A retained viability index (RVI10) for evaluation of a cyanobacterial powder fertilizer

The preparation of a dry and powder fertilizer based on five nitrogen-fixing cyanobacterial strains is described. Tolypothrix tenuis and Nostoc muscorum resisted the drying and milling processes and showed a suitable recovering capacity in liquid media of different pH and salinity. Although a decrease in the cellular viability was observed with the storage time, the biomass of Nostoc muscorum retained viability for 16 months. The results were evaluated in terms of the retained viability index (RVI₁₀) specifically designed for the fertilizer material.     

洗涤剂对蚕豆根和叶片的作用

研究了家用洗衣粉对蚕豆根生长、细胞分裂和叶片叶绿素含量的影响。结果表明:不同浓度的洗衣粉均能抑制蚕豆根的生长,降低根尖细胞有丝分裂指数,诱发细胞产生高频率的微核且是明显的时间与剂量效应关系和叶绿素含量明显下降。     

植物拉丁学名及其索引编排标准化的重要意义

从植物学科技期刊标准化编辑、加工的实践出发,阐述了植物拉丁学名及其索引编排的规范化和标准化,论述了植物拉丁学名及其索引在植物科学研究中的重要作用,以及MICROSOFT EXCEL软件在编排植物拉丁学名索引中的应用。     

烟草抗CMV突变体的抗病性分析

在突变体植株“Ea201主、Ea201侧、Aa201侧”的5～6叶期接种CMV汁液,并按优选法去除病症最严重的病株,6周后将剩余植株分别移栽到田间露地和防虫网内,到盛花期分别统计植株的感病情况。其结果为：在田间露地和防虫网内,①感病的对照品种的植株高度只及健康的对照植株高度的30％和40％,突变体的则可达到70％和80％;②对照品种的植株感CMV的病情指数可达90％和50％,突变体的则只有30％和3％;③对照品种植株感TMV的病情指数可达60％和30％,突变体植株感TMV的病情指数只有30％和10％;④突变体植株群体中有症状回复现象,同时其育性不受任何影响。从而表明所筛选到的烟草突变体“Ea201主、Ea201侧、Aa201侧”对CMV、TMV的相对抗性较好,具有较高的抗病性。     

Fetal Origins of Obesity

The worldwide epidemic of obesity continues unabated. Obesity is notoriously difficult to treat, and, thus, prevention is critical. A new paradigm for prevention, which evolved from the notion that environmental factors in utero may influence lifelong health, has emerged in recent years. A large number of epidemiological studies have demonstrated a direct relationship between birth weight and BMI attained in later life. Although the data are limited by lack of information on potential confounders, these associations seem robust. Possible mechanisms include lasting changes in proportions of fat and lean body mass, central nervous system appetite control, and pancreatic structure and function. Additionally, lower birth weight seems to be associated with later risk for central obesity, which also confers increased cardiovascular risk. This association may be mediated through changes in the hypothalamic pituitary axis, insulin secretion and sensing, and vascular responsiveness. The combination of lower birth weight and higher attained BMI is most strongly associated with later disease risk. We are faced with the seeming paradox of increased adiposity at both ends of the birth weight spectrum—higher BMI with higher birth weight and increased central obesity with lower birth weight. Future research on molecular genetics, intrauterine growth, growth trajectories after birth, and relationships of fat and lean mass will elucidate relationships between early life experiences and later body proportions. Prevention of obesity starting in childhood is critical and can have lifelong, perhaps multigenerational, impact.     

化学性大气污染的植物修复与绿化树种选择(综述)

简要介绍化学性大气污染的植物修复过程与机理,阐述植物对空气污染物抗性研究的主要方法和抗性指标,以及修复大气污染绿化树种的选择依据。     

Structural and Functional Changes in the Leaves of Plants from Steppe Communities as Affected by Aridization of the Eurasian Climate

Morphological and physiological characteristics of leaves from plant species collected in steppe communities in the various climatic zones in Eurasia were compared. The changes in leaf structure correlated with the major climatic factors. The mean thickness of leaves increased with increasing mean temperature of July and decreasing mean precipitation, which corresponded to aridity increase. The increased leaf thickness correlated with an increase in the specific leaf weight. The content of chlorophylls (a + b) in leaves greatly varied with plant habitats, whereas the chlorophyll a/b ratio remained unchanged. The chlorophyll content in leaf tissues had a general tendency to decrease with increasing leaf thickness. The leaf chlorophyll content positively correlated (R ² = 0.77) with the proportion of chlorenchyma in leaf tissues. It is concluded that steppe plants adapt to climate aridization at the structural level by increasing the proportion of protective heterotrophic components of the leaf without changing the functional activity of photosynthetic tissues.     

