Hemoglobin Portland 1: a new human hemoglobin unique in structure

A new hemoglobin (Hb), Portland 1, has been found in a newborn infant having multiple congenital anomalies and complex autosomal chromosomal mosaicism. The new hemoglobin has a unique tetrameric structure (molecular weight, 66,000) composed of two pairs of different types of chains, neither of which is alpha, gamma(2)x(2). The x-chain of Hb Portland 1 may be a new type of hemoglobin chain, but the available evidence suggests that it may be identical with the epsilon chain. We suggest that Hb Portland 1 is an embryonic hemoglobin that persisted until after birth in relatively large amounts in this patient.     

Whole-genome patterns of common DNA variation in three human populations

Individual differences in DNA sequence are the genetic basis of human variability. We have characterized whole-genome patterns of common human DNA variation by genotyping 1,586,383 single-nucleotide polymorphisms (SNPs) in 71 Americans of European, African, and Asian ancestry. Our results indicate that these SNPs capture most common genetic variation as a result of linkage disequilibrium, the correlation among common SNP alleles. We observe a strong correlation between extended regions of linkage disequilibrium and functional genomic elements. Our data provide a tool for exploring many questions that remain regarding the causal role of common human DNA variation in complex human traits and for investigating the nature of genetic variation within and between human populations.     

改革开放进程中的社会阶层利益结构调整

改革的过程实际上就是社会各阶层既得利益重新分配的过程,也即社会阶层利益结构的重大调整过程.这一调整在对社会发展产生积极影响的同时,也导致了社会阶层利益结构的失衡.因此,需要从加快经济发展、完善制度建设和加强思想道德建设等多个层面不断优化阶层利益结构,促进社会良性协调发展.     

不同生长模式下人参土壤微生物群落结构研究

为明确不同生长模式下人参土壤微生物群落结构组成,以野山参、林下参和农田栽参土壤作为试验材料,利用磷脂脂肪酸分析法(PLFA)测定人参土壤微生物群落结构组成。结果表明,不同生长模式下人参土壤中C、N含量不同,野山参土壤中全C和全N含量均显著高于林下参和农田栽参土壤(P0.05),是农田栽参土壤的10.30和4.61倍;C/N比为野山参土壤林下参土壤农田栽参土壤,野山参和林下参土壤C/N比差异不显著,但远高于农田栽参土壤;野山参土壤微生物总量最高为1 671.05 nmol·g~(-1),农田栽参土壤最低为266.80 nmol·g~(-1)。不同人参生长模式下细菌均为优势菌群,但放线菌在野山参土壤中含量为187.18 nmol·g~(-1),林下参土壤中为26.12nmol·g~(-1),农田栽参土壤中为6.77 nmol·g~(-1)。通过挖掘功能微生物发现,代表抗逆性微生物指标蓝细菌(182ω6)及革兰氏阳性菌与革兰氏阴性菌比值(G+/G-)均为野山参土壤林下参土壤农田栽参土壤,野山参土壤中蓝细菌含量是林下参土壤的3.51倍,农田栽参土壤则未检出;野山参土壤中G+/G-分别是林下参土壤和农田栽参土壤的6.93和9.10倍。野山参土壤微生物量大、种群丰度高,生产实践中可通过添加外援微生物改变土壤微生物群落结构及组成提高农田栽参土壤肥力。     

不同耕作模式对稻田土壤真菌丰度及群落结构的影响

为分析我国典型的稻田耕作模式下土壤真菌丰度及群落结构差异,以长期（10 a）4种典型稻田耕作模式为研究对象,设置以下处理：双季稻（DR）、早稻-晚稻（MR）、中稻-油菜（MROR）及中稻-小白菜-油菜（MRPOR）,利用实时荧光定量PCR及高通量测序手段测定土壤真菌的丰度及群落组成。结果显示,双季稻转变为单季稻及水旱轮作模式后显著改变了真菌的丰度,其中双季稻转变为中稻-小白菜-油菜后显著增加了真菌的丰度,相关性分析发现,硝态氮与真菌的丰度呈显著的正相关关系;双季稻转为单季稻及水旱轮作模式后显著改变了真菌的群落结构,冗余分析发现水分含量是影响真菌群落结构最主要的环境因子。综上研究表明,不同轮作模式下稻田土壤真菌群落丰度、组成及多样性存在差异。不同处理下真菌丰度受土壤硝态氮影响较大,而真菌群落结构主要受土壤含水量的影响。     

