The domestication of social cognition in dogs

Dogs are more skillful than great apes at a number of tasks in which they must read human communicative signals indicating the location of hidden food. In this study, we found that wolves who were raised by humans do not show these same skills, whereas domestic dog puppies only a few weeks old, even those that have had little human contact, do show these skills. These findings suggest that during the process of domestication, dogs have been selected for a set of social-cognitive abilities that enable them to communicate with humans in unique ways.     

Biology, politics, and the emerging science of human nature

In the past 50 years, biologists have learned a tremendous amount about human brain function and its genetic basis. At the same time, political scientists have been intensively studying the effect of the social and institutional environment on mass political attitudes and behaviors. However, these separate fields of inquiry are subject to inherent limitations that may only be resolved through collaboration across disciplines. We describe recent advances and argue that biologists and political scientists must work together to advance a new science of human nature.     

Development of a human adaptive immune system in cord blood cell-transplanted mice

Because ethical restrictions limit in vivo studies of the human hemato-lymphoid system, substitute human to small animal xenotransplantation models have been employed. Existing models, however, sustain only limited development and maintenance of human lymphoid cells and rarely produce immune responses. Here we show that intrahepatic injection of CD34+ human cord blood cells into conditioned newborn Rag2-/-gammac-/- mice leads to de novo development of B, T, and dendritic cells; formation of structured primary and secondary lymphoid organs; and production of functional immune responses. This provides a valuable model to study development and function of the human adaptive immune system in vivo.     

查尔斯·泰勒的社群主义整体本体论评析——基于语言共同体的视角

政治哲学家查尔斯·泰勒认为,对于人不能仅仅进行自然科学研究,或仅仅利用自然科学方法进行研究,因为如此研究漠视或否认自我解释与自我理解对人之存在所具有的决定性意义。因而,为全面准确地理解人就必须研究人的自我解释与自我理解,此研究必然内含对作为关键性先决条件的人的语言的研究。语言构造了人的生活,构成人之存在的方式。然而,语言不是单一个体的独立创造,语言及其承载的意义只有在语言共同体中才能生成与存在。语言共同体相对于个人而言都具有存在的必要性与优先性。任何人只有在语言共同体之中才是自我,任何个体都不可能是他自己的自我,而必须是处于对话网络之中的自我。     

The chromosomal basis of human neoplasia

High-resolution banding techniques for the study of human chromosomes have revealed that the malignant cells of most tumors analyzed have characteristic chromosomal defects. Translocations of the same chromosome segments with precise breakpoints occur in many leukemias and lymphomas, and a specific chromosome band is deleted in several carcinomas. Trisomy, or the occurrence of a particular chromosome in triplicate, is the only abnormality observed in a few neoplasias. It is proposed that chromosomal rearrangements play a central role in human neoplasia and may exert their effects through related genomic mechanisms. Thus, a translocation could serve to place an oncogene next to an activating DNA sequence, a deletion to eliminate an oncogene repressor, and trisomy to carry extra gene dosage.     

Genetic implications of common region sequence comparisons of lambda immunoglobulin chains differing at position 190

The common regions of two lambda chains (amino acid residues 109 to 213) have been partially sequenced. These two human immunoglobulin chains have lysine at position 190, but are otherwise identical in their common-region sequence to four reported lambda chains that have arginine at position 190. The single amino acid interchange at position 190 may be explained either by an ambiguous codon at this position or by a gene duplication so recent that only a single mutational event has occured.     

基于源分离人尿的资源化利用技术研究进展

人尿中含有丰富的营养物质,随意排放不仅带来环境污染,而且会造成资源的浪费。近几年,源分离人尿的资源化利用在工程领域受到了越来越多的关注。本文综述了以资源化利用为目的的人尿处理技术,包括农田利用技术、氮回收技术、磷回收技术、钾回收技术及生化药品提取技术,旨在为我国人尿高效资源化利用寻求可推广可应用的技术方法。综述结果表明尿液具有巨大的资源回收利用潜力,用于处理源分离尿液的技术有很多,但是除了直接还田技术外,其他技术均还停留在实验室研究阶段,尿液资源化利用技术的实际工程应用还有待进一步研究推广。     

现代科学技术与人类发展

技术进步是人发展的基本动力,人类借助于技术进步不断地在延长体外功能:延长人类思维;扩大人的活动范围、认识视野和人的交往方式。同时,技术进步也引发了人类发展难题。以人的"二次提升"抑制技术的负效应,以科学发展观为指导,建构生态政治,营造良好的政治环境是人类克服技术效应悖论的唯一出路。     

