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1.
林敏  姚斌 《生物技术进展》2022,12(3):321-324
21世纪初兴起的合成生物技术被誉为影响世界未来的颠覆性技术之一,其在农业中应用将为世界性农业生产难题提供革命性解决方案,培育农业碳经济和氨经济等生物经济新形态,引领细胞农业、低碳农业和智能农业等新动能和新业态革命。简要总结了国际合成生物技术的发展现状与趋势,深入探讨了我国农业合成生物技术创新的发展战略与总体目标。  相似文献   

2.
武志杰  张丽莉 《生态学杂志》2006,25(10):1245-1251
循环经济是经济效益与环境效益有机结合的一种新的经济发展模式,将经济发展推向循环经济的轨道是保证可持续发展的重要举措。循环经济具有深刻的经济学基础和生态学基础,发展循环经济具有重要的现实意义,它是生态社会最适宜的经济发展模式,世界发达国家已在发展循环经济领域取得了较大成就。本文从循环经济的基础理论入手,阐述了我国发展循环经济的现状、重要意义和所面临的问题,提出我国发展循环经济的对策,并指出循环经济是中国21世纪经济可持续发展模式的必然选择。  相似文献   

3.
The most recognized definition of the circular economy is that it is a restorative and regenerative economy. Despite the wide use and importance attributed to the concepts of “restoration” and “regeneration,” they are rarely defined or explained in the circular economy literature. In this context, this study critically examines the two terms, while providing guidance on their future utilization and development. Specifically, the study investigates the origin of the concepts, their adoption in frameworks that anticipated the idea of the circular economy, and their connotations in the circular economy literature. The examination supports the need for clear and distinct definitions, combined with precision in usage. From a review of the literature, restoration is a better‐defined concept than regeneration, although it needs conceptual re‐enforcement relative to the biological/ecological aspects of the circular economy. This study suggests looking in the direction of restoration ecology, a well‐established branch of ecological research. Conversely, regeneration is a symbolic/evocative term with little practical application in the context of circular systems except in the case of certain agricultural practices. Until new conceptual developments intervene, regeneration does not seem to be applicable to the economy as a whole and because of this, might be abandoned as a guiding principle of the circular economy. Unlike regeneration, restoration can be considered a core principle because it has widespread application and can be a point of reference for circular applications. This does not preclude the possibility that other concepts may be needed to augment restoration.  相似文献   

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关于森林基础设施属性的探讨   总被引:1,自引:1,他引:0  
分析了生态基础设施概念的由来和发展,国际社会对森林功能和作用的认识过程,森林对我国经济建设和生态安全的重要性,以及当前林业生态建设的形势和所面临的问题,提出应将森林定位为现代社会国民经济和社会发展的基础设施,强调了森林基础设施定位对转变当前林业生态建设方式的重要作用.在综合分析森林生态系统特点的基础上,认为森林基础设施属性具有一定的特殊性,即主体由活体的生物材料构成,权属带有明显的多元性质,所以林业生态建设的模式和管理体制既要遵循基础设施的基本原则,又应考虑到森林的特殊性.提出了当前开展林业生态建设的4点建议:发展以人与自然和谐为核心的现代生态观;建立长期稳定的林业生态建设投资渠道;按照基础设施建设的原则实施林业生态建设工程;按照基础设施管理的原则经营森林.  相似文献   

6.
Antibodies are high value therapeutic, diagnostic, biotechnological, and research tools. Combinatorial approaches to antibody discovery have facilitated access to unique antibodies by surpassing the diversity limitations of the natural repertoire, exploitation of immune repertoires from multiple species, and tailoring selections to isolate antibodies with desirable biophysical attributes. The V-gene repertoire of the chicken does not utilize highly diverse sequence and structures, which is in stark contrast to the mechanism employed by humans, mice, and primates. Recent exploitation of the avian immune system has generated high quality, high affinity antibodies to a wide range of antigens for a number of therapeutic, diagnostic and biotechnological applications. Furthermore, extensive examination of the amino acid characteristics of the chicken repertoire has provided significant insight into mechanisms employed by the avian immune system. A paucity of avian antibody crystal structures has limited our understanding of the structural consequences of these uniquely chicken features. This paper presents the crystal structure of two chicken single chain fragment variable (scFv) antibodies generated from large libraries by phage display against important human antigen targets, which capture two unique CDRL1 canonical classes in the presence and absence of a non-canonical disulfide constrained CDRH3. These structures cast light on the unique structural features of chicken antibodies and contribute further to our collective understanding of the unique mechanisms of diversity and biochemical attributes that render the chicken repertoire of particular value for antibody generation.  相似文献   

