DNA Barcoding, Fungal Diversity,and Authentication of Wild Gourmet Mushrooms

The application of molecular tools for the identification of strains, populations and species has become a common practice in a variety of applied and basic investigations in many parts of the world. However, standardization of such applications varies widely among organisms and scientific fields. In this mini-review, the author provides a brief introduction to one of the most prominent effort for species identification - the international barcode of life (iBOL) project, discusses the features of fungal diversity including the proposed fungal barcode DNA fragment-the intergenic spacer regions (ITS) of the nuclear ribosomal RNA gene clusters, and illustrates the potential promises and problems of using ITS for barcoding and for analyzing the phylogeographic pattern of the wild gourmet mushroom Tricholoma matsutake species complex. The analyses show that identification to species level is often insufficient for practical applications and that sequences from multiple genes in combination with critical morphological and physiological evaluations are needed to identify strains, populations and species.     

全豆豆腐中腐败菌分离、鉴定及货架期研究

全豆豆腐是保留大豆中营养物质的新型豆腐,研究全豆豆腐中腐败菌及货架期,可提高农产品利用效率。文章对全豆豆腐中腐败菌16S r DNA作序列分析,利用Logistic方程和Modified Gompertz方程拟合腐败菌生长动力学曲线,在一级模型基础上,采用延滞期模型和平方根模型分析温度对腐败菌延滞期(Lag time)和最大比生长速率(μmax)影响,采用一级模型研究并评估全豆填充豆腐货架期。结果表明,全豆豆腐中腐败菌经鉴定为Bacillus cereus和Bacillus subtilis。15~30℃下,Modified Gompertz模型拟合精度高于Logistic模型。豆腐贮藏温度由30℃降至15℃,腐败菌最大比生长速率(μmax)降低,延滞期(Lag time)增大。Modified Gompertz方程延滞期模型和平方根模型拟合度(R2)依次为0.98和0.99,拟合精度高于Logistic方程,相对误差低于Logistic方程。15℃下Logistic方程和Modified Gompertz方程计算实际货架期为41.38和40.73 h,10℃下Modified Gompertz方程预测全豆豆腐货架期为143.96 h(5.99 d)。结果表明,Modified Gompertz方程更适用于全豆填充豆腐货架期预测。     

Implementing the new U.S. dual-use policy

After a decade of intensive policy discussions on the topic of dual-use research of concern (DURC) in the life sciences, there has been a lack of consensus on how to practically define DURC; whether it is feasible to identify and regulate DURC experiments; how to address the risks associated with DURC; and how to balance this risk with the necessity of fostering life sciences research for public health and biodefense. The publication of two avian influenza studies has brought the DURC issue back into sharp focus and has resulted in a new set of federal guidelines. However, the new DURC policy raises questions regarding whether this is the best policy solution to a complicated biosecurity concern.     

浅谈居住区景观设计

当前随着人们生活质量、品位的不断提升,更加关注居住环境。好的景观设计能使楼盘的附加值得到全方位提升,楼盘环境成为消费者辨别产品优劣的最直观标准[1]。在当前绿色、低碳生活的指引下,景观设计已不再是停留在表面的形式上,而是注重生态价值与生态美学、功能与思想内涵的更高层次的统一。     

Rates of molecular evolution are linked to life history in flowering plants

Variable rates of molecular evolution have been documented across the tree of life, but the cause of this observed variation within and among clades remains uncertain. In plants, it has been suggested that life history traits are correlated with the rate of molecular evolution, but previous studies have yielded conflicting results. Exceptionally large phylogenies of five major angiosperm clades demonstrate that rates of molecular evolution are consistently low in trees and shrubs, with relatively long generation times, as compared with related herbaceous plants, which generally have shorter generation times. Herbs show much higher rates of molecular change but also much higher variance in rates. Correlates of life history attributes have long been of interest to biologists, and our results demonstrate how changes in the rate of molecular evolution that are linked to life history traits can affect measurements of the tempo of evolution as well as our ability to identify and conserve biodiversity.     

