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1.
Interpreting the functional content of a given genomic sequence is one of the central challenges of biology today. Perhaps the most promising approach to this problem is based on the comparative method of classic biology in the modern guise of sequence comparison. For instance, protein-coding regions tend to be conserved between species. Hence, a simple method for distinguishing a functional exon from the chance absence of stop codons is to investigate its homologue from closely related species. Predicting regulatory elements is even more difficult than exon prediction, but again, comparisons pinpointing conserved sequence motifs upstream of translation start sites are helping to unravel gene regulatory networks. In addition to interspecific studies, intraspecific sequence comparison yields insights into the evolutionary forces that have acted on a species in the past. Of particular interest here is the identification of selection events such as selective sweeps. Both intra- and interspecific sequence comparisons are based on a variety of computational methods, including alignment, phylogenetic reconstruction, and coalescent theory. This article surveys the biology and the central computational ideas applied in recent comparative genomics projects. We argue that the most fruitful method of understanding the functional content of genomes is to study them in the context of related genomic sequences. In particular, such a study may reveal selection, a fundamental pointer to biological relevance.  相似文献   

2.
Behavioral genomics of honeybee foraging and nest defense   总被引:8,自引:1,他引:8  
The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits. We review what is known about the genetics and physiology of two behavioral traits in honeybees, foraging specialization (pollen versus nectar), and defensive behavior, and present evidence that map-based cloning of genes is more feasible in the bee than in other metazoans. We also present bioinformatic analyses of candidate genes within QTL confidence intervals (CIs). The high recombination rate of the bee made it possible to narrow the search to regions containing only 17–61 predicted peptides for each QTL, although CIs covered large genetic distances. Knowledge of correlated behavioral traits, comparative bioinformatics, and expression assays facilitated evaluation of candidate genes. An overrepresentation of genes involved in ovarian development and insulin-like signaling components within pollen foraging QTL regions suggests that an ancestral reproductive gene network was co-opted during the evolution of foraging specialization. The major QTL influencing defensive/aggressive behavior contains orthologs of genes involved in central nervous system activity and neurogenesis. Candidates at the other two defensive-behavior QTLs include modulators of sensory signaling (Am5HT 7 serotonin receptor, AmArr4 arrestin, and GABA-B-R1 receptor). These studies are the first step in linking natural variation in honeybee social behavior to the identification of underlying genes.  相似文献   

3.
Intelligent behavior is a complex adaptive phenomenon that has evolved to enable organisms to deal with variable environmental circumstances. Maximizing fitness requires skill in foraging for necessary resources (food) in competitive circumstances and is probably the activity in which intelligent behavior is most easily seen. Biologists suggest that intelligence encompasses the characteristics of detailed sensory perception, information processing, learning, memory, choice, optimisation of resource sequestration with minimal outlay, self-recognition, and foresight by predictive modeling. All these properties are concerned with a capacity for problem solving in recurrent and novel situations. Here I review the evidence that individual plant species exhibit all of these intelligent behavioral capabilities but do so through phenotypic plasticity, not movement. Furthermore it is in the competitive foraging for resources that most of these intelligent attributes have been detected. Plants should therefore be regarded as prototypical intelligent organisms, a concept that has considerable consequences for investigations of whole plant communication, computation and signal transduction.  相似文献   

4.
用电厂粉煤灰处理中药废水   总被引:4,自引:1,他引:4  
针对耒阳电厂粉煤灰和中药厂排出废水的特点,考查了粉煤灰的投加量、颗粒度、改性剂、搅拌吸附时间和pH值等因素对处理效果的影响.用改性后的粉煤灰进行了L9(34)正交实验,根据实验结果,确定了适合的条件为:每升废水中投加粉煤灰90 g,在pH值=7.5时搅拌45min,沉淀35min.在此实验条件下,CODCr,色度,浊度的去除率分别为84.2%,83.2%,79.2%.  相似文献   

5.
通过对自来水厂、净化厂及两厂混合后的泥水的研究,来分析两厂泥水的匹配性。实验表明:自来水厂泥水排入净化厂与其泥水一起处理,能够促进净化厂泥水的浓缩,降低浓缩后污泥的比阻,而且在一定范围内能够降低污泥的最终体积,达到减量化的目的。  相似文献   

6.
仙女河污水处理厂升级改造中脱氮除磷的中试研究   总被引:1,自引:0,他引:1  
对该污水厂所面临的一级A升级改造任务,设计日处理水量2 t的中试装置,分别进行化学除磷和以甲醇为碳源的后置反硝化试验研究,得出化学除磷工艺最佳药剂投加量以及后置反硝化工艺最佳运行参数.  相似文献   

7.
阐述了电厂灰场植被覆盖技术的原理、实施方案和主要效益  相似文献   

8.
《环境》2010,(6):67-67
广州珠江电厂为广州发展实业控股集团股份有限公司属下企业,位于广州市南沙区,地处珠江三角洲经济区几何中心和电力负荷中心,总装机容量为4×300MW燃煤发电机组,是广州市最大的电力生产企业和广东网主力电厂之一。广州珠江电厂先后获得全国一流火力发电厂、全国电力行业质量管理奖、广东省先进集体、广州市安全生产先进单位、广东省环保诚信企业等两百多个荣誉称号。  相似文献   