7.
李婧  黄璐  严力蛟 《生态学杂志》2016,27(6):1785-1794
“珠江模式”、“温州模式”、“苏南模式”的发源地是中国经济发展的前沿地带,评估其可持续发展情况对中国经济的下一步发展具有重要的指导意义.本文采用真实发展指标(GPI),评估了1995—2012年中国“三大经济模式”下广州、深圳、温州、苏州、无锡、常州6个典型城市的可持续发展情况.结果表明: 研究期间,6个城市的GDP呈指数型增长,但GPI在1995—2005年间并无增长,2005年以后才开始上升,GPI与GDP的差距越来越大;“珠江模式”虽然经济增长迅猛,但经济、社会、环境损耗突出,实现其可持续发展必须解决分配不均、交通拥堵、环境污染等问题;“温州模式”人均GPI后期与其他城市拉开差距,发展后劲不足,贫富差距突出,社会账户水平较低且增长缓慢,发展方式亟待转型;“苏南模式”虽然资源消耗较为突出,但各类损耗处于中等水平,经济增长迅猛,社会账户水平稳步提高,GPI所反映出的真实发展水平也较高,相对具有可持续发展潜力.“三大经济模式”应持续关注可持续发展的经济、环境与社会三大方面,而“珠江模式”、“温州模式”应更积极地寻求发展转型.  相似文献   

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蓝以信  张庆  李婵 《生态学报》2021,41(23):9216-9227
提高生态效率是实现县域经济绿色发展的重要方式,在充分考虑江苏省县域经济发展合作共赢以及发展导向差异的前提下,遴选一产、二产、三产的增加值为关键指标并设置了3种不同的县域经济发展导向,采用权重约束的仁慈型交叉效率模型和Malmquist生产率指数测算了2015-2017年间江苏省32个县域在3种发展导向下的生态效率和生态全要素生产率,剖析各县域生态效率的差异性及其全要素生产率变动的驱动力,探寻各县域的差异化绿色发展模式。研究结果显示:(1)整体上看,江苏省县域总体生态效率水平较高,但同一地级市下辖的县域生态效率排名差距较大,且生态效率高的县域辐射效应不足。(2)从不同发展导向来看,县域平均生态效率值在绿色经济导向下最高,乡村振兴导向下次之,新型工业导向下最低;同时,同一县域在不同导向下的生态效率排名差异较大,隶属于乡村振兴类的县域最多,绿色经济类次之,新型工业类最少。(3)从动态分析来看,江苏省县域生态效率逐步提升,技术进步指数的增长是促进江苏省县域生态全要素生产率指数增长的主导因素,而绝大多数县域的技术效率变化指数保持不变或呈现衰退现象,表明分析期内江苏省县域生态技术效率未有所提升。  相似文献   

10.
Soybean agglutinin (gSBA) is a tetrameric legume lectin, each of whose subunits are glycosylated. Earlier studies have shown that this protein shows exceptionally high stability in terms of free energy of unfolding when compared to other proteins from the same family. This article deals with the unfolding reactions of the nonglycosylated recombinant form of the protein rSBA and its comparison with the glycosylated counterpart gSBA. The nonglycosylated form features a lower stability when compared to the glycosylated form. Further, the unfolding pathways in the two are widely different. Although the glycosylated form undergoes a simple two-state unfolding, the nonglycosylated species unfolds via a compact monomeric intermediate that is not a molten globule. Representative isothermal and thermal denaturation profiles show that glycosylation accounts for a stabilization of approximately 9 kcal/mol of the tetramer, whereas the difference in T(m) between the two forms is 26 degrees C. Computational studies on the glycan-protein interactions at the noncanonical interface of the protein show that quite a number of hydrogen bond and hydrophobic interactions stabilize the glycoprotein tetramer.  相似文献   

11.
We analyze data on the height and weight of mothers and newborn babies between 1980 and 2005 in St. Petersburg, Russia. We find that women's living standards, as measured by their height, improved steadily from the end of World War II through those born in 1972, hence reached adulthood in 1990. Thereafter, heights declined. Evidence on both the length and weight of babies corroborates this pattern. Their values trace a "U" shaped curve with troughs near the mid-1990s. Thus, the anthropometric results on newborn as well as for their mother point to the strains and challenges to living standards experienced during the restructuring of the post-Soviet economy. This is a general result that has become a recurring pattern: economic transitions are almost always accompanied by biological strains.  相似文献   