The structure of haplotype blocks in the human genome

Haplotype-based methods offer a powerful approach to disease gene mapping, based on the association between causal mutations and the ancestral haplotypes on which they arose. As part of The SNP Consortium Allele Frequency Projects, we characterized haplotype patterns across 51 autosomal regions (spanning 13 megabases of the human genome) in samples from Africa, Europe, and Asia. We show that the human genome can be parsed objectively into haplotype blocks: sizable regions over which there is little evidence for historical recombination and within which only a few common haplotypes are observed. The boundaries of blocks and specific haplotypes they contain are highly correlated across populations. We demonstrate that such haplotype frameworks provide substantial statistical power in association studies of common genetic variation across each region. Our results provide a foundation for the construction of a haplotype map of the human genome, facilitating comprehensive genetic association studies of human disease.     

安徽合肥地区杨树林节肢动物群落结构变化规律研究

为分析杨树林节肢动物群落结构动态变化规律,在对安徽舍肥杨树林系统调查的基础上.分别用通径分析、聚类分析和最优分割等方法进行了分析.结果表明,群落中均匀度.,与多样性H'关系密切,物种数S、优势集中性C和物种丰富度R是影响群落多样性的重要因素.全年13次调查结果可将群落聚为5类,D为1.474 1.反映出群落的变化状况,聚类交替现象则反映出群落在较长时间内的复杂性.将群落结构按1年中的时间顺序分割为4段(3～4月、5～8月、9～10月、11～12月),反映了群落结构的季节性变化规律.     

Warriors, levelers, and the role of conflict in human social evolution

The origins of such varied features of contemporary life as the national state and the desire to uphold generous and civic social norms are to be found in a combination of conflict between groups and attenuation of both inequalities and conflicts within groups. In contrast to the adoption of a better tool or a more productive crop, which can be adopted by a single individual, a new institution works only if most people adopt it. This explains why collective action against those benefitting from the status quo at the expense of others, as well as conflict between groups governed by different norms and institutions, figures so prominently in our capacity to adapt to changing circumstances and to harness new knowledge for human benefit.     

The social sense: susceptibility to others' beliefs in human infants and adults

Human social interactions crucially depend on the ability to represent other agents' beliefs even when these contradict our own beliefs, leading to the potentially complex problem of simultaneously holding two conflicting representations in mind. Here, we show that adults and 7-month-olds automatically encode others' beliefs, and that, surprisingly, others' beliefs have similar effects as the participants' own beliefs. In a visual object detection task, participants' beliefs and the beliefs of an agent (whose beliefs were irrelevant to performing the task) both modulated adults' reaction times and infants' looking times. Moreover, the agent's beliefs influenced participants' behavior even after the agent had left the scene, suggesting that participants computed the agent's beliefs online and sustained them, possibly for future predictions about the agent's behavior. Hence, the mere presence of an agent automatically triggers powerful processes of belief computation that may be part of a "social sense" crucial to human societies.     

Interhemispheric asymmetries of the modular structure in human temporal cortex

Language-relevant processing of auditory signals is lateralized and involves the posterior part of Brodmann area 22. We found that the functional lateralization in this area was accompanied by interhemispheric differences in the organization of the intrinsic microcircuitry. Neuronal tract tracing revealed a modular network of long-range intrinsic connections linking regularly spaced clusters of neurons. Although the cluster diameter was similar in both hemispheres, their spacing was about 20 percent larger in the left hemisphere. Assuming similar relations between functional and anatomical architecture as in visual cortex, the present data suggest that more functionally distinct columnar systems are included per surface unit in the left than in the right area 22.     

