生物农药与生物防治发展战略浅谈

目前我国化学农药施用量超标和农药残留污染严重,成为保障食品安全,提高人们生活质量的重要影响因素之一。从我国生物农药产业发展和产品研发的现状出发,分析了我国生物农药产业发展与国际同行业间的差距等问题,强调了生物农药与生物防治技术的应用在粮食安全生产中的重要作用,指出了生物防治产业发展中的瓶颈问题,提出了促进生物农药与生物防治产业发展战略措施与建议。     

非肉食性鱼类饲料中用动植物蛋白源替代鱼粉的研究进展

鱼粉的全球性缺乏已成为制约水产增养殖业可持续发展的重要影响因素。作者综述了近年来在非肉食性鱼类日粮中用动植物蛋白源替代鱼粉方面的研究成果,对替代后造成的负面影响（生产性能下降,生理和免疫机能降低,肉质品质劣化等）进行了总结,并对其原因和对策进行了归纳、分析和探讨,旨在为非肉食性鱼类低鱼粉乃至无鱼粉日粮的开发提供思路和基础资料。     

中国海水养殖业资源-环境-经济系统耦合协调发展分析

推进海水养殖业绿色发展是建设海洋强国的重要举措。正确处理产业发展过程中资源、环境与经济发展的关系,是中国海水养殖业破除发展瓶颈,由海水养殖大国向强国转变的重中之重。本文在构建中国海水养殖业资源-环境-经济综合评价体系的基础上,运用耦合协调度模型等方法分析其协调发展程度。结果表明：2011~2018年中国海水养殖资源与环境发展指数均呈下降趋势,而经济发展指数则在振荡中上升;中国海水养殖复合系统处于低发展水平下的高耦合中级协调状态,资源-环境及环境-经济系统协调度呈濒临失调的振荡下降态势,资源-经济系统呈振荡增长态势,复合系统协调度地理分布呈北高南低发展态势。建议各地区聚焦发展短板,加强养殖技术创新,以资源-环境协调发展为主线,以期推进海水养殖业绿色可持续发展。     

Multiple microtektite horizons in upper eocene marine sediments: no evidence for mass extinctions

Microtektites have been recovered from three horizons in eight middle Eocene to middle Oligocene marine sediment sequences. Five of these occurrences are coeval and of latest Eocene age (37.5 to 38.0 million years ago); three are coeval and of early late Eocene age (38.5 to 39.5 million years ago); and three are of middle Oligocene age (31 to 32 million years ago). In addition, rare probable microtektites have been found in sediments with ages of about 36.0 to 36.5 million years. The microtektite horizon at 37.5 to 38.0 million years can be correlated with the North American tektite-strewn field, which has a fission track age (minimum) of 34 to 35 million years and a paleomagnetic age of 37.5 to 38.0 million years. There is no evidence for mass faunal extinctions at any of the microtektite horizons. Many of the distinct faunal changes that occurred in the middle Eocene to middle Oligocene can be related to the formation of the Antarctic ice sheet and the associated cooling phenomena and intensification of bottom currents that led to large-scale dissolution of calcium carbonate and erosion, which created areally extensive hiatuses in the deep-sea sediment records. The occurrence of microtektite horizons of several ages and the lack of evidence for faunal extinctions suggest that the effects of extraterrestrial bolide impacts may be unimportant in the biologic realm during middle Eocene to middle Oligocene time.     

Secondary sewage treatment versus ocean outfalls: an assessment

Simplified models have been developed to obtain order of magnitude estimates of the oxygen demand of municipal and industrial wastes and of their potential eutrophication effects in the marine environment. The models have been applied to assess two major corrective actions that might be considered for such pollution problems-secondary sewage treatment and ocean outfalls. It is concluded that the arguments for secondary sewage treatment as the proper corrective action are not compelling and that the problem should be reexamined with appropriate scientific and engineering evaluations. One goal of such scientific evaluations should be a more thorough understanding of the life histories of possible trace contaminants and pathogens which may have long biological, chemical, or geological retention times in the marine environment.     

Strong top-down control in southern California kelp forest ecosystems

Global-scale changes in anthropogenic nutrient input into marine ecosystems via terrestrial runoff, coupled with widespread predator removal via fishing, have created greater urgency for understanding the relative role of top-down versus bottom-up control of food web dynamics. Yet recent large-scale studies of community regulation in marine ecosystems have shown dramatically different results that leave this issue largely unresolved. We combined a multiyear, large-scale data set of species abundances for 46 species in kelp forests from the California Channel Islands with satellite-derived primary production and found that top-down control explains 7- to 10-fold more of the variance in abundance of bottom and mid-trophic levels than does bottom-up control. This top-down control was propagated via a variety of species-level direct and indirect responses to predator abundance. Management of top-down influences such as fishing may be more important in coastal marine ecosystems, particularly in kelp forest systems, than is commonly thought.     