African Cassava Whitefly,Bemisia tabaci,Resistance in African and South American Cassava Genotypes

The whitefly, Bemisia tabaci, is a major pest of cassava, particularly in Africa where it is responsible both for the transmission of plant viruses and, increasingly, for direct damage due to feeding by high populations. To date, there have been no practical solutions to combat this emerging problem, due to the inability of the subsistence farmers that grow cassava to afford expensive inputs such as insecticides. A programme of research was carried out linking institutes in Africa, the UK and South America, to identify possible resistance sources in cassava to the whitefly, Bemisia tabaci. The South American genotype MEcu 72 and several Ugandan cassava landraces including Ofumba Chai, Nabwire 1 and Mercury showed good levels of resistance to B. tabaci. Field and screen-house experiments showed that all of the improved, high-yielding cassava mosaic disease (CMD) resistant cassava genotypes assessed were highly susceptible to B. tabaci and supported high populations of all life stages. These data support the hypothesis that the continuing high populations of cassava B. tabaci in Uganda are due, in part, to the widespread adoption of CMD-resistant cassava varieties during the CMD pandemic. They also show that the whitefly, Aleurotrachelus socialis, resistance present in the South American cassava genotypes could have broader applicability in the Old World.     

Life cycle, individual thrift, and the wealth of nations

One theory of the determinants of individual and national thrift has come to be known as the life cycle hypothesis of saving. The state of the art on the eve of the formulation of the hypothesis some 30 years ago is reviewed. Then the theoretical foundations of the model in its original formulation and later amendment are set forth, calling attention to various implications, some distinctive to it and some counterintuitive. A number of crucial empirical tests, both at the individual and the aggregate level, are presented as well as some applications of the life cycle hypothesis of saving to current policy issues.     

Living with the past: evolution, development, and patterns of disease

Epidemiological observations have led to the hypothesis that the risk of developing some chronic noncommunicable diseases in adulthood is influenced not only by genetic and adult life-style factors but also by environmental factors acting in early life. Research in evolutionary biology, developmental biology, and animal and human physiology provides support for this idea and suggests that environmental processes influencing the propensity to disease in adulthood operate during the periconceptual, fetal, and infant phases of life. This "developmental origins of health and disease" concept may have important biological, medical, and socioeconomic implications.     

生活方式、生产结构、生态环境与中国古代社会经济

本文通过对生活方式、生产结构和生态环境的角度,分析中国历史上社会经济与文化发展的进程。文章指出群居的生活方式、多子继承制度、食尽一山则移一山移民的模式、单一的种植业生产结构等,对古代生态环境产生重要的影响,其结果是供养了较多的人口,进而形成了环境依赖型经济,江南地区由于优越的环境,经济发达。文章最后解释了许多由于生活方式、生产结构和生态环境的原因所形成了经济社会现象。     

生活事件、应对方式对大学生不良情绪的影响

研究以长春市4所高校的439名大学生为被试,经问卷调查,了解当代大学生的心理健康状况及应对方式特点,探讨生活事件、应对方式对大学生不良情绪的作用机制,结果表明：生活事件各因子与焦虑呈显著正相关,应对方式中除解决问题,其余5个因子与焦虑呈显著正相关。焦虑与抑郁之间也有显著正相关,而抑郁与生活事件和应对方式各因子的相关都未达到显著性水平,应对方式作为生活事件与焦虑的中介变量,在应激过程中,与生活事件协同作用于焦虑,中介效应显著。     

林业机械设备寿命周期费用的计算、分析和应用研究

寿命周期费用理论是现代设备管理的重要理论。本文首先阐述了寿命周期费用的概念和各种计算方法,包括总费用的静态、动态计算方法和年平均费用的静态、动态计算方法。然后介绍了寿命周期费用分析步骤。在此基础上探讨了寿命周期费用分析在设备评价和设备更新效益计算中的应用方法。     

我国猪肉价格上涨成因、影响及建议

随着经济水平的提升、人们的生活水平的提高以及生活节奏的加快，人们已经不满足于自给 自足，而是要追求生活品质。近年来，由于种种原因，猪肉价格不断上涨，给人们生活带来极大影响。 我国应该采取合理措施促进猪肉价格平稳发展。     