Variable number of tandem repeat (VNTR) markers for human gene mapping

A large collection of good genetic markers is needed to map the genes that cause human genetic diseases. Although nearly 400 polymorphic DNA markers for human chromosomes have been described, the majority have only two alleles and are thus uninformative for analysis of genetic linkage in many families. A few known marker systems, however, detect loci that respond to restriction enzyme cleavage by producing a fragment that can have many different lengths. This polymorphism is due to variation in the number of tandem repeats of a short DNA sequence. Because most individuals will be heterozygous at such loci, these markers will provide linkage information in almost all families. Ten oligomeric sequences derived from the tandem repeat regions of the myoglobin gene, the zeta-globin pseudogene, the insulin gene, and the X-gene region of hepatitis B virus, were used to develop a series of single-copy probes. These probes revealed new, highly polymorphic genetic loci whose allele sizes reflected variation in the number of tandem repeats.     

Mutational inactivation of STAG2 causes aneuploidy in human cancer

Most cancer cells are characterized by aneuploidy, an abnormal number of chromosomes. We have identified a clue to the mechanistic origins of aneuploidy through integrative genomic analyses of human tumors. A diverse range of tumor types were found to harbor deletions or inactivating mutations of STAG2, a gene encoding a subunit of the cohesin complex, which regulates the separation of sister chromatids during cell division. Because STAG2 is on the X chromosome, its inactivation requires only a single mutational event. Studying a near-diploid human cell line with a stable karyotype, we found that targeted inactivation of STAG2 led to chromatid cohesion defects and aneuploidy, whereas in two aneuploid human glioblastoma cell lines, targeted correction of the endogenous mutant alleles of STAG2 led to enhanced chromosomal stability. Thus, genetic disruption of cohesin is a cause of aneuploidy in human cancer.     

Evolutionary formation of new centromeres in macaque

A systematic fluorescence in situ hybridization comparison of macaque and human synteny organization disclosed five additional macaque evolutionary new centromeres (ENCs) for a total of nine ENCs. To understand the dynamics of ENC formation and progression, we compared the ENC of macaque chromosome 4 with the human orthologous region, at 6q24.3, that conserves the ancestral genomic organization. A 250-kilobase segment was extensively duplicated around the macaque centromere. These duplications were strictly intrachromosomal. Our results suggest that novel centromeres may trigger only local duplication activity and that the absence of genes in the seeding region may have been important in ENC maintenance and progression.     

Recombinant human tumor necrosis factor-alpha: effects on proliferation of normal and transformed cells in vitro

Modulation of the growth of human and murine cell lines in vitro by recombinant human tumor necrosis factor-alpha (rTNF-alpha) and recombinant human interferon-gamma (rIFN-gamma) was investigated. rTNF-alpha had cytostatic or cytolytic effects on only some tumor cell lines. When administered together with rIFN-gamma, rTNF-alpha showed enhanced antiproliferative effects on a subset of the cell lines tested. In contrast to its effects on sensitive tumor cells, rTNF-alpha augmented the growth of normal diploid fibroblasts. Variations in the proliferative response induced by rTNF-alpha were apparently not due to differences in either the number of binding sites per cell or their affinity for rTNF-alpha. These observations indicate that the effects of rTNF-alpha on cell growth are not limited to tumor cells, but rather that this protein may have a broad spectrum of activities in vivo.     

Human-mouse somatic cell hybrids with single human chromosome (group E): link with thymidine kinase activity

Mouse somatic cells lacking thymidine kinase were mixed in culture with human diploid cells lacking hypoxanthine guanine phosphoribosyl transferase, and hybrid cells were isolated and maintained in a selective medium containing hypoxanthine, aminopterin, and thymidine. The hybrid cells at the time of isolation had karyotypes consisting predominantly of mouse chromosomes but with one human chromosome, a submetacentric member of group E, apparently giving thymidine kinase to the hybrid cell. However, after long-term propagation in the selective medium this chromosome has been lost, although cells continue to show thymidine kinase activity as demonstrated by the incorporation of (3)H-thy-midine into DNA in the hybrid cell. The hybrid cells have only mouse electro-phoretic variants for glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and malate dehydrogenase, suggesting that the human genetic loci for these enzymes are not represented in the hybrid genome and may be unlinked to that for thymidine kinase.     

