样品用于种子发芽率(GI)试验。在0、20、60天取样,结合扩增子测序,分析堆肥细菌群落结构。【结果】添加复合菌剂的T3处理升温速度最快,在发酵第3天就达到47.8℃,在发酵第17天,T3处理首先进入高温期(>50℃),比CK处理提前5天;复合菌剂加速了羊粪尾菜堆肥中有机碳的分解,对有机质降解有一定的促进作用。发酵结束时CK、T2、T3处理全氮含量分别为21.4、23.1、19.7 g/kg,NH_(4)^(+)-N含量分别为155、144、45.6mg/kg,NO_(3)^(-)-N含量分别为218、283、344 mg/kg,T3处理堆肥全氮和铵态氮含量较CK组与T2组下降明显,但硝态氮含量高于CK和T2组,最终其GI值达到129.2%,高于CK组与T2组处理。菌群分析发现高原环境中Psychrobacter在堆肥初始阶段有着优势地位。加入自制的复合菌剂改变了堆肥过程中微生物的群落结构,增加了细菌多样性和特定细菌丰度,T3处理中Actinobacteriota水平明显升高。【结论】与不使用菌剂和使用商品菌剂相比,添加自行筛选制备的复合菌剂有效促进了青藏地区富含纤维素的羊粪尾菜混合堆肥的腐熟,延长了高温期,促进了有机质降解,同时减弱腐熟阶段的反硝化作用。加入的复合菌剂增加了堆肥中的细菌多样性,较高的嗜冷杆菌(Psychrobacter)相对丰度有助于堆肥初始阶段的升温,具有高效纤维素降解能力的放线菌(Streptomyces sp.)的加入有助于纤维素的降解。因此,使用复合菌剂是实现西藏地区羊粪及尾菜混合堆肥处理的有效措施。

鲫复合种隐性感染洪湖碘泡虫调查及遗传多样性分析

洪湖碘泡虫是中国异育银鲫养殖中常见的一种粘孢子虫,严重感染时病鱼出现眼球凸起,咽部发炎肿胀等症状,造成苗种和成鱼死亡。为探究严重危害养殖异育银鲫“喉孢子虫病”病原的宿主范围以及不同宿主寄生虫株间的遗传差异,本研究广泛采集了金鱼、红鲫、异育银鲫、彭泽鲫、方正银鲫、淇河鲫、金背鲫、杂交鲫等我国常见鲫复合种样品,采用18S rDNA PCR检测了各样品伪鳃的洪湖碘泡虫感染率,并进一步通过巢式PCR克隆测序获得部分样品洪湖碘泡虫的ITS2序列(登录号:OR744899–OR744905)。PCR检测结果显示,来自7个地区8种鲫属鱼类品系都存在洪湖碘泡虫的隐性感染,感染率为25.0%~88.2%;ITS2序列分析表明,感染鲫复合种的洪湖碘泡虫株系间序列差异较低,所获得的序列间仅有6个差异信息位点,平均遗传距离为0.003;不同来源虫株间共存在7种单倍型,其中H1、H2和H3只出现在金鱼、红鲫寄生虫株,H5广泛存在不同来源的异育银鲫寄生虫株。系统发育分析显示,来自不同鲫复合种的洪湖碘泡虫聚集为2个分支,其中寄生金鱼的虫株与瓶囊碘泡虫亲缘关系较近。本研究结果为阐明异育银鲫“喉孢子虫病”的流行病学规律和防控疾病发生提供重要基础数据。