不同种植模式对桑园土壤肥力和土壤细菌群落结构的影响

【目的】揭示间作下桑园土壤肥力、土壤微生物结构、多样性之间的关系,为改进桑园间套作模式和桑园培肥管理提供参考。【方法】以桑树净作为对照(CK),设桑树间作大豆(MSS)、桑树间作花生(MPP)和桑树间作甘薯(MST)3个间作模式,开展2年田间试验,分析4种种植模式下桑园土壤理化性状、细菌多样性指数和群落结构特征。【结果】土壤养分含量、OTU数量、α多样性指数和土壤细菌群落结构均随种植模式而变化。与CK相比,间作显著改变了土壤pH、速效钾含量,提高了土壤有机质、全磷和有效磷含量。α多样性分析结果表明,间作桑园土壤中细菌OTU数量及ACE、Chao1、Simpson指数均高于CK,其中间作处理的ACE指数与CK差异显著(P<0.05)。高通量测序分析结果表明,种植模式影响桑园土壤中大于1%的优势细菌门数量,在丰度前10的细菌门类中,变形杆菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)、芽单孢菌门(Gemmatimonadetes)、硝化螺旋菌门(Nitrospirae)是间作土壤中的优势种群,相对丰度之和在62.32%~71.27%;在属水平上,鞘氨醇单胞菌(Sphingomonas)、Uncultured_bacterium_f_SC-I-84、Uncultured_bacterium_f_Chitinophagaceae、酸微菌(Ilumatobacter)、硝化螺旋菌(Nitrospira)、JGI_0001001-H03、砂壤土杆菌(Ramlibacter)和黄色土源菌(Flavisolibacter)是间作土壤的优势细菌属,较CK分别高60.9%、50.0%、19.1%、17.9%、11.3%、25.0%、50.5%和45.6%。此外,各模式下土壤细菌属群落相对丰度与土壤养分含量存在一定的相关关系。【结论】不同桑园间作模式显著改变了桑园土壤pH及碱解氮和速效钾含量,并影响桑园土壤中优势细菌分类水平组成(门、属)和优势细菌的相对丰度,改变了细菌群落结构和丰富度;发展桑园间作大豆和花生有利于改良土壤理化性状,提高土壤细菌多样性,维护桑园土壤肥力。     

不同种植模式下凤丹根际微生物群落结构和多样性分析

为探究不同种植模式下凤丹根际微生物群落结构和多样性,采用高通量测序技术对采自榉树(Zelkova serrata)下种植(ZS)、娜塔栎(Quercus nattallii)下种植(QS)、露天种植(OS)的凤丹根际以及空白土壤(CK)样品土壤细菌和真菌进行测序。结果显示,与空白土壤相比,种植凤丹提高了根际微生物群落的丰富度和多样性,不同种植模式下凤丹根际微生物群落结构有所差异。3种种植模式下细菌的优势菌门均为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)以及疣微菌门(Verrucomicrobia),但不同种植模式下每个门的相对丰度有所差异。所有样品中总共检测出12个真菌门,3种种植模式下真菌的优势菌门均为子囊菌门(Ascomycota)和担子菌门(Basidiomycota),不同种植模式下各真菌门的相对丰度存在差异;属水平上真菌群落结构差异较大,ZS组、QS组和OS组的优势菌属分别为Exophiala、Thelephoraceae＿unclassified、Ascomycota＿unclassified。...     

The fine-scale structure of recombination rate variation in the human genome

The nature and scale of recombination rate variation are largely unknown for most species. In humans, pedigree analysis has documented variation at the chromosomal level, and sperm studies have identified specific hotspots in which crossing-over events cluster. To address whether this picture is representative of the genome as a whole, we have developed and validated a method for estimating recombination rates from patterns of genetic variation. From extensive single-nucleotide polymorphism surveys in European and African populations, we find evidence for extreme local rate variation spanning four orders in magnitude, in which 50% of all recombination events take place in less than 10% of the sequence. We demonstrate that recombination hotspots are a ubiquitous feature of the human genome, occurring on average every 200 kilobases or less, but recombination occurs preferentially outside genes.     

浙江天童披针叶茴香-南酸枣群落优势种群结构及空间格局

以浙江天童披针叶茴香Illicium lanceolatum-南酸枣Choerospondias axiliaris群落为对象,应用每木调查法、时空互代法和相邻格子法研究分析群落优势种群结构和分布格局。种群结构分析包括胸径级结构和垂直层次结构,空间格局分析包括各种不同垂直层次个体的空间分布格局。5个优势种群总体相对优势度达到74.85%,大小级指数除南酸枣和橄榄槭Acer olivaceum为正值外,披针叶茴香、红楠Machilus thunbergii和华东楠M.leptophylla均为负值,各个种在垂直空间上占据了不同的位置。不同种之间以及同种不同层次之间表现出复杂多样的分布格局,体现出多级复合分布特征,披针叶茴香、华东楠表现为聚集分布,而南酸枣、橄榄槭表现为均匀分布,红楠表现为随机分布。各个物种通过占据不同的水平和垂直空间,在群落中得以共存。     