甲骨文披露的薏苡文化——作物产量构成公式三因素之密度、株数判定及证考Ⅰ

薏苡(Coix)作为我国最早栽培的作物品种,这一事实可从许多证据得到证考;甲骨文作为最早记载人类活动的文字之一,不仅推动了人类文明的进程,也最早记载了作物产量株的构成。文章通过大量文献资料对这一事实进行了判定及证考,推定出了甲骨文记载的作物产量公式的要素,即密度(穗数)、穗粒数、籽粒重(千粒重),是最早记载作物产量构成公式的三要素,鉴于篇幅所限,本文只讨论密度(株、穗数)之内容。     

人力资本的代际收入传递效应研究

人力资本的跨代传递影响着收入的代际不平等性，影响我国的收入分配政策以及医疗和教育体制改革。父母对子女的人力资本投资动机不仅来源于自身的利他主义倾向和人力资本投资的边际回报率，同时还受到人力资本的代际传导强度和人力资本对收入的边际贡献率的影响。忽略人力资本的直接代际传导将导致对代际收入弹性的低估。以健康和教育为代表的人力资本变量具有显著的跨代传递效应，反映出我国人口在教育和健康机会上的不平等性。父亲—女儿的收入传递弹性高于父亲—儿子，农村人口的跨代收入传递弹性高于城镇，反映出代际机会不均等问题在女性和农村子女等弱势群体中体现得更为严重。     

Genetic clues to dispersal in human populations: retracing the past from the present

Ongoing debate about proper interpretation of DNA sequence polymorphisms and their ability to reconstruct human population history illustrates a important change in perspective that we have achieved in the past 20 years of population genetics. To what extent does the history of a locus represent the history of a population? Tools originally developed for molecular systematics, where genetic lineages have been separated by speciation events, are routinely applied to the analysis of variation within our species, with conflicting results. Because of automated technologies and linkage analysis, we are poised to harvest a wealth of information about our past, if we are successful in moving beyond a current polarization regarding models of human evolution. Rather than just suggesting that true resolution will only come by considering fossil or archaeological evidence, the realistic and appropriate application of genetic models for analysis of population structure is also necessary. Three examples from different dispersal events are highlighted here.     

Poster: the macaque genome

The rhesus macaque (Macaca mulatta) facilitates an extraordinary range of biomedical and basic research, and the publication of the genome only makes it a more powerful model for studies of human disease; moreover, the macaque's position relative to humans and chimpanzees affords the opportunity to learn about the processes that have shaped the last 25 million years of primate evolution. To allow users to explore these themes of the macaque genome, Science has created a special interactive version of the poster published in the print edition of the 13 April 2007 issue. The interactive version includes additional text and exploration, as well as embedded video featuring seven scientists discussing the importance of the macaque and its genome sequence in studies of biomedicine and evolution. We have also created an accompanying teaching resource, including a lesson plan aimed at teachers of advanced high school life science students, for exploring what a comparison of the macaque and human genomes can tell us about human biology and evolution. These items are free to all site visitors.     

The medial temporal lobe memory system

Studies of human amnesia and studies of an animal model of human amnesia in the monkey have identified the anatomical components of the brain system for memory in the medial temporal lobe and have illuminated its function. This neural system consists of the hippocampus and adjacent, anatomically related cortex, including entorhinal, perirhinal, and parahippocampal cortices. These structures, presumably by virtue of their widespread and reciprocal connections with neocortex, are essential for establishing long-term memory for facts and events (declarative memory). The medial temporal lobe memory system is needed to bind together the distributed storage sites in neocortex that represent a whole memory. However, the role of this system is only temporary. As time passes after learning, memory stored in neocortex gradually becomes independent of medial temporal lobe structures.     

英汉语言的社会文化内涵

语言是人类社会进行交际的重要工具,同时也是文化的重要而突出的组成部分。英汉这两种各具特色、大相径庭的语言,其表达方式与习惯存在一定差异。本篇论文通过了解语言与文化之间的关系,从英汉颜色词、风俗习惯、宗教信仰及历史典故的不同,进一步探讨英汉语言的社会文化内涵。     

Cognition. The holey grail of general intelligence

Exactly what is human intelligence and how should we measure it? Such questions have plagued us since the time of Plato, who first proposed that the seat of intelligence is in the brain. In a Perspective, Sternberg discusses new findings (Duncan et al.) that purport to show that the seat of general intelligence is located in the brain's frontal lobes. But, as Sternberg points out, measures of intelligence are only as good as the tests you use and the conclusions that you draw from them.