四川不同寄主禾谷镰孢菌复合种的群体遗传多样性及相互侵染关系

【目的】探明四川地区小麦、玉米和大豆3种寄主禾谷镰孢菌复合种(Fusarium graminearum species complex,FGSC)的群体遗传多样性及相互侵染关系。【方法】采用多重PCR和PCR-VNTR分子标记技术分析不同寄主来源菌株的毒素类型和群体遗传多样性,并通过高粱粒接种法检测菌株在不同寄主间的相互侵染作用。【结果】来源于3种寄主的禾谷镰孢菌复合种菌株被鉴定为禾谷镰孢菌(F. graminearum)和亚洲镰孢菌(F. asiaticum),其中禾谷镰孢菌的毒素化学型为3-乙酰基脱氧雪腐镰刀菌烯醇(3-ADON)和15-乙酰脱氧雪腐镰刀菌烯醇(15-ADON),而亚洲镰孢菌的毒素化学型为雪腐镰刀菌烯醇(NIV);各寄主菌株的群体遗传多样性存在差异,以小麦菌株群体遗传多样性最高,且与大豆菌株遗传距离较远;同时,各寄主菌株间能够相互侵染,但致病力存在差异。【结论】来源于四川小麦、玉米和大豆3种寄主的禾谷镰孢菌复合种遗传多样性存在差异,但可相互侵染致病,具有加重其所致病害在该地区发生的风险。

复合寡糖施用对促进黄瓜生长与改善细菌群落结构的影响

植物刺激素寡糖具有提高作物抗逆作用、促进作物生长的功效。在黄瓜生长早期及生长期施用复合寡糖制剂,通过分析复合寡糖对植株光合作用特性、产量和黄瓜3个生长阶段植株叶片、根系及根围土微生物群落,阐明复合寡糖施用对黄瓜的增产增效作用。采用大棚小区试验,设置清水对照、化学常规和复合寡糖3个处理,于盛花期、盛果期和拉秧期分别采集黄瓜叶片、根系和根围土样本,测定各个采样时期黄瓜产量、叶绿素含量和抗氧化酶活性,进行高通量测序检测样本细菌群落结构和组成。复合寡糖的施用与清水对照相比,提高了单株黄瓜产量,使得每公顷的产量增加了4.96%;显著提高了黄瓜叶片叶绿素的含量,复合寡糖处理对比其他处理能够显著提升叶片叶绿素含量的相对值(SPAD)6.14%~11.46%;同时提高了叶片的超氧化物歧化酶活性39.9%~81.5%,提高了过氧化氢酶活性8.4%~40.4%,提高了过氧化物酶活性1.19%~18.5%。高通量测序分析结果表明,复合寡糖的施用提高了叶片微生物群落中鞘氨醇单胞菌属(Sphingomonas sp.)和甲基杆菌属(Methylobacterium sp.)的丰度,它们均具有促进植物生长和协助植物抗病的效果。另外,复合寡糖提高了根围土的微生物群落中生防菌芽孢杆菌属(Bacillus sp.)的丰度。黄瓜生长早期及生长期施用复合寡糖,可以提高黄瓜产量和植株抗氧化酶活性,延缓植株衰老,同时提高植株生长体系中有益菌的丰度,可以为进一步深层次揭示复合寡糖的作用机制提供基础数据。

配位驱动组装单组分白光发光金属-有机配合物材料的研究进展

金属-有机配合物材料基于其结构种类多样性及发光性能可调控的特点,被广泛应用于安全防伪、信息存储、智能传感、显示装置、白光照明等领域。本综述详细介绍了单组分金属-有机配合物在白光发光领域内的研究进展。按照Au/Ag/Cu配合物、Zn/Cd配合物、Eu和Tb共掺杂Ln配合物、染料掺杂配合物、其他主族元素/过渡元素/镧系元素掺杂/多元素掺杂配合物5个类别对配合物结构特点、发光机理、白光发光组成、白光性能指标进行分析,归纳不同类别配合物白光发光材料的构筑策略,总结金属-有机配合物材料作为白光候选材料具备的优势,并从理论研究和实际应用2个方面提出待进一步解决的问题,以期早日实现金属-有机配合物发光材料的工业化生产及应用。