食品营养标签常见问题与对策分析

食品营养标签是衡量食品安全的重要标准。随着《食品安全法》和《食品安全国家标准预包装食品营养标签》政策的推出,食品营养标签的常见问题也发生了变化。本文分析了食品营养标签存在的问题,及其对市场造成的影响,并提出了解决食品营养标签问题的对策,以期为食品安全生产提供参考。     

G protein-coupled receptors in Anopheles gambiae

We used bioinformatic approaches to identify a total of 276 G protein-coupled receptors (GPCRs) from the Anopheles gambiae genome. These include GPCRs that are likely to play roles in pathways affecting almost every aspect of the mosquito's life cycle. Seventy-nine candidate odorant receptors were characterized for tissue expression and, along with 76 putative gustatory receptors, for their molecular evolution relative to Drosophila melanogaster. Examples of lineage-specific gene expansions were observed as well as a single instance of unusually high sequence conservation.     

西藏农作物良种推广限制因素及解决方案浅析

近年来,西藏农业科研育种部门通过不懈地努力,选育出了一大批高产优质的作物新品种,但由于各种因素的限制,使这些新品种难以在生产中大面积推广应用,导致了西藏农业生产中良种更换速度慢、周期长。找出并解决这些不利因素,加快西藏农业生产中良种更换速度,进一步提高西藏农作物产量和品质,是西藏农业生产中亟待解决的问题。良种是各种增产技术的核心。水、土、肥资源及调控,病虫害综合防治等生产技术,以及物质、资金、劳动力等要素投入,都是围绕良种这个中心要素进行统筹。同时,所有这些技术,最终是依靠品种来实现其最终的生产效益。据统计目前我国良种对粮食增产的贡献率已超过40％。因此良种的推广应用对保障粮食安全,促进农民增收意义重大。     

干旱区绿洲制种玉米生命周期环境影响评价——以张掖市为例

为定量分析干旱区绿洲农业的生态环境影响,在张掖市统计局投入产出调查基础上增补专项调查,以黑河流域中游张掖市主要三县区的制种玉米为例,采用生命周期评价(LCA)方法,将灌溉用水量纳入LCA清单,定量评估作物生命周期内投入产出的环境影响。结果显示,张掖市甘州区、高台县和临泽县制种玉米环境综合影响指数分别为0.608 0、0.538 1和1.259 5,其中:化肥的生产和施用对环境影响十分显著;淡水消耗量高于华北地区,低于陕西关中地区;与实行轮作的地区比较,环境污染指数较高。建议加大技术指导,测土配方施肥,并在气候及生产条件允许的区域改变耕作制度,调整种植结构。     

拟南芥突变体lls糖信号响应异常

拟南芥突变体lls(long life span)是生活周期很长的单基因突变体.为了研究该突变对糖信号途径的影响,本文通过形态和生理学分析,结果发现lls突变体具有一些糖相关的表型特征,如:植株矮小,叶色深绿,生长缓慢等.通过测定植株的可溶性糖含量及叶绿素和花青素含量,结果显示lls植株的叶绿素和可溶性糖水平升高,可能由此引起花青素含量升高.施加外源的葡萄糖和蔗糖的实验结果表明lls突变体对外源糖信号敏感,这说明LLS突变可能严重影响了糖代谢或糖响应的某一途径.     

指纹图谱与山西省作物种质资源的研究

作物种质资源亦称遗传资源或基因资源,它蕴藏于作物各类品种、品系、类型、野生种和近缘野生植物中,是改良农作物的基因来源,是农作物新品种选育和相关学科研究的重要物质基础和可靠保证。而指纹图谱是鉴别品种、品系的有力工具。鉴于此介绍了山西省作物种质资源的丰富度、当前国际、国内及山西省作物种质资源的研究现状,分析了存在的问题及原因,并从指纹图谱方面对山西省作物种质资源的研究提出了相应的对策。     

应用同工酶对梨属下种、品种及芽变的鉴定

用POD和EST同工酶分析26个梨品种.POD同工酶可将26份试验材料中的12个样品区分出来,EST同工酶可将7个样品区分出来.综合两种同工酶谱带可对15个品种(含2个芽变)进行鉴定.