The Cultural Relics Distribution Characteristics Along the Canal Line and Appraisal of its Influence by the Middle Route Project for Water Transferring from South to North China

Assessments of the impacts of environmental hazards on ecological systems and human health have become a subject of ever-increasing importance. In this work, we extend current ecological hazard evaluation to the problem of protecting cultural relics from hazards attributable to the presence of a large-scale canal system being planned in China. The development and utilization of water resources must be closely combined with the preservation of cultural relics. The Middle Route Project for Water Transfer from South to North China (MRWT) is a current example. In this paper, the engineering background of this project is briefly introduced. The distribution of cultural relics related to it is also summarized in terms of different geographical divisions. An influence index E = f(L, δh, k, I, v, s) is introduced to measure the comprehensive effect of the canal on cultural relics. Because this function is really established at the preconstruction stage, it is treated by use of fuzzy mathematics. Each cultural relic has its own E value. Cultural relics with E values greater than 0.75 should be paid high attention, while those with E less than 0.5 may generally be ignored. What must be preserved through use of engineering measures are cultural relics with E values greater than 0.9. As to those cultural relics with E ranging between 0.5 and 0.75, whether they should be preserved with engineering controls depends upon practical circumstances specific to each relic.     

Global synthesis of leaf area index observations: implications for ecological and remote sensing studies

Aim We present the first global synthesis of plant canopy leaf area index (LAI) measurements from more than 1000 published estimates representing ～400 unique field sites. LAI is a key variable for regional and global models of biosphere‐atmosphere exchanges of energy, carbon dioxide, water vapour, and other materials. Location The location is global, geographically distributed. Results Biomes with LAI values well represented in the literature included croplands, forests and plantations. Biomes not well represented were deserts, shrublands, tundra and wetlands. Nearly 40% of the records in the database were published in the past 10 years (1991–2000), with a further 20% collected between 1981 and 1990. Mean (± SD) LAI, distributed between 15 biome classes, ranged from 1.3 ± 0.9 for deserts to 8.7 ± 4.3 for tree plantations, with temperate evergreen forests (needleleaf and broadleaf) displaying the highest average LAI (5.1–6.7) among the natural terrestrial vegetation classes. Following a statistical outlier analysis, the global mean (± SD) LAI decreased from 5.2 (4.1) to 4.5 (2.5), with a maximum LAI of 18. Biomes with the highest LAI values were plantations > temperate evergreen forests > wetlands. Those with the lowest LAI values were deserts < grasslands < tundra. Mean LAI values for all biomes did not differ statistically by the methodology employed. Direct and indirect measurement approaches produced similar LAI results. Mean LAI values for all biomes combined decreased significantly in the 1990s, a period of substantially more studies and improved methodologies. Main conclusions Applications of the LAI database span a wide range of ecological, biogeochemical, physical, and climate research areas. The data provide input to terrestrial ecosystem and land‐surface models, for evaluation of global remote sensing products, for comparisons to field studies, and other applications. Example uses of the database for global plant productivity, fractional energy absorption, and remote sensing studies are highlighted.     

Refolding of proteins from inclusion bodies is favored by a diminished hydrophobic effect at elevated pressures

The application of high hydrostatic pressure is an effective tool to promote dissolution and refolding of protein from aggregates and inclusion bodies while minimizing reaggregation. In this study we explored the mechanism of high-pressure protein refolding by quantitatively assessing the magnitude of the protein-protein interactions both at atmospheric and elevated pressures for T4 lysozyme, in solutions containing various amounts of guanidinium hydrochloride. At atmospheric pressure, the protein- protein interactions are most attractive at moderate guanidinium hydrochloride concentrations (approximately 1-2 molar), as indicated by a minimum in B(22) values. In contrast, at a pressure of 1,000 bar no minimum in B(22) values is observed, indicating that high pressures colloidally stabilize protein against aggregation. Finally, experimental values of refractive index increments as a function of pressure indicate that at high pressures, wetting of the hydrophobic surfaces is favored, resulting in a reduction of the hydrophobic effect. This reduction in the hydrophobic effect reduces the driving force for aggregation of (partially) unfolded protein.