12.
The economic usefulness and potential of endangered and rare plants in the United States was surveyed to assess some of the potential impacts of plant extinction on the world’s largest economy. We analyzed relationships between an existing comprehensive database of U.S. rare plants, and a new database that synthesizes available information on worldwide plant uses and U.S. crop values. While few rare plants are directly useful, nearly 80% of the U.S. plant genera with rare taxa contain at least one useful species. Moreover, two-thirds of the 2949 U.S. rare and endangered taxa are congeneric with cultivated species. Examples of this close relationship between rare plants and their economically significant congenerics were translated into dollar values. For instance, the annual U.S. wholesale farm value of food crop congenerics of rare plants is $9 billion. Since many crops require periodic genetic infusions from close relatives to combat threats from climatic change and disease, or to supply features such as improved nutritional value, we conclude that the threats to the rare wild plants of the U.S. also constitute threats to the future of many contemporary crops.  相似文献   

13.
In indigenous communities in the Ecuadorian Andes, textile entrepreneurs have been building new homes in a distinctive, modern style. In contrast, their neighbors have perpetuated traditional motifs and forms. Underlying these designs are two economic systems: the national cash economy and the subsistence economy with its networks of labor reciprocity. In recent years, architecture has provided families with a forum for working out the social meaning and prestige of these different economic relationships and assets. The study of consumption patterns allows anthropologists to trace how societies transform new forms of wealth into locally structured relations of power and symbols of identity.  相似文献   

14.
Sture Lagercrantz 《Ethnos》2013,78(1-2):63-70
Lætadianism—the religious revival as it appeared in Northern Norway in the second half of the last century—is analyzed as a form of symbolic opposition (Schwimmer 1972) from the Sámi and the Kvens against the Norwegian policy of cultural and economic integration. The expansion of Norwegian administration and economy from the middle of the 19th century, established new status‐sets and fields of interaction within agriculture, school‐system and health service. Events and interaction within each of these fields created circumstances for what took place in the actor's other relationship and this dynamic is thus analysed as implication systems (Grenhaug 1978).

All interaction with Norwegian society was built upon Norwegian statuses and values and the Sámi and Kvens established a new definition of the situation by reversing the Norwegian standards through the medium of Christianity. Their material poverty was converted into spiritual wealth and thus a different inter‐ethnic context of interaction surfaced. This new opportunity situation (Barth 1966) made it possible to reject the Norwegian society which earlier had rejected them.  相似文献   

15.
Factors responsible for the spatial and temporal clustering of Burkholderia pseudomallei in the environment remain to be elucidated. Whilst laboratory based experiments have been performed to analyse survival of the organism in various soil types, such approaches are strongly influenced by alterations to the soil micro ecology during soil sanitisation and translocation. During the monsoonal season in Townsville, Australia, B. pseudomallei is discharged from Castle Hill (an area with a very high soil prevalence of the organism) by groundwater seeps and is washed through a nearby area where intensive sampling in the dry season has been unable to detect the organism. We undertook environmental sampling and soil and plant characterisation in both areas to ascertain physiochemical and macro-floral differences between the two sites that may affect the prevalence of B. pseudomallei. In contrast to previous studies, the presence of B. pseudomallei was correlated with a low gravimetric water content and low nutrient availability (nitrogen and sulphur) and higher exchangeable potassium in soils favouring recovery. Relatively low levels of copper, iron and zinc favoured survival. The prevalence of the organism was found to be highest under the grasses Aristida sp. and Heteropogon contortus and to a lesser extent under Melinis repens. The findings of this study indicate that a greater variety of factors influence the endemicity of melioidosis than has previously been reported, and suggest that biogeographical boundaries to the organisms’ distribution involve complex interactions.  相似文献   

