Vertical adaptive radiation in ocean Prochlorococcus: Evolutionary implications of the Chl b/a ratio from molecular evidence

Prochlorococcus is a marine cyanobacterium of global significance. Two ecotypes are adapted to either high-light (HL) or low-light (LL) conditions. The ratio between chlorophyll (Chl) a and b is a distinguishing characteristic of these two ecotypes. However, how this ratio evolved in Prochlorococcus during this ecotype differentiation remains unclear. Our analyses reveal that the ancestor of Prochlorococcus was typically low-light adapted. The LL ecotype showed a stagnant evolution, and the HL ecotype was recently diverged. There was an adaptive radiation after directional evolution in the Chl b/a ratio regulation. Recombination in chlorophyllide a oxygenase (CAO) and positive selection on Clp protease contributed to the directional evolution of Prochlorococcus. The recombinant fragments of CAO were correlated with a large group of shared coevolving sites. Evidence of positive selection was found in both subunits of Clp. Chl b/a ratio evolution, as annotated by molecular evidence, appears to be among the crucial reasons that explain how Prochlorococcus has become the dominant photosynthetic organism in the ocean.     

Model tests on anomalous low friction and pendulum-type wave phenomena

The anomalous low friction (ALF) and pendulum-type wave (μwave) phenomena were two typical,nonlinear,geo-mechanical,and dynamic responses in deep-block rock mass discovered from in situ observations,which occurred from the movement of the geo-blocks under the impact of external pulses,such as deep confined explosion,earthquake,and rock bursts.With the aim to confirm the existence of the above two phenomena and study the variation laws of them experimentally,laboratory tests on the granite and cement mortar continuum and blocks models were conducted on the self-independently developed multipurpose testing system,respectively.The ALF phenomenon was realized under two loading schemes,the blocks model and working block were acted upon by the joint action of vertical impact and horizontal static force as well as the joint action of both vertical and horizontal impacts with different time intervals.It revealed that the discrete time delays corresponding to the local maximums and minimums of the horizontal displacement amplitudes and residual horizontal displacements of the working block satisfied the canonical sequences with the multiple of √2,most of which satisfied the quantitative expression (√2)~i △/V_p.Besides,the one-dimensional impact experiments were carried out on the blocks granite model,continuum,and blocks cement mortar models,respectively.Based on the comparison and analysis of the propagation properties (amplitudes and the Fourier spectrums of acceleration time histories of blocks) of the 1D stress wave in the above models,it is indicated that the fractures in rock mass have tremendous effect on the attenuation of acceleration amplitudes and high-frequency waves.By comparison of the model test data with the in situ measurement conclusions,the existence of the μ wave was confirmed experimentally in the cement mortar blocks model with larger dimensions,and the frequencies corresponding to the local maximums of spectral density curves of three-directional acceleration time histories of sub-blocks also satisfied several canonical sequences with the multiple of √2.     

广西喀斯特地区城镇用地扩张及来源预测——以河池市金城江区为例

以河池市金城江区1991,1999,2006年三期TM/ETM+遥感影像为数据源,分析了城镇用地的遥感信息机理,提取了研究区三期土地利用现状图,并采用GIS空间分析技术,对城镇用地扩张的时空过程进行了研究.分析表明:城镇用地规模不断扩大,增长速度不均匀,城镇用地变化区域差异较大,城镇用地在中心城镇高度集聚.旱地、荒草地、独立工矿用地和坑塘水面是城镇用地扩张的主要来源.     

两种藜芦生品与醋制品中虎杖苷和白藜芦醇含量变化研究

采用柱层析色谱法从两种藜芦即黒紫藜芦(Veratrum japonicum)和藜芦(Veratrum nigrum L.)中分离得到二苯乙烯类化合物虎杖苷和白藜芦醇,利用核磁共振技术鉴定了它们的化学结构,其中虎杖苷为首次从该属植物中分离得到. 结合HPLC-UV法,比较了两种藜芦生品与醋制品中虎杖苷和白藜芦醇含量变化. 结果表明两种藜芦经醋制后,虎杖苷含量降低,白藜芦醇含量升高,并且两种藜芦中白藜芦醇含量差异不大,但藜芦中虎杖苷含量明显高于黑紫藜芦.     

分析化学开放式实验教学模式的构建与探索

阐述和分析了在医学检验专业《分析化学》课程中开设开放式实验教学对创新型人才培养的重要性,探讨了开放式实验教学的课程体系和教学模式．     

创新型企业的评价指标体系和方法研究

在充分分析了现有研究成果和实践的基础上,提出了创新型企业的评价指标体系,通过问卷调查、专家评价和实地测试等方法对指标体系进行了优化,并给出了各指标的权重和具体的评价方法,使其具有很好的实际应用价值。     

扩容图及其谱性质

目的 研究扩容图的若干性质.方法 用代数分析法研究图的结构.结果 利用图的剖分线图的结构,给出了新的广义线图,我们称之为扩容图.结论 讨论了扩容图的若干基本性质,给出了图与其扩容图参数之间的关系,并由此确定了扩客图谱性质.     

基于GIS与工作流技术的设施管理系统

为了提高设施管理的商务协同能力和实现GIS图形处理与管理系统的一体化.简要介绍了GIS和工作流技术的特点,分析了工作流管理系统的参考模型,在此基础上将GIS和工作流技术应用到设施管理系统的构建中,给出了GIS与工作流集成的方法,并提出了设施管理系统的三层分布式体系结构.该结构以工作流引擎为控制核心,以异构的分布式节点为逻辑层,以关系型数据库为基础,具有多层次集成管理的特点,可为后续设施管理系统的开发提供技术上的参考和借鉴.     

中国传统风水元素在室内设计中的合理引用

无论是进行城市规划和建设,或者是进行房地产项目的开发,还是设计私家住宅,建造者如果能透彻的研究中国古代风水学,并对之用心体会、细意观察、科学运用,就能建造对身心有良好作用的、藏风聚气、称心如意的好房屋,也会使人们对建筑物产生舒适感和亲切感。只有在这样的环境中生活,人们才会身心健康,吉祥幸福。     

幼儿科学教育的智慧取向

教育的最终目的就在于启迪学生获得智慧,完善人生．随着社会的进步和科技的发展,智慧教育已经成为当代世界教育改革与发展的主题．幼儿科学教育是对幼儿进行科学启蒙的教育,它与智慧教育有着天然的联系,同时,世界教育改革的发展和建设创新型国家的需要也决定了幼儿科学教育必须走智慧教育的道路．幼儿科学教育应该把培养幼儿科学素养,启发幼儿探究与质疑,注重个性化的教学以及走向生活化等作为提高幼儿智慧品质的重要途径．