稻田不同轮作休耕模式下土壤反硝化功能基因群落结构

为了探索不同轮作休耕种植模式下稻田土壤氮素及相关微生物群落结构的变化,采用乙炔抑制法测定土壤反硝化潜势,利用高通量测序手段分析反硝化微生物群落多样性和组成,以传统种植模式紫云英-早稻-晚稻（A）为对照,比较分析4种轮作休耕种植模式：紫云英-早稻-玉米||甘薯（B）、油菜-甘蔗||春大豆（C）、紫云英-春大豆-秋大豆（D）和休耕（E）的土壤理化性状、土壤反硝化潜势及相关微生物组成变化。结果显示：4种轮作休耕模式的土壤反硝化潜势显著低于传统轮作模式,有效减少了土壤氮素气态损失;4种轮作休耕模式的nirK和nirS功能基因群落结构存在显著差异,其中nirK基因群落结构受轮作休耕模式的影响小于nirS功能基因;与传统种植模式相比,休耕模式更有利于nirS功能基因α多样性的积累;从nirS和nirK基因群落物种相对丰度来看,轮作休耕模式的优势物种丰度高于传统轮作模式,其中紫云英-早稻-玉米||甘薯（B）和休耕（E）的菌属丰度相对较高。并且影响反硝化潜势的关键菌属是大豆根瘤菌Bradythizobium（r² = 0.85,P <0.05）和unclassified_p_Proteobacteria（r² = 0.88,P <0.05）;相关性分析及冗余分析发现,pH、有效磷、速效钾、硝态氮（NO₃^--N）与反硝化潜势呈显著相关,而影响nirK和nirS功能基因群落结构的重要影响因子是含水率。结果表明：稻田适当采用水旱、旱旱轮作及休耕模式,会改变土壤的淹水环境,影响反硝化功能基因群落结构,有助于抑制土壤氮素的气态流失,促进土壤肥力提高及土壤结构改良,其中“紫云英-早稻-玉米||甘薯”和“休耕”种植模式效果最佳。     

人类活动对黄土高原子午岭森林景观格局的影响

以黄土高原子午岭1∶25000植被图为基础,利用GIS手段和缓冲区分析技术,研究了人类活动对子午岭森林景观格局的影响。结果表明,黄土高原子午岭森林景观以辽东栎(Quercus liaotungensis)林、山杨(Populusdavidiana)林为主体,但因人为破坏等原因,灌木林和非林地景观类型亦占较重要地位。人类活动的强弱与景观破碎化有一定的相关性,人类作用强的地区平均斑块面积较小,景观破碎化程度较高;人类作用弱的地区斑块面积较大,破碎化程度较低。人为干扰增加了景观的异质性,从而使森林景观多样性增加,优势度指数下降,均匀度指数增加,破碎度指数增加。表明人类活动是导致子午岭森林景观破碎化的重要原因。     

基于土地利用结构变化的河南省碳排放时空格局及驱动力分析

河南省面临生态环境脆弱、生态承载力较低和碳排放基数较大等诸多问题,这给双碳战略的有效实施带来了挑战。本研究旨在系统研究河南省土地利用变化对碳排放量时空格局的影响,为政府制定低碳土地利用模式以及差异化的碳减排政策提供科学依据。基于2000—2020年河南省土地利用和能源消费数据,结合土地利用碳排放量方法和ArcGIS技术,本研究量化了河南省碳排放的时空格局分布,并借助地理探测器方法分析了河南省土地利用碳排放量空间分异的影响因素。结果表明：建设用地和耕地是河南省主要的碳源,林地则是主要的碳汇,碳吸收量占总吸收量的90%以上。总体上,河南省碳排放量呈现出先快速增长后缓慢下降的趋势,从2000年的3.367×107 t增长到2010年的7.337×107 t,增长率为118%;而在2010—2020年下降了5.247×106 t,下降率为7%。空间上,不同市域之间存在着显著的碳排放量水平差异,部分市域存在碳收支不平衡,且碳排放量远超碳吸收量。此外,城镇化水平、人口规模和建设用地占比对碳排放量产生显著影响,尤其是建设用地q值增长幅度最大,而人口规模q值在2020年最高。通过探究土地利用变化导致的碳排放量变化和空间格局变化以及碳排放格局的驱动力,对推动河南省土地利用方式向低碳化转变,制定有效的政策具有重大意义。     

Rooted in grass: Challenging patterns of knowledge exchange as a means of fostering social change in a southeast Minnesota farm community

By convening a multidisciplinary team(the Monitoring Team) that included farmers,university and agency researchers, andnon-profit staff; a small group of farmers insoutheast Minnesota, U.S.A., bolstered thelegitimacy of the sustainable agriculturemovement. Through the experience of forming ateam and working with individuals who operatedwithin the mainstream knowledge paradigm,farmers gained validation of their knowledgeabout farming, while researchers came to valuealternative knowledge systems. In the contextof a socially embedded movement, farmers wereempowered by sharing their knowledge withresearchers, and ultimately contributed to thesustainable agriculture movement by challengingtraditional patterns of knowledge exchange.