我国南极磷虾资源开发利用技术发展现状与对策

南极磷虾资源开发与利用日益受到国际关注。随着南极磷虾捕捞与加工技术的不断成熟,不同国家对南极磷虾资源的开发策略也发生了变化。分析了我国在南极磷虾资源开发利用方面的技术瓶颈,以及在自主设计研发南极磷虾捕捞装备和虾粉、虾油制备方面取得的进展;通过分析有关南极磷虾专利申请信息,认为当前国内研发主体较为关注磷虾油和饲料的制备及生产工艺,而国际上已将研发重点和专利申请的焦点转移至医药领域。在开发海洋生物资源战略需求下,认为应进一步加快设计与建造南极磷虾捕捞加工专业船的进程,同时完善南极磷虾加工技术与专利布局,为抢占和开拓南极磷虾消费市场提供技术支撑和保障。     

Terminal cretaceous extinction scenario for a catastrophe

All the biotic changes that occurred at the end of Cretaceous time, including the extinction of the dinosaurs, may be the result of a single terrestrial catastrophe. The Arctic spillover model, first proposed to explain the marine extinctions, would have caused a rapid and intense change in the earth's climate including a lowering of temperature and of precipitation. This change in climate may have triggered a series of ecological disasters that included the radical change in the distribution of vegetation on the earth as well as the extinction of the dinosaurs.     

Molecular models for DNA damaged by photoreaction

Structural models of a DNA molecule containing a radiation-induced psoralen cross-link and of a DNA containing a thymine photodimer were constructed by applying energy-minimization techniques and model-building procedures to data from x-ray crystallographic studies. The helical axes of the models show substantial kinking and unwinding at the sites of the damage, which may have long-range as well as local effects arising from the concomitant changes in the supercoiling and overall structure of the DNA. The damaged areas may also serve as recognition sites for repair enzymes. These results should help in understanding the biologic effects of radiation-induced damage on cells.     

资源环境约束下的内蒙古自治区粮食增产问题研究

"十年九旱"的内蒙古,为粮食增产付出的资源和环境成本巨大。因为资源和环境已成为粮食增产的双重瓶颈,又是内蒙古经济社会可持续发展的主要瓶颈。由此,内蒙古要切实加快25°以上坡耕地的退耕还林还草,改善生态环境,发展内涵式的粮食生产方式和节粮型畜牧业,发挥农牧结合的优势,顺应气候变化,从而逐步缓解资源和环境的瓶颈,保障粮食增产,提高农民收入。     

Biologic features of HIV-1 that correlate with virulence in the host

Individuals infected with the human immunodeficiency virus type 1 (HIV-1) may be asymptomatic or have AIDS-related complex or the acquired immuno deficiency syndrome (AIDS). Little is known about the factors that influence progression of infection to AIDS. In this study of isolates of HIV-1 obtained at intervals during the infection of four individuals, the development of disease was found to be correlated with the emergence of HIV-1 variants that were more cytopathic in vitro as the disease progressed and that replicated more efficiently in a wide variety of different human cells. The biologic properties of HIV-1 in vitro thus appear to reflect its virulence in the host. Further studies of such sequentially isolated viruses may lead to the identification of viral genes that govern pathogenesis.     

单体型关联分析方法研究进展

基于单体型的分析方法在当前的复杂疾病和数量性状候选基因的研究中扮演越来越重要的角色。本文综述了开展单体型关联分析研究的动机,单体型的生物功能及单体型的统计优势。介绍了单体型关联分析的回归分析模型,应用的局限和需要进一步的研究的领域。     

Organic carbon fluxes and ecological recovery from the cretaceous-tertiary mass extinction

Differences between the carbon isotopic values of carbonates secreted by planktic and benthic organisms did not recover to stable preextinction levels for more than 3 million years after the Cretaceous-Tertiary mass extinction. These decreased differences may have resulted from a smaller proportion of marine biological production sinking to deep water in the postextinction ocean. Under this hypothesis, marine production may have recovered shortly after the mass extinction, but the structure of the open-ocean ecosystem did not fully recover for more than 3 million years.     