16.
In this paper we introduce a new method to expressly use live/corporeal data in quantifying differences of time series data with an underlying limit cycle attractor; and apply it using an example of gait data. Our intention is to identify gait pattern differences between diverse situations and classify them on group and individual subject levels. First we approximated the limit cycle attractors, from which three measures were calculated: δM amounts to the difference between two attractors (a measure for the differences of two movements), δD computes the difference between the two associated deviations of the state vector away from the attractor (a measure for the change in movement variation), and δF, a combination of the previous two, is an index of the change. As an application we quantified these measures for walking on a treadmill under three different conditions: normal walking, dual task walking, and walking with additional weights at the ankle. The new method was able to successfully differentiate between the three walking conditions. Day to day repeatability, studied with repeated trials approximately one week apart, indicated excellent reliability for δM (ICCave > 0.73 with no differences across days; p > 0.05) and good reliability for δD (ICCave  =  0.414 to 0.610 with no differences across days; p > 0.05). Based on the ability to detect differences in varying gait conditions and the good repeatability of the measures across days, the new method is recommended as an alternative to expensive and time consuming techniques of gait classification assessment. In particular, the new method is an easy to use diagnostic tool to quantify clinical changes in neurological patients.  相似文献   

17.
Traditionally, protein-protein interactions were thought to be mediated by large, structured domains. However, it has become clear that the interactome comprises a wide range of binding interfaces with varying degrees of flexibility, ranging from rigid globular domains to disordered regions that natively lack structure. Enrichment for disorder in highly connected hub proteins and its correlation with organism complexity hint at the functional importance of disordered regions. Nevertheless, they have not yet been extensively characterised. Shifting the attention from globular domains to disordered regions of the proteome might bring us closer to elucidating the dense and complex connectivity of the interactome. An important class of disordered interfaces are the compact mono-partite, short linear motifs (SLiMs, or eukaryotic linear motifs (ELMs)). They are evolutionarily plastic and interact with relatively low affinity due to the limited number of residues that make direct contact with the binding partner. These features confer to SLiMs the ability to evolve convergently and mediate transient interactions, which is imperative to network evolution and to maintain robust cell signalling, respectively. The ability to discriminate biologically relevant SLiMs by means of different attributes will improve our understanding of the complexity of the interactome and aid development of bioinformatics tools for motif discovery. In this paper, the curated instances currently available in the Eukaryotic Linear Motif (ELM) database are analysed to provide a clear overview of the defining attributes of SLiMs. These analyses suggest that functional SLiMs have higher levels of conservation than their surrounding residues, frequently evolve convergently, preferentially occur in disordered regions and often form a secondary structure when bound to their interaction partner. These results advocate searching for small groupings of residues in disordered regions with higher relative conservation and a propensity to form the secondary structure. Finally, the most interesting conclusions are examined in regard to their functional consequences.  相似文献   

18.
NIKLAS  KARL J. 《Annals of botany》1991,68(3):253-262
The flexural stiffness EI, elastic modulus E, second momentof area I, length L, and weight Wt of foliage leaves from 26species of pine were measured to determine the manner in whichEI is scaled to leaf size (L or Wt, or both) and to determineif the biomechanical attributes of foliage leaves could be juxtaposedwith the systematic affiliations of species within Pinus Biomechamcaland morphometric data were explored based on a model from engineeringtheory that predicts the relationships among EI, Wt and L providedthat the maximum tip-deflection max of an untapered cantileveredbeam sustaining its own weight is maintained as the beam eitherincreases in length or weight, or both, I e max = Wt L2/8EIThe data show that EI disproportionately increased as eitherWt or L, or both increased The allometry of leaves did not conformto that predicted by the model Rather, EI was proportional tothe product of Wt and L raised to an exponent slightly greaterthan one Thus, Omax was predicted not to be maintained as eitherWt or L, or both, increased, as verified by observations Therelationship between El and Wt(L) differed for species typicallyproducing two leaves per fascicle and those bearing more thantwo leaves per fascicle Also, El is geometrically constrainedby the number of leaves produced per fascicle, principally interms of the effects of the number of leaves per fascicle onI Pinus, pine, leaves, biomechanics, Young's modulus  相似文献   

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江苏省常熟市地处长江南岸阳澄湖畔,临近大中城市,距上海100km,离苏州、无锡、南通不足50km,历史上为苏南重点商品粮基地之一。因地理位置、地形、地貌及大气环流等因素所决定,常熟属北亚热带南部湿润地区,年平均气温15.5℃,年日照时数2202.9小时,年雨量1038.4mm。全市境内湖泊、河流纵横交错连结成网,有水域1.75×10~4ha,大小河流4477条。全境总面积1142.2km~2,北部较高,海拔3.11m左右,向南缓缓降低,最低地区海拔0.61m。  相似文献   

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