9.
随着中国国民经济的不断发展和城乡一体化建设的发展,市政工程设施建设获得了空前发展。随着国民环保意识的增强,国家对城市污水治理及排放标准提高,政府提倡节能减排。因此,国内现有众多的污水处理厂需进行大量的提标改造,为了更好的利用原有的水处理构筑物,减少浪费,根据近些年的水处理构筑物改造与加固设计工程实践,对污水处理厂水处理构筑物的改造与加固技术进行了探索与总结,供类似的工程设计参考借鉴。  相似文献   

10.
对PTA装置的腐蚀状况进行了描述,围绕据装置的流程特点、操作条件、设备选材和制造等方面对装置的腐蚀类型和影响因素进行了分析,提出了工艺防腐、材料选择和制造质量控制等方面的改进措施。  相似文献   

11.
淮北国家城市湿地公园野生植物区系及栽培植物营建   总被引:1,自引:0,他引:1  
论文对淮北煤矿塌陷区国家城市湿地公园野生植物区系进行调查,对公园栽培植物营建进行分析。结果表明:1)该区共有野生植物42科95属115种,其中单子叶植物6科27种,双子叶植物35科87种,蕨类植物1科1种。菊科(Compositae)、禾本科(Gramineae)和豆科(Leguminosae)为优势科;属的成分相对分散,均为寡种属和单种属;植物以农田杂草为主,区系成分简单,野生湿地植物种类优势明显。2)湿地公园湿地植被划分为2个植被型组、5个植被型和18个群系。白茅(Imperata cylindrical)、藜(Chenopodium album)、狗牙根(Cynodon dactylon)、苍耳(Xanthium sibiricum)、芦苇(Phragmites australis)、香蒲(Typha orientalis)等为湿地公园湿地植物优势种群,形成大面积优势群落。3)栽培植物共计19科31属34种,主要有意杨(Populus × canadensis ‘I-214’)、垂柳(Salix babylonica)、冬青卫矛(Euonymus japonica)、马尼拉草(Zoysia tenuifolia)等。4)园区有喜旱莲子草(Alternanthera philoxeroides)等外来植物共10种,其中小花山桃草(Gaura parviflora)为安徽省首次记录。论文针对公园野生植物保护及栽培植物营建中存在的主要问题,提出了相应的保护及修复对策。  相似文献   

12.
分析了武汉石油化工厂聚丙烯装置的主要环境污染源,介绍了装置采取的主要清洁生产措施及取得的效果,提出了改进的方向.  相似文献   

13.
滇池水生植物研究概述   总被引:21,自引:0,他引:21  
在总结前人工作的基础上,分别从滇池大型水生植物种类、滇池水生植物群落、水生植物与水生生态环境相互关系和滇池水生植物与水生生态系统等方面,对滇池水生植物群落动态和演替及其与环境的相互关系进行分析,为滇池大型水生植物群落恢复、重建及调控提供科学依据。  相似文献   

14.
对污水处理场在运中存在的问题进行了分析,采取了改进措施,取得了较好效果。  相似文献   

15.
综述了有机污染土壤植物修复的基本类型,修复机理及研究进展,分析了植物修复的优势存在问题及发展前景。  相似文献   

16.
郑重 《云南环境科学》2001,20(2):12-14,56
本文在对动,植物生态学研究进展论述的基础上,提出在退化生态系统的恢复与重建过程中,运物种群与植物种群具有密切相关性的构思,认为动物种群与植物种群以“联合种群”的方式存在于此系统中,二者应作为一个有机的整体来加以研究。  相似文献   

17.
Agroecosystem functional assessment indicators provide a necessary bridge between decision-makers and scientists. The development of acceptable indicators, however, remains a difficult task because the current knowledge and understanding of ecosystems is not sufficient to allow an objective assessment of all ecosystem functions. These difficulties were summarized from three perspectives. First, there are difficulties in individual function assessment. Of the four functions associated with agroecosystems-energy flow, materials cycling,information flow and value flow-data on material cycling and information flow remain difficult to obtain and the indicators relatively immature. Secondly, there are difficulties of integration. During the assessment process, the integration of the agroecosystem functions remains the biggest obstacle. Until now, there has been no practical or effective methodology established to resolve the problem. At present, the makeshift approach has been to weight the various indicators and then add them together. Thirdly, there is the problem of obscure concepts and concept confusion. When assessments of agroecosystems are conducted, concepts such as structure, function, benefit,and resource utilization are used extensively. To date, no logical relationship (either real or implied) has been developed between any of these concepts. Are they causes and results such that the relationship between them is linear, or are they independent from one another such that the relationship is parallel? Thus far, the essence of this question is yet to be explored.  相似文献   

18.
19.
对某延迟焦化装置的腐蚀情况进行了描述,根据装置的流程特点、操作条件、设备选材和结构,对装置的腐蚀类型和腐蚀原因进行了分析,提出了工艺防腐、材料升级和结构改进等方面的措施。  相似文献   

20.
污泥处理系统产生的污泥,含水率很高,体积很大,输送、处理或处置都不方便。污泥浓缩可使污泥初步减容,使其体积减小为原来的几分之一,从而为后续处理或处置带来方便。文中详细介绍了三种污泥浓缩工艺形式、污泥浓缩的机理以及影响因素.  相似文献   

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