海水鱼类保鲜技术的研究进展

随着对海洋鱼类的研究开发,人们意识到海水鱼类具有更高的营养价值,例如含有高度不饱和脂肪酸等,于是越来越倾向于食用海水鱼类。海水鱼类的保鲜技术主要有低温保鲜、化学和生物保鲜、高压保鲜、气调保鲜、辐照保鲜、臭氧保鲜等,通过逐一对其进行介绍,最后提出了今后的研究方向,以便为海水鱼类贮藏保鲜技术的发展提供依据。     

Viviparity and K-selected life history in a Mesozoic marine plesiosaur (Reptilia, Sauropterygia)

Viviparity is known in several clades of Mesozoic aquatic reptiles, but evidence for it is lacking in the Plesiosauria. Here, we report a Late Cretaceous plesiosaur fossil consisting of a fetus preserved within an adult of the same taxon. We interpret this occurrence as a gravid female and unborn young and hence as definitive evidence for plesiosaur viviparity. Quantitative analysis indicates that plesiosaurs gave birth to large, probably single progeny. The combination of viviparity, large offspring size, and small brood number differs markedly from the pattern seen in other marine reptiles but does resemble the K-selected strategy of all extant marine mammals and a few extant lizards. Plesiosaurs may have shared other life history traits with these clades, such as sociality and maternal care.     

Self-assembling amphiphilic siderophores from marine bacteria

Most aerobic bacteria secrete siderophores to facilitate iron acquisition. Two families of siderophores were isolated from strains belonging to two different genera of marine bacteria. The aquachelins, from Halomonas aquamarina strain DS40M3, and the marinobactins, from Marinobacter sp. strains DS40M6 and DS40M8, each contain a unique peptidic head group that coordinates iron(III) and an appendage of one of a series of fatty acid moieties. These siderophores have low critical micelle concentrations (CMCs). In the absence of iron, the marinobactins are present as micelles at concentrations exceeding their CMC; upon addition of iron(III), the micelles undergo a spontaneous phase change to form vesicles. These observations suggest that unique iron acquisition mechanisms may have evolved in marine bacteria.     

分子生物学技术在鞘翅目昆虫分类研究中的应用

随着生物技术的迅猛发展,分子生物学技术已越来越多地被应用在昆虫的分类学研究中.笔者概述了核酸序列分析、RFLP技术、RAPD技术、分子杂交技术、同工酶电泳技术、SSCP以及DSCP技术在鞘翅目昆虫分类研究中的应用情况,并展望了分子生物学技术在鞘翅目昆虫研究中的广阔前景.     

Genesis of Hydrocarbons of Low Molecular Weight in Organic-Rich Aquatic Systems

Mild heat treatment of water-wet marine muds resulted in the genesis of three aromatic hydrocarbons characteristic of crude oils, but which are seldom found in significant quantities in recent sediments. Whereas part of the toluene and xylenes may have stemmed from carotenoid pigments, the source of the benzene as well as the larger amount of the toluene and xylene is as yet unknown.     

Origin of ancient potash evaporites: clues from the modem nonmarine qaidam basin of Western china

Modern potash salt deposits and associated brines of the Qaidam Basin, western China, demonstrate that some anomalous marine evaporites may have formed from nonmarine brines instead of seawater. Qaidam Basin brines are derived from meteoric river inflow mixed with small amounts of CaCl spring inflow similar in composition to many saline formation waters and hydrothermal brines. Evaporation of springenriched inflow yields a predicted mineral sequence including carnallite, bischofite, and tachyhydrite that is identical to several anomalous marine evaporites. Other mixtures of river and spring inflow produce the salt assemblage expected from evaporation of seawater.     

A terminal mesozoic "greenhouse": lessons from the past

The late Mesozoic rock and life records implicate short-term (up to 10(5) to 10(6) years) global warming resulting from carbon dioxide-induced "greenhouse" conditions in the late Maestrichtian extinctions that terminated the Mesozoic Era. Oxygen isotope data from marine microfossils suggest late Mesozoic climatic cooling into middle Maestrichtian, and warming thereafter into the Cenozoic. Animals adapting to climatic cooling could not adapt to sudden warming. Small calcareous marine organisms would have suffered solution effects of carbon dioxide-enriched waters; animals dependent upon them for food would also have been affected. The widespread terrestrial tropical floras would likely not have reflected effects of a slight climatic warming. In late Mesozoic, the deep oceanic waters may have been triggered into releasing vast amounts of carbon dioxide into the atmosphere in a chain reaction of climatic warming and carbon dioxide expulsion. These conditions may be duplicated by human combustion of the fossil fuels and by forest clearing.