血色浪漫

在一些浪漫神奇的魔术背后都隐藏着化学反应。本实验围绕以大众感兴趣的,且与“血色浪漫”相关的神奇现象展开,以简单有趣的几个现象科普化学反应的魅力。其中由硫氰酸钾与铁离子发生络合反应生成血红色絮状络合物,其生成物与氟化钠反应后血红色便会立刻消失,而血红蛋白中的铁可与鲁米诺产生蓝色荧光。在展现这些神奇而浪漫的现象的同时向各个层次人群科普化学知识,解密神奇魔术,探索化学之美,让人们用科学的角度来看待事物,敬佩化学,也充分展示化学的神奇与魅力,有助于激发中小学生和社会大众对化学的探索兴趣与热爱。

Tree species identity and interaction determine vertical forest structure in young planted forests measured by terrestrial laser scanning

Vertical forest structure is closely linked to multiple ecosystem characteristics,such as biodiversity,habitat,and productivity.Mixing tree species in planted forests has the potential to create diverse vertical forest structures due to the different physiological and morphological traits of the composing tree species.However,the relative importance of species richness,species identity and species interactions for the variation in vertical forest structure remains unclear,mainly because traditional forest inventories do not observe vertical stand structure in detail.Terrestrial laser scanning(TLS),however,allows to study vertical forest structure in an unprecedented way.Therefore,we used TLS single scan data from 126 plots across three experimental planted forests of a largescale tree diversity experiment in Belgium to study the drivers of vertical forest structure.These plots were 9–11years old young pure and mixed forests,characterized by four levels of tree species richness ranging from monocultures to four-species mixtures,across twenty composition levels.We generated vertical plant profiles from the TLS data and derived six stand structural variables.Linear mixed models were used to test the effect of species richness on structural variables.Employing a hierarchical diversity interaction modelling framework,we further assessed species identity effect and various species interaction effects on the six stand structural variables.Our results showed that species richness did not significantly influence most of the stand structure variables,except for canopy height and foliage height diversity.Species identity on the other hand exhibited a significant impact on vertical forest structure across all sites.Species interaction effects were observed to be site-dependent due to varying site conditions and species pools,and rapidly growing tree species tend to dominate these interactions.Overall,our results highlighted the importance of considering both species identity and interaction effects in choosing suitable species combinations for forest management practices aimed at enhancing vertical forest structure.

一种林分水平结构多样性新参数及其在北京国家植物园的应用

【目的】研究构建了一种基于相邻木关系的林分水平空间结构多样性的新指数,首次全面评价和比较北京国家植物园内典型林分的水平空间结构多样性。【方法】描述林分水平空间结构的4个参数可以分别表达林木及其最近相邻木的格局、大小、树种和竞争等空间结构的多样性。将参数组合,则可以全面描述林分的水平结构多样性。用修正的遗传绝对距离表达林分结构单元类型的均匀性,用林分结构参数组合数与最大类型数的比值表达林分空间结构的复杂性,构造林分水平结构多样性指数(FSDN)。以北京国家植物园两个典型林分为分析对象,以同地区和南方地区的其他人工林为比较林分,采用FSDN指数分析不同结构参数组合类型个数的多少及其占比,评价林分水平空间结构的多样性。【结果】北京国家植物园内两种典型林分虽然在林分类型、树种多少、林分密度等多个方面都有差异,但其水平结构多样性非常相似。同地区的侧柏人工林结构多样性更低,但以等级划分时,其等级和国家植物园两个林分的等级相同,均为中等。【结论】北京国家植物园典型林分类型的水平格局多样性处于中等的水平,这与中国同地区或南方地区的人工林相似。新的水平格局多样性指数由结构种类分布的均匀性和结构的复杂性两部分组成,可量化林分水平不同方面的多样性,也方便综合描述,并明确阐释多样性高低的原因,以及均匀性和复杂性的贡献程度。这将为森林经营,尤其是致力于提升和优化森林结构多样性的经营目